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“The  Journal  of 
ARACHNOLOGY 

OFFICIAL  ORGAN  OF  THE  AMERICAN  ARACHNOLOGICAL  SOCIETY 


VOLUME  33 


NUMBER  3 


THE  JOURNAL  OF  ARACHNOLOGY 


EDITOR-IN-CHIEF:  Daniel  J.  Mott,  Texas  A&M  International  University 

MANAGING  EDITOR:  Paula  Cushing,  Denver  Museum  of  Nature  & Science 

SUBJECT  EDITORS:  Ecology — Soren  Toft,  University  of  Aarhus;  Systematics — Mark 
Harvey,  Western  Australian  Museum;  Behavior  and  Physiology — Gail  Stratton,  Univer- 
sity of  Mississippi 

EDITORIAL  BOARD:  Alan  Cady,  Miami  University  (Ohio);  James  Carrel,  University 
of  Missouri;  Jonathan  Coddington,  Smithsonian  Institution;  William  Eberhard,  Univer- 
sidad  de  Costa  Rica;  Rosemary  Gillespie,  University  of  California,  Berkeley;  Charles 
Griswold,  California  Academy  of  Sciences;  Marshal  Hedin,  San  Diego  State  University; 
Herbert  Levi,  Harvard  University;  Brent  Opell,  Virginia  Polytechnic  Institute  & State 
University;  Norman  Platnick,  American  Museum  of  Natural  History;  Ann  Rypstra,  Mi- 
ami University  (Ohio);  Paul  Selden,  University  of  Manchester  (U.K.);  Matthias  Schaefer, 
Universitset  Goettingen  (Germany);  William  Shear,  Hampden- Sydney  College;  Petra  Si- 
erwald.  Field  Museum;  I-Min  Tso,  Tunghai  University  (Taiwan). 

The  Journal  of  Arachnology  (ISSN  0161-8202),  a publication  devoted  to  the  study  of 
Arachnida,  is  published  three  times  each  year  by  The  American  Arachnological  Society. 
Memberships  (yearly):  Membership  is  open  to  all  those  interested  in  Arachnida.  Sub- 
scriptions to  The  Journal  of  Arachnology  diwd  American  Arachnology  (the  newsletter),  and 
annual  meeting  notices,  are  included  with  membership  in  the  Society.  Regular,  $40;  Stu- 
dents, $25;  Institutional,  $125  . Inquiries  should  be  directed  to  the  Membership  Secretary 
(see  below).  Back  Issues:  Patricia  Miller,  P.O.  Box  5354,  Northwest  Mississippi  Commu- 
nity College,  Senatobia,  Mississippi  38668  USA.  Telephone:  (601)  562-3382.  Undelivered 
Issues:  Allen  Press,  Inc.,  1041  New  Hampshire  Street,  P.O.  Box  368,  Lawrence,  Kansas 
66044  USA. 


THE  AMERICAN  ARACHNOLOGICAL  SOCIETY 

PRESIDENT:  Elizabeth  Jacob  (2006-2008),  Department  of  Psychology,  University  of 
Massachusetts,  Amherst,  MA  01003  USA. 

PRESIDENT-ELECT:  Paula  Cushing  (2006-2008),  Denver  Museum  of  Nature  & Sci- 
ence, Denver,  CO  80205  USA. 

MEMBERSHIP  SECRETARY:  Jeffrey  W.  Shultz  (appointed).  Department  of  Entomology, 
University  of  Maryland,  College  Park,  MD  20742  USA. 

TREASURER:  Karen  Cangialosi,  Department  of  Biology,  Keene  State  College,  Keene, 
NH  03435-2001  USA. 

SECRETARY:  Alan  Cady,  Dept,  of  Zoology,  Miami  University,  Middletown,  Ohio  45042 
USA. 

ARCHIVIST:  Lenny  Vincent,  Fullerton  College,  Fullerton,  California  92634  USA. 

DIRECTORS:  James  Carrel  (2001-2003),  Rosemary  G.  Gillespie  (2002-2004),  Brent 
D.  Opell  (2003-2005). 

PAST  DIRECTOR  AND  PARLIAMENTARIAN:  H.  Don  Cameron  (appointed),  Ann  Arbor, 
Michigan  48105  USA. 

HONORARY  MEMBERS:  C.D.  Dondale,  H.  W.  Levi,  A.F.  Millidge,  W.  Whitcomb. 


Cover  photo:  The  pseudoscorpion  Saetigerocreagris  setifera.  Photo  by  Rick  Vetter. 


Publication  date:  28  December  2005 

©This  paper  meets  the  requirements  of  ANSI/NISO  Z39.48-1992  (Permanence  of  Paper). 


2005.  The  Journal  of  Arachnology  33:641-662 


THE  MALE  GENITALIA  OF  THE  FAMILY 
ATEMNIDAE  (PSEUDOSCORPIONES) 

Finn  Erik  Klausen:  Department  of  Natural  Sciences,  Agder  University  College, 
Servicebox  422,  N-4604  Kristiansand,  Norway.  E-mail:  finn.e.klausen@hia.no 

ABSTRACT.  Knowledge  of  the  male  genitalia  of  the  Atemnidae  is  still  limited,  although  several  authors 
have  previously  contributed  to  our  understanding  of  their  structure.  This  study  deals  with  the  morphology 
and  configuration  of  the  male  genital  organs.  Forty-four  species  belonging  to  16  different  genera  have 
been  investigated,  including  species  of  4 genera  of  Miratemninae.  Anatemnus  longus  Beier  1932  is  syn- 
onymized  with  A.  voeltzkowi  (Ellingsen  1908),  Paratemnoides  ceylonicus  (Beier  1932)  is  synonymized 
with  P.  palUdus  (Balzan  1892),  and  P.  minor  (Balzan  1892)  with  P.  nidificator  (Balzan  1888).  Tamenus 
equestroides  (Ellingsen  1906)  is  moved  to  the  genus  Cyclatemnus.  The  genitalia  of  the  investigated  spec- 
imens are  described  and  a general  diagnostic  description  of  the  male  genitalia  of  the  family  is  given.  The 
study  reveals  an  overall  uniformity  in  the  genitalic  configuration  of  the  family,  which  indicates  monophyly. 
With  respect  to  the  affinities  with  other  families  of  the  Cheliferoidea,  the  male  genitalia  suggest  that  the 
Atemnidae  might  be  closer  to  the  Withiidae  than  to  the  Cheliferidae  or  Chernetidae.  Claimed  differences 
between  the  Atemninae  and  Miratemninae  are  considered,  but  the  morphology  of  the  male  genitalia  does 
not  support  their  division  into  two  families.  Comparison  of  species  of  the  genera  Anatemnus,  Catatemnus, 
Oratemnus  and  Paratemnoides  reveals  greater  variation  within  the  genera  than  between  different  genera. 
This  infers  that  the  present  systematic  grouping  of  species  does  not  reflect  true  phylogenetic  relationships 
within  the  family. 

Keywords;  Arachnida,  pseudoscorpion,  genitalia,  morphology,  phylogenetic  relationships 


The  male  genitalia  of  pseudoscorpions  are 
used  for  indirect  sperm  insertion,  the  male 
produces  a spermatophore  with  a sperm  pack- 
et on  a stalk  which  is  deposited  on  the  sub- 
stratum. The  female  is  later  inseminated  from 
the  sperm  in  this  spermatophore.  Accordingly 
the  male  has  no  copulatory  organ,  but  the 
whole  of  the  male  genitalia  is  internally  situ- 
ated with  the  opening  located  between  the  sec- 
ond and  third  sternite  of  the  abdomen.  The 
spermatophore  is  produced  in  the  chitinized 
genital  chamber  with  its  diverticula  and  as- 
sociated glands.  The  genitalia  can  have  a com- 
plex structure,  which  to  a certain  degree  is  re- 
flected in  a correspondingly  complex  structure 
of  the  spermatophore.  The  complex  structure 
of  the  genitalia  is  perhaps  most  pronounced  in 
the  Cheliferoidea  which  includes  the  family 
Atemnidae,  and  may  have  potential  in  system- 
atic work. 

Several  authors  have  dealt  with  the  mor- 
phology of  the  male  genitalia  of  species  in  the 
family  Atemnidae,  most  extensively  Vachon 
(1938a);  but  others  have  contributed,  notably 
Chamberlin  (1931,  1939,  1947),  Dashdamirov 
and  Schawaller  (1993),  Dumitresco  and  Orgh- 


idan  (1969),  Heurtault  (1970)  and  Harvey 
(1988). 

The  complex  structure  and  the  internal  lo- 
cation makes  the  genitalia  difficult  to  examine 
in  situ,  this  may  be  part  of  the  reason  why  the 
knowledge  of  the  morphology  is  still  rather 
limited  and  has  been  used  very  little  for  di- 
agnostic characters  in  the  description  of  gen- 
era and  species.  However,  an  early  attempt  to 
discriminate  taxonomically  between  different 
species  in  the  genera  Catatemnus  Beier  1932, 
Cyclatemnus  Beier  1932  and  Tamenus  Beier 
1932  was  made  by  Vachon  (1938b). 

Traditionally  the  delimitation  of  the  family 
Atemnidae  and  the  diagnoses  of  the  different 
genera  in  the  family  was  thus  based  on  exter- 
nal characters.  The  family  was  erected  by 
Chamberlin  (1931)  and  subdivided  into  sev- 
eral genera  by  Beier  (1932a,  1932b).  Beier 
further  divided  the  family  into  two  subfami- 
lies, Atemninae  and  Miratemninae.  The  Mir- 
atemninae was  elevated  to  full  family  level, 
Miratemnidae  by  Dumitresco  and  Orghidan 
(1970),  partly  based  on  their  investigation  on 
the  male  genitalia  of  Diplotemnus  insolitus 
Chamberlin  1933  and  its  difference  in  orien- 


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THE  JOURNAL  OF  ARACHNOLOGY 


tation  compared  to  the  Atemninae.  But  Har- 
vey (1991,  1992)  did  not  accept  the  family 
status  of  the  miratemnids.  He  argued  against 
it  and  returned  them  to  the  family  Atemnidae. 

The  subfamily  Atemninae  comprises  genera 
which  have  a problematic  taxonomic  position. 
The  delimitations  of  the  genera  are  based  on 
external  characters  which  on  several  occasions 
appear  to  be  continuous  and  thus  of  less  di- 
agnostic value.  This  implies  that  the  present 
delimitations  of  the  genera  probably  do  not 
reveal  the  true  relationship  between  them.  In 
this  context,  it  might  be  valuable  to  make  a 
broader  survey  of  male  genitalia  both  of  the 
Miratemninae  and  the  Atemninae,  in  an  at- 
tempt to  use  these  organs  in  the  delimitation 
of  monophyletic  taxa. 

METHODS 

This  investigation  is  based  on  the  exami- 
nation of  male  genital  organs  from  the  follow- 
ing 44  species  representing  16  of  the  19  extant 
genera,  including  species  of  four  genera  of 
Miratemninae.  The  nomenclature  follows  the 
catalogue  of  Harvey  (1991). 

Abbreviations. — AUC  = Agder  University 
College,  Norway;  BPBM  = Bernice  R Bishop 
Museum,  Honolulu;  CAS  = California  Acad- 
emy of  Sciences,  San  Francisco;  MHNG  = 
Museum  d’Histoire  naturelle,  Geneva; 
NHMW  = Naturhistorisches  Museum,  Wien; 
NMP  “ Natal  Museum,  Pietermaritzburg; 
NRMS  = Naturhistoriska  Riksmuseet,  Stock- 
holm; RMCA  Royal  Museum  of  Central 
Africa,  Tervuren;  SMNS  = Staatliches  Mu- 
seum fiir  Naturkunde,  Stuttgart;  TMP  = 
Transvaal  Museum,  Pretoria;  WAM  = West- 
ern Australian  Museum,  Perth;  ZMB  = Mu- 
seum fiir  Naturkunde,  Humboldt-UniversitM, 
Berlin;  ZMUO  = Zoological  Museum,  Uni- 
versity of  Oslo. 

Family  Atemnidae  Chamberlin  1930 
Subfamily  Miratemninae  Beier  1932 
Brazilatemnus  browni  Muchmore  1975 

Material  examined. — BRAZIL:  Para,  Por- 
to Trompetas,  August  1992,  J.D.  Majer  leg. 
(WAM;  Harvey  det.). 

Diplotemnus  insolitus  Chamberlin  1933 

Material  examined. — SPAIN:  Gran  Cana- 
ria, Maspalomas,  dunes,  16  March  1994,  C. 
Wurst  leg.  (SMNS,  no.  3448;  Schawaller  det.). 


Miratemnus  hirsutus  Beier  1955 

Material  examined. — SOUTH  AFFRICA: 
Pretoria,  1958  (RMCA;  Beier  det.);  Cape 
Province,  Cape  Houtbaai,  December  1960 
(TMP,  no.  ZA  46;  Klausen  det.);  E.Cape, 
Grahamstown,  Harpers  Hall,  October  1943, 
W G.  Rump  leg.  (NMP,  no.  668).  RHODESIA 
(ZIMBABWE):  Inyanda,  February  1969,  R. 
Mussard  leg.  (MHNG;  Beier  det.). 

Miratemnus  kenyaensis  Mahnert  1983 

Material  examined. — KENYA:  Namanga, 
21  March  69,  A.  Holm  leg.  (MHNG; 
paratype);  Lake  Elmenteita,  1800  m,  SS.  pier- 
res  (under  stones?),  7 November  1977,  Mah- 
nert & Perret  leg.  (MHNG;  paratype). 

Miratemnus  zuluanus  Lawrence  1937 

Material  examined, — SOUTH  AFRICA: 
KZN,  Drummond,  February  1942,  W.G. 
Rump  leg.  (NMP,  no.  661;  Beier  det.). 

Tullgrenius  indicus  Chamberlin  1933 

Material  examined. — INDIA:  Tamil  Nadu; 
Amman  Nagar,  N.of  Coimbatore,  6 December 
2000,  F Klausen  leg.  (AUC;  Klausen  det.) 

Subfamily  Atemninae  Chamberlin  1930 

Anatemnus  angustus  (Redikorzev  1938) 

Material  examined. — VIETNAM:  Plateau 
Lang  Biang  (—  Cao  Nguyen  Lam  Vien), 
1938-39,  C.  Dawydoff  leg.  (NHMW;  Beier 
det.). 

As  Oratemnus  indicus:  INDIA:  Mysore,  12 
mil.  E of  Virajpet,  24  February  1962,  Ross  & 
Cavagnaro  leg.  (CAS;  Beier  det.). 

As  Anatemnus  nilgiricus:  INDIA:  Mysore, 
8 mi.  NE  Mercara,  1000  m,  22  February  1962, 
E.  S.  Ross  & D.  Q.  Cavagnaro  leg.  (CAS; 
Beier  det.). 

Remarks. — The  specimens  identified  as  O. 
indicus  and  A.  nilgiricus  are,  as  far  as  I can 
judge,  both  in  configuration  of  the  genitalia 
and  in  outer  morphology  identical  to  A.  an- 
gustus. The  specimens  of  O.  indicus  have 
been  compared  with  the  holotype  of  Chelifer 
indicus  deposited  in  Zoological  Museum  in 
Copenhagen  and  the  description  given  by 
With  (1906).  The  dorsal  tubercle  of  the  tro- 
chanter of  the  holotype  is  blunt  ended  and  not 
pointed  as  in  the  specimens  in  my  custody.  I 
have  not  been  able  to  compare  the  specimen 
identified  as  A.  nilgiricus  with  the  type  ma- 


KLAUSEN— MALE  GENITALIA  OF  ATEMNIDAE 


643 


terial  in  the  Roewer  collection.  However,  in 
the  description  given  by  Beier  (1932a)  of  A. 
nilgiricus,  he  states  that  the  dorsal  tubercle  of 
the  trochanter  is  blunt  ended  or  rounded,  con- 
trary to  the  specimen  above  which  has  a con- 
ical and  pointed  dorsal  tubercle. 

The  genitalia  of  A.  angustus  are  identical 
with  those  of  the  syntype  of  Catatemnus  bir- 
manicus  from  Naturhistoriska  Riksmuseet, 
Stockholm.  Moreover,  apart  from  the  appear- 
ance of  the  carapace  of  C.  birmanicus  they  are 
similar  in  external  morphology.  That  is,  the 
shape  of  the  trochanter  and  patella  of  the  ped- 
ipalps  are  similar,  the  trichobothria  of  the  fin- 
gers have  the  same  configuration  and  so  have 
the  tergal  seta  of  the  abdomen. 

Anatemnus  elongatus  (Ellingsen  1902) 

Material  examieed.—- -ECUADOR:  As 
Chelifer  (Atemnus)  elongatus:  by  Guayaquil, 
June  1901,  Ortoneda  leg.  (ZMUO,  no.  102; 
syntype) 

Anatemnus  javanus  (Thorell  1883) 

Material  examined. — PAPUA  NEW 

GUINEA:  As  Chelifer  {Atemnus)  javanus: 
Bismarck  Archipelago,  Fr.  Dahl  leg.  (ZMUO, 
no.  319;  Ellingsen  det). 

Anatemnus  novaguineensis  (With  1908) 

Material  examined. — PAPUA  NEW 
GUINEA:  Finschhafen,  17  April  1944,  E.  S. 
Ross  leg.  (CAS;  Beier  det.). 

Anatemnus  orites  (Thorell  1889) 

Material  examined.- — As  Chelifer  (=  An- 
atemnus) orites:  BURMA  (MYANMAR): 
Thenasserim,  Plapoo,  Fea  leg.  (NRMS,  no.  6; 
ColL[ection  of?]  Thorell);  [Probably  Carin 
Ghecu,  Tao,  13-1400  m, 1885-1887],  Fea  leg. 
(ZMUO,  no.  566;  Ellingsen  det.). 

As  Chelifer  (=  Oratemnus)  indicus:  IN- 
DIA: Gravely,  1912  (ZMUO,  no.  593;  Elling- 
sen [?]  det.). 

Remarks.— The  specimens  identified  as  A. 
orites  have  been  compared  with  syntypes  of 
Chelifer  orites  from  Zoological  Museum  in 
Copehagen.  They  are  identical  in  outer  mor- 
phology, and  so  is  the  specimen  identified  as 
Chelifer  indicus  which  has  been  compared 
with  the  holotype  of  C.  indicus.  The  only  di- 
vergence is  the  form  of  the  conical  dorsal  tu- 
bercle of  the  trochanter  which  is  slightly  high- 
er in  the  holotype  of  C.  indicus. 


The  genitalia  of  A.  orites  are  very  similar 
to  those  of  A.  angustus.  With  respect  to  the 
characters  of  the  outer  morphology  they  are 
similar  except  for  the  conical  dorsal  tubercle 
of  the  trochanter  which  is  blunt  ended  in  A. 
orites  and  pointed  in  A.  angustus. 

Anatemnus  subvermiformis 
Redikorzev  1938 

Material  examined. — VIETNAM:  Plateau 
Lang  Biang  [—  Cao  Nguyen  Lam  Vien], 
1938-39,  C.  Dawydoff  leg.  (NHMW;  Beier 
det.). 

Anatemnus  voeltzkowi  (Ellingsen  1908) 

Chelifer  {Atemnus)  voeltzkowi  elongata  Ellingsen 
1908:  488  (junior  primary  homonym  of  Chelifer 
{Atemnus)  elongatus  Ellingsen,  1902). 

Anatemnus  longus  Beier  1932:  586  (replacement 
name  for  Chelifer  (Atemnus)  voeltzkowi  elongata 
Ellingsen  1908).  NEW  SYNONYMY. 

Material  examined. — As  Chelifer  {Atem- 
nus) voeltzkowi:  MADAGASCAR:  SW  Mad- 
agascar, Voeltzkow  leg.  (ZMUO,  no.  307;  syn- 
type). 

As  Chelifer  {Atemnus)  voeltzkowi  elongata: 
MADAGASCAR:  Marovoay,  September 
1906,  W.  Kaudern  leg.  (ZMUO,  no.  336;  syn- 
type). 

Remarks.— The  specimens  of  A.  voeltzko- 
wi and  A.  longus  in  ZMUO  are  unquestion- 
ably syntypes,  the  rest  of  the  type  series  being 
deposited  in  the  Zoological  Museums  in  Ber- 
lin and  in  Stockholm.  Anatemnus  longus  was 
originally  described  by  Ellingsen  (1908)  as  a 
variety  of  A.  voeltzkowi.  I can  find  no  signif- 
icant differences  in  external  morphology  be- 
tween the  two  and  the  male  genitalia  are  iden- 
tical. Accordingly  I consider  A.  longus  as  a 
synonym  of  A.  voeltzkowi. 

Atemnus  politus  (Simon  1878) 

Material  examined.— ITALY:  prov.  Basi- 
licata, Lido  San  Basilia,  comm.  Metaponta, 
sieving  in  Pinetum  near  shore,  4 September 
1993,  V.  Mahnert  leg.  (MHNG;  Mahnert  det.). 
SPAIN:  Rincon  de  Ademuz,  N.  Puebla  de  San 
Miguel,  Quercus  forest,  22  April  1984,  Scha- 
waller  leg.  (SMNS,  no  1057;  Schawaller  det.); 
Mallorca,  Road  between  Poreres  and  Vilafran- 
ca,  5 May  2000,  under  stones  in  Quercus  ilex 
forest,  F.  Klausen  leg.  (AUC;  Klausen  det.). 
TURKEY:  Anatolien,  Akzehir,  22  April  1960 
(NHMW;  Beier  det.). 


644 


THE  JOURNAL  OF  ARACHNOLOGY 


Atemnus  syriacus  (Beier  1955) 

Material  examined. — TURKEY:  Koyceg- 
iz,17  February  1969  (NHMW;  Beier  det.). 

Athleticatemnus  pugil  Beier  1979 

Material  examined. — As  Cyclatemnus 
granulatus:  BELGIAN  CONGO  (DEMO- 
CRATIC REPUBLIC  OF  CONGO):  Kivu, 
Terre  Kalehe,  Frangi,  18  August  1960,  Mu- 
sanola  & Kangeta  leg.  (RMCA,  no.  118.580; 
Beier  det.). 

Remarks. — Although  Beier  (1979)  placed 
this  genus  close  to  Titanatemnus  in  his  de- 
scription of  the  species,  the  single  specimen 
identified  by  me  is  very  similar  to  Cyclatem- 
nus granulatus  in  external  morphology.  Apart 
from  the  shallow  or  very  blunt  dorsal  tubercle 
of  the  trochanter  in  A.  pugil  (which  is  pointed 
in  C.  granulatus)  the  characters  are  similar  in- 
cluding the  configuration  of  discal  setae  on  the 
tergites.  Admittedly,  the  palpal  hand  of  A. 
pugil  is  very  robust  in  the  dorsoventral  direc- 
tion, but  so  is  the  palpal  hand  of  C.  granula- 
tus, even  if  this  is  slightly  less  so.  The  male 
genitalia  is  closer  to  Cyclatemnus  in  appear- 
ance than  to  Titanatemnus,  although  it  is  not 
similar  to  C.  granulatus. 

Catatemnus  birmanicus  (Thorell  1889) 

Material  examined. — BURMA  (MYAN- 
MAR): Bhamo  (NRMS;  syntype,  Doria  ded. 
[sic]). 

As  Che  lifer  (Anatemnus)  orites:  INDONE- 
SIA: Sumatra,  [probably:  Si-Rambe  or  Pangh- 
erang-Pisang,  1891/94,  E.  Modigliani  leg.] 
(ZMUO,  no.  539,  Ellingsen  det.). 

Remarks. — The  syntypes  from  Naturhis- 
toriska  Riksmuseet,  Stockholm  have  been 
compared  with  the  syntypes  from  Zoological 
Museum  in  Copenhagen.  They  are  all  identi- 
cal in  outer  morphology  and  thus  seem  to  be 
a homogenous  group  of  syntypes. 

The  species  (and  genus)  are  separated  from 
those  of  Anatemnus  and  Oratemnus  by  the 
character  of  the  carapace,  given  as  a transver- 
sal furrow  or  “Querfurche”  by  Beier  (1932a, 
1932b).  As  remarked  under  the  species  A.  an- 
gustus  and  A.  orites,  the  genitalia  of  these  two 
are  similar  or  identical  to  C.  birmanicus, 
which  seem  to  contradict  the  separation  of 
them  in  different  genera. 


Catatemnus  granulatus  Mahnert  1978 

Material  examined. — CAMEROON: 
S.Kribi,  Rocheur  de  Loup  17  February  1980, 
primary  forest,  Ferrara  & Schlogal  leg. 
(SMNS,  no.  513;  Mahnert  det.). 

As  Cyclatemnus  burgeoni:  BELGIAN 
CONGO  (DEMOCRATIC  REPUBLIC  OF 
CONGO):  Ibembo,  February  1952,  R.E  Hut- 
sebaut  leg.  (RMCA,  no. 72. 809;  Beier  det.). 

Catatemnus  togoensis  (Ellingsen  1910) 

Material  examined. — NIGERIA:  Lagos, 
Iseri,  26  March  1949  [1929?]),  Malkin  leg. 
(NHMW;  Beier  det.).  GHANA:  Akumadan  2 
September  1966.  350  m.  E.S.Ross  & K.  Lor- 
entzen  leg.  (CAS;  Beier  det.). 

As  Catatemnus  congicus:  BELGIAN  CON- 
GO (DEMOCRATIC  REPUBLIC  OF  CON- 
GO): 50  km.  S.of  Chela,  26  July  1957.  Ross 
& Leech  leg.  (CAS;  Beier  det.). 

As  Cyclatemnus  fallax:  KENYA:  Kaiomosi 
Mission,  27  mi.  NE  of  Kisumu,1650  m,  29 
November  1957  (CAS;  Beier  det.). 

As  Tamenus  femoratus  (in  part):  IVORY 
COAST:  Divo,  16  August  1963.  J.  Decelle 
leg.  (RMCA,  no.  16 1.1 32;  Heurtault  det.). 

As  Chelifer  {=  Titanatemnus)  sjoestedti: 
CAMEROON:  (no  locality  and  date  given), Y. 
Sjostedt  leg.  (NRMS;  Tullgren  det.);  Itoki, 
February  1891,  Y.  Sjostedt  leg.  (NRMS;  in- 
cluded in  syntype  material  of  Chelifer  sjoes- 
tedti, Tullgren  det.). 

Remarks. — The  identification  of  C.  to- 
goensis as  r.  sjoestedti  is  probably  due  to  a 
misinterpretation  of  the  specimens  as  juve- 
niles of  T.  sjoestedti.  The  4 males  and  3 fe- 
males from  the  vial  with  no  locality  and  date 
given  were  labeled  juveniles.  The  same  expla- 
nation probably  applies  for  the  single  speci- 
men included  in  the  type  material  of  T.  sjoes- 
tedti (12  males,  15  females,  1 juvenile).  Both 
outer  morphology  and  genitalia  tell  that  these 
specimens  are  undoubtedly  C.  togoensis. 

Cyclatemnus  burgeoni  (Beier  1932) 

Material  examined. — BELGIAN  CONGO 
(DEMOCRATIC  REPUBLIC  OF  CONGO): 
Kuri,  terr.  de  Kabare,  Bitale,  1600  m,  29  June 
1951,  N.  Leleup  leg.  (RMCA,  no.  110949- 
110950;  Beier  det.). 

Cyclatemnus  centralis  Beier  1932 

Material  examined. — BELGIAN  CONGO 
(DEMOCRATIC  REPUBLIC  OF  CONGO): 


KLAUSEN— MALE  GENITALIA  OF  ATEMNIDAE 


645 


Katanga,  Terr,  d’Alberville,  mont.  Kabobo, 
Ht.  Kiymbi,  1700  m,  September  1958,  N.  Le- 
leup  leg.  (RMCA,  no.  112.741;  Beier  det.). 
RUANDA  (RWANDA):  78  km  W of  Astrida, 
1957  (CAS;  Beier  det.). 

Cyclatemnus  dolosus  Beier  1964 

Material  examined. — RHODESIA  (ZIM- 
BABWE): Northern  Rhodesia,  Abercorn,  gal- 
lery forest,  Riwer  Mwengo,  8 miles  N.  of 
Abercorn,  1800  m,  June  1960,  N.  Leleup  leg. 
(RMCA,  no.  15.078;  Beier  [?]  det). 

Cyclatemnus  equestroides 

(Ellingsen  1906),  NEW  COMBINATION 

Material  examined. — -EQUATORIAL 
GUINEA:  Isl.  Fernando  Poo  [Bioko],  Punta 
Frailes,  October  1901,  L.  Fea  leg.  (ZMUO,  no. 
217;  syntype).  PORTUGUESE  GUINEA 
(GUINEA-BISSAU):  Rio  Cassine,  Febmary- 
April  1900,  L.  Fea  leg.  (ZMUO,  no.  218;  syn- 
type). 

Remarks.— Although  these  specimens  are 
not  labelled  as  type  material,  the  collection 
details  leave  no  doubt  they  form  part  of  the 
type  material  used  by  Ellingsen  (1906)  in  his 
description  of  the  species.  The  remainder  of 
the  type  material  is  deposited  in  the  Museo 
Civico  di  Storia  Naturale,  Genova. 

Beier  (1932a,  1932b)  placed  this  species  in 
the  genus  Tamenus,  but  was  clearly  in  doubt 
about  this  decision.  After  examining  the  spec- 
imens, it  is  quite  clear  that  they  do  not  belong 
in  Tamenus.  They  lack  a transverse  groove  on 
the  carapace  as  Ellingsen  (1906)  himself  point- 
ed out,  and  the  configuration  of  the  trichoboth- 
ria  is  different.  On  the  other  hand,  these  char- 
acters fit  very  well  with  those  of  Cyclatemnus. 
The  difference  between  C equestroides  and  the 
Cyclatemnus  spp.  investigated  by  me  is  that  the 
palpal  patella  of  C.  equestroides  is  slightly 
broader  seen  in  lateral  view.  The  male  genitalia 
are  almost  identical  to  those  of  Cyclatemnus 
centralis.  Accordingly  I transfer  this  species  to 
the  genus  Cyclatemnus. 

Cyclatemnus  globosus  Beier  1947 

Material  examined. — SOUTH  AFRICA: 
E.  Cape,  Pirie  Forest,  March  1937,  R.E 
Lawrence  leg.  (NMP;  Beier  det.) 

Cyclatemnus  granulatus  Beier  1932 

Material  examined.— IVORY  COAST: 
Bingerville.  16  April  1962,  J.  Decelle  leg. 


(RMCA,  no.  121.999;  Beier  det.).  CAME- 
ROON: 10  mi.  W Bertona,  640  m,  5 October 
1966,  Ross  & Lorentzen  leg.  (CAS;  Beier 
det.). 

Cyclatemnus  minor  Beier  1944 

Material  examined. — KENYA:  Athi  Riv- 
er, 1500  m,  19  October  1957,  Ross  & Leech 
leg.  (CAS;  Beier  det.). 

Cyclatemnus  robustus  Beier  1959 

Material  examined. — BELGIAN  CONGO 
(DEMOCRATIC  REPUBLIC  OF  CONGO): 
Tshibinda,  February  1932  (RMCA,  no. 
54.233-54.234;  Beier  det.);  Nioka,  October 
1953  (RMCA,  no.  80.090;  Beier  det.).  TAN- 
ZANIA: TANGANYIKA?:  12.miles  NE  of 
Sumbawanga  (RMCA,  no.  116.008;  Beier 
det.); 

Micratemnus  crassipes  Mahnert  1983 

Material  examined. — KENYA:  Nakuru, 
Lake  Elmenteita,  SS.  pierres  [under  stones?], 
1900  m,  7 November  1974,  Mahnert  & Perret 
leg.  (MHNG;  paratype). 

Oratemnus  loyolai  Sivaraman  1980 

Material  examined. — INDIA:  Tamil  Nadu, 
Redhills,  Madras,  6 August  1976  (MHNG; 
paratype);  Tamil  Nadu,  Ganesaduram,  N.of 
Coimbatore,  6 December  2000,  K.R.  Klausen 
& F.  Klausen  leg.  (AUC;  E Klausen  det.); 
Karnataka,  Mysore,  park  by  Ghandi  Square, 
29  November  2000,  K.R.  Klausen  & F Klau- 
sen leg.  (AUC;  F.  Klausen  det.).  SRI  LANKA: 
Peradeniya,  Kandy  District,  Botanical  Garden, 
20  February  2000,  D.  Huber  leg.  (AUC;  F. 
Klausen  det.). 

Oratemnus  navigator  (With  1906) 

Material  examined.— INDONESIA:  Java, 
Batavia,  March  1889,  L.  Loria  leg.  (ZMUO, 
no.  377;  Ellingsen  [?]  det.);  Bali,  Brama  Kutri, 
Singapadu,  12  March  1999,  K.R.  Klausen  & 
F.  Klausen  leg.  (AUC;  F.  Klausen  det.);  Be- 
tween Papuan  and  Bantran,  10  March  1999, 
K.R.  Klausen  & F.  Klausen  leg.  (AUC;  E 
Klausen  det.).  MALAYSIA:  East  Coast,  17 
km  N of  Kuantan,  3 1 March  2002,  F Klausen 
leg.  (AUC;  F Klausen  det.). 

As  Oratemnus  brevidigitatus:  SEY- 
CHELLES: Praslin,  Cote  d^Or,  30  July  1982, 
C.I.  Voucher  leg.  (MHNG;  Mahnert  det.). 

As  Oratemnus  philippinensis:  PHILIP- 


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THE  JOURNAL  OF  ARACHNOLOGY 


PINES:  Luzon  isl.,  Kiangan/Ifugao,  1982, 
Margraf  leg.  (SMNS,  no.  1543;  Schawaller 
det.). 

As  Oratemnus  saigonensis:  THAILAND: 
Doi  Sutep,  E slope,  260  m,  15  July  1962,  E. 
S.  Ross  & D.Q.  Cavagnaro  leg.  (CAS;  Beier 
det.). 

Remarks. — The  material  from  the  Zoolog- 
ical Museum  in  Oslo  and  the  material  col- 
lected by  me  on  Bali  and  in  Malaysia  has  been 
compared  with  the  description  given  by  With 
(1906)  of  Oratemnus  navigator  and  the  ho- 
lotype  from  Zoological  Museum  in  Copen- 
hagen. There  is  no  doubt  that  they  are  iden- 
tical. Moreover,  when  Schawaller  (1994) 
synonymized  O.  saigonensis  with  O.  semidi- 
visas,  he  suggested  that  O.  navigator  belongs 
to  the  same  species  together  with  O.  proximus, 
O.  loyolai  and  O.  yodai.  Oratemnus  loyolai  is 
definitely  not  conspecific  with  the  others, 
judging  from  its  very  different  and  character- 
istic genitalia.  However,  the  male  genitalia  of 
the  others  investigated  by  me  are  identical. 
Since  the  investigated  specimens  listed  above 
of  O.  brevidigitatus,  O.  philippinensis  and  O. 
saigoneneis  (—  O.  semidivisus)  have  been 
identified  by  very  able  specialists,  there  is  a 
possible  synonymy,  perhaps  together  with  O. 
proximus  and  O.  yodai. 

Oratemnus  punctatus  (L.  Koch  1885) 

Material  examined. — AUSTRALIA: 
Queensland,  55  km  N.  of  Goomeri,  23  Janu- 
ary 1982,  M.  Baehr  leg.  (SMNS,  no.898;  Har- 
vey det.). 

Paratemnoides  ellingseni  (Beier  1932) 

Material  examined. — MOZAMBIQUE: 
Chitengo,  Gorongoza  Game  Reserve,  Septem- 
ber 1957,  R.F.  Lawrence  leg.  (NMP,  no.  5155; 
Beier  det.).  MADAGASCAR:  Morondava, 
Betela  Mission  Station,  20  February  1998, 
Klausen  leg.  (AUC;  Klausen  det.).  SOUTH 
AFRICA:  Zululand,  1938  (NHMW;  Beier 
det.);  KZN,  Gollel,  August  1938,  R.F. 
Lawrence  leg.  (NMP,  no.  630;  Beier  det.); 
Lovedale,  on  trees  (TMP,  no.  4899;  Judson 
det.).  UGANDA:  Apac  District,  Aboke,  near 
St  Marys  College,  16  May  2002,  Klausen  leg. 
(AUC;  Klausen  det.);  Kampala,  Golf  Course, 
18  May  2002,  Klausen  leg.  (AUC;  Klausen 
det.). 

As  Paratemnus  pallidus  (in  part):  BEL- 
GIAN CONGO  (DEMOCRATIC  REPUBLIC 


OF  CONGO):  Garamba,  1951  (NHMW;  Beier 
[?]  det.). 

As  Paratemnus  braunsi:  ETHIOPIA:  Bahar 
Dar,  12  October  1968,  K.W  and  H.  Harde  leg. 
(SMNS,  no.  202;  Beier  and  Mahnert  det.). 

Remarks. — The  identification  as  P.  braun- 
si raises  the  question  of  a possible  synonymy. 
The  species  was  placed  in  Catatemnus  by 
Beier  (1932a),  obviously  due  to  what  he  in- 
terpreted as  a transverse  furrow  on  the  cara- 
pace. However,  when  Tullgren  (1907)  de- 
scribed the  species  based  on  one  female,  he 
explicitly  wrote  that  “Querfurchen  fehlen 
vollstandig,  nur  auf  der  Mitte  da,  wo  die  zwei- 
te  Furche  sein  sollte,  bemerkt  man  einen  klei- 
nen  Eindruck.”  In  a paper  by  Weygoldt 
(1970),  some  of  the  material  used  and  iden- 
tified by  Beier  is  referred  to  as  Paratemnus 
braunsi,  which  suggests  that  Beier  was  aware 
of  a misplacement  in  Catatemnus.  So  indi- 
cates this  identification  by  Beier  and  Mahnert. 
The  specimen  investigated  by  me  is  decidedly 
a P.  ellingseni,  but  since  I have  not  investi- 
gated the  type  of  C.  braunsi  deposited  in  the 
Natural  History  Museum  in  Hamburg,  I leave 
it  as  a misidentification  for  the  moment. 

Paratemnoides  insubidus  (Tullgren  1907) 

Material  examined. — NAMIBIA:  Kobos, 
40  miles  S of  Rehoboth,  19  July  1937  (TMP, 
no.  7894;  Beier  det.). 

Paratemnoides  nidificator  (Balzan  1888) 

Chelifer  nidificator  Balzan,  1888a:  no  pagination, 

figs. 

Chelifer  (Atemnus)  nidificator  minor  Balzan,  1892: 

510-511,  fig.  1.  NEW  SYNONYMY. 

Material  examined.— -As  Paratemnus  mi- 
nor: BRAZIL:  Manaos,  27  August  1973,  R. 
Schuster  leg.  (MHNG,  no.  BR-331;  Mahnert 
det.). 

As  Paratemnoides  nidificator:  BRAZIL: 
Mato  Grosso  State,  Nova  Mutum,  Fazenda 
Buriti,  12  June  2003,  H.F  Mendes  leg.  (AUC; 
Klausen  det.);  Sao  Paulo,  Riberto  Preto,  4 
June  2003,  H.F.  Mendes  leg.  (AUC;  Klausen 
det.).  COSTA  RICA:  near  Ajugas,  5 Decem- 
ber 1996,  Klausen  leg.  (AUC;  Klausen  det.); 
Manuel  Antonio,  8 December  1996,  Klausen 
leg.  (AUC;  Klausen  det.);  Golfito,  9 Decem- 
ber 1996,  Klausen  leg.  (AUC;  Klausen  det.). 

Remarks. — Balzan  (1892)  described  P.  mi- 
nor as  a variety  of  P.  nidificator.  He  stated 
that  P.  minor  is  insignificantly  smaller  than  P. 


KLAUSEN— MALE  GENITALIA  OF  ATEMNIDAE 


647 


nidificator,  but  the  palps  and  the  chelal  hand 
do  not  differ.  Contrary  to  this  he  gave  the 
body  length  of  P,  minor  to  be  4 mm  (Balzan 
1892)  and  that  of  P.  nidificator  to  be  3 mm 
(Balzan  1890).  With  (1908)  in  his  description 
of  P.  nidificator  obviously  considered  P.  mi- 
nor as  a variety  of  the  former.  Beier  (1932a, 
1932b)  eventually  raised  P.  minor  to  species 
level,  stating  that  the  two  are  very  similar,  aL 
though  P,  minor  is  smaller.  The  dimensions 
given  of  the  palps  and  the  fourth  pair  of  legs 
are  slightly  smaller  for  P.  minor,  the  ratio  be- 
tween  lengths  and  widths  are  very  close  to  P. 
nidificator. 

I have  examined  55  specimens,  comprising 
five  specimens  of  Paratemnoides  minor  from 
Manaos,  Brazil  as  given  above,  two  specie 
mens  as  Chelifer  nidificator  from  Haiti  (TulL 
gren  det.),  16  from  Sao  Paulo,  Brazil,  16  from 
Mato  Grosso,  Fazenda  Buriti,  Brazil  and  16 
specimens  from  the  three  localities  in  Costa 
Rica  as  given  above.  Admittedly,  the  speci- 
mens of  P.  minor  and  those  from  Costa  Rica 
are  slightly  smaller  compared  to  the  average 
measures  of  those  from  the  other  localities 
identified  as  P.  nidificator.  However,  the  pop- 
ulations of  P.  nidificator  from  Mato  Grosso 
and  Sao  Paulo  both  have  specimens  as  small 
as  those  of  P.  minor.  In  other  words  the  spec- 
imens of  P.  minor  are  within  the  range  of  P. 
nidificator.  Moreover,  when  comparing  the  ra- 
tios between  the  lengths  and  widths  of  the  in- 
dividual segments  of  the  pedipalps  and  the 
fourth  legs,  they  are  almost  identical,  no  mat- 
ter if  they  are  taken  from  P.  minor  or  P.  ni- 
dificator. The  outer  morphological  characters 
are  identical,  so  are  the  genital  characters  of 
the  males  investigated.  Thus  there  is  no  di- 
agnostic character  which  separates  them  as 
two  species.  Accordingly  I consider  P.  minor 
as  a junior  synonym  of  P.  nidificator. 

Paratemnoides  pallidus  (Balzan  1892) 

Chelifer  (Atemnus)  pallidus  Balzan,  1892:  511-512, 

figs.  2,  2a. 

Chelifer  {Atemnus)  guineensis  Ellingsen,  1906:  246. 

Synonymized  by  Harvey  (1991). 

Paratemnus  congicus  Beier,  1932b:  566-567,  fig.  7. 

Synonymized  by  Beier  (1972). 

Paratemnus  ceylonicus  Beier,  1932b:  569,  fig.  8. 

NEW  SYNONYMY. 

Material  examined. — As  P.  ceylonicus:  S- 
CEYLON  (SRI  LANKA):  Habaraduwa,  20 


January-4  February  1983,  T.  Osten  leg. 
(SMNS,  no.  1542;  Schawaller  det.). 

As  P.  congicus:  BELGIAN  CONGO 
(DEMOCRATIC  REPUBLIC  OF  CONGO): 
Brazzaville,  11  January  1964,  Balogh  & Zicsi 
leg.  (MHNG,  no.  653;  Mahnert  det.). 

As  P.  guineensis:  BELGIAN  CONGO 
(DEMOCRATIC  REPUBLIC  OF  CONGO): 
Brazzaville,  27  December  1963,  Balogh  & 
Zicsi  leg.  (MHNG,  no.  589;  Mahnert  det.). 

As  P.  pallidus:  BELGIAN  CONGO  (DEM- 
OCRATIC REPUBLIC  OF  CONGO):  Gar- 
amba,  1951,  (NHMW;  Beier  det.).  UGANDA: 
Kampala,  Golf  Course,  1 8 May  2002,  Klausen 
leg.  (AUC;  Klausen  det.).  SRI  LANKA:  Per- 
adeniya,  Botanical  Gardens,  Kandy  District, 
20  February  2000,  D.  Huber  leg.  (AUC;  Klau- 
sen det.).  MALAYSIA:  Kuala  Lumpur,  3 
April  2002,  Klausen  (AUC;  Klausen  det.). 

Remarks.' — The  descriptions  given  by 
Beier  (1932a,  1932b)  for  P.  pallidus  and  P. 
ceylonicus  indicate  that  the  main  distinction  is 
based  on  differences  in  the  dimensions  and 
proportions  of  the  appendages.  I have  com- 
pared P.  ceylonicus  (13  specimens)  from  Sri 
Lanka  and  Malaysia  with  P.  congicus  and  P. 
guineensis  (2  specimens)  from  Belgian  Congo 
and  P.  pallidus  (8  specimens)  from  Uganda.  I 
can  find  no  significant  differences  in  the  ped- 
ipalps and  the  4th  legs  of  the  two  groups,  ei- 
ther in  dimensions  or  in  proportions.  More- 
over, in  his  key  to  the  genus  Paratemnus, 
Beier  (1932a,  1932b)  used  the  length  of  the 
palpal  finger  compared  to  the  width  of  the 
chela  as  a diagnostic  character  to  separate  P. 
ceylonicus  (and  P.  congicus)  from  P.  pallidus. 
In  my  material  all  the  specimens  have  the 
fixed  finger  longer  than  the  width  of  the  palpal 
chela.  In  a later  publication  Beier  (1972)  syn- 
onymized P.  congicus  with  P.  pallidus  which 
suggests  that  he  no  longer  considered  this  to 
be  a discriminating  character.  Based  on  my 
measurements  and  the  fact  that  the  male  gen- 
italia are  identical,  I consider  P.  ceylonicus  to 
be  a synonym  of  P.  pallidus. 

Paratemnoides  salomonis  (Beier  1935) 

Material  examined. — SOLOMON  IS- 
LANDS: Guadalcanal,  9 May  1965  (NHMW; 
Beier[?]  det.).  PAPUA  NEW  GUINEA:  New 
Britain,  Volo  volo,  6 July  1995,  K.R.  Klausen 
& F.  Klausen  leg.  (AUC;  F.  Klausen  det.);  We- 
vak,  by  Windjammer  Hotel,  9 July  1995,  K.R. 


648 


THE  JOURNAL  OF  ARACHNOLOGY 


Klausen  & E Klausen  leg.  (AUC;  F.  Klausen 
det.). 

Stenatemnus  fuchsi  (Tullgren  1907) 

Material  examined. — INDONESIA:  Nias 
Island,  Eastcoast,  Lawalo,  phoretic  on  Passal- 
idae,  23  September  1979,  D.  Erber  leg. 
(SMNS,  no.  296;  Schawaller  det.);  Sumatra 
[probably:  Si-Rambe,  1891-94,  E.  Modigliani 
leg.]  (ZMUO,  no. 538;  Ellingsen  det.). 

Tamenus  femoratus  Beier  1932 

Material  examined. — IVORY  COAST: 
Divo,  16  August  1963,  J.  Decelle  leg. 
(RMCA,  no.  83.161.132;  Heurtault  det.). 

Titanatemnus  gigas  Beier  1932 

Material  examined. — CAMEROON:  Bos- 
um,  scrub,  20  May  1914,  Tessmann  leg. 
(ZMB,  no.  31190;  paratype) 

Titanatemnus  natalensis  Beier  1932 

Material  examined. — SOUTH  AFRICA: 
Durban,  March  1916,  C.  Akerman  leg.  (NMP, 
no.  5106;  Beier  det.). 

As  Chelifer  (=  Titanatemnus)  equester.  Na- 
tal, Durban,  C.N.  Barker  leg.  (ZMUO,  no. 553; 
Ellingsen  det.). 

Remarks. — The  main  difference  between 
T.  natalensis  and  T.  equester  is  the  size,  with 
the  latter  being  the  larger  of  the  two.  Because 
size  is  not  the  best  of  criteria  for  separating 
species,  an  investigation  of  the  genitalia  of  T. 
equester  might  give  a clue  to  their  relation- 
ship. 

Titanatemnus  palmquisti  (Tullgren  1907) 

Material  examined. — Kenya:  Meru,  25 
April  1957  (NHMW;  Leleup  det.).  NYASSA 
(MALAWI?):  1899,  Fiilleborn  leg.  (ZMUO, 
no.  306;  identified  by  Ellingsen  det.). 

Titanatemnus  sjoestedti  (Tullgren  1901) 

Material  examined. — As  Chelifer  sjoes- 
tedti: CAMEROON:  Itoki,  February  1891,  Y. 
Sjostedt  leg.  (NRMS:  syntype).  FRENCH 
CONGO  (CONGO):  N'kogo,  December  1902, 
L.  Fea  leg.  (ZMUO,  no.  211;  Ellingsen  det). 

Titanatemnus  tessmanni  Beier  1932 

Material  examined. — As  Chelifer  sjoes- 
tedti: PORTUGUESE  GUINEA  (GUINEA- 
BISSAU):  Rio  Cassine,  January-April  1900, 
L.  Fea  leg.  (ZMUO,  no.  210;  Ellingsen  det). 


Titanatemnus  thomeensis  (Ellingsen  1906) 

Material  examined. — SAO  THOME: 
Agua  Ize,  400-700  m,  December  1900,  L.  Fea 
leg.  (ZMUO,  no.219;  syntype). 

The  genital  organs  were  dissected  with 
honed  steel  needles  under  a stereomicroscope. 
Following  24  hours  soaking  in  a solution  of 
2%  pepsin  in  water  acidified  with  HCl  at  room 
temperature,  the  organs  were  washed  and 
placed  in  successive  alcohol  baths  ending  with 
a mixture  of  96%  alcohol  and  Euparal  es- 
sence. I prefer  this  method  to  soaking  in  po- 
tassium hydroxide  because  it  is  probably  more 
gentle  to  the  delicate  chitinized  parts.  The 
specimens  were  finally  mounted  on  slides  in 
Euparal. 

Specimens  were  examined  and  photo- 
graphed under  a stereomicroscope  using  dark- 
field/lightfield  equipment.  Drawings  were 
made  using  a compound  microscope  with  a 
drawing  tube. 

Dissection  of  the  genital  organs  from  the 
body  was  necessary  because  their  orientation 
in  situ  makes  it  almost  impossible  to  obtain  a 
correct  interpretation.  Moreover,  the  translu- 
cent parts  are  particularly  difficult  to  see  in 
this  position.  All  genital  organs  have  accord- 
ingly been  examined  after  dissection.  They 
were  orientated  on  the  slide  in  a position  with 
the  lateral  apodemes  and  lateral  rods  lying  up- 
permost, horizontal  to  the  light  axis  of  the  mi- 
croscope. 

DESCRIPTION  OF  THE  GENITALIA 

The  description  concentrates  on  the  chitin- 
ized parts  of  the  genitalia,  i.e.  the  different 
diverticula  of  the  genital  atrium  and  their  as- 
sociated apodemes,  as  well  as  the  ejaculatory 
canal  and  its  atrium.  Legg  (1974)  has  given  a 
generalized  description  of  the  genital  organs 
of  male  pseudoscorpions.  I have  followed  his 
terminology  when  possible. 

The  genital  organ  as  a whole  can  be  di- 
rected more  or  less  anteriorly  from  the  genital 
opening  in  some  species  and  posteriorly  in 
others.  It  is  therefore  confusing  to  use  the 
terms  dorsal  and  ventral  side  when  referring 
to  the  different  parts  of  the  organ.  To  avoid 
confusion  I use  the  term  “anterior  side”  as 
the  side  of  the  organ  which  is  connected  to 
the  anterior  part  of  the  genital  aperture  and 
“posterior  side”  for  the  side  connected  to  pos- 
terior part  of  it  (Figs.  3 & 4). 


KLAUSEN— MALE  GENITALIA  OF  ATEMNIDAE 


649 


Figures  l~2. — Generalized  view  of  atemnid  male  genitalia.  Anterior  side:  a.  lateral  apodeme;  b.  hooked 
branch;  c.  sclerotized  bar;  d.  longitudinal  fold  of  medial  diverticulum;  e.  ejaculatory  canal  atrium;  f.  lateral 
rods;  g.  dorsal  apodeme;  h.  ventral  diverticulum;  1.  lateral  lip  of  lateral  apodeme.  Posterior  side:  i.  dorsal 
diverticulum;  j.  apophysis  of  posterior  dorsal  gland;  k.  extension  of  medial  diverticula. 


Moreover,  I use  the  term  “proximal”  for 
the  parts  lying  near  the  genital  aperture  and 
the  term  “distal”  for  parts  near  the  seminal 
vesicles  (Figs.  3 & 4).  However,  when  the 
words  are  part  of  established  terms,  like  in 
“dorsal  diverticulum”  or  “dorsal  apodeme”, 
I have  kept  them  to  make  my  descriptions 
compatible  with  that  of  Legg  (1974). 

The  size  of  the  genital  organ  is  correlated 
with  the  size  of  the  species:  the  larger  species 
like  Titanatemnus  (Figs.  11-14)  have  the  most 
prominent  organs  with  distinctly  colored  apo- 
demes;  in  the  smaller  species  of  Paratemno- 
ides  (Figs.  18—20),  Brazilatemnus  and  Stena- 
temnus  (Figs.  6 & 10)  the  organ  is  small, 
transparent  and  almost  colorless.  The  sped- 
men  of  Anatemnus  javanus  (Fig.  24)  studied 
is  completely  colorless,  but  this  is  probably 
due  to  coeservational  conditions. 

The  most  conspicuous  parts  on  the  anterior 
side  of  the  organ  are  the  lateral  apodemes  and 
the  lateral  rods,  connected  to  the  dorsal  apo- 
deme  and  the  ejaculatory  canal  atrium  (Fig.l). 
The  posterior  side  is  dominated  by  the  prom- 


inent and  translucent  bilobed  dorsal  and  me- 
dial diverticula  lying  side  by  side  along  the 
sagittal  plane  (Fig.  2). 

Dorsal  diverticula  (Figs.  2,  3 & 4:  i).— 
On  the  posterior  side  of  the  genital  organ  the 
proximal  part  of  the  dorsal  diverticula  is  con- 
nected to  the  atrium  of  the  posterior  dorsal 
gland  with  its  support  and  rugose  entrance 
area.  The  posterior  dorsal  gland  is  attached  to 
this  area  which  has  a small,  knob-shaped 
apophysis  (Figs.  2,  3 & 4:  j).  Distally  the  dor- 
sal diverticula  are  confined  by  a transverse 
fold  overlying  the  medial  diverticula  and  run- 
ning between  the  hooked  branches  of  the  two 
lateral  apodemes  (Figs.  1,  3 & 4:  b).  On  the 
lateral  side  of  the  dorsal  diverticula  the  sur- 
face is  very  rugose.  It  is  made  up  of  a dense 
layer  of  more  or  less  conical  tubercles,  each 
with  a minute  hole  in  the  utmost  tip.  They 
obviously  are  the  seat  of  glands,  like  the  en- 
trance area  of  the  posterior  dorsal  gland.  In 
most  species  the  dorsal  diverticula  are  almost 
fused  in  the  sagittal  plane  on  the  posterior 
side.  The  dorsal  diverticula  are  extended  lat- 


650 


THE  JOURNAL  OF  ARACHNOLOGY 


posterior 


Figures  3-4. — Male  genitalia,  left  lateral  view:  3.  Diplotemnus  insolitus;  4.  Paratemnoides  ellingseni. 
Scale  lines  = 0.2  mm;  abbreviations  as  in  Figs.  1-2. 


erally  and  enfold  the  proximal  part  of  the  me- 
dial diverticula  on  the  anterior  side.  Here  the 
dorsal  diverticula  are  dominated  by  the  lateral 
apodemes  with  their  hooked  branches. 

Medial  diverticula  (Figs.  1,  2,  3 & 4:  d, 
k). — Distally  the  medial  diverticula  extend 
beyond  the  dorsal  diverticula  to  the  level  of 
the  ejaculatory  canal  atrium.  Here  they  are 
mostly  made  up  of  the  lateral  apodemes. 


In  many  species  the  two  medial  diverticula 
have  a prominent  extension  along  the  sagittal 
plane  on  the  posterior  side  of  the  genital  organ 
(Figs.  2 & 3:  k).  Both  of  these  extend  to  the 
level  of  the  ejaculatory  canal  atrium  and  are 
fused  along  the  midline,  forming  a finger-like 
bulge.  This  is  easily  seen  from  the  anterior 
side  for  instance  in  Titanatemnus  gigas,  T. 
tessmanni,  Cyclatemnus  centralis  and  Cata- 


KLAUSEN— MALE  GENITALIA  OF  ATEMNIDAE 


651 


Figures  5-10. — Male  genitalia,  anterior  side:  5.  Miratemnus  hirsutus;  6.  Brazilatemnus  browni;  7.  Tull- 

grenius  indicus;  8.  Diplotemnus  insolitus;  9.  Atemnus  politus;  10.  Stenatemnus  fuchsi.  Scale  lines  = 0.2 
mm. 


temnus  togoensis  (Figs.  11,  14,  21,  28).  In  Di- 
plotemnus insolitus  it  is  pointed  posteriorly 
and  can  best  be  seen  from  the  lateral  side  (Fig. 
3:  k).  In  Oratemnus  loyolai  it  is  very  con- 
spicuous and  protrudes  beyond  the  lateral  apo- 


demes  (Fig.  15).  In  others  like  Paratemnoides 
and  Tullgrenius  indicus  this  extension  is  re- 
duced or  almost  lacking  (Figs.  4k,  7,  18-20, 
22).  Proximally,  the  medial  diverticula  are 
covered  by  the  dorsals  and  their  associated  lat- 


652 


THE  JOURNAL  OF  ARACHNOLOGY 


eral  apodemes  on  the  anterior  side  of  the  gen- 
ital organ. 

On  the  anteromedial  side  the  membranous 
wall  of  both  the  medial  diverticula  is  folded- 
over,  forming  a longitudinal  fold  running  from 
the  distal  end  of  the  lateral  apodeme  right  up 
to  the  proximal  part  of  the  same  (Fig.  Id). 
Here  the  fold  is  covered  by  the  lateral  apo- 
deme (Fig.  Ic).  In  most  genera  the  fold  has  a 
projection  midway  along  its  length.  This  can 
be  distinctly  pointed,  as  for  instance  in  Mir- 
atemnus  hirsutus,  Atemnus  politus,  Titanatem- 
nus  palmquisti  and  Cyclatemnus  centralis 
(Figs.  5,  9,  12,  21).  In  Oratemnus  navigator 
the  pointed  projection  typically  has  a small 
indentation  (Fig.  16).  Catatemnus  birmanicus 
and  C granulatus  have  the  projection  of  the 
longitudinal  fold  more  gently  rounded,  and  in 
the  latter  species  it  has  a distinct  notch  (Figs. 
26,  27).  In  others,  like  T.  gigas,  T.  sjoestedti, 
T.  tessmanni  and  Anatemnus  voeltzkowi  the 
projection  is  more  like  a lobe  (Figs.  11,  13, 
14,  25).  Tullgrenius  indicus  is  aberrant  in  hav- 
ing two  lobes  (Fig,  7)  as  is  Anatemnus  nova- 
guineensis  in  having  three  overlapping  lobes 
(Fig.  23).  In  Brazilatemnus  browni,  Stenatem- 
nus  fuchsi,  Paratemnoides  pallidus,  P.  nidifi- 
cator  and  P.  salomonis  (Figs.  6,  10,  18-20) 
the  projection  of  the  longitudinal  fold  is  lack- 
ing. 

Ventral  diverticulum  (Fig.  1:  h). — The 

anterior  wall  is  mostly  sclerotized,  but  can  be 
colorless  and  almost  transparent  in  some  of 
the  smaller  species.  Typically  it  is  bilobed, 
most  pronouncedly  so  in  the  Titanatemnus 
species  (Figs.  11,  13,  14).  In  the  four  miratem- 
nine  genera  this  diverticulum  is  very  wide  and 
has  a somewhat  hood-like  appearance  (Figs. 
5-8) 

Lateral  apodemes  (Fig.  1:  a). — The  lateral 
apodemes  are  sclerotized  regions  formed  by 
the  anterolateral  side  of  the  two  dorsal  and 
medial  diverticula.  The  apodemes  run  along 
either  side  of  the  lateral  rods.  The  apodemes 
are  oriented  parallel  to  the  rods  but  can  be 
differently  shaped  in  the  different  species. 
This  is  most  marked  at  the  distal  end.  Gen- 
erally they  are  distinctly  colored  and  sclero- 
tized in  the  larger  species,  whereas  in  the 
smaller  species  they  are  delicate  and  almost 
colorless. 

The  lateral  apodemes  can  be  divided  in  2 
principal  parts:  A proximal  part  situated  on 
the  dorsal  diverticula  characterized  by  a 


hooked  branch  situated  on  the  lateral  side.  In 
the  miratemnines  Miratemnus  hirsutus,  Bra- 
zilatemnus browni  and  Tullgrenius  indicus 
(Figs.  5-7),  the  hooked  branch  forms  an  al- 
most straight  stub  perpendiculary  to  the  axis 
of  the  whole  organ,  less  so  in  Diplotemnus 
solitus  (Fig.  8).  In  the  atemnines  this  branch 
is  bowed  distally.  In  both  Miratemninae  and 
Atemninae  it  always  terminates  in  a plate-like 
tip,  perhaps  with  the  exception  of  B.  browni. 
This  can  be  very  pronounced  as  in  Atemnus 
politus,  Titanatemnus  gigas,  Paratemnoides 
ellingseni  and  Anatemnus  voeltzkowi  (Figs.  9, 
11,  22,  25).  This  tip  is  the  only  part  of  the 
lateral  apodemes  which  has  muscles  attached 
to  it.  The  proximal  part  always  has  a sclero- 
tized rugose  area  on  either  side  of  the  sagittal 
line  (Fig.lc).  It  is  often  delimited  on  the  me- 
dial side  by  a darker  bar.  The  function  of  this 
might  be  to  reinforce  the  lateral  apodeme 
when  subjected  to  muscular  contractions.  In 
species  with  smaller  genitalia  this  bar  is  col- 
orless and  probably  reduced. 

A distal  part  situated  on  the  medial  diver- 
ticula and  more  or  less  expanded  laterally. 
This  part  of  the  lateral  apodemes  takes  a wide 
range  of  different  forms,  being  the  most  var- 
iable from  one  species  to  another.  Though  this 
part  can  be  very  variable  it  always  has  a lat- 
eral lip  which  is  either  bowed,  rolled  or 
wrapped  up  (Fig.  11).  In  Titanatemnus  gigas 
it  is  almost  like  a spoon;  in  Oratemnus  punc- 
tatus  and  Cyclatemnus  centralis  it  has  the 
same  shape  but  is  bowed  concavely  (Figs.  11, 
17  and  21).  Catatemnus  birmanicus,  Anatem- 
nus voeltzkowi,  A.  angustus  and  A.  orites  have 
a distinct  inner  ridge  bowed  into  a semicircle, 
which  make  them  stand  apart  from  the  others 
(Figs.  25,  26).  In  P.  ellingseni  the  lateral  lip 
is  rolled  into  a tube  (Figs.  4a,  22).  In  the  other 
Paratemnoides  and  in  Stenatemnus  fuchsi  the 
lateral  lip  is  diminutive,  almost  lacking  (Figs. 
10,  18-20).  In  Atemnus  politus  the  distal  part 
is  proportionally  smaller,  as  is  the  case  for  Ca- 
tatemnus togoensis  (Figs,  9,  28)  and  Micra- 
temnus  crassipes.  In  the  miratemnines  the  lat- 
eral lip  is  transversely  directed.  The  same  is 
true  of  Anatemnus  novaguineensis  and  A.  ja- 
vanus,  but  here  as  if  the  whole  genital  organ 
has  been  compressed  in  a longitudinal  direc- 
tion (Fig.  23,  24). 

Lateral  rods  (Fig.  1:  f). — Lateral  rods, 
which  flank  the  ejaculatory  canal,  are  present 
in  all  species  examined.  The  tips  of  their  ends 


KLAUSEN— MALE  GENITALIA  OF  ATEMNIDAE 


653 


Figures  11-14. — Male  genitalia,  anterior  side:  11.  Titanatemnus  gigas\  12.  T.  palmquisti;  13.  T.  sjoes- 
tedti;  14.  T.  tessmanni.  Scale  lines  0.2  mm. 


654 


THE  JOURNAL  OF  ARACHNOLOGY 


Figures  15-22. — Male  genitalia,  anterior  side:  15.  Oratemnus  loyolai;  16.  O.  navigator,  17.  O.  punc- 

tatus;  18.  Paratemnoides  pallidus;  19.  P.  nidificator;  20.  P.  salomonis;  21.  Cyclatemnus  centralis',  22.  P. 
ellingseni.  Scale  lines  = 0.2  mm. 


KLAUSEN— MALE  GENITALIA  OF  ATEMNIDAE 


655 


Figures  23-28. — Male  genitalia,  anterior  side:  23.  Anatemnus  novaguineensis;  24.  A.  Javanus;  25.  A. 
voeltzkowi;  26.  Catatemnus  birmanicus;  27.  C.  granulatus;  28.  C.  togoensis.  Scale  lines  = 0.2  mm. 


are  always  placed  inside  the  ventral  divertic- 
ulum. Here  the  tips  diverge,  except  in  Mira- 
temnus  hirsutus  and  Paratemnoides  pallidus, 
P.  nidificator  and  P.  salomonis  (Figs.  5,  18- 
20).  In  most  cases  the  lateral  rods  are  bowed 
when  seen  from  the  anterior  side,  forming  a 


lyre-like  structure  before  they  fuse  with  the 
dorsal  apodeme.  Seen  from  the  lateral  side, 
they  are  mostly  recurved  as  in  P.  ellingseni 
(Fig.  4f)  or  may  be  bent  in  a procurved  angle 
as  in  D.  insoUtus  (Fig.  3f). 

Dorsal  apodeme  (Fig.  1:  g). — The  dorsal 


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THE  JOURNAL  OF  ARACHNOLOGY 


apodeme  is  bowed  in  the  sagittal  plane,  run- 
ning from  the  lateral  rods  in  a curve  around 
the  ejaculatory  canal  atrium  (Figs.  3g,  4g). 
This  structure  seem  to  be  made  up  of  the  fused 
elongation  of  the  two  lateral  rods.  In  the  mir- 
atemnines  it  is  distinctly  bifid  at  the  distal  end, 
very  prominent  in  Miratemnus  hirsutus  and 
Diplotemnus  insoUtus  in  which  the  dorsal  apo- 
deme is  shaped  like  a narrow  rake  with  two 
prongs  (Figs.  5,  8).  In  the  atemnines  the  two 
distal  tips  are  almost  completely  joined,  but 
can  always  be  identified  as  two  minute  spikes 
or  knobs  lying  side  by  side,  as  for  instance  in 
T.  gigas  and  P.  pallidus  (Figs.  11,  18).  The 
apodeme  is  distinctly  colored  proximally,  but 
more  or  less  transparent  at  the  distal  end. 
Muscles  are  connected  to  the  distal  end. 

Ejaculatory  canal  atrium  (Fig.  1;  e). — 
The  atrium  of  the  ejaculatory  canal  covers  the 
prostatic  reservoir.  It  is  bowl  or  cup  shaped 
when  seen  laterally,  fairly  simply  constructed 
in  the  atemnines,  but  more  elaborate  in  the 
miratemnines  (Figs.  3e,  4e).  When  seen  from 
the  anterior  side,  the  atrium  of  the  atemnines 
is  more  or  less  crescent-shaped  on  either  side, 
marking  the  openings  for  the  incoming  ducts 
of  the  seminal  vesicles.  The  distal  end  of  the 
atrium  is  typically  either  procurved  or  flat- 
tened in  the  atemnines.  The  atrium  of  Atemnus 
politus  is  aberrant  in  this  respect  (Fig.  9).  In 
the  miratemnines  the  configuration  of  the  atri- 
um seems  to  differ  more  between  the  genera 
than  is  the  case  in  the  atemnines. 

DISCUSSION 

Characters  diagnostic  of  the  family. — 
The  male  genitalia  of  the  Atemnidae  share 
common  features  which  make  them  stand 
apart  from  other  pseudoscorpion  families. 
Compared  to  the  other  families  of  the  Cheli- 
feroidea,  they  clearly  constitute  a monophy- 
letic  group  in  this  respect.  The  characters 
which  unite  them  can  be  summed  up  in  the 
following  diagnostic  description.  The  letters 
refer  to  those  of  Figs  1 and  2:  (a)  Distal  part 
of  lateral  apodemes  more  or  less  sclerotized, 
especially  the  lateral  border.  The  lateral  border 
is  always  bowed,wrapped  or  rolled-up  in  a lat- 
eral lip,  sometimes  to  the  extent  of  giving  the 
lateral  apodeme  a snout-  or  rod-like  appear- 
ance; (b)  Proximal  part  of  each  lateral  apo- 
deme with  a hooked  branch  laterally.  Typi- 
cally these  are  sclerotized,  but  when  reduced 
they  are  translucent  and  hard  to  see;  (c)  Prox- 


imal part  of  each  lateral  apodeme  furnished 
with  a rugose  darker  area  and  delimited  by  a 
bar  medially,  strengthening  this  area;  (d)  Me- 
dial diverticulae  more  or  less  wrapped  up  on 
the  anterior  side  along  the  sagittal  line  and 
overlying  the  lateral  apodemes,  often  with  a 
pointed  or  rounded  projection  midway;  (e) 
Atrium  of  the  ejaculatory  canal  more  or  less 
bowl-shaped;  (f)  Lateral  rods  long  and  con- 
spicuous, running  parallell  to  the  sagittal  line. 
Usually  diverging  proximally;  (g)  A long  dor- 
sal apodeme  is  always  present,  made  up  of  the 
fused  elongation  of  the  lateral  rods.  Bifurcate 
or  bilobate  distally;  (h)  Anterior  wall  of  the 
ventral  diverticulum  bilobed  or  bipartite;  (i) 
Distal  part  of  the  two  dorsal  diverticulae  are 
folded  transversally  making  up  the  border 
against  the  medial  diverticulae  on  the  poste- 
rior side;  (j)  A knob-shaped  apophysis  pres- 
ent, which  may  have  an  attachment  function 
for  the  posterior  dorsal  gland. 

Affinities  to  other  families. — The  Atem- 
nidae including  the  Miratemninae  are  placed 
in  the  Cheliferoidea  together  with  the  Cheli- 
feridae,  Chernetidae  and  Withiidae.  Harvey 
(1992)  dealt  with  the  affinites  between  these 
four  families  and  placed  the  first  three  in  a 
trichotomy  because  he  could  not  find  any  apo- 
morphies  that  might  split  this  group  in  smaller 
entities.  Proctor  (1993)  has  pointed  to  the  fact 
that  the  spermatophore  stalk  of  the  Cheliferi- 
dae  and  the  Chernetidae  possess  a droplet  that 
is  absent  in  the  Atemnidae  and  the  Withiidae. 
This  resolves  the  trichotomy  and  places  the 
Cheliferidae  and  Chernetidae  in  a clade  sep- 
arated from  the  other  two.  Although  this  does 
not  imply  any  closer  connection  between  the 
atemnids  and  the  withiids,  it  might  be  noted 
that  the  overall  configuration  of  the  male  gen- 
italia of  atemnids  seem  to  be  closer  to  the 
withiids  than  to  the  other  two  families. 

In  Chernetidae  the  almost  circular 
apodemes  have  the  distal  ends  fused  or  united, 
this  configuration  seem  to  be  very  consistent 
and  very  different  from  that  of  the  atemnids. 
The  absence  of  lateral  rods  in  the  chemetids 
also  make  them  stand  apart  from  the  atemnids. 

When  considering  the  Cheliferidae  there  are 
some  similarities.  They  have  the  same  long, 
parallel  lateral  rods  as  the  Atemnidae  but  there 
is  one  significant  difference,  at  least  when 
compared  to  Chelifer  cancroides  and  Dactyl- 
ochelifer  latreillii  as  pictured  by  Vachon 
(1938a)  and  Legg  and  Jones  (1988).  This  is 


KLAUSEN— MALE  GENITALIA  OF  ATEMNIDAE 


657 


that  the  proximal  ends  of  the  lateral  rods  are 
merged  in  the  cheliferids,  which  is  never  the 
case  in  the  atemnids  investigated  by  me.  An- 
other very  important  difference  between  the 
two  families  is  the  presence  of  ram’s  horn  or- 
gans in  the  cheliferids,  which  are  absent  in  the 
atemnids. 

This  leaves  us  with  the  Withiidae,  which 
has  the  long,  parallel  lateral  rods  not  merged 
proximally,  just  as  in  the  Atemnidae.  More- 
over, the  lateral  apodemes  of  the  withiids  have 
the  same  pronounced  hooked  branches  as  in 
the  atemnids,  as  shown  by  Heurtault  (1971) 
and  Harvey  (1988).  Judged  from  these  char- 
acter states  of  the  male  genitalia,  I consider 
the  Withiidae  as  the  sister  group  to  the  Atem- 
nidae. 

Differences  between  Atemninae  and  Mir- 
atemninae. — Despite  the  differences  between 
the  genera  and  between  the  species,  the  over- 
all structures  of  the  male  genitalia  and  their 
orientation  are  remarkably  uniform  in  atem- 
nines  and  miratemnines.  However,  because 
the  miratemnines  have  earlier  been  raised  to 
family  level  partly  because  of  certain  charac- 
teristics of  their  male  genitalia,  it  seems  ap- 
propriate to  discuss  their  affinities  here. 

When  Vachoe  (1938a)  compared  the  male 
genitalia  of  Titanatemnus  congicus,  Atemnus 
politus  and  Catatemnus  schlottkei  with  those 
of  Miratemnus  hispidus,  he  concluded  that  the 
apodemes  of  the  latter  differed  in  being  di- 
rected in  the  opposite  direction  to  those  of  the 
former.  He  also  concluded  that  in  this  respect 
Miratemnus  came  closer  to  Withius  than  to  the 
other  three.  Dumitresco  & Orghidan  (1969, 
1970)  used  this  as  an  important  argument  in 
favor  of  raising  the  miratemnines  to  family 
level. 

However  Vachon’s  observations  on  atem- 
nines  and  miratemnines  are  not  based  on  fun- 
damental differences  in  the  structure  of  the 
genitalia  or  in  the  mutual  arrangement  of  these 
structures,  a fact  that  Vachon  certainly  must 
have  been  aware  of.  The  differences  simply 
depend  on  the  orientation  of  the  genitalia. 
When  examined  in  situ,  the  genitalia  of  the 
atemnines  Titanatemnus  and  Atemnus  are  bent 
anteriorly  from  the  genital  opening,  whereas 
those  of  Miratemnus  are  bent  posteriorly.  In  a 
ventral  view,  then,  in  the  atemnines  one  ac- 
tually observes  the  organ  with  the  anterior 
side  lying  nearest  to  the  sternites,  while  in  the 
miratemnines  Miratemnus  and  Diplotemnus 


one  has  the  posterior  side  nearest  to  the  ster- 
nites, as  shown  by  the  side  view  of  Paratem- 
noides  ellingseni  and  Diplotemnus  insolitus 
(Figs.  3,  4). 

Hence,  the  crucial  point  is  whether  this  dif- 
ference in  bending  is  sufficient  to  justify  a 
separation  into  two  families.  In  fact,  this  dif- 
ference is  not  absolute  between  the  two 
groups.  The  miratemnine  Tullgrenius  has  an 
organ  in  which  the  distal  part  is  bent  at  a 45° 
angle  anterior  to  the  genital  aperture  and  in 
the  Asiatic  and  American  atemnids  of  the  ge- 
nus Paratemnoides  the  whole  organ  is  direct- 
ed almost  dorsoventrally.  Harvey  (1988)  ob- 
served that  the  orientation  of  the  lateral  rod  in 
Paratemnoides  assimilis  was  more  similar  to 
Miratemninae  than  to  the  atemnines  Atemnus 
and  Titanatemnus.  Obviously  the  angle  of  the 
genitalia  varies  in  both  atemnines  and  mira- 
temnines and  does  not  provide  a useful  diag- 
nostic difference  between  the  groups. 

Even  if  there  are  no  fundamental  differenc- 
es separating  the  miratemnines  and  atemnines, 
the  morphology  of  the  male  genitalia  of  mir- 
atemnines shows  characteristics  which  sepa- 
rate them  from  the  atemnines.  These  might  be 
used  as  diagnostic  character  states  of  the  mir- 
atemnines. They  can  be  summarized  as  fol- 
lows: (a)  The  anterior  wall  of  the  ventral  di- 
verticulum is  very  wide,  covering  the  most 
proximal  part  of  the  lateral  apodemes  and  hav- 
ing a hood-like  appearance. (b)  The  hooked 
branch  of  the  lateral  apodemes  is  straight 
when  seen  from  the  anterior  side,  mostly  per- 
pendicular to  the  longitudinal  axis  of  the 
whole  organ. (c)  The  distal  end  of  the  dorsal 
apodeme  is  distinctly  bifurcated  into  two  sep- 
arate branches,  which  are  not  merged  as  in  the 
atemnines. 

Differences  between  genera. — The  inves- 
tigation of  the  genitalia  of  the  different  species 
reveals  a very  striking  result.  The  variation 
between  the  different  species  within  a genus 
is  often  greater  than  the  variations  between 
species  from  different  genera.  The  obvious  ex- 
planation must  be  that  several  of  the  genera 
are  not  monophyletic.  The  reason  for  this 
might  be  that  the  delimitation  of  the  genera  is 
based  on  external  morphological  characters 
which  in  some  cases  are  difficult  to  observe 
and  of  dubious  diagnostic  value.  This  relates 
to  both  discrete  and  continuous  characters.  For 
instance,  size  is  used  by  Beier  (1932a,  1932b) 
as  a diagnostic  character  to  separate  Titana- 


658 


THE  JOURNAL  OF  ARACHNOLOGY 


temnus  from  Cyclatemnus  and  Paratemnoides 
and  Oratemnus  is  separated  from  Atemnus, 
Anatemnus  and  Micratemnus  by  the  slimmer 
stalk  of  the  patella. 

Another  important  diagnostic  character  is 
the  presence  or  absence  of  a transverse  groove 
or  furrow  on  the  carapace.  This  is  used  as  a 
major  distinguishing  feature  to  separate  sev- 
eral genera  of  Atemninae.  According  to  Beier 
(1932a,  1932b)  those  atemnines  with  a groove 
are  Catatemnus,  Metatemnus,  Stenatemnus 
and  Tamenus.  This  follows  the  original  de- 
scription by  Thorell  (1889)  of  Chelifer  bir- 
manicus  (the  type  species  of  Catatemnus) 
where  he  states  that  the  carapace  has  a “sulco 
transverse  singulo”,  i.e.  a single  transverse 
groove  or  furrow.  This  groove  can  be  very 
difficult  to  define,  and  any  slight  depression 
on  the  carapace  might  have  been  interpreted 
as  a groove.  This  problem  is  discussed  by 
With  (1906)  who  makes  a distinction  between 
groove,  stripe  and  line;  in  C birmanicus  he 
described  this  character  as  a transverse  stripe 
and  in  C.  concavus  and  C.  monitor  as  a trans- 
verse line,  all  three  later  included  in  the  genus 
Catatemnus  by  Beier  (1932a,  1932b).  In  fact, 
when  scrutinized,  the  transverse  stripe  of  C 
birmanicus  actually  is  the  borderline  between 
the  dark  colored  frontal  part  and  the  pale  pos- 
terior part  of  the  carapace,  at  least  in  those 
syntypes  which  have  been  available  to  me  de- 
posited in  Naturhistoriska  Riksmuseet  in 
Stockholm  and  in  Zoological  Museum  in  Co- 
penhagen. The  absence  of  a furrow  or  groove 
is  particularly  obvious  when  the  specimens 
are  looked  at  from  the  lateral  side,  seeing  the 
outline  of  the  carapace. 

However,  in  several  other  species  where  the 
specimens  are  prepared,  a sort  of  transverse 
fold  can  be  observed  in  the  same  area,  as  if  a 
narrow  part  of  the  anterior  of  the  carapace  is 
wrapped  over  the  posterior.  Specimens  of  Ca- 
tatemnus togoensis,  C.  granulatus,  Tamenus 
femoratus  and  Stenatemnus  fuchsi  show  this 
fold.  Another  species,  Micratemnus  crassipes, 
does  have  a transversal  fold,  although  the  ge- 
nus was  originally  described  as  being  without 
a groove  on  the  carapace.  The  same  fold  is 
pronounced  in  Miratemnus  and  Diplotemnus 
but  very  weak  or  absent  in  Tullgrenius,  al- 
though the  groove  as  such  is  evident  in  all 
Miratemninae.  On  the  other  hand,  the  syntype 
of  Catatemnus  birmanicus,  the  type  species  of 
that  genus,  definitely  does  not  have  a fold.  To 


sum  up,  this  character  is  obviously  not  a dis- 
crete one,  but  varies  through  different  phases 
from  a very  distinct  groove  accompanied  with 
a fold,  to  a groove  or  slight  depression  with 
no  fold  or  to  a fold  with  no  groove;  or  just  a 
difference  in  color  and  sclerotisation  between 
the  anterior  and  posterior  part.  This  diversity 
might  be  looked  at  as  the  different  expressions 
of  the  vestigial  border  between  the  head  and 
the  first  segment  of  the  carapace. 

Variation  within  genera* — Anatemnus 
species  (Figs.  23-25):  Of  the  three  species 
figured  here,  A.  javanus  (the  type  species)  and 
A.  novaguineensis  seem  to  constitute  a group 
with  synapomorphic  character  states.  Their 
peculiar  shape,  as  if  the  whole  organ  has  been 
compressed  in  a longitudinal  direction,  distin- 
guishes them  from  all  other  species  compared 
here.  This  compression  has  placed  the  lateral 
lip  in  an  almost  transversal  position,  ending  in 
a small  projecting  snout  at  the  distalmost  end. 
Another  shared  characteristic  which  makes 
them  stand  apart  from  other  species  is  their 
comparatively  small  hooked  branches.  Ana- 
temnus subvermiformis  has  the  same  transver- 
sally  placed  lateral  lips  but  lacks  the  project- 
ing snout  and  has  the  same  small  hooked 
branches.  There  can  be  no  doubt  that  these 
three  species  are  closely  related.  Anatemnus 
elongatus  has  the  same  transversally  directed 
lateral  lips  and  the  same  projecting  snout  at 
the  distalmost  end  as  in  A.  javanus  and  A.  nov- 
aguineensis, but  it  has  the  hooked  branches 
projecting  wider  to  each  side. 

In  contrast,  A.  voeltzkowi  has  the  lateral 
apodemes  quite  differently  shaped.  The  lateral 
lips  of  this  species  have  a strongly  curved  me- 
dial border,  shared  with  Catatemnus  birman- 
icus and  A.  angustus.  The  shape  of  the  ejac- 
ulatory canal  atria  is  also  very  similar. 
Although  the  shape  of  the  ventral  diverticu- 
lum and  the  projection  of  the  longitudinal 
folds  are  different  and  more  reminiscent  of 
those  of  Titanatemnus,  the  overall  similarity 
indicates  a closer  connection  between  these 
two  species  than  existing  systematic  positions 
implies. 

Anatemnus  angustus  is  identical  to  C bir- 
manicus in  genital  configuration  as  well  as  in 
external  morphology,  apart  from  carapace,  as 
noted  in  the  species  list.  The  male  genitalia  of 
A.  orites  are  very  similar  to  A.  angustus.  The 
only  difference  is  that  the  whole  organ  of  A. 
orites  is  slightly  slimmer  across  the  lateral  lips 


KLAUSEN— MALE  GENITALIA  OF  ATEMNIDAE 


659 


of  the  lateral  apodemes  and  their  lateral  in- 
curvation are  less  pronounced  than  in  A.  an- 
gustus.  Taking  all  this  into  account  the  genus 
Anatemnus  seems  to  be  polyphyletic.  At  least, 
based  on  the  male  genitalia,  it  can  be  roughly 
divided  into  two  groups,  one  very  close  to  C 
birmanicus  and  another  standing  apart  from 
all  other  species  investigated. 

Catatemnus  species  (Figs.  26-28):  This  is 
another  genus  in  which  there  are  few  common 
features  in  the  character  states  of  the  genitalia. 
The  ventral  diverticulum  of  Catatemnus  gran- 
ulatus  and  C.  togoensis  are  similar  but  differ 
from  the  more  deeply  bilobed  ventral  diver- 
ticulum of  C birmanicus  (the  type  species). 
The  longitudinal  folds  of  the  medial  divertic- 
ula are  different  in  all  three  species,  as  are  the 
lateral  lips  of  the  lateral  apodemes  and  the 
ejaculatory  canal  atria  do  not  have  any  strik- 
ing resemblances.  However,  when  external 
morphology  is  considered,  both  C granulatus 
and  C.  togoensis  have  a transverse  fold  on  the 
carapace,  which  is  lacking  in  C.  birmanicus. 
The  trochanter  of  the  pedipalps  has  a rounded 
dorsal  bulge  in  the  former  two,  whereas  in  C. 
birmanicus  this  bulge  is  pointed.  Seen  in  lat- 
eral view,  the  patella  is  bulb-  or  vase-shaped 
in  C.  birmanicus,  but  in  C.  granulatus  and  C. 
togoensis  it  is  more  elongated  and  spindle 
shaped.  On  the  other  hand  the  presence  of  dis- 
cal  seta  on  the  tergites  of  all  three  species 
might  indicate  relationship. 

In  this  context  it  is  worth  noticing  that  Ta- 
menus  femoratus  has  the  transverse  fold  on 
the  carapace,  present  in  C.  granulatus  and  C. 
togoensis  but  lacking  in  C.  birmanicus.  The 
genitalia  have  the  characteristic  configuration 
of  the  lateral  lip  seen  in  C.  birmanicus  and 
Anatemnus  voeltzkowi,  even  if  the  lateral  bor- 
der is  almost  straight  rather  than  incurved, 
more  like  that  in  A.  orites.  The  ventral  diver- 
ticulum of  T.  femoratus  is  distinctly  bilobed, 
much  as  in  A.  voeltzkowi,  but  the  longitudinal 
fold  is  almost  straight  with  a small  fin-like 
projection  midway,  not  gently  curved  as  in  C. 
birmanicus  and  A.  voeltskowi.  Another  species 
worth  mentioning  in  connection  with  Cata- 
temnus is  Micratemnus  crassipes.  This  species 
have  genitalia  with  a strong  recemblance  to  C. 
togoensis,  especially  the  distal  part  of  the  lat- 
eral apodeme,  even  if  the  whole  organ  is 
smaller  and  corresponding  to  the  smaller  size 
of  the  animal. 

Cyclatemnus  species  (Fig.  21):  The  species 


C.  burgeoni,  C.  dolosus,  C.  globosus,  C.  gran- 
ulatus and  C.  robustus  have  genitalia  almost 
identical  to  those  of  Cyclatemnus  centralis 
(the  type  species),  as  does  C minor  although 
these  are  smaller.  The  differences  between 
them  are  confined  to  slight  variations  in  the 
curvature  of  the  lateral  lips  of  the  lateral  apo- 
deme. At  least  when  considering  the  male 
genitalia,  this  genus  seem  to  be  very  homog- 
enous. However,  C granulatus  is  divergent  in 
its  external  morphology.  It  has  discal  seta  on 
tergites  IV-X,  as  in  Catatemnus,  this  is  in  ac- 
cordance with  the  observation  of  Vachon 
(1952).  The  other  species  lack  the  discal  seta 
on  the  tergites  IV-VIII,  which  contradicts  the 
observations  of  Maheert  (1983)  on  Cyclatem- 
nus centralis. 

Athleticatemnus  pugil  (the  type  and  sole 
species)  bears  a strong  likeness  to  C granu- 
latus in  external  morphology  as  noted  earlier. 
The  genitalia  of  A.  pugil  resemble  those  of 
Cyclatemnus,  but  the  curvature  of  the  distal 
part  of  the  lateral  apodeme  is  more  straight 
angled,  the  lateral  lip  is  slimmer  and  the  most 
distal  part  of  the  lip  is  drawn  up  in  a dorso- 
ventral  direction. 

Oratemnus  species  (Figs.  15—17):  It  is  hard 
to  find  any  common  denominators  in  the  gen- 
italia of  the  three  species  treated  here  that 
might  be  called  apomorphic  character  states 
and  thus  make  them  stand  apart  from  the  oth- 
ers as  a single  entity.  They  all  have  a rather 
shallow  bilobation  of  the  ventral  diverticulum 
but  then  so  have  several  others,  such  as  Sten- 
atemnus  fuchsi,  Catatemnus  granulatus  and 
C.  togoensis.  The  ejaculatory  canal  atrium  of 
O.  loyolai  is  reminiscent  of  that  of  Cyclatem- 
nus centralis,  whereas  that  of  O.  punctatus  is 
more  like  the  atrium  of  Anatemnus  javanus  or 
Stenatemnus  fuchsi.  The  atrium  of  O.  navi- 
gator is  intermediate  between  that  of  Anatem- 
nus novaguineensis  and  Catatemnus  togoen- 
sis. The  most  divergent  character  among  the 
three  is  the  configuration  of  the  lateral  lips, 
Oratemnus  punctatus  has  the  lateral  lip 
formed  almost  like  those  of  Cyclatemnus  or 
Titanatemnus,  in  fact,  the  organ  as  a whole 
might  easily  be  that  of  a Cyclatemnus  species. 
The  lateral  lips  of  O.  loyolai  do  show  some 
resemblance  to  those  of  Paratemnoides  elling- 
seni,  but  O.  loyolai  differs  clearly  in  the  bulg- 
ing shape  of  the  medial  diverticular  extension. 
Oratemnus  navigator  stands  apart  from  the 
other  two  in  having  a very  small  lateral  lip 


660 


THE  JOURNAL  OF  ARACHNOLOGY 


and  by  having  an  additional  fin  in  front  of  the 
projection  of  the  longitudinal  fold.  In  its  ex- 
ternal morphology  O.  navigator  differs  mostly 
in  having  discal  seta  on  the  tergites,  which  are 
absent  in  the  other  two.  Judged  from  the  con- 
figuration of  the  male  genitalia  in  the  three 
species  I have  investigated,  the  genus  Oratem- 
nus  seems  to  be  polyphyletic. 

Paratemnoides  species  (Figs.  4,  18—20, 
22):  In  this  genus  the  three  species  P.  nidifi- 
cator,  P.  pallidus  (the  type  species)  and  P. 
salomonis  are  very  much  alike;  they  are  only 
separated  by  minor  differences  in  the  propor- 
tions of  the  hooked  branch  and  the  distal  part 
of  the  lateral  apodeme.  Although  the  differ- 
ences are  small  they  seem  to  be  very  constant 
in  the  specimens  investigated  by  me,  indicat- 
ing that  they  are  specific.  The  aberrant  species 
is  obviously  P.  ellingseni,  which  clearly 
stands  apart  from  the  others  in  the  configura- 
tion of  the  genitalia.  Except  for  the  size  alone, 
the  shape  of  the  lateral  apodemes  are  totally 
different,  the  longitudinal  fold  has  a pro- 
nounced projection,  the  lateral  rods  are  di- 
verging proximally  inside  the  ventral  divertic- 
ulum, and  the  ejaculatory  canal  atrium  has 
crescent  shaped  openings  on  either  side  which 
are  lacking  in  the  other  Paratemnoides.  Con- 
sidering these  characters,  it  is  hard  to  believe 
that  P.  ellingseni  could  be  congeneric  with  the 
others.  The  external  morphology  is  indeed 
very  similar,  which  of  course  is  the  main  rea- 
son that  this  species  has  been  placed  in  Par- 
atemnoides. However  there  are  some  differ- 
ences: the  trochanter  of  P.  ellingseni  has  a 
pointed  bulge  dorsally,  whereas  in  the  others 
this  bulge  is  less  pronounced  and  rounded;  the 
shape  of  the  patella  in  lateral  view  is  almost 
flattened  in  P.  ellingseni,  like  a short  sausage, 
whereas  in  the  others  it  is  bean-shaped.  The 
last  species  on  my  list,  Paratemnoides  insub- 
idus,  is  very  close  to  P.  ellingseni.  Its  genitalia 
are  almost  identical,  but  it  differs  in  the  ex- 
ternal morphology  by  having  a patella  that  is 
wider  seen  in  lateral  view,  having  a shape  like 
the  seed  bulb  of  a poppy.  The  trochanter,  how- 
ever, has  the  same  pointed  bulge  dorsally  as 
P.  ellingseni.  Considering  the  differences  in 
this  group,  I must  conclude  that  this  genus  is 
polyphyletic  with  P.  ellingseni  and  P.  insub- 
idus  forming  a separate  group  that  stands  apart 
from  the  others, 

Titanatemnus  species  (Figs.  11-14):  The 

species  examined  in  this  genus  seem  to  con- 


stitute a fairly  homogenous  group,  perhaps 
with  T.  palmquisti  being  the  most  divergent. 
All  other  species  have  a pronounced  bipartite 
ventral  diverticulum,  a lobed  or  rounded  pro- 
jection on  the  longitudinal  fold,  a significant 
extention  of  the  medial  diverticulae  and  a 
characteristic  form  of  the  ejaculatory  canal 
atrium.  Titanatemnus  natalensis  is  very  close 
to  T.  gigas  (the  type  species)  in  genital  con- 
figuration, with  the  extension  of  the  medial 
diverticulae  being  less  protruding  and  the  lat- 
eral lip  of  the  lateral  apodeme  slightly 
straighter,  more  like  in  T.  sjoestedti.  However 
T.  palmquisti  is  aberrant  in  having  a less  cleft 
bilobation  of  the  ventral  diverticulum,  a more 
pointed  projection  on  the  longitudinal  folds 
and  slightly  more  transversely  directed  lateral 
lips.  The  overall  configuration  lies  somewhere 
between  the  Titanatemnus  and  Cyclatemnus 
type.  In  the  light  of  this  it  is  interesting  to  note 
that  Mahnert  (1983)  has  pointed  to  some  af- 
finites  between  this  species  and  Cyclatemnus 
fallax  and  C burgeoni. 

In  conclusion,  when  considering  the  config- 
uration of  the  male  genitalia  within  existing 
genera,  it  is  obvious  that  the  diagnostic  char- 
acters currently  used  have  led  to  misplace- 
ments and  to  systematic  groupings  that  do  not 
reflect  true  phylogenetic  relationship  inside 
the  family.  Admittedly,  the  external  morphogy 
has  only  occasionally  been  taken  into  consid- 
eration in  the  present  discussion  and  has  not 
been  treated  in  a systematic  manner.  A more 
meticulous  treatment  of  these  characters  in  a 
cladistic  analysis,  together  with  those  of  gen- 
italia, should  provide  a clearer  understanding 
of  relationships  between  the  genera. 

ACKNOWLEDGMENTS 

I wish  to  thank  Dr.  Mark  Judson,  Museum 
national  d’Histoire  naturelle,  Paris,  Dr.  Volker 
Mahnert,  Museum  d’Histoire  naturelle,  Ge- 
neva, Dr.  Mark  Harvey,  Western  Australian 
Museum,  Perth  and  Dr.  Gerald  Legg,  Booth 
Museum  of  Natural  History,  Brighton  for  giv- 
ing me  very  valuable  criticism  and  advice. 
What  this  paper  has  gained  in  quality  is  cer- 
tainly due  to  their  efforts,  the  remaining  weak- 
nesses are  of  course  my  responsibility.  Fur- 
thermore, I wish  to  thank  all  the  persons  at 
the  museums  stated  earlier  who  kindly  lent  me 
specimens  for  investigation  and  generously 
and  patiently  extended  loans,  often  several 
times,  when  necessary. 


KLAUSEN— MALE  GENITALIA  OF  ATEMNIDAE 


661 


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Manuscript  received  7 February  2003,  revised  3 
February  2004. 


2005.  The  Journal  of  Arachnology  33:663-669 


EXTREMELY  SHORT  COPULATIONS  DO  NOT  AFFECT 

HATCHING  SUCCESS  IN  ARGIOPE  BRUENNICHI 
(ARANEAE,  ARANEIDAE) 


Jutta  M.  Schneider  and  Lutz  Fromhage:  Biozentrum  Grindel,  Martin-Luther-King 
Platz  3,  28146  Hamburg,  Germany 

Gabriele  Uhl:  Institut  fur  Zoologie,  Abt.  Neuroethologie,  Endenicher  Allee  11-13, 
53115  Bonn,  Germany 

ABSTRACT.  Females  of  the  orb- weaving  spider  Argiope  bruennichi  are  very  cannibalistic  and  regularly 
terminate  copulations  by  aggressively  attacking  the  male.  Few  males  survive  mating  and  they  escape  only 
if  they  mate  no  longer  than  8 seconds  on  average.  We  speculated  that  the  brief  copulations  of  surviving 
males  will  not  result  in  complete  fertilization  of  all  of  a female’s  eggs  and  that  multiple  mating  is  necessary 
to  compensate  for  that.  Surprisingly,  we  found  no  difference  in  the  proportion  of  hatched  young  in  clutches 
of  females  that  were  experimentally  assigned  to  mate  once  or  twice.  Even  females  that  mated  with  one 
male  for  less  than  10  seconds  produced  clutches  with  hatching  rates  no  different  than  treatments  with  two 
matings.  The  question  remains  why  males  risk  their  lives  by  prolonging  copulation  duration.  Possible 
causes  and  functions  in  the  context  of  sexual  selection  are  discussed. 

Keywords:  Sexual  cannibalism,  sexual  conflict,  orb-weaving  spiders,  mating  behavior 


Theory  suggests  that  male  fitness  increases 
with  the  number  of  females  with  whom  they 
mate  (Bateman  1948).  However,  it  is  less  clear 
why  females  mate  with  more  than  one  male 
in  many  animal  species.  A considerable  body 
of  recent  literature  investigates  the  question 
why  females  mate  multiply  and  which  kind  of 
direct  (Arnqvist  & Nilsson  2000)  or  indirect 
(Jennions  & Petrie  2000)  benefits  could  be  re- 
sponsible. One  such  potential  benefit  is  the 
avoidance  of  unfertilized  eggs  due  to  sperm 
limitation  (Arnqvist  & Nilsson  2000).  A con- 
sequence of  multiple  mating  by  females  is  that 
the  sperm  of  different  males  competes  for  the 
fertilization  of  a female’s  eggs.  Sperm  com- 
petition selects  for  male  strategies  that  en- 
hance the  relative  success  of  males  (Elgar 
1998;  Simmons  2001).  The  duration  of  cop- 
ulation is  an  important  trait  in  this  respect  be- 
cause it  may,  for  example,  determine  the 
quantity  of  sperm  transferred,  aid  removal  of 
sperm  from  previous  males,  increase  the  prob- 
ability that  females  will  store  and  use  the 
sperm  or,  for  long  copulations  decrease  the 
opportunities  for  females  to  copulation  with 
another  male.  Males  are  thus  under  strong  se- 
lection to  achieve  an  optimal  duration  of  cop- 


ulation. However,  mating  can  be  costly  to  fe- 
males. For  example  males  can  manipulate 
female  reproductive  behavior  (Chapman  et  al. 
2003)  or  even  cause  direct  physical  harm  to 
females  (Crudgington  & Siva-Jothy  2000).  In 
these  cases,  we  expect  a sexual  conflict  over 
the  duration  of  copulation  where  females  will 
often  attempt  to  end  copulation  earlier  than 
the  males  (Stockley  1997). 

In  spiders,  the  duration  of  copulation  varies 
largely  across  taxa  (Elgar  1995;  Stratton  et  al. 
1996)  and  is  relatively  short  in  the  orb- web 
spiders,  particularly  in  the  genus  Argiope  Au- 
douin  1826.  Orb-weavers  show  a high  fre- 
quency of  post-mating  sexual  cannibalism  and 
in  a comparative  analysis,  Elgar  (1995)  found 
that  within  the  Araneidae,  sexually  cannibal- 
istic genera  have  shorter  copulation  durations 
than  other  taxa. 

From  the  female  perspective,  the  timing  of 
cannibalism  during  mating  seems  an  ideal  in- 
strument to  control  the  duration  of  copulation. 
In  Argiope  keyserlingi  Karsch  1878,  females 
can  adjust  the  relative  paternity  of  two  males 
by  selectively  timing  copulation  duration 
through  attacking  the  male  (Elgar  et  al.  2000). 
It  was  therefore  suggested  that  cannibalism 


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evolved  under  sexual  conflict  over  the  control 
of  mating  (Elgar  et  al.  2000;  Schneider  & El- 
gar 2001;  Schneider  et  al.  2000). 

In  Argiope  bruennichi  Scopoli  1772  as  in 
other  Argiope  species,  the  female  often  ter- 
minates copulation  aggressively  by  attacking 
the  male.  Most  such  cannibalistic  attacks  are 
fatal  to  the  male.  Unlike  some  other  spiders 
(Forster  1992;  Andrade  1996),  Argiope  males 
will  try  to  escape,  at  least  after  their  first  cop- 
ulation (Sasaki  & Iwahashi  1995;  Elgar  et  al. 
2000).  Surviving  males  usually  lose  at  least 
one  of  their  legs  in  the  attempt  to  escape  the 
fangs  of  the  female  (Fromhage  et  al.  2003). 
An  experimental  study  showed  that  surviving 
males  copulated  less  than  10  seconds  while 
cannibalized  males  remained  attached  to  the 
females  up  to  8 times  longer  (Fromhage  et  al. 
2003).  If  the  brief  copulations  with  surviving 
males  are  not  sufficient  to  allow  sperm  trans- 
fer, what  appears  to  be  post-mating  cannibal- 
ism will  be  classified  more  appropriately  as 
pre-mating  cannibalism. 

Here,  we  explore  this  possibility  by  mea- 
suring hatching  success  in  relation  to  sexual 
cannibalism  and  in  relation  to  the  number  and 
duration  of  copulations.  We  allowed  females 
to  mate  with  one  or  with  two  males  and  com- 
pared hatching  success  of  three  successive  egg 
sacs.  We  expected  that  a single  short  copula- 
tion would  not  result  in  complete  fertilization 
of  a female’s  eggs.  In  double  mating  trials  we 
expected  that  females  which  received  a very 
brief  first  copulation  would  compensate  for 
this  by  acquiring  an  increased  sperm  supply 
from  a following  male. 

METHODS 

Subadult  females  (80)  and  adult  males 
(about  120)  of  A.  bruennichi  were  collected  in 
July  and  August  2002,  from  dense  populations 
in  patches  of  grassland  within  the  city  of 
Bonn,  Germany.  Voucher  specimens  are  de- 
posited at  the  Museum  Alexander  Koenig  in 
Bonn,  Germany.  Females  were  housed  in  in- 
dividual plastic  cups  (400  ml)  where  they 
were  watered  6 days  per  week  and  fed  about 
3-4  Calliphora  sp.  flies  every  2-3  days.  Adult 
females  were  housed  in  separate  Perspex 
frames  (30  cm  x 30  cm  x 6 cm),  where  they 
built  typical  orb- webs.  After  mating,  they 
were  retransferred  to  plastic  cups  where  they 
were  checked  for  egg  sacs  6 days  per  week. 
Egg  sacs  were  stored  in  individual  plastic  vi- 


als and  preserved  in  alcohol  after  26-29  days 
of  incubation  at  25  °C.  Hatchlings  and  unde- 
veloped eggs  were  subsequently  counted  un- 
der the  microscope.  Clutch  size  was  the  com- 
bined number  of  the  number  of  hatchlings  and 
the  number  of  undeveloped  eggs.  After  the 
natural  death  of  a female,  we  used  calipers  to 
take  the  tibia-patella  length  of  a first  foreleg 
as  a measure  of  its  fixed  body  size.  We  ran- 
domized the  choice  of  left  or  right  leg  but 
used  the  intact  leg  if  one  of  the  front  legs  was 
obviously  shorter  than  the  other  or  the  second 
leg.  We  used  body  mass  divided  by  tibia-pa- 
tella length  as  an  estimate  for  condition,  en- 
suring the  requirement  that  the  relation  be- 
tween these  parameters  was  largely  isometric 
within  the  range  of  our  data.  Since  females 
were  weighed  after  their  final  molt  and  after 
mating,  we  could  quantify  their  mass  gain.  In 
order  to  correct  this  mass  difference  for  body 
size,  we  used  condition.  We  obtained  condi- 
tion at  maturity  as  mass  at  maturity  divided 
by  fixed  body  size,  and  condition  at  mating  as 
mass  at  mating  divided  by  fixed  body  size 
(= tibia-patella  length).  Males  were  of  un- 
known mating  status  since  they  were  collected 
in  the  field  as  adults.  The  majority  of  these 
males  possessed  all  eight  legs.  Given  the  high 
mortality  rate  during  copulation  and  a high 
probability  of  survivors  to  have  lost  at  least 
one  leg  (Fromhage  et  al.  2003)  and  the  ob- 
servation that  each  pedipalp  is  used  only  once 
(unpub.  data),  we  assume  that  most  of  these 
males  were  virgin.  In  the  lab,  they  were  main- 
tained in  individual  cups  (150  ml)  on  a diet 
of  Drosophila.  Shortly  before  mating,  each 
male  was  weighed  and  the  tibia-patella  length 
of  a foreleg  was  measured  while  he  was  im- 
mobilized by  covering  him  with  plastic  film. 

Females  were  randomly  assigned  to  one  of 
two  different  mating  treatments:  they  were  ei- 
ther presented  with  a single  male  that  was  al- 
lowed one  insertion  or  with  two  males  in  suc- 
cession each  allowed  a single  insertion.  There 
were  38  females  in  each  of  the  two  treatments. 
The  mean  duration  of  the  copulation  did 
not  differ  between  treatments  (Mann-Whit- 
ney-U-Test,  Z = —1.48,  P = 0.14).  Matings 
were  staged  by  placing  a male  near  a support 
thread  of  the  females’  orb- web.  When  the 
male  entered  the  web,  the  female  would  typ- 
ically assume  a distinctive  posture  with  its 
body  lifted  from  the  web,  often  swaying 
slightly.  The  male  then  traversed  the  web  to 


SCHNEIDER  ET  AL.— EXTREMELY  SHORT  COPULATIONS  IN  ARGIOPE 


665 


the  hub  and  ran  over  the  female  a few  times 
before  he  inserted  one  of  his  pedipalps.  Time 
to  copulation  was  measured  with  a stopwatch 
from  the  moment  the  male  entered  the  web 
until  the  beginning  of  copulation.  We  mea- 
sured copulation  duration  from  pedipalp  in- 
sertion until  withdrawal. 

Data  analyses  were  carried  out  using  IMP 
4,02.  Not  all  data  were  available  for  each  mat- 
ing trial  and  therefore  sample  sizes  may  differ 
between  analyses.  To  fit  a normal  distribution, 
copulation  duration,  total  copulation  duration 
and  male  mass  were  log-transformed  when 
parametric  statistics  were  performed.  We  used 
noeparametric  statistics  where  normally  dis- 
tributed residuals  could  not  be  obtained,  or 
where  variances  were  unequal.  The  use  of 
Spearman  correlations  is  indicated  by  the 
symbol  ig  for  the  correlation  coefficient,  the 
use  of  Chi-square  tests  by  indication  of  x^i- 

RESULTS 

Clutch  size  and  hatching  success.— Mated 
females  in  the  laboratory  (all  treatments  com- 
bined) laid  an  average  of  2.1  ± 0.2  clutches 
(mean  ± SE,  ri  = 76).  The  average  clutch  size 
was  170.7  ± 5.2  (clutch  1-3,  n = 133)  and 
did  not  differ  significantly  between  1®^  2"^  and 
3^*^  clutches  (Oneway- Anova:  F2,  j3o  — 2.01,  P 
= 0.14).  If  clutch  sizes  of  successive  clutches 
are  compared  considering  individual  females 
as  block  effects,  we  also  found  no  significant 
difference  (Oeeway-Anova:  F2  68  = 2.68,  P = 
0.076). 

The  proportion  of  hatched  eggs  differed 
significantly  between  successive  clutches  (xi 
= 23.84,  P < 0.0001).  Pairwise  comparisons 
of  the  means  using  Dunns  method  for  noe- 
parametric comparisons  with  unequal  sample 
sizes  (Zar  1999)  revealed  a significantly  lower 
percentage  of  hatched  eggs  in  third  clutches 
(0.42  ± 0.06,  ri  — Bo)  liimi  in  first  (0.60  ± 
0.05,  n = 53)  and  second  (0.73  ± 0.05,  n = 
45)  clutches  {P  < 0.05).  Egg  sacs  collected 
from  the  habitat  of  the  source  population  con- 
tained an  average  of  271.7  ± 20,0  eggs  with 
a proportion  of  hatched  eggs  of  0.98  ± 0.02 
(«  - 20). 

Size  of  the  first  clutch  was  significantly  re- 
lated to  female  fixed  body  size  = 0.54,  P 
< 0.001,  n = 55),  female  condition  at  mating 
(ig  = 0.38,  P = 0.021,  n = 36),  but  not  with 
female  condition  at  maturation  (ig  = 0.25,  P 
= 0.11,  n - 43). 


None  of  these  female  body  parameters  was 
correlated  with  the  proportion  of  hatched  eggs 
in  the  1®^  clutch  (female  fixed  adult  size  (tibia- 
patella  length):  = -0.08,  P = 0.6,  n = 55; 
female  mass  at  maturity:  ig  ==  —0.11,  P = 
0.44;  female  condition  at  maturation:  = 

—0.07,  P = 0.67,  n = 43;  female  condition  at 
mating:  = -0.15,  P = 0.41,  n = 36).  Clutch 
size  and  hatching  success  were  not  correlated 
for  P*  and  clutches  although  we  found  a 
positive  correlation  for  2“^  clutches  (1®‘  egg 
sac:  ig  = 0.21,  P = 0.14;  2"^  egg  sac:  = 

0.45,  P = 0.002;  3^^  egg  sac:  ig  = 0.22,  P = 
0.20). 

Sperm  availability  and  copulation  dura- 
tion*—There  were  no  indications  that  sperm 
availability  is  a limiting  factor  of  female  re- 
productive success.  Neither  the  proportion  of 
eggs  hatched  nor  the  number  of  hatchlings 
significantly  depended  on  the  number  of  mat- 
ings that  a female  experienced  (number  of 
matings  vs.  % hatched  eggs:  egg  sac:  Xi  = 

0.22,  P = 0.64,  2"d  egg  sac:  Xi  = 1-86,  P = 
0.17,  egg  sac:  Xi  = 1^98,  F - 0.16  (Fig. 
1);  number  of  matings  vs.  number  of  hatch- 
lings: P^  egg  sac:  Xi  = 0.12,  P = 0.73,  2"*^  egg 
sac:  Xi  = 0.02,  P = 0.89,  3^^^  egg  sac:  Xi  == 
2.78,  P = 0.10). 

Similarly,  the  total  duration  of  copulation 
that  a female  experienced  was  not  correlated 
with  the  absolute  number  of  hatchlings  nor 
with  relative  hatching  success  of  clutches: 
noE-parametric  correlations  of  total  copulation 
duration  vs,  % hatched  eggs:  P*  egg  sac:  = 
-0.14,  P = 0.32,  w = 53  (Fig.  2),  2"^^  egg  sac: 
Ig  = 0.01,  P = 0.94,  n = 45,  3^*^  egg  sac:  ig  = 
—0,04,  P ==  0.83,  n = 35;  total  copulation 
duration  vs.  number  of  hatchlings:  P^  egg  sac: 
Ig  = —0.03,  P = 0.86,  n = 55,  2"^  egg  sac:  ig 
= 0.25,  F = 0.10,  « = 48,  3'''^  egg  sac:  = 
0.03,  F = 0.85,  n = 36). 

Copulation  duration  of  cannibalistic  mat- 
ings was  much  longer  than  in  copulations  with 
surviving  males,  as  reported  elsewhere  (From- 
hage  et  ah,  2003).  While  cannibalized  males 
mated  for  a mediae  of  23  s (upper  quartile  = 
35.9s,  lower  quartile  = 10.27s,  n = 148),  sur- 
vivors copulated  for  a mediae  of  only  7.8s 
(upper  quartile  = lL5s,  lower  quartile  = 6s, 
n = 40)  (mediae  is  given  because  the  data  are 
not  normally  distributed). 

Regarding  cannibalistic  first  matings  (with 
two  outliers  excluded  to  obtain  a normal  dis- 
tribution), the  duration  of  copulation  was  pos- 


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THE  JOURNAL  OF  ARACHNOLOGY 

1st  clutch 
2nd  clutch 
3rd  clutch 


One  Two  One 


Two 


One 


Two 


Number  of  matings 

Figure  1 .-—Proportion  of  young  hatched  in  three  successive  egg  sacs  of  females  that  mated  with  one 
or  two  males.  Box  plots  show  median,  interquartiles  and  range. 


itively  predicted  by  fixed  male  body  size  (lin- 
ear regression:  = 0.09,  P = 0.03,  n = 58) 
but  not  by  male  body  mass  (r^  ™ 0.04,  P = 
0.15,  n = 59)  nor  time  to  copulation  (linear 
regression:  P = 0.01,  P = 0.61,  n = 59).  In 
25  cases,  where  females  were  cannibalistic  to- 
wards both  of  her  mates,  the  difference  in 
body  size  of  the  males  did  not  correlate  with 
the  difference  in  copulation  duration  (r^  = 
-0.1,  P = 0.58). 

First  and  second  matings  of  the  same  fe- 
males revealed  no  significant  difference  re- 
garding copulation  duration  when  compared 
with  the  Wilcoxoe  signed  rank  test  for 
matched  pairs  (Z  = -0.43,  P = 0.68,  n = 
38).  Females  that  received  short  noe-canni- 
balistic  matings  (N  = 7)  did  not  copulate 
longer  with  the  2"^^  male  than  31  females  that 


cannibalized  their  mate  (mean  ± SE,  can- 
nibalistic: 20.45  ± 4.1,  non-cannibalistic: 
25.86  ± 8.58  ; t-test:  t = 0.57,  P = 0.57).  In 
addition,  females  whose  first  mating  was 
shorter  than  10s  (independent  of  cannibalism) 
did  not  mate  longer  with  a 2"*^  male  than  fe- 
males with  a longer  F*  copulation  (22.37s  ± 
3.5,  n = 26  long  vs  19.45s  ± 8.9,  « =12  short 
copulations;  Wilcoxoe  Test:  Z = — 1.13,  E = 
0.25). 

Large  females  produced  more  eggs,  but  fe- 
male size  did  not  influence  the  duration  of  her 
F^  (r,  = 0.013,  P = 0.9)  or  2"^  (r,  = 0.29,  P 
= 0.1)  copulation. 

DISCUSSION 

Argiope  bruennichi  females  are  very  can- 
nibalistic and  aggressively  attack  most  males 


SCHNEIDER  ET  AL»— EXTREMELY  SHORT  COPULATIONS  IN  ARGIOPE 


667 


Figure  2.-=“Tlie  proportion  of  young  hatched  in  the  1®‘  clutch  as  a function  of  the  total  duration  of 
copulation  a female  experienced. 


that  mate  with  them.  In  80%  of  all  cases,  the 
female  kills  and  consumes  the  male,  thereby 
terminating  copulation.  The  duration  of  cop- 
ulation  strongly  depends  on  the  fate  of  the 
male,  with  copulations  of  survivors  being  ex- 
tremely short  (median  of  8 seconds).  We  spec- 
ulated that -Sperm  transfer  in  extremely  brief 
matings  would  not  be  sufficient  to  fertilize  all 
eggs  in  a female’s  successive  clutches. 

To  our  surprise,  we  did  not  find  any  rela- 
tionship between  the  duration  of  copulation 
and  hatching  success.  Eggs  of  females  who 
copulated  once  for  only  5 seconds  achieved 
hatching  late-s  comparable  to  females  who 
mated  twice,  aed/or  experienced  those  with 
much  longer  copulations.  We  did  not  detect 
any  predictor  of  hatching  success:  hatching 
success  w^as  not  related  to  female  body  size 
and  mass  nor  to  the  size  of  the  clutch.  How- 
ever, we  found  a positive  correlation  between 
clutch  size  and  hatching  rate  for  2“*^  clutches. 
As  known  for  many  spider  species  (Marshall 
& Gittleniaii  1994),  clutch  size  in  A.  bruen- 
nichi  is  a function  of  female  size  and  condi- 
tion at  mating.  This  may  suggest  that  large 
females  with  large  clutches  achieve  higher  fer- 
tilization rates  because  males  mate  longer  and/ 


or  are  more  willing  to  risk  their  lives  when 
mating  with  more  fecund  females.  However, 
female  size,  mass,  and  condition  were  not  cor- 
related with  the  duration  of  copulation  (From- 
hage  et  al.  2003). 

Hatching  success  in  the  laboratory  was 
lower  than  in  the  field,  which  is  likely  a con- 
sequence of  the  conditions  that  we  provided. 
However,  conditions  were  controlled  and  the 
same  for  all  the  females.  It  is  therefore  un- 
likely that  our  results  are  affected  by  the  gen- 
erally low  hatching  success.  A factor  that  we 
cannot  exclude  is  that  females  in  the  field  mat- 
ed with  many  more  than  two  males  and  that 
more  males  are  necessary  to  guarantee  com- 
plete fertilization.  However,  in  18  clutches 
we  found  a hatching  success  above  90%  and 
among  these  fem.ales,  50%  mated  once,  one 
female  for  only  7 seconds. 

Although  3^^^  clutches  had  lower  hatching 
rates  than  1®^  clutches,  this  is  not  explained  by 
the  mating  experience  of  the  female.  Fertiliza- 
tion rates  may  simply  go  down  with  time,  per- 
haps through  loss  or  aging  of  stored  sperm 
cells.  In  this  case,  polyandry  in  A.  bruennichi 
Scopoli  1772  may  serve  as  a strategy  to  re- 


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THE  JOURNAL  OF  ARACHNOLOGY 


duce  this  cost  through  repeated  transfer  of  vi- 
able  sperm. 

Our  results  suggest  that  males  can  transfer 
enough  sperm  within  a few  seconds  to  ensure 
complete  fertilization.  Why  then  would  males 
mate  longer  and  risk  their  lives?  Given  the 
high  risk  of  cannibalism  for  males  that  mate 
longer  than  a few  seconds,  a benefit  of  pro- 
longed copulation  is  predicted  that  may  offset 
the  costs  of  losing  all  future  mating  chances. 
There  are  a number  of  possibilities  that  need 
to  be  investigated  in  future  research  projects. 
Firstly,  sperm  transfer  may  continue  and  even 
though  additional  sperm  is  not  required  for  the 
purpose  of  fertilization,  increased  sperm  num- 
bers may  be  advantageous  in  sperm  competi- 
tion (Simmons  2001).  This  is  likely  if  the  out- 
come of  sperm  competition  is  determined  by 
the  relative  quantity  of  sperm  of  rival  males 
much  like  in  a fair  raffle  (Parker  1990;  Wedell 
et  al.  2002).  Such  mechanisms  have  been 
demonstrated  in  insects  (e.g.  Dickinson  1986; 
Keller  & Passera  1992).  In  a congener  of  our 
study  species,  A.  keyserlingi,  relative  copula- 
tion duration  of  two  competing  males  deter- 
mines their  relative  paternity  (Elgar  et  al. 
2000),  and  similar  relationships  have  been  de- 
tected in  Nephila  edulis  Labillardiere  1799 
(Schneider  et  al.  2001)  and  Pholcus  phalan- 
gioides  Fuesslin  1775  (Schafer  & Uhl  2002). 
However,  in  none  of  these  studies  has  it  been 
determined  whether  the  transfer  of  sperm  was 
responsible  for  the  advantage  in  sperm  com- 
petition. In  fact,  the  linear  relationship  be- 
tween copulation  duration  and  sperm  transfer 
that  has  been  demonstrated  for  many  insects 
may  not  be  valid  for  spiders.  Several  studies 
on  spiders  found  no  such  relationship  (Bu- 
kowski  & Christenson  1997;  Christenson  & 
Cohn  1988;  Willey  Robertson  & Adler  1994, 
Uhl  unpubl.  data),  indicating  that  large  parts 
of  spider  copulatory  behavior  serve  functions 
other  than  sperm  release  (Eberhard  1994, 
1996). 

Given  that  under  sperm  competition  copu- 
lation duration  influences  relative  paternity, 
males  will  have  an  interest  to  prolong  copu- 
lation while  females  may  benefit  by  selective- 
ly terminating  copulation.  If  copulation  dura- 
tion is  largely  under  female  control,  males 
will  best  serve  their  interest  by  speeding  up 
the  mating  procedure.  This  in  turn  will  feed 
back  on  the  female  behavior.  A conflict  over 
copulation  duration  may  therefore  drive  an  an- 


tagonistic co-evolution,  with  copulations  be- 
coming shorter  and  shorter  until  an  absolute 
minimal  duration  sets  a limit  to  the  evolution- 
ary race. 

ACKNOWLEDGMENTS 
This  project  was  funded  by  a grant  of  the 
Deutsche  Forschungsgemeieschaft  to  IMS 
Sche561/5).  We  are  grateful  to  the  city  council 
of  Bonn  for  their  support. 

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2005.  The  Journal  of  Arachnology  33:670-680 


PARAMETERS  AFFECTING  FECUNDITY  OF 

LOXOSCELES  INTERMEDIA  MELLO-LEITAO  1934 
(ARANEAE,  SICARIIDAE) 


Marta  L.  Fischer:  Departamento  de  Biologia,  Centro  de  Ciencias  Biologicas  e da 
Saude,  Pontificia  Universidade  Catolica  do  Parana.  Niicleo  de  Estudos  do 
Comportamento.  Av.  Silva  Jardim,  1664/1101-CEP  80250-200-Curitiba,  Parana, 
Brazil.  E-mail:  nephilla@terra.com.br 

Joao  Vasconcellos-Neto:  Departamento  de  Zoologia,  Institute  de  Biologia- 

Universidade  Estadual  de  Campinas-UNICAMP-C.R  6109-Campinas,  Sao  Paulo, 
Brazil.  CEP  13083-970,  Brazil. 

ABSTRACT.  In  this  study,  the  process  of  egg  sac  construction  and  the  factors  that  determine  fecundity 
in  the  spider  Loxosceles  intermedia  were  analyzed  by  comparing  lab-reared  females  that  had  mated  only 
once  {n  — 180  ovipositions)  and  females  with  unknown  reproductive  histories  {n  = 76  ovipositions). 
Among  females  known  to  have  mated  only  once  (n  = 84),  the  number  of  viable  eggs  correlated  positively 
with  the  duration  of  mating  and  with  the  age  of  the  female  at  the  time  of  fertilization  and  decreased 
significantly  with  successive  ovipositions.  In  females  with  unknown  (ji  = 36)  reproductive  histories,  up 
to  three  fertile  egg  sacs  were  obtained  from  the  same  female  with  a third  oviposition  being  observed  only 
once.  Oviposition  was  more  frequent  among  larger  females  than  smaller  females.  Among  the  reproductive 
variables  evaluated,  there  were  correlations  between  the  number  of  eggs  and  the  weight  of  the  female 
spiders.  More  fertile  eggs  were  laid  by  females  with  unknown  reproductive  histories  than  by  females  that 
mated  only  once.  The  existence  of  more  stable  environmental  conditions,  abundant  food,  and  multiple 
fertilizations  are  probable  factors  which  favor  greater  fertility  of  L.  intermedia  in  urban  Curitiba,  located 
in  southern  Brazil,  and  can  partly  explain  the  success  of  this  species  in  occupying  this  ecological  niche. 

Keywords*  Ovipositions,  fertility,  reproduction,  mating  success 


Spider  egg  sacs  protect  developing  eggs 
against  abiotic  (temperature,  luminosity  and 
relative  humidity  of  the  air)  and  biotic  (pred- 
ators and  parasites)  factors.  Egg  sac  construc- 
tion is  a rigidly  controlled  and  programmed 
behavior  (Foelix  1996).  Fecundity  is  often  de- 
fined as  the  number  of  eggs  or  offspring  an 
animal  produces  during  each  reproductive  cy- 
cle (Begon  et  al.  1990).  Various  studies  have 
examined  fecundity  in  spiders  (Cooke  1965; 
Levy  1970;  Muniappan  & Chada  1970)  and, 
according  to  Downes  (1985),  the  estimates  of 
fecundity  should  include  the  number  of 
emerged  spiderlings  and  all  of  the  individuals 
in  different  stages  of  development  which  be- 
long to  the  same  ovisac,  including  undevel- 
oped eggs.  Inter-  and  intraspecific  variation  in 
fecundity  have  been  attributed  to  factors  such 
as  foraging  success  (Figueira  & Vasconcellos- 
Neto  1993),  temperature  and  humidity 
(Downes  1988),  and  photoperiod  (Miyashita 


1987).  In  addition,  individual  variation  in  re- 
production have  been  attributed  to  factors 
such  as  size,  age  and  physiological  state  of  the 
female  (Turnbull  1962;  Eberhard  1979;  Ca- 
pocasale  et  al.  1984;  Costa  & Capocasale 
1984;  Fritz  & Morse  1985),  energy  investment 
(Hoffmaster  1982),  parental  care  (Enders 
1976;  Christenson  & Wenzl  1980;  Krafft 
1982;  Opell  1984;  Nuessly  & Goeden  1984; 
Downes  1984;  Fink  1986;  Ruttan  1991),  sper- 
matic depletion  (Jackson  1978)  and  reproduc- 
tive tactics  (Killebrew  & Ford  1985).  Quan- 
titative and  qualitative  fertility  studies  have 
been  done  in  the  laboratory  for  some  Araneae 
species  (Christenson  et  al.  1979;  Downes 
1985,  1987;  Gonzales  1989;  Willey  & Adler 
1989;  Suter  1990;  Wheeler  et  al.  1990).  For 
this  study,  in  which  we  examined  a variety  of 
factors  that  may  influence  reproductive  suc- 
cess in  Loxosceles,  we  defined  fecundity  as 
the  total  reproductive  effort  of  the  female  (in- 
cluding multiple  clutches). 


670 


FISCHER  & VASCONELLOS=NETO— FECUNDITY  IN  LOXOSCELES 


671 


The  genus  Loxosceles  is  cosmopolitan  and 
is  frequently  associated  with  human  settle- 
ments where  the  physical  and  environmental 
conditions  favor  an  increase  in  the  spider  pop- 
ulations. Despite  the  medical  importance  of 
many  species  of  this  genus  and  their  synan- 
thropic  habits,  only  a few  studies  have  ex- 
amined fecundity  in  Loxosceles  species.  These 
studies  recorded  only  the  number  of  eggs  for 
L.  rufipes  (Lucas  1834)  (Delgado  1966),  L. 
reclusa  Gertsch  & Mulaik  1940  (Hite  et  al. 
1966;  Horner  & Stewart  1967),  L.  laeta  (Nic- 
olet  1849)  (Galiano  1967;  Galiano  & Hall 
1973),  L.  gaucho  Gertsch  1967  (Biicherl 
1961;  Rinaldi  et  al.  1997)  and  L.  hirsuta  Mel- 
lo-Leitao  1931  (Fischer  & Marques  da  Silva 
2001).  A comparative  study  of  the  number  of 
eggs  laid  by  L.  intermedia  and  L.  laeta  was 
done  by  Andrade  et  aL  (2000),  Some  of  the 
studies  (e.g.,  Biicherl  1961,  Galiano  1967, 
Delgado  1966,  Andrade  et  al.  2000)  used  spi- 
ders with  unknown  reproductive  histories  for 
characterization  of  fecundity  of  the  respective 
species.  The  city  of  Curitiba  (lat.  25°25'48"  S 
and  long.  49°16'15"  W),  capital  of  the  Brazil- 
ian state  of  Parana,  has  a large  population  of 
Loxosceles  that  is  responsible  for  hundreds  of 
bites  each  year,  with  the  species  being  either: 
L.  intermedia  (90%  of  collections)  or  L.  laeta 
(10%  of  collections)  (Fischer  1994).  The  spe- 
cies L.  intermedia  has  a restricted  distribution 
to  the  south  and  southeast  of  Brazil.  The  wide 
distribution  in  the  city  and  predominance  of 
L.  intermedia  over  L.  laeta  is  related  to  many 
factors  such  as  the  more  generalist  habits  of 
L.  intermedia,  as  well  as  temperature  and  hu- 
midity favorable  to  L.  intermedia.  However, 
little  is  known  of  the  factors  which  affect  fe- 
male fecundity  in  this  species.  In  this  study, 
we  examined  the  reproductive  potential  and 
factors  that  affect  the  egg  viability  of  L.  in- 
termedia females.  These  data  will  be  useful 
for  future  experimental  studies  as  well  as 
management  plans  for  the  spiders  to  minimize 
spider  bites.  For  the  present  study  we  com- 
pared the  reproductive  output  of  lab-reared  fe- 
males known  to  have  mated  once  with  virgin 
males  (both  males  and  females  born  and 
raised  in  laboratory,  with  known  feeding  his- 
tory) with  wild-caught  adult  females  (number 
of  mates,  age  and  feeding  history  unknown). 

METHODS 

Egg  sac  construction, — Details  of  egg  sac 

construction  were  observed  in  ten  females 


chosen  randomly,  based  on  direct  ad  libitum 
observations. 

Fecundity  of  females  reared  in  the  lab 
and  mated  once,^ — The  fecundity  of  84  fe- 
males born,  raised  and  mated  once  in  the  lab- 
oratory was  evaluated.  And,  because  we  had 
detailed  information  about  mating  and  matu- 
ration of  these  spiders,  we  looked  at  correla- 
tions of  fecundity  with  duration  of  mating  and 
age  of  the  females.  The  spiders  used  in  this 
study  were  kept  in  the  laboratory  from  No- 
vember 1994-December  1999.  The  spiders 
were  maintained  at  ambient  temperature  21.4 
± 2.3  °C,  n - 19;  range  = 16.2-24.7  °C,  air 
humidity  73.9  ± 11.4%,  n — 19;  range  = 
57.8-95.7  with  lighting  from  12:12  L:D  cycle. 
The  air  temperature  and  relative  humidity 
were  monitored  daily  using  a thermohydro- 
graph. Young  spiders  were  kept  in  120  ml 
plastic  containers  (diameter  of  base  4.8  cm). 
All  spiders  were  fed  up  to  the  4th  iestar  a 
standardized  diet  consisting  of  two  larval  and 
adult  Drosophila  melanogaster  twice  a week. 
After  the  4th  instar,  the  spiderlings  were  fed 
two  Tenebrio  molitor  larvae  twice  a week  and 
were  placed  in  plastic  containers  (750  ml), 
lined  with  paper  and  kept  in  a laboratory  in 
the  Department  of  Zoology  at  Federal  Uni- 
versity of  Parana. 

Once  mature,  the  virgin  females  were  each 
mated  once  with  virgin  males  that  had  also 
been  raised  in  laboratory.  The  mating  of  all 
the  couples  {n  = 84)  was  induced  during  Jan- 
uary-April  1996.  The  virgin  females  copulat- 
ed with  a single  male  and  the  duration  of  mat- 
ing was  the  time  that  the  embolous  were 
inserted  in  the  receptacles  of  the  female,  in  a 
single  encounter,  typically  1289  ± 822  sec,  n 
= 84;  range  = 73-3733  sec  (Fischer  & Vas- 
concellos-Neto  2000).  Once  the  females  had 
been  mated  and  egg  sacs  constructed,  the  egg 
sacs  were  maintained  with  the  female,  at  the 
site  of  oviposition,  until  spiderlings  had 
emerged  from  the  egg  sacs.  The  relationships 
between  the  total  number  of  eggs,  the  number 
of  spiderlings,  and  the  number  of  unhatched 
eggs  versus  the  duration  of  mating  and  age  of 
the  female  were  examined. 

Fecundity  of  wild-caught  females  with 
unknown  reproductive  histories. — Sixty 
four  females  were  collected  from  residences 
in  Curitiba  and  maintained  in  the  laboratory 
until  egg  sacs  were  deposited.  For  this  portion 
of  the  study  we  were  most  interested  in  cor- 


672 


THE  JOURNAL  OF  ARACHNOLOGY 


relation  in  body  size  with  fecundity.  Mature 
spiders  were  collected  from  March-June  1994 
and  were  maintained  in  individual  containers. 
Temperature  ranged  from  18  °C  to  29  °C  and 
air  humidity  ranged  from  63-88%  humidity 
(details  in  Tables  4 & 5)  from  June  1 994- 
No  vember  1995.  Temperature  and  humidity 
were  measured  for  each  individual.  The  egg 
sacs  were  laid  between  September  1994- 
March  1995.  Thirty  six  of  the  64  females  con- 
structed egg  sacs.  When  the  spiderlings 
emerged,  they  were  weighed  and  fixed  in  70% 
alcohol.  In  order  to  evaluate  the  influence  of 
the  weight  of  the  female  on  her  fecundity,  the 
adult  female  was  weighed  to  the  nearest  0.1 
mg  an  analytical  electronic  balance  immedi- 
ately after  oviposition.  In  addition  we  mea- 
sured cephalothorax  area  (length  X width  in 
mm)  and  the  femur  length  of  right  leg  I using 
a stereoscopic  microscope  with  an  ocular  mi- 
crometer. 

The  number  of  hatched  eggs  was  consid- 
ered as  an  index  of  egg  viability.  Besides  this 
index  we  also  measured  number  of  egg  sacs, 
the  total  number  of  eggs,  unhatched  eggs,  spi- 
derlings, and  the  duration  of  incubation.  We 
investigated  correlations  of  these  variables 
with  female  cephalothorax  area  (mm^),  female 
weight  after  oviposition,  spiderling  weight, 
average  of  natural  temperature  and  relative 
humidity  during  the  incubation  period,  and  the 
time  between  consecutive  ovipositions. 

Statistical  analysis* — The  chi-squared  test 
was  used  to  assess  differences  between  the 
number  of  females  that  laid  eggs  and  those 
which  did  not,  relative  to  their  size.  For  this, 
the  females  were  divided  into  two  groups,  i.e. 
those  with  a cephalothorax  area  less  than  or 
greater  than  15  mm^.  Matrix  correlations  and 
multiple  linear  regression  were  used  to  ex- 
amine the  relationships  between  the  parame- 
ters and  the  fecundity  variables  in  females 
with  unknown  reproductive  histories.  Stu- 
dent’s t test  was  used  to  compare  the  fecundity 
parameters  between  consecutive  ovipositions 
when  the  variances  were  homogeneous  and 
the  Kruskal-Wallis  (H)  test  was  used  when 
variances  were  not  homogenous.  The  Mann- 
Whitney  (U)  test  was  used  to  compare  the  fe- 
cundity parameters  between  females  with  only 
one  fertilization  and  those  with  unknown  re- 
productive histories. 

Male  and  female  voucher  specimens  are  de- 
posited in  Arachnological  collection  Dra.  Vera 


Regina  von  Eicksted  in  the  section  of  poison- 
ous arthropods  of  the  Imunologic  Production 
and  Research  Center  (SESA-PR),  Piraquara, 
Parana,  Brazil. 

RESULTS 

Egg  sac  construction. — Egg  sac  construc- 
tion began  with  the  substrate  being  covered 
with  thin  silk  threads.  The  female  spider 
moved  in  circles  with  the  abdomen  directed 
towards  the  center  of  the  web  in  order  to  join 
the  radiating  points.  The  female  subsequently 
positioned  herself  vertically  to  begin  egg  lay- 
ing. Approximately  30  min  later,  as  soon  as 
the  egg  mass  became  granular  and  the  outline 
of  each  egg  was  visible,  the  spider  started  to 
construct  the  cover.  The  abdomen  was  placed 
over  the  eggs  and  threads  were  woven  attach- 
ing the  apex  of  the  egg  mass  to  the  substrate. 
The  abdomen  was  moved  left  to  right  and  up 
and  down,  with  the  body  being  turned  clock- 
wise and  counter-clockwise.  Construction  of 
the  cover  required  about  4 h (n  = 10).  The 
first  silk  was  similar  to  that  of  the  substrate, 
with  thicker  threads  being  added  through 
movements  of  the  abdomen,  legs  and  pedi- 
palps.  After  finishing  the  construction,  the  fe- 
male rested,  and  positioned  herself  over  or 
next  to  the  egg  sac. 

The  egg  sacs  were  disc-shaped  and  whitish, 
with  an  average  diameter  of  18.8  ± 1.1  mm 
{n  = 25;  range  = 14-20).  The  egg  mass  had 
an  average  diameter  of  9.9  ± 2.4  mm  {n  = 
25;  range  = 8-15  mm)  with  a domed  arrange- 
ment, and  the  eggs  had  an  average  diameter 
of  0.99  ± 0.01  mm  {n  = 25;  range  = 0,06- 
1). 

Fecundity  of  females  reared  in  the  lab 
and  mated  once. — In  this  study,  180  egg  sacs 
were  obtained  from  84  females  from  February 
1996-February  1998.  Three  peaks  of  egg-lay- 
ing were  observed  (October  and  December 
1996,  and  March  1997)  (Fig.  1). 

Of  the  84  mated  females,  75  (89%)  laid  egg 
sacs.  Of  these,  61.1%  {n  = 110)  were  viable 
(spiderlings  emerged);  21.1%  {n  = 38)  were 
destroyed  by  the  females  (the  eggs  were  eat- 
en) before  eclosion  and  in  17.8%  {n  = 32)  the 
eggs  dried  out.  In  41%  (n  = 75)  of  the  spiders, 
only  one  egg  sac  was  constructed.  However 
many  also  laid  between  two  and  six  egg  sacs 
31.1%  {n  = 56)  laid  two  egg  sacs,  22.2%  {n 
= 40)  laid  three,  5%  {n  = 9)  laid  four,  1.6% 
(n  = 3)  laid  five  while  one  female  laid  a 6th 


FISCHER  & VASCONELLOS-NETO— FECUNDITY  IN  LOXOSCELES 


673 


Months 

Figure  1. — Ovipositions  (fertile,  destroyed  and  non-ecloded  eggs)  of  75  L.  intermedia  females  with 
known  reproductive  histories.  The  dates  were  obtained  in  the  laboratory  from  February  1996-February 

1998. 


egg  sac.  Fertile  egg  sacs  were  not  obtained  in 
the  5th  and  6th  ovipositions  (Table  1). 

Fertile  egg  sacs  had  an  average  incubation 
time  of  50.4  ± 11.7  days  {n  = 110;  range  == 
30-106),  an  average  number  of  spiderlings  of 
20.4  ± 21.1  {n  = 110;  range  — 1-110)  and 
an  average  number  of  non-ecloded  eggs  of 
10.8  ± 13.8  {n  = 108;  range  = 0-68).  The 
average  rate  of  egg  viability  was  70.2  ± 
30.9%  {n  = 108;  range  — 4.2-100%).  The  re- 
sults obtained  in  successive  ovipositions  are 
shown  in  Table  2.  The  number  of  viable  eggs 
had  a slight  but  significant  positive  correlation 
with  the  time  spent  in  mating  1280  ± 836  sec 
(«  = 75;  range  = 73-3757)  (r^  = 0.123;  F < 


0.01)  and  with  the  age  of  the  female  spider  at 
the  time  of  mating  490  ± 39.9  days  {n  ^ 75; 
range  - 245-551)  (r^  - 0.054;  P < 0.05).  The 
period  of  latency  (period  between  two  ovi- 
positions) was  not  correlated  with  the  total 
number  of  eggs  in  any  of  the  ovipositions. 

The  number  of  viable  eggs  decreased  in 
successive  ovipositions  (H  = 10.3;  P < 0.01), 
and  the  latency  period  increased  from  the  2nd 
oviposition  onwards  (H  = 71.8;  P < 0.0001). 
However,  the  length  of  incubation  (H  = 5.3; 
P > 0.05)  and  the  number  of  unhatched  eggs 
(H  = 5.1  ; P > 0.05)  were  not  significantly 
different. 

Fecundity  of  wild-caught  females  with 


Table  1 
female  L. 

. — Relative  frequency  of  fertile,  destroyed  and  dried  egg  sacs 
intermedia  fertilized  only  once. 

in  successive 

ovipositions  by 

Egg  sacs 

1st 

oviposition 

2nd 

oviposition 

3rd 

oviposition 

4th 

oviposition 

5th 

oviposition 

6th 

oviposition 

Fertile 

63.5% 

66.7% 

66.7% 

11.1% 

0 

0 

{n  = 47) 

{n  = 36) 

{n  ~ 26) 

{n  = 1) 

Destroyed 

27% 

24% 

10.2% 

0 

33.3% 

0 

{n  = 20) 

{n  = 13) 

(^  = 4) 

in  = 1) 

Dried 

9.5% 

9.3% 

23.1% 

88.9% 

66.7% 

100% 

{n  = 7) 

{n  = 5) 

{n  = 9) 

(n  = 8) 

{n  = 2) 

{n  = 1) 

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THE  JOURNAL  OF  ARACHNOLOGY 


Table  2. — Fecundity  parameters  for  L.  intermedia  females  known  to  have  mated  only  once.  (The  values 
are  the  mean  ± s.e.  with  the  sample  size  {n)  and  range  in  parentheses.) 


Egg  sacs 

1st 

oviposition 

2nd 

oviposition 

3rd 

oviposition 

4th 

oviposition 

5th 

oviposition 

6th 

oviposition 

Incubation  (days) 

52, 

,8  ± 

14.5 

50.6 

+ 

10.3 

45.4 

± 4.7 

48 

(«  = 

= 1) 

— 

— 

(47; 

33- 

106) 

(36; 

30 

-80) 

(26; 

31-53) 

Spiderlings 

36, 

,5  ± 

21.8 

26.4 

-1- 

22.5 

22 

± 14.2 

20 

{n  = 

= 1) 

— 

— 

(47; 

1-1 

10) 

(36; 

2- 

77) 

(26; 

1-59) 

Unhatched  eggs 

7, 

.4  ± 

8.8 

16.8 

+ 

19.4 

9.1 

± 9.4 

0 

{n  = 

= 1) 

— 

— 

(47; 

0-42) 

(36; 

0- 

-68) 

(26; 

0-35) 

Latency  (days) 

173, 

,5  ± 

81.8 

69.2 

H- 

45.6 

71.9 

± 50.6 

114. 

,4  ± 

66.1 

153 

± 107.1 

1142 

(75; 

25- 

656) 

(36; 

11 

-238) 

(26; 

10-212) 

(9; 

32-; 

239) 

(3; 

75-203) 

{n  = 1) 

unknown  reproductive  histories. — From  the 

64  females  collected,  36  constructed  egg  sacs 
(56.2%).  Of  these,  20  laid  multiple  egg  sacs, 
A total  of  76  egg  sacs  were  observed  between 
September  1994  and  March  1995.  Of  these, 
57  were  viable  and  19  were  destroyed  by  the 
females  (Fig.  2). 

Oviposition  was  more  frequent  among  larg- 
er females  (x^  = 7.53;  P < 0.01;  df  = 1)  than 
smaller  females  (x^  = 0.95;  P > 0.05;  df  = 
1)  (Fig.  3).  In  females  with  unknown  repro- 
ductive histories,  up  to  three  fertile  egg  sacs 
were  obtained  from  the  same  female  with  a 
third  oviposition  being  observed  only  once. 


The  average  number  of  days  between  consec- 
utive ovipositions  was  68.8  ± 26  days  {n  = 
20;  range  = 18-136  days).  In  our  sample, 
36.8%  of  the  ovipositions  showed  100% 
hatching,  with  the  average  percentage  of  non- 
viable  eggs  per  egg  sac  being  17.5  ± 28.5% 
{n  = 57;  range  = 0-97%).  The  average  L. 
intermedia  egg  viability  (proportion  of  hatch- 
ing eggs  per  egg  sac)  was  81.4  ± 30.9%  {n 
= 57;  range  = 1-100%)  (Tables  3,  4).  The 
number  of  eggs  (t  = 1.6;  P > 0.05;  df  = 54), 
spiderlings  (t  = 1.1;  P > 0.05;  df  = 54)  and 
non-viable  eggs  (t  = 0.53;  P > 0.05;  df  = 54) 
did  not  significantly  differ  between  the  first 


Figure  2. — Ovipositions  by  36  Loxosceles  intermedia  females  of  unknown  reproductive  histories  in  the 
laboratory,  from  September  1994-March  1995. 


FISCHER  & VASCONELLOS^NETO— FECUNDITY  IN  LOXOSCELES 


675 


10 

9 


o No  oviposition  ( n = 22) 
• Oviposition  ( n = 16) 


o No  oviposition  { n = 6) 
® Oviposition  ( n = 20) 


1 


0 

5 6 7 8 9 10  11  12  13  14  15  16  17  18  19  20  21  22  23  24  25 


Cephalothorax  area  (mm 

Figure  3. — Relationship  between  the  sizes  of  female  Loxosceles  intermedia,  leg  I femur  length  and 
cephalothorax  area  with  an  unknown  reproductive  history  and  the  tendency  to  lay  eggs. 


Table  3, — Fecundity  in  the  laboratory  for  Loxosceles  intermedia  with  an  unknown  reproductive  history 

(the  values  are  the  mean  ± SD  with  the  sample  size  {n)  and  range  in  parentheses). 


1st  oviposition 

2nd  oviposition 

3rd  oviposition 

Total 

n 

Average 

n 

Average 

n 

Average 

n 

Average 

48 

2 

1 

76 

# of  egg  sacs 

1 

# of  fertile  egg  sacs 

36 

2 

n 

1 

57 

# of  destroyed  egg  sacs 

12 

u 

7 

— 

19 

Total  number  of  eggs 

19 

53  ± 23.3 

6 

43.1  ± 19 

— 

47  {n  = 

1) 

2823 

49.4  ±21.9 

08 

(36;  6-92) 

2 

(20;  8-84) 

(57;  6-92) 

Spiderlings 

15 

44.2  ± 17 

3 

36.5  ± 21 

— 

30  {n  = 

1) 

2351 

41.2  ± 25 

91 

(36;  2-92) 

0 

(20;  7-84) 

(57;  2-92) 

Egg  viability  (%) 

— 

80.3  ± 31 

— 

85.7  ± 25 

— 

64  {n  = 

1) 

— 

81.8  ± 28 

(36;  2-100) 

(20;  15-100) 

(57;  2-100) 

Undeveloped  eggs 

31 

8.2  ± 15.9 

3 

6.6  ± 11.8 

— 

36  {n  = 

1) 

466 

8.5  ± 14.9 

7 

(36;  0-80) 

2 

(20;  0-41) 

(57;  0-80) 

Incubation  time  (days) 

— 

46.2  ± 9.5 

— 

47.9  ± 14.1 

— 

65  {n  = 

1) 

— 

47.1  ± 11.4 

(32-45) 

(20;  37-92) 

(57;  32-92) 

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THE  JOURNAL  OF  ARACHNOLOGY 


Table  4. — Variables  for  fertile  egg  sacs  from  L.  intermedia  with  unknown  reproductive  histories  main- 
tained in  the  laboratory  (September  1 994~March  1995).  (The  values  are  the  mean  ± SD  with  the  sample 
size  («)  and  range  in  parentheses.) 


n 

Mean  ± SD 

Range 

Female  cephalothorax  area  (mm^) 

57 

15.5  ± 3.7 

8.9-23.1 

Female  weight  (mg) 

57 

103.9  ± 53.4 

34.6-264 

Spiderling  weight  (mg) 

57 

0.078  ± 0.048 

0.001-0.0024 

Temperature  during  the  incubation  period  (°C) 

57 

23.8  ± 2.1 

20.9-29.2 

Air  humidity  during  the  incubation  period  (%) 

57 

72.6  ± 5.5 

63.3-88.7 

Latency  between  ovipositions  (days) 

20 

68.8  ± 25.8 

18-136 

and  second  ovipositions  (Tables  3,  4),  despite 
a tendency  to  increase. 

The  length  of  incubation  appeared  to  be  re- 
lated to  air  temperature  and  relative  humidity. 
Most  of  the  fertile  ovipositions  were  incubat- 
ed at  21  °C  to  27  °C  at  a relative  air  humidity 
of  64-76%.  Larger  females  tended  to  deposit 
more  eggs  (r^  = 0.062;  P = 0.06;  n = 57;  df 
= 56),  with  a slight  but  significant  correlation 
between  female  weight  the  number  of  eggs 
(r2  - 0.072;  P < 0.05;  n = 57;  df  = 56). 

There  was  no  correlation  between  spider- 
ling  weight  or  latency  to  oviposition  and  the 
total  number  of  eggs,  spiderlings  or  non-via- 
ble  eggs.  {P  = 0.008,  P = 0.4,  df  = 105;  r^ 
= -0.0003,  P = 0.3,  df  = 105;  = -0.018, 

P = 0.9,  df  - 105  and  - 0.003;  P = 0.2, 
df  = 105;  r2  = 0.003;  P = 0.2;  df  = 105; 

= 0.009;  P = 0.9;  df  = 105,  respectively). 

In  the  case  of  destroyed  egg  sacs,  the  av- 
erage time  in  which  they  remained  intact  was 
8 ± 8.3  days  {n  — 19;  range  = 0-26  days). 
Five  eggs  which  fell  from  destroyed  egg  sacs, 
developed  normally.  Their  temperature  and 
relative  humidity  during  the  incubation  period 
are  shown  in  Table  5. 

Females  remained  close  to  the  egg  sac 
throughout  the  whole  incubation  period.  Four 
females  opened  the  egg  sac  about  six  days  be- 
fore the  eggs  hatched.  In  one  of  these  cases, 
the  female  spider  ate  the  spiderling. 


The  average  weight  of  the  wild-caught  fe- 
males (105.3  ± 57  mg  {n  = 36;  range  = 39.7- 
264.8])  did  not  differ  of  the  spiders  reared  at 
laboratory  (107.8  ±5.1  mg  [n  — 75;  range  = 
101-118])  {t  = -0.3;  P = 0.7;  df  - 108).  In 
egg  sacs  from  females  with  unknown  repro- 
ductive histories,  the  average  number  of  spi- 
derlings (41.2)  (U  = 2151;  P < 0.01),  the  total 
number  of  eggs  (49.5)  (U  = 2788.5;  P < 0.01) 
per  egg  sac,  and  the  average  percentage  of  egg 
viability  (82.7%)  (U  = 2120.5;  P < 0.001) 
were  greater  than  in  females  subjected  to  only 
one  mating  (29.4,  36.5  and  70.2%,  respective- 
ly). Nevertheless,  the  average  number  of  un- 
hatched eggs  per  egg  sac  (U  = 2323.5;  P < 
0.01)  and  the  duration  of  incubation  (U  — 
2033;  P < 0.001)  were  greater  in  females  with 
one  mating  than  in  those  with  unknown  re- 
productive histories. 

DISCUSSION 

The  egg  sac  construction  of  L.  intermedia 
(behavior  and  time),  and  oviposition  of  the 
egg  in  the  number  of  sacs  agree  with  the  re- 
ported patterns  for  the  genus  (Galiano  1967 
for  L.  laeta’,  Hite  et  al.  1966  and  Homer  & 
Stewart  1967  for  L.  reclusa  and  Rinaldi  et  al. 
1997  for  L.  gaucho).  Only  Delgado’s  (1966) 
description  for  L.  rufipes  was  different.  This 
author  noted  that  oviposition  required  one  to 


Table  5. — Variables  related  to  egg  sacs  destroyed  by  L.  intermedia  with  unknown  reproductive  histories 
in  the  period  from  September  1994-March  1995.  (The  values  are  the  mean  ± SD  with  the  sample  size 
{n)  and  range  in  parentheses.) 


n 

Mean  ± SD 

Range 

Incubation  period  (days) 

19 

8.42  ± 8.3 

0-26 

Temperature  during  the  incubation  period  (°C) 

19 

22.3  ± 2.3 

18-25.3 

Air  humidity  during  the  incubation  period  (%) 

19 

69.6  ± 1 

51.9-87 

FISCHER  & VASCONELLOS-NETO— FECUNDITY  IN  LOXOSCELES 


677 


two  weeks  and  that  the  female  positioned  her- 
self over  the  egg  sac  within  a silk  covering. 

Females  with  unknown  reproductive  histo- 
ries produced  up  to  three  fertile  consecutive 
egg  sacs  and  the  period  of  egg-laying  was  re- 
stricted to  seven  out  of  the  18  months  ob- 
served. On  the  other  hand,  females  with  only 
one  insemination  constructed  up  to  four  fertile 
egg  sacs  during  26  of  48  months  of  observa- 
tion. Hite  et  al.  (1966)  reported  similar  results 
for  L.  reclusa,  in  which  already  mated  females 
produced  a smaller  number  of  egg  sacs  than 
females  mated  only  once  in  the  laboratory. 
However,  the  possibility  that  the  females  de- 
posited other  egg  sacs  could  account  for  the 
results  of  the  latter  study,  the  difference  be- 
tween our  results  and  those  of  Andrade  et  al. 
(2000).  In  these  studies  already  fertilized  L. 
intermedia  oviposited  up  to  five  times.  De- 
spite the  probable  relationships  between  spi- 
der weight  and  size  and  the  number  of  eggs 
produced,  the  number  of  egg  sacs  is  very  sim- 
ilar among  many  species  of  the  genus.  For  L. 
hirsuta,  up  to  the  three  fertile  egg  sacs  have 
been  reported  (Fischer  & Marques  da  Silva 
2001).  For  L.  gaucho,  56.5%  of  the  females 
that  constructed  more  than  one  egg  sac  ovi- 
posited three  or  four  times  (Rinaldi  et  al. 
1997)  and  Bucherl  (1961)  also  reported  that 
L.  laeta  and  L.  gaucho  laid  up  to  three  egg 
sacs.  For  L.  reclusa  (Hite  et  al.  1966)  and  L. 
laeta  (Galiano  & Hall  1973),  5~15  oviposi- 
tions  per  female  have  been  observed.  How- 
ever, these  data  were  not  confirmed  by  later 
studies  of  L.  reclusa  (up  to  three  egg  sacs) 
(Homer  & Stewart  1967)  and  L.  laeta  (up  to 
four  egg  sacs)  (Andrade  et  al.  2000). 

The  total  number  of  eggs  and  number  of 
fertile  eggs  was  significantly  greater  in  fe- 
males with  unknown  reproductive  histories, 
suggesting  that  these  spiders  may  have  been 
fertilized  more  than  once  or  were  healthier 
from  living  in  the  wild.  It  is  possible  that  mul- 
tiple matings  can  favor  reproductive  success 
resulting  in  a larger  number  of  fertile  eggs 
than  females  that  copulated  once.  The  same 
point  can  be  made  about  multiple  egg  sacs. 
According  to  Horner  & Stewart  (1967),  fe- 
male L.  reclusa  that  mated  repeatedly  during 
the  season  were  more  fertile  since  additional 
mating  protected  against  the  gradual  loss  of 
sperm  viability  and  inadequate  storage  capa- 
bilities. 

Oviposition  was  more  frequent  in  larger  fe- 


males which  also  tended  to  lay  a greater  total 
number  of  eggs  and  more  eggs  per  egg  sac. 
These  observations  indicate  the  importance  of 
foraging  success  on  fertility.  Interspecific  var- 
iations have  been  recorded  for  L.  laeta  and  L. 
intermedia  (Andrade  et  al.  2000)  with  the  for- 
mer species  laying  a greater  number  of  eggs 
because  of  its  greater  size  and  weight.  The 
average  number  of  eggs  per  egg  sac  varies 
considerably  in  Loxosceles,  e.g.  50.1  in  L.  re- 
clusa (Hite  et  al.  1966),  61.3  in  L.  gaucho 
(Rinaldi  et  al.  1997),  33.7  in  L.  hirsuta  (Fi- 
scher & Marques  da  Silva  2001),  and  88.4  in 
L.  laeta  (Galiano  1967).  Various  factors,  in- 
cluding the  female’s  physiological  state,  can 
influence  those  results  since  an  average  of 
only  23  eggs  per  egg  sac  has  been  reported 
for  L.  reclusa  (Horner  & Stewart  1967).  Rin- 
aldi et  al.  (1997)  attributed  the  low  values  re- 
ported by  Bucherl  (1961)  for  L.  laeta  and  L. 
gaucho  (12-15  eggs  per  egg  sac)  to  the  con- 
struction of  egg  sacs  during  female  senes- 
cence. The  existence  of  morphological  and 
numerical  variations  in  the  seminal  recepta- 
cles of  L.  intermedia  females  must  also  be 
considered  (Buckup  1980;  Fischer  1994),  with 
the  relationships  between  the  number  of  re- 
ceptacles, their  functionality  and  female  fe- 
cundity requiring  further  detailed  studies.  For 
the  females  reared  in  the  laboratory,  the  num- 
ber of  viable  eggs  of  L.  intermedia  correlated 
with  the  duration  of  mating  and  female  age. 
According  to  Rinaldi  et  al.  (1997),  if  the  first 
mating  in  L.  gaucho  females  lasted  more  than 
double  the  female’s  age,  number  of  offspring 
per  oviposition  was  lower.  In  the  Lyniphiidae, 
the  relationship  between  the  duration  of  mat- 
ing and  egg  viability  was  related  to  the  time 
required  for  the  transfer  of  sufficient  sperm  for 
the  construction  of  three  egg  sacs  (Suter  & 
Parkhill  1990). 

The  length  of  incubation  in  L.  intermedia 
appeared  to  be  related  to  the  air  temperature 
and  relative  humidity,  and  these  factors  ap- 
peared to  influence  how  long  the  spiderlings 
remained  within  the  egg  sac.  Similar  studies 
have  reported  values  of  36.7  days  for  L.  re- 
clusa (Hite  et  al.  1966),  40.1  days  for  L.  gau- 
cho (Rinaldi  et  al.  1997)  and  56.9  days  for  L. 
hirsuta  (Fischer  & Marques  da  Silva  2001), 
and  these  appear  to  be  little  affected  by  vari- 
ations in  the  environmental  conditions.  The 
time  interval  between  consecutive  oviposi- 
tions  may  also  be  influenced  by  the  spiders’ 


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THE  JOURNAL  OF  ARACHNOLOGY 


nutritional  state,  sperm  storage  and  stress 
since  there  was  an  increase  in  this  interval  af- 
ter the  second  oviposition.  In  the  present 
study,  females  with  unknown  reproductive 
histories  had  smaller  intervals  (68.8  days) 
than  females  with  one  mating  (116.7  days), 
although  a greater  number  of  egg  sacs  were 
observed  in  the  former 

Loxosceles  intermedia  thus  has  a greater  in- 
terval between  oviposition  than  L.  gaucho 
(39.2  days)  (Rinaldi  et  al.  1997)  and  L.  reclu- 
sa  (32  days)  (Horner  & Stewart  1967). 

The  average  number  of  non-viable  eggs  did 
not  differ  between  the  two  groups,  although 
non-viable  eggs  were  seen  in  63.2%  of  the  egg 
sacs  produced  by  female  L.  intermedia  with 
unknown  reproductive  histories  compared  to 
83.5%  in  females  with  only  one  mating.  The 
presence  of  non-viable  eggs  could  reflect  a 
lack  of  fertilization,  the  interruption  of  devel- 
opment because  of  environmental  or  biologi- 
cal conditions  and  the  possibility  that  these 
eggs  were  eaten  by  older  spiderlings.  Non-vi- 
able eggs  have  also  been  reported  for  L.  hir- 
suta  (42.7%  of  cases:  Fischer  & Marques  da 
Silva  2001)  and  for  other  spider  groups  (Val- 
erio 1974;  Anderson  1978;  Christenson  et  al. 
1979;  Downes  1985;  Gonzales  1989). 

The  decrease  in  the  number  of  viable  eggs 
in  successive  egg  sacs  was  insignificant  in  fe- 
males fertilized  only  once.  Contrary  to  the 
findings  of  Eberhard  (1979),  a reduction  in  the 
number  of  eggs  in  successive  ovipositions  has 
also  been  observed  in  L.  hirsuta  (Fischer  & 
Marques  da  Silva  2001),  L.  gaucho  (Rinaldi 
et  al,  1997)  and  other  spiders  (Downes  1985; 
Gonzales  1989;  Willey  & Adler  1989;  Suter 
1990;  Wheeler  et  al,  1990). 

The  destruction  of  egg  sacs  may  have  been 
influenced  by  various  factors.  In  females 
which  did  not  oviposit  more  and  which  later 
destroyed  their  egg  sac,  this  behavior  may 
have  been  influenced  by  physiological  condi- 
tions such  as  infertility,  age,  nutrient  shortage 
or  stress.  Also,  since  sperm  storage  was  not 
an  important  factor  in  egg  sac  destruction,  the 
influence  of  air  temperature,  relative  humidity 
and  stress  must  be  considered.  Although  the 
relationship  between  the  incubation  length  and 
the  air  temperature  and  relative  humidity  was 
low,  there  nevertheless  appeared  to  be  some 
minimum  requirements  for  oviposition  and 
egg  development  to  occur.  The  destruction  of 
egg  sacs  by  females  has  been  recorded  for  L. 


reclusa  (Hite  et  al.  1966)  in  which  the  females 
sometimes  ate  their  own  eggs  and  the  eggs  in 
some  egg  sacs  did  not  eclode.  In  L.  hirsuta, 
55.6%  of  the  females  that  destroyed  their  egg 
sacs  constructed  other  fertile  sacs.  A similar 
behavior  was  observed  in  Lycosa  malitiosa 
Tullgren  1905  (Lycosidae)  (Capocasale  et  al. 
1984)  and  was  attributed  to  the  peak  of  syn- 
chronization between  the  spontaneous  open- 
ing of  the  egg  sac  by  the  mother  and  spider- 
ling  development.  As  observed  here,  Horner 
& Stewart  (1967)  also  noted  that  L.  reclusa 
spiderlings  did  not  need  help  to  leave  the  egg 
sac,  but  if  the  mother  was  present,  she  helped 
to  tear  the  egg  sac. 

Reproductive  success  in  L.  intermedia  is  in- 
fluenced by  numerous  factors  that  can  affect 
spider  fertility,  including:  air  temperature,  rel- 
ative humidity,  length  of  mating,  female 
weight,  and  female  age.  These  factors  are  rel- 
evant for  L.  intermedia  since  these  spiders  live 
in  and  around  buildings  and  are,  therefore 
subject  to  smaller  oscillations  of  environmen- 
tal conditions,  have  food  in  abundance,  have 
large  populations  with  numerous  males  that 
can  potentially  inseminate  any  given  females, 
the  fecundity  is  likely  to  be  high  and  could 
explain  the  abundance  of  this  species  in  Cur- 
itiba. 

ACKNOWLEDGMENTS 

The  authors  thank  Prof.  Dr.  Luis  Amilton 
Foerster,  Dra.  Sylvia  Lucas  and  Dra.  Gail 
Stratton  for  their  comments  and  help  in  pre- 
paring this  manuscript  and  Liliani  Tiepolo  and 
Claudia  Staudacher  for  supplying  the  female 
L.  intermedia.  This  paper  is  suported  by  Curso 
de  Pos-Graduagao  em  Zoologia — Universida- 
de  Federal  do  Parana — UFPR  and  CAPES.  J. 
Vasconcellos-Neto  was  supported  by  a grant 
from  Conselho  Nacional  de  Desenvolvimento 
Cientifico  e Tecnologico  (CNPq,  grant  no. 
300539/94-0)  and  BIOTA/FAPESP— The 
Biodiversity  Virtual  Institute  Program  (grant 
no.  99/05446-8). 

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Manuscript  received  9 June  2003,  revised  15  June 
2004, 


2005.  The  Journal  of  Arachnology  33:681-702 


REFINING  SAMPLING  PROTOCOLS  FOR  INVENTORYING 
INVERTEBRATE  BIODIVERSITY:  INFLUENCE  OF 
DRIFT-FENCE  LENGTH  AND  PITFALL 
TRAP  DIAMETER  ON  SPIDERS 


Karl  E,C.  Brennan,  Jonathan  D.  Majer  and  Melinda  L.  Moir:  Department  of 
Environmental  Biology,  Curtin  University  of  Technology,  GPO  Box  U1987,  Perth 
WA  6845,  Australia.  E-mail:  kbrennan@unimelb.edu.au 

ABSTRACT.  The  limited  resources  available  to  inventory  biodiversity  and  conduct  ecological  moni- 
toring requires  efficient  protocols  for  sampling  with  pitfall  traps.  Here  we  consider  adding  different  length 
drift-fences  to  pitfall  traps  on  spiders.  Four  different  fencing  treatments  (no  fence,  or  fence  lengths  of  2, 
4 and  6 m)  were  evaluated  in  combination  with  three  trap  diameters  (4.3,  7.0  and  11.1  cm).  Three-way 
ANOVAs  revealed  no  significant  interaction  effects  between  any  combinations  of  fencing  treatments,  trap 
size  or  the  spatial  positioning  of  transects  within  the  study  site  along  which  traps  were  arranged.  Post-hoc 
tests  showed  fences  significantly  increased  the  abundance  of  individuals  and  richness  of  spider  families, 
and  species  collected.  Traps  with  6 m fences  were  significantly  higher  in  all  of  these  variables  than  traps 
with  2 m fences.  ANOSIMs  revealed  taxonomic  composition  differed  significantly  between  fenced  and 
unfenced  traps  at  familial,  and  specific  ranks.  Among  fenced  traps,  taxonomic  composition  was  influenced 
primarily  by  trap  diameter  rather  than  fence  length.  ANOSIMs  showed  significant  differences  in  taxonomic 
composition  between  each  trap  diameter  for  fenced  traps.  An  optimal  combination  of  fencing  treatment 
and  trap  diameter  was  determined  by  constructing  smoothed  species  accumulation  curves  for  increasing 
numbers  of  traps.  Four  criteria  were  considered:  equivalent  numbers  of  traps,  standardized  cumulative  trap 
circumference,  standardized  cumulative  fence  length  (fenced  traps  only)  and  standardized  cumulative  han- 
dling time.  For  the  same  number  of  traps,  11.1  cm  traps  with  4 and  6 m fences  collected  the  most  species. 
At  a standardized  trap  circumference,  long  fences  were  best,  with  all  trap  sizes  catching  similar  numbers 
of  species.  When  fence  length  was  standardized,  11.1  cm  traps  with  2 or  4 m fences  collected  the  most 
species.  At  a standardized  handling  time  all  traps  caught  very  similar  numbers  of  species,  although  most 
11.1  cm  diameter  traps  collected  more  species  than  other  trap  sizes  and  those  with  4 m fences  were  most 
efficient.  Given  the  similar  performance  of  fenced  and  unfenced  traps  for  standardized  handling  time,  we 
outline  reasons  why  unfenced  traps  may  be  best. 

Keywords:  Arthropods,  barriers,  guides,  inventory,  sampling  methods 


Little  doubt  exists  that  global  biodiversity 
is  decreasing  rapidly  (Chappin  et  al.  2000; 
Pimm  & Raven  2000;  Purvis  & Hector  2000). 
Calls  have  been  made  to  inventory  global  spe- 
cies diversity  (Wilson  1985;  Raven  & Wilson 
1992;  Stork  & Samways  1995),  however, 
there  are  inadequate  resources  available  for 
this  task  (May  1988;  Gaston  & May  1992; 
Hawksworth  1995).  Methods  that  sample  taxa 
quickly  and  efficiently  are  needed  (Colwell  & 
Coddington  1995;  Dobyns  1997).  Addition- 
ally, limitations  of  sampling  methods,  or  de- 
viations from  an  accurate  representation  of 
community  structure,  must  be  known  (Chur- 
chill 1993;  Churchill  & Arthur  1999;  Skerl  & 
Gillespie  1999).  Rapid  development  and  ac- 


ceptance of  standardized  sampling  protocols 
represents  a key  conservation  goal  as  it  facil- 
itates comparisons  between  studies  where  to 
date,  comparisons  have  been  either  tenuous  or 
impossible  (Coddington  et  al.  1991;  Beattie  et 
al.  1993;  New  1999).  Standardized  sampling 
protocols  have  recently  been  advanced  for 
ground  dwelling  ants  and  beetles  (Agosti  & 
Alonso  2000;  Niemela  et  al.  2000).  Standard- 
ized methods  will  facilitate  comparisons  be- 
tween studies  and  renew  interest  in  their  use 
for  ecological  monitoring. 

Considerable  refinements  for  collecting  spi- 
ders have  been  made.  Horizontal  stratification 
by  different  spider  families  and  species  within 
habitats  has  long  been  known  (Muma  & 


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Muma  1949;  Turnbull  1973,  Merrett  1983).  To 
target  all  habitat  strata  many  different  collect- 
ing  techniques  are  required.  Moreover,  given 
the  heterogeneous  nature  of  spider  communi- 
ties, sampling  needs  to  be  conducted  over  dif- 
ferent spatial  and  temporal  scales  (Churchill 
& Arthur  1999).  Comparisons  of  methods  to 
date  include  pitfall  trapping,  beating,  sweep- 
netting, suction  sampling  with  D-vac  or  other 
devices,  extraction  from  litter  by  Tullgren  fun- 
nels or  hand,  and  hand  collecting  from  differ- 
ent non-canopy  habitat  strata  (Duffey  1962; 
Uetz  & Unzicker  1976;  Merrett  & Snazell 
1983;  Coddington  et  ah  1991,  1996;  Topping 
& Sunderland  1992;  Edwards  1993;  Churchill 
1993;  Samu  & Sarospataki  1995;  Dobyns 
1997;  Churchill  & Arthur  1999;  Standen 
2000).  The  standardized  sampling  protocol 
advanced  by  Coddington  et  ah  (1991,  1996) 
targeted  spiders  in  all  non-canopy  habitat  stra- 
ta. Their  collecting  methods  were  beating, 
hand  collecting  looking-up,  hand-collecting 
looking-down,  and  extraction  of  spiders  from 
leaf  litter  with  Tullgren  funnels  or  by  hand. 
They  suggested  that  using  pitfall  traps  in  com- 
bination with  the  above  methods  might  be 
beneficial.  Considerable  sampling  biases  and 
limits  to  data  interpretation  are  known  for  pit- 
fall  traps  (Greenslade  1964;  Southwood  1966; 
Adis  1979;  Spence  & Niemela  1994;  Mel- 
bourne 1999),  Despite  this,  many  authors  have 
found  pitfall  traps  valuable  in  their  collecting 
repertoire  (Duffey  1972;  Uetz  & Unzicker 
1976;  Churchill  1993).  Establishing  a stan- 
dardized pitfall  trapping  protocol  for  inven- 
torying spiders  is  needed  (Brennan  et  al. 
1999). 

Many  advances  in  sampling  with  pitfall 
traps  have  been  made.  Various  materials  and 
designs  have  been  used  to  construct  inverte- 
brate pitfall  traps,  including  cups,  cans,  jars 
and  troughs  (Duffey  1962;  Merrett  1967;  Luff 
1975).  Refinements  increasing  capture  success 
of  spiders  have  included  fitting  aprons  around 
pitfall  traps;  this  increased  the  catch  of  clu- 
bionids,  gnaphosids,  salticids  and  thomisids 
(Cutler  et  ak  1975;  Uetz  & Unzicker  1976). 
Aprons  may  also  reduce  sampling  error  aris- 
ing from  alteration  of  microclimate,  distur- 
bance by  mammals,  flooding,  and  litter  fall 
(Uetz  & Unzicker  1976).  Traps  containing  a 
killing/preserving  solution  collect  more  spi- 
ders than  dry  traps  (Curtis  1980;  Gurdebeke 
& Maelfait  2002),  and  adding  detergent  to 


ethylene  glycol  catches  more  linyphiids  (Top- 
ping & Luff  1995).  Funnels  placed  inside 
traps  decrease  captures,  but  by  decreasing 
evaporation  of  ethanol  can  yield  better  speci- 
mens for  DNA  analysis  (Gurdebeke  & Mael- 
fait 2002).  With  roughened  surfaces  on  the  in- 
terior of  pitfall  traps  (including  wear  from 
reuse)  collection  of  linyphiids  declines  (Top- 
ping & Luff  1995).  Larger  diameter  traps  col- 
lect more  species  than  smaller  traps  (Brennan 
et  al.  1999;  Work  et  al.  2002).  Large  traps  are 
more  efficient  than  smaller  traps  when  mea- 
sured by  handling  time  (Brennan  et  al.  1999). 
Size  of  rain  covers  has  no  effect  on  spider 
catch  (Work  et  al.  2002).  Length  of  trapping 
period  can  influence  interpretation  of  com- 
munity composition  for  linyphiids  and  other 
surface-active  spiders,  with  longer  periods  of 
collecting  preferable  (Topping  & Luff  1995; 
Riecken  1999).  More  traps  collect  more  spe- 
cies (Samu  & Lovei  1995),  although  taxonom- 
ic composition  remains  fairly  constant  with 
fewer  traps  (Niemela  et  al.  1986;  Riecken 
1999).  Consequently,  where  resources  are  lim- 
ited, decreasing  the  number  of  traps,  rather 
than  sampling  period,  may  permit  more  ac- 
curate interpretation  of  community  structure 
(Riecken  1999). 

Recently,  attaching  fences  to  pitfall  traps  to 
facilitate  spider  captures  has  aroused  interest. 
Different  authors  have  used  the  terms  “barri- 
ers”, “drift-fences”,  “fences”  and  “guides” 
synonymously  and  for  different  structures. 
Here  “fences”  refers  to  structures  erected  to 
guide  surface-active  animals  into  traps.  These 
differ  from  structures  erected  to  form  an  en- 
closure around  traps,  which  limits  the  spatial 
area  from  which  traps  sample  (e.g.  Gist  & 
Crossley  1973;  Mommertz  et  al.  1996;  Hol- 
land & Smith  1999).  In  savanna  woodland  and 
mown  lawn  of  tropical  northern  Australia 
fences  increase  the  catch  of  spiders  and  many 
dominant  spider  taxa.  The  effectiveness  of 
fences,  however,  varies  over  time  (Churchill 
unpub.  data).  The  taxonomic  composition  of 
spiders  collected  also  varies  with  trap  design. 
Trap  size  differences  (4.5  cf.  8 cm  diameter 
traps)  were  greatest  between  unfenced  com- 
pared to  fenced  traps  (Churchill  unpub.  data). 

Here  we  determine:  1)  if  fences  increase 
spider  catchability  in  the  jarrah  {Eucalyptus 
marginata)  forest  of  temperate  south-western 
Australia,  and  2)  if  fence  length  influences 
taxonomic  richness  and  composition?  3)  For 


BRENNAN  ET  AL.— DRIFT-FENCE  LENGTH  AND  PITFALL  TRAP  SIZE 


683 


fenced  traps,  does  trap  size  influence  taxo- 
nomic richness  and  composition?  4)  How 
many  traps  are  required,  and  what  is  the  op- 
timum combination  (trap  diameter  and  fence 
length)  for  sampling  spiders  in  this  habitat? 
Our  optimal  combination  is  based  on  catching 
the  most  species  using  the:  a)  least  number  of 
traps;  b)  lowest  sampling  intensity  (minimal 
cumulative  trap  circumference);  c)  least 
amount  of  fence;  and  d)  least  amount  of  time. 

METHODS 

Study  site. — Spiders  were  collected  from 
unmined  forest  surrounding  Alcoa  World  Alu- 
mina Australia’s  (formerly  Alcoa  of  Australia) 
Jarrahdale  mine  (32°17'  S,  116°08'  E)  on  the 
Darling  Plateau,  approximately  45  km  south- 
east of  Perth.  The  region  has  a Mediterranean 
climate,  with  hot  dry  summers  and  cool  wet 
winters.  Annual  rainfall  is  1200  mm,  with 
most  falling  between  May  and  September. 
Soils  are  highly  weathered  and  composed  of 
coarse  ferrinous  gravel  (>  2 mm  particle  size) 
in  a matrix  of  yellow-brown  sand  derived 
from  a lateritic  profile  (Churchward  & Dim- 
mock  1989). 

Vegetation  at  the  site  (450  X 250  m)  was  a 
tall  forest  (to  35  m)  of  jarrah  and  marri  (Cor- 
ymbia  calophylla)  trees.  Other  small  trees  (3- 
7 m)  were  present  also;  mainly  Bull  Banksia 
(Banksia  grandis),  and  Snotty  gobble  (Per- 
soonia  longifolia).  These  overtopped  under- 
storey species  such  as  grass-trees  (Xanthor- 
rhoea  preissii  and  Kingia  australis),  cycads 
(Macrozamia  riedlei)  and  legumes  (Acacia, 
Bossiaea  and  Kennedia).  Leaf  litter  varied 
from  25-100  % cover  and  a depth  of  1-40 
mm. 

Sampling  spiders.— Effects  of  pitfall  trap 
size  and  fence  length  on  spider  catchability 
were  investigated  using  a three-way  factorial 
design,  composed  of  pitfall  trap  diameters 
(4.3,  7.0  and  11.1  cm),  fence  length  (0,  2,  4 
and  6 m)  and  spatial  positioning  of  transects 
within  the  study  site  along  which  the  pitfall 
traps  were  arranged.  Pitfall  traps  were  ar- 
ranged as  follows:  15  parallel  transects  were 
positioned  30  m apart.  Along  each  transect  12 
traps  were  positioned  14  m apart  with  each 
trap  representing  a different  combination  of 
trap  size  and  fencing  treatment  (3  trap  diam- 
eters X 4 fence  lengths  = 12  traps  per  tran- 
sect, 12  traps  X 15  transects  = 180  traps). 
Transects  were  grouped  into  three  sets  based 


on  their  location  within  the  site;  southern 
(transects  1-5),  central  (transects  6-10)  and 
northern  (transects  11-15).  This  design  per- 
mitted potential  differences  in  spider  catcha- 
bility related  to  the  spatial  positioning  of  tran- 
sect groups  within  the  study  site  to  be 
considered.  For  brevity,  focus  is  restricted 
here  to  trap  diameter  and  fence  length. 

Pitfall  traps  were  clear  plastic  containers 
that  varied  in  diameter  but  not  depth  (7.5  cm). 
Each  trap  comprised  three  plastic  containers. 
The  first  was  dug  into  the  soil  so  that  its  rim 
was  flush  with  the  soil  surface.  The  second 
was  filled  with  soil,  placed  inside  the  first  con- 
tainer, and  left  in  situ  for  two  weeks.  This  was 
to  allow  any  disturbance  effects  caused  by 
“digging  in”  the  traps  to  abate  (Joosse  & 
Kapteijn  1968;  Greenslade  1973).  For  trap- 
ping, the  soil-filled  container  was  removed 
and  replaced  with  a third  that  was  half-filled 
with  Gaits  solution  (Main  1976)  plus  2 ml  of 
detergent  (to  decrease  surface  tension).  The 
use  of  this  solution  is  no  longer  recommend- 
ed. To  ensure  that  the  rim  of  the  third  trap  was 
flush  with  the  soil  surface  a small  amount  of 
soil  was  added  where  necessary.  Traps  were 
open  for  one  week  (12-19  September  1997). 

Fences  consisted  of  black  plastic  (200  um 
thick),  approximately  25  cm  high  and  buried 
5 cm  into  the  ground.  They  were  aligned  par- 
allel to  transects  and  secured  with  wooden 
skewers  (0.25  cm  diameter,  20  cm  long) 
where  necessary.  Fences  did  not  span  the  trap 
but  were  cut  into  two  pieces  and  orientated 
such  that  an  imaginary  line  joining  the  two 
fences  together  would  bisect  the  pitfall  trap 
into  equal  halves.  Considerable  care  was  taken 
to  ensure  that  fence  edges  closest  to  each  trap 
were  not  folded  against  the  outer  rim  (which 
might  have  prevented  a spider  moving  along 
the  fence  to  fall  into  the  trap).  Traps  were 
checked  on  the  third  day  of  sampling.  Any 
litter  debris  that  had  fallen  into  the  trap  and 
was  likely  to  reduce  retaining  efficiency  was 
removed. 

Adult  spiders  were  sexed  and  identified  to 
species  level  and  assigned  a code  when  no 
name  could  be  found.  Most  species  at  Jarrah- 
dale are  undescribed  and  many  older  taxo- 
nomic keys  are  inadequate  (Brennan  et  al. 
2004).  Juveniles,  penultimate  instar  males  and 
sub-aduit  females  could  not  be  identified  with 
certainty  beyond  family  level  (and  sometimes 
genus),  so  are  not  considered  here.  A refer- 


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ence  collection  of  taxa  has  been  deposited  in 
the  Western  Australian  Museum. 

Data  analysis.- — Data  were  analyzed  using 
univariate  and  multivariate  analyses  plus  spe- 
cies accumulation  curves  (collectors  curves). 

Univariate  analysis:  Univariate  analyses  in- 
volved three-way  and  two-way  analysis  of 
variances  (ANOVAs)  that  had  Type  III  sums 
of  squares  (Underwood  1997).  Dependent 
variables  were  abundance,  and  taxon  richness 
at  familial  and  specific  rank.  Factors  were 
FENCE,  TRAP  and  LOCATION.  Levels  for 
FENCE  were  the  fence  lengths  0,  2,  4 and  6 
m.  Levels  for  TRAP  were  the  trap  sizes  4.3, 
7,0  and  11.1  cm.  Levels  for  LOCATION  were 
southern,  central  and  northern. 

Our  full  data  set  included  all  combinations 
of  fence  length  and  trap  size  across  all  tran- 
sects. It  was  analyzed  using  three-way  ANO- 
VAs. Means  for  each  trap  size  were  derived 
from  all  traps  comprising  that  size  class  {n  = 
60)  and  means  for  each  fence  length  were  de- 
rived from  all  traps  comprising  that  fence 
length  {n  = 45);  means  for  each  location  were 
derived  from  all  traps  from  the  five  transects 
making  up  each  location  {n  = 60). 

For  fenced  traps,  the  effect  of  trap  size  on 
species  richness  was  considered  separately  for 
each  fence  length.  Three  data  subsets  were  an- 
alyzed with  two-way  ANOVAs:  short  fences 
(traps  with  2 m fences);  medium  fences  (traps 
v/ith  4 m fences);  and  long  fences  (traps  with 
6 m fences).  For  each  subset,  factors  consid- 
ered were  TRAP  and  LOCATION,  with  spe- 
cies richness  being  the  dependent  variable. 
Means  for  each  trap  size  were  derived  from 
all  traps  within  the  fence  length  being  consid- 
ered {n  = 15).  Means  for  each  location  were 
derived  from  all  traps  within  the  fence  length 
being  considered  {n  — 15). 

The  effect  of  fence  length  on  species  rich- 
ness was  also  considered  separately  for  each 
trap  size.  Three  data  subsets,  namely  those 
from  small  traps  (4.3  cm  diameter),  medium 
traps  (7.0  cm  diameter),  and  large  traps  (11.1 
cm  diameter)  were  analyzed  using  two-way 
ANOVAs.  For  each  subset,  factors  considered 
were  FENCE  and  LOCATION  with  species 
richness  being  the  dependent  variable.  Means 
for  each  fence  length  were  derived  from  all 
traps  within  the  trap  diameter  being  consid- 
ered {n  = 15).  Means  for  each  location  were 
derived  from  all  traps  within  the  trap  diameter 
being  considered  {n  = 15). 


Assumptions  of  ANOVA  were  considered 
before  analysis.  Abundance  data  were  trans- 
formed to  the  log  of  the  value  plus  one,  while 
family  and  species  richness  were  transformed 
to  the  square  root  of  the  value  plus  0.5  (Zar 
1984).  Post-hoc  means  comparisons  utilized 
Scheffe’s  S test  (Day  & Quinn  1989).  Vari- 
ance ratios  (F)  were  considered  significant 
when  P < 0.05.  All  univariate  analysis  were 
performed  using  SPSS  7.5  (SPSS  1996). 

Multivariate  analysis:  To  determine  the  in- 
fluence of  different  trap  diameter/fence  length 
combinations  on  the  taxonomic  composition 
of  spiders,  we  used  the  Bray-Curtis  (1957) 
measure  to  construct  a similarity  matrix  on 
standardized  root  transformed  data.  The  Bray- 
Curtis  measure  takes  the  form,  C = 2w/(x  + 
y),  where  x is  the  number  of  adults  collected 
by  one  method,  y is  the  total  number  of  adults 
collected  by  another  method,  and  w is  the  sum 
of  the  lesser  values  for  those  species  present 
in  both  samples.  Standardization  limits  differ- 
ences between  samples  that  may  arise  through 
differences  in  abundance  by  dividing  each 
count  by  the  total  abundance  of  all  species 
within  each  collecting  method.  Root  transfor- 
mation reduces  the  influence  of  the  most 
abundant  species  to  dominate  results  (Clarke 
& Green  1988). 

For  ease  of  interpreting  similarities,  non- 
metric multidimensional  scaling  (1,000  itera- 
tions) was  used  to  represent  data  in  two-di- 
mensional ordination  space  (Clarke  1993). 
Confirmation  of  interpretations  from  MDS 
was  obtained  by  hierarchical  clustering,  with 
group-average  linking.  Analysis  of  similarities 
(ANOSIMs,  see  Clarke  & Green  1988)  were 
used  to  test  for  differences  in  taxonomic  com- 
position between:  a)  unfenced  and  fenced 
traps  (unfenced  vs.  fences  of  lengths  2,  4,  and 
6 m);  b)  trap  sizes  (4.3  vs.  7.0  vs.  11.1  cm 
diameter)  irrespective  of  fencing;  c)  fencing 
treatments  (unfenced  vs,  2 m vs.  4 m vs.  6 m 
fences);  d)  fenced  traps  with  different  diame- 
ters (4.3  vs.  7.0  vs.  11.1  cm).  An  understand- 
ing, of  which  species  made  the  greatest  con- 
tribution to  our  MDS  and  ANOSIM  results, 
was  obtained  through  similarity  percentages 
(SIMPER,  see  Clarke  1993)  on  root-trans- 
formed standardized  data  with  cut-off  contri- 
butions set  at  50  %. 

To  determine  whether  results  held  at  a high- 
er taxonomic  rank,  we  also  constructed  a sim- 
ilarity matrix  on  standardized,  root  trans- 


BRENNAN  ET  AL.— DRIFT-FENCE  LENGTH  AND  PITFALL  TRAP  SIZE 


685 


formed  family  level  data.  A Mantel’s  test 
(1,000  randomizations)  using  Spearman’s 
Rank  correlation  (Manly  1994)  was  then  used 
to  test  for  a relationship  between  the  species 
and  family  level  matrices.  Finally  the  MDS, 
hierarchical  clustering,  and  ANOSIMs  out- 
lined above  were  repeated  at  familial  rank.  For 
brevity  only  the  MDS  results  are  presented. 
All  multivariate  analyses  were  performed  us- 
ing Primer  5.2.2  (Primer-E  2001). 

Species  accumulation  curves:  To  determine 
an  optimal  combination  of  trap  size/fence 
length  we  standardized  at  equivalent  measures 
of  collecting  effort  on  randomized  species  ac- 
cumulation curves  (Colwell  & Coddington 
1995),  Curves  plotted  cumulative  species 
richness  versus  increasing  numbers  of  traps, 
smoothed  through  10,000  iterations.  This 
method  allowed  integration  of  patchiness  in 
species  occurrences  between  samples  that  is 
lost  when  samples  are  pooled  with  classical 
rarefaction  (Colwell  1994-2000).  Curves 
were  produced  using  Estimates  5.0  (Colwell 
1994-2000). 

An  optimal  combination  of  trap  size/fence 
length  was  determined  for  four  measures  of 
collecting  effort,  namely;  number  of  traps, 
trap  circumference,  fence  length  and  handling 
time.  The  optimal  trap  size/fence  length  com- 
bination for  a standardized  number  of  traps 
was  that  which  gave  the  greatest  species  rich- 
ness for  15  traps.  Optimal  trap  size  and  fence 
length  for  a standardized  trap  mouth  was  de- 
termined by  comparing  the  total  species  rich- 
ness sampled  when  the  accumulated  circum- 
ference was  approximately  206  cm.  This  value 
was  chosen  as  it  represented  the  maximum 
number  of  traps  available  (15)  with  a diameter 
of  4.3  cm.  Nine  7.0  cm  traps  and  six  11.1  cm 
traps  were  needed  at  this  value.  The  trap  size/ 
fence  length  combination  maximizing  species 
richness  at  this  intensity  was  considered  op- 
timal. 

The  optimal  combination  for  a standardized 
fence  length  was  determined  by  comparing 
the  total  species  richness  sampled  when  the 
accumulated  length  of  fence  used  for  those 
traps  with  fences  was  24  m.  This  required  12 
traps  with  2 m fences,  six  traps  with  4 m fenc- 
es and  four  traps  with  6 m fences.  The  com- 
bination sampling  the  highest  species  richness 
was  considered  optimal. 

The  optimal  combination  for  a standardized 
handling  time  was  that  giving  the  highest  spe- 


cies richness  within  a given  period.  Handling 
time  for  a single  trap  from  each  trap  size  was 
calculated  by  summing  the  mean  of  the  fol- 
lowing time  measurements:  dig  in  trap  and  in- 
stall the  fence  (if  appropriate);  pour  the  trap- 
ping solution;  set  the  trap;  and  collect  the  trap. 
Mean  handling  time  represented  five  repeti- 
tions of  each  task.  Cumulative  handling  times 
for  increasing  numbers  of  traps  was  calculated 
by  multiplying  the  mean  handling  time  for 
each  combination  by  the  number  of  traps 
used.  Standardization  of  handling  time  was 
achieved  when  the  accumulated  handling  time 
was  approximately  23  minutes  and  50  sec- 
onds. This  value  represented  the  maximum 
period  that  utilized  all  15  traps  for  the  most 
efficient  trap  size/fence  length  combination. 

RESULTS 

Pitfall  trapping  resulted  in  the  capture  of 
610  adult  spiders,  representing  24  families  and 
63  species.  As  expected,  increasing  trap  size 
and/or  increasing  fence  length  resulted  in 
greater  captures  of  spiders. 

Univariate  analysis. — For  our  full  data  set, 
ANOVAs  revealed  differences  in  mean  spider 
abundance,  plus  family  and  species  richness 
for  trap  size,  fence  length,  and  location  (Table 
1;  Figs.  1-4).  No  significant  interaction  ef- 
fects were  found  between  the  factors  FENCE, 
TRAP  and  LOCATION. 

Comparisons  of  means  revealed  traps  with 
fences  collected  significantly  higher  abun- 
dances and  more  families  and  species  than 
traps  without  fences  (Figs.  1-4;  Table  2). 
Also,  traps  with  6 m fences  were  significantly 
greater  in  these  variables  than  traps  with  2 m 
fences.  All  trap  diameters  were  found  to  differ 
significantly  from  each  other  for  family  and 
species  richness,  but  not  abundance.  Signifi- 
cantly increases  in  abundance  were  found 
only  when  trap  diameter  was  increased  from 
4 to  11.1  cm  and  from  7 to  11.1  cm  (Figs.  1- 
4;  Table  2). 

When  individual  fence  lengths  were  consid- 
ered separately  in  their  own  data  subsets,  the 

largest  trap  size  always  resulted  in  more  spe- 
cies being  caught.  No  significant  interactions 
were  found  between  TRAP  and  LOCATION 
(Table  3).  For  2 m fences,  11.1  cm  diameter 
traps  caught  more  species  than  4.3  cm  traps 
(Fig.  5;  Table  4).  For  4 m fences,  11.1  cm 
diameter  traps  caught  more  species  than  4.3 
or  7.0  cm  traps  (Fig.  6;  Table  4).  For  6 m 


Table  1. — F-ratios  and  significance  levels  from  three-way  ANOVAs  of  TRAP,  FENCE  and  LOCATION  on  transformed  spider  variables  for  the  full  data 
set.  Bold  text  denotes  statistically  significant  difference  at  ***  P < 0.001,  **  p < 0.01,  * P < 0.05;  '^denotes  non-significant  trend  at  P < 0.1. 


686 


THE  JOURNAL  OF  ARACHNOLOGY 


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fences,  ILl  cm  diameter  traps  also  caught 
more  species  than  4.3  cm  traps  (Fig.  7;  Table 
4).  Unlike  the  full  data  set,  however,  no  data 
subsets  showed  a significant  increase  in  spe- 
cies richness  as  trap  size  increased  from  4.3- 
7.0  cm  diameter  (Table  4). 

Traps  with  fences  caught  more  species  of 
spiders  for  each  individual  trap  size  when 
fence  length  was  examined  separately  in  in- 
dividual data  subsets  for  the  4.3  cm  and  11.1 
cm  diameter  traps  (Figs.  8-9).  Unlike  the  full 
data  set,  no  significant  difference  in  species 
richness  occurred  between  the  2 m and  6 m 
fences  for  11.1  cm  traps  (Table  4).  No  signif- 
icant interactions  were  found  between  FENCE 
and  LOCATION  for  these  data  (Table  3),  For 
the  7.0  cm  diameter  traps  data  subset  a sig- 
nificant interaction  occurred  between  the  fac- 
tors FENCE  and  LOCATION.  We  do  not  con- 
sider it  further. 

Multivariate  analysis. — The  taxonomic 
composition  of  spider  species  collected  was 
quite  similar  between  some  trap  diameter/ 
fence  length  combinations  (similarity  > 60 
%).  Yet,  between  others,  similarity  was  low 
(<  25  %).  Multidimensional  scaling  permitted 
us  to  represent  these  similarities  adequately  in 
two-dimensional  ordination  space  with  a rel- 
atively low  amount  of  distortion,  stress  < or 
= 0.1  (Figs.  10-11).  Similar  results  were  ob- 
tained with  hierarchical  clustering  (Fig.  12). 

Fenced  v^.  unfenced:  The  addition  of  a 
fence  caused  a marked  alteration  in  species 
composition.  MDS  showed  all  traps  with  fenc- 
es to  cluster  loosely  together,  and  apart  from 
traps  without  fences  (Fig.  10).  Similarly,  hi- 
erarchical clustering  showed  fenced  traps  to 
form  a terminal  branch  (Fig.  12).  ANOSIM 
confirmed  that  when  combined,  traps  without 
fences  were  significantly  different  in  species 
composition  to  traps  with  fences,  (unfenced 
vs.  2 m,  4 m and  6 m fences)  (Table  5).  SIM- 
PER analysis  revealed  that  almost  47  % of  the 
similarity  in  species  composition  between  un- 
fenced traps  with  diameters  of  4.3,  7.0  and 
11.1  cm  was  attributable  to  a single  species, 
Myrmopopaea  sp.  1 (Oonopidae).  This  spe- 
cies, along  with  Ambicodamus  marae  (Nico- 
damidae)  and  Longepi  woodman  (Lamponi- 
dae),  were  also  primarily  responsible  for 
almost  49  % of  the  similarity  in  species  com- 
position between  fenced  traps.  Despite  this, 
Myrmopopaea  sp.  1 made  only  a small  con- 
tribution (2.26  %)  to  the  difference  between 


BRENNAN  ET  AL.— DRIFT-FENCE  LENGTH  AND  PITFALL  TRAP  SIZE 


687 


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b 


be 


o-* 


b 


0 2 4 6 4 6 8 10  1^2 

Fence  length  (m)  Trap  diameter  (cm) 

Figures  1-4. — Effect  of  increasing  fence  length  (1,  2)  and  increasing  trap  diameter  (3,  4)  on  spider 
catchability:  (1,3)  abundance,  and  (2,  4)  species  richness.  Different  lower  case  letters  denote  significantly 
different  means  (established  from  post-hoc  tests  on  transformed  data.  Table  2).  Error  bars  are  ± one 
standard  error  of  the  mean. 


fenced  and  unfenced  traps.  This  difference 

was  determined  by  high  and  low  abundances 
of  many  species  (Table  6).  Also,  unfenced  7.0 
and  1 L 1 cm  traps  were  more  similar  in  com- 
position to  fenced  traps  than  unfenced  4.3  cm 
traps  (Figs.  10,  12). 

Fence  length:  No  difference  in  taxonomic 
composition  was  found  between  any  pairwise 
combination  of  traps  with  2,  4 or  6 m fences. 
The  only  difference  in  taxonomic  composition 
found  was  between  fenced  and  unfenced  traps. 
ANOSIMs  revealed  significantly  differences 
in  species  composition  between  unfenced 
traps  and  those  with  4 or  6 m fences  (Tables 
5,  7). 

Trap  diameter:  When  all  trap  diameter/ 
fence  length  combinations  were  considered  in 
the  one  analysis,  no  difference  in  taxonomic 
composition  was  found  between  the  different 
trap  diameters  (Table  5). 

Trap  diameter  (fenced  traps  only):  For 
fenced  traps,  trap  diameter,  rather  than  fence 
length,  appeared  to  be  the  primary  factor  in- 


fluencing similarity  in  taxonomic  composi- 
tion. Hierarchical  clustering  revealed  that  4.3 
cm  fenced  traps  formed  a terminal  branch,  as 
did  fenced  traps  with  11.1  cm  diameters  (Fig. 
12).  With  unfenced  traps  excluded,  ANOSIMs 
revealed  significant  differences  in  species 
composition  between  pairwise  combinations 
of  trap  sizes  (4.3  cm  vs.  7.0  cm  vs.  ILl  cm 
diameter)  (Tables  5,  7).  SIMPER  analysis  re- 
vealed >11  species  contributed  to  the  first  50 
% of  the  difference  in  taxonomic  composition 
between  all  combinations,  with  no  individual 
species  contributing  more  than  6.9  % (Table 
8). 

Effect  of  trap  diameter  and  fence  length  at 
higher  taxonomic  levels:  The  results  outlined 

above  for  species  were  generally  maintained 
when  we  repeated  our  analysis  at  familial 
rank.  In  fact,  MDS  ordinations  obtained  at 
species  and  family  ranks  were  remarkably 
similar  (Figs.  10  vs.  11).  Testing  between  un- 
derlying similarity  matrices  with  the  Mantel’s 
test  confirmed  both  were  significantly  similar 


688 


THE  JOURNAL  OF  ARACHNOLOGY 


Table  2. — Mean  differences  obtained  from  post-hoc  means  comparisons  using  Scheffe’s  S for  TRAP 
and  FENCE  on  transformied  spider  variables  for  the  full  data  set.  Bold  text  denotes  statistically  significant 
difference  of  ***  P < 0.001,  **  p < 0.01  or  * F < 0.05,  TD4  denotes  trap  diameter  4.3  cm,  TD7  denotes 
trap  diameter  7.0  cm,  TDl  1 denotes  trap  diameter  1 LI  cm,  FLO  denotes  no  fence,  FL2  denotes  2 m fence, 
FL4  denotes  4 m fence,  FL6  denotes  6 m fence. 


Effects 


FENCE  TRAP 


Dependent 

variables 

FLO 

vs. 

FL2 

FLO 

vs. 

FL4 

FLO 

vs. 

FL6 

FL2 

vs. 

FL4 

FL2 

vs. 

FL6 

FL4 

vs. 

FL6 

TD4 

vs. 

TD7 

TD4 

vs. 

TDll 

TD7 

vs. 

TDll 

Abundance 

0.96*** 

1.23*** 

0.25 

0.52*** 

0.27 

0.17 

0,54*** 

037** 

Family  richness 

0.65*** 

0.85*** 

0.18 

037** 

0.20 

0.20* 

0.45*** 

0.26** 

Species  richness 

0.51*** 

0.72*** 

032*** 

0.21 

0^41*** 

0.20 

0.20* 

0.52*** 

032*** 

(sample  statistic  Rho  ” 0.879;  permuted  sta= 
tistics  > Rho  = 0;  P < 0.001).  The  result  of 
the  ANOSIMs  reported  above  at  species  level 
also  remained  unchanged  at  family  rank.  The 
only  changed  result  was  in  the  structuring  of 
7.0  and  ILl  cm  traps  with  fences  in  the  hi- 
erarchical  clustering  dendrogram. 

Determinatioin  of  an  optimal  combina- 
tion of  trap  size/feece  length* — Smoothed 
species  accumulation  curves  for  increasing 
numbers  of  traps  revealed  that  different  trap 
size/feece  length  combinations  accrued  spe^ 
cies  at  different  rates.  Fenced  traps  accumu^ 
lated  species  more  rapidly  than  unfenced  traps 
(Fig.  13).  Moreover,  for  each  trap  size,  longer 
fences  accrued  species  more  rapidly.  Addi- 
tionally, species  were  still  being  accumulated 
for  all  combinations  of  trap  size/fence  length 
as  no  curves  had  reached  an  asymptote  (Fig. 
13). 

Standardized  number  of  traps:  Standardiz- 
ing at  15  traps  revealed  large  differences  in 


the  number  of  species  collected  by  each  trap 
size/fence  length  combination  (Fig.  13).  At  15 
traps,  4.3  cm  unfenced  traps  caught  only  five 
species,  whereas  11.1  cm  traps  with  fences  of 
4 m or  greater  collected  more  than  30  species. 
Traps  with  fences  generally  caught  more  spe- 
cies than  traps  without  fences.  The  only  ex- 
ception was  the  4.3  cm  trap  with  a 2 m fence, 
which  caught  only  10  species  compared  to  the 
12  species  collected  by  the  11.1  cm  unfenced 
trap.  The  11.1  cm  traps  with  4 or  6 m fences 
were  considered  optimal  for  a standardized 
number  of  traps. 

Standardized  trap  circumference:  Standard- 
izing at  a cumulative  circumference  also  re- 
vealed large  differences  in  the  number  of  spe- 
cies collected  by  each  trap  size/fence  length 
combination  (Fig.  14).  Unfenced  traps  caught 
< six  species  compared  to  > 10  for  fenced 
traps.  Traps  with  long  fences  were  optimal  for 
this  criterion.  All  traps  with  6 m fences  and 


Table  3. — F-ratios  and  significance  levels  from  two-way  ANOVAs  of  TRAP  and  LOCATION  or  FENCE 
and  LOCATION  on  transformed  spider  species  richness  for  data  subsets.  Bold  text  denotes  statistically 
significant  difference  at  ***  P < 0.001,  **  F < 0.01,  * F < 0.05. 


Effects 


Data  subset 

FENCE  X 
LOCATION 
d.f.  6,  144 

TRAP  X 
LOCATION 
d.f.  4,  144 

FENCE 
d.f.  3,  144 

TRAP 
d.f.  2,  144 

LOCATION 
d.f.  2,  144 

Small  traps  (4.3  cm  diameter) 

0.994 

. — 

10.951*** 

1.179 

Medium  traps  (7  cm  diameter) 

3,567** 

— 

— 

— 

— 

Large  traps  (11.1  cm  diameter) 

1.120 

— 

12.578*** 

2.307 

Short  fences  (2  m) 

1.064 

___ 

4.498*** 

1.869 

Medium  fences  (4  m) 

— 

2.257 

— 

11.711*** 

4.056* 

Long  fences  (6  m) 

— 

0.337 

— 

6.297** 

4,241* 

BRENNAN  ET  AL.— DRIFT=FENCE  LENGTH  AND  PITFALL  TRAP  SIZE 


689 


n = 15 


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4 m fences 


10  12 


6-1 


o-J 


6 m fences 


ab 


4 6*"  8 ~io  ?2 

Trap  diameter  (cm) 

Figures  5-7. — Effect  of  increasing  trap  diameter 
on  spider  species  richness  for  fenced  traps  with:  (5) 
short  fences  of  2 m,  (6)  medium  fences  of  4 m,  or 
(7)  long  fences  of  6 m.  Different  lower  case  letters 
denote  significantly  different  means  (established 
from  post-hoc  tests  on  transformed  data,  Table  4). 
Error  bars  are  ± one  standard  error  of  the  mean. 


the  11.1  cm  diameter  trap  with  a 4 m fence 
collected  high  numbers  of  species  (>  16). 

Standardized  fence  length:  For  fenced 
traps,  standardizing  at  a cumulative  fence 
length  of  24  m revealed  large  traps  generally 
collected  more  species.  All  11.1  cm  traps  coL 
lected  >13  species,  whereas  most  7.0  cm  and 
all  4.3  cm  diameter  traps  caught  fewer  than 


1 1 species  (Fig.  15).  That  said,  when  each  trap 
diameter  was  considered  separately,  and  traps 
were  ranked  by  the  number  of  species  col- 
lected, traps  with  2 m fences  always  collected 
the  most  species  (Fig.  15). 

Standardized  handling  time:  Standardizing 
for  handling  time  revealed  very  different  re- 
sults compared  to  a standardized  number  of 
traps  or  trap  circumference.  All  traps  collected 
very  similar  numbers  of  species  (Fig.  16),  de- 
spite mean  handling  times  differing  for  each 
trap  size/fence  length  combination  (Table  9). 
Overall,  the  11.1  cm  trap  with  a 4 m fence 
was  optimal,  as  it  could  be  expected  to  collect 
more  species  than  all  other  traps  (>13),  during 
the  standardized  handling  period  (Fig.  16). 
Other  subtle  differences  between  trap  size/ 
fence  length  combinations  were  evident.  First- 
ly, the  number  of  species  expected  to  be  col- 
lected increased  with  trap  size.  Between  four 
to  six  species  were  collected  from  4.3  cm  di- 
ameter traps.  Six  to  nine  species  were  caught 
by  7.0  cm  traps.  The  most  species  were  col- 
lected by  11.1  cm  traps  (8  to  14).  Secondly, 
when  each  trap  size  was  considered  separate- 
ly, and  traps  were  ranked  by  the  number  of 
species  collected,  traps  with  6 m fences  al- 
ways collected  the  least. 

DISCUSSION 

Does  adding  fences  to  pitfall  traps  in- 
crease spider  catchability  in  Western  Aus- 
tralian jarrah  forest? — We  found  fenced 
traps  caught  greater  abundance  of  individuals 
and  more  spider  families,  and  species  in  this 
habitat.  These  findings  support  earlier  re- 
search in  the  monsoonal  tropics  of  northern 
Australia  where  increased  abundances  of  spi- 
ders and  dominant  taxa  were  captured  in 
fenced  traps  compared  to  unfenced  traps 
(Churchill  unpub.  data).  It  is  important,  how- 
ever, that  the  role  of  trap  diameter  and  fence 
design  be  tested  in  other  habitats  and  over  dif- 
ferent periods  and  seasons. 

To  date,  fenced  traps  have  not  been  widely 
used  to  sample  spiders.  However,  they  are 
used  frequently  to  sample  amphibians,  reptiles 
and  small  mammals  (Blomberg  & Shine  1996; 
Halliday  1996).  For  vertebrates,  fences  in- 
creased abundance  and  species  richness  of  an- 
imals collected  (Bury  & Corn  1987;  Morton 
et  al.  1988;  Friend  et  al.  1989),  but  see  Wil- 
liams & Braun  (1983).  For  invertebrates  other 
than  spiders,  fenced  traps  are  uncommon.  In- 


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THE  JOURNAL  OF  ARACHNOLOGY 


Table  4. — Mean  differences  obtained  from  post-hoc  means  comparisons  using  Scheffe’s  S for  TRAP 
and  FENCE  on  transformed  spider  species  richness  for  data  subsets.  Bold  text  denotes  statistically  sig- 
nificant difference  of  ***  P < 0.001,  **  p < 0.01  or  * P < 0.05.  TD4  denotes  trap  diameter  4.3  cm, 
TD7  denotes  trap  diameter  7.0  cm,  TDll  denotes  trap  diameter  11.1  cm,  FLO  denotes  no  fence,  FL2 
denotes  2 m fence,  FL4  denotes  4 m fence,  FL6  denotes  6 m fence. 


Effects 

FENCE  TRAP 


Data  subset 

FLO 

vs. 

FL2 

FLO 

vs. 

FL4 

FLO 

vs. 

FL6 

FL2 

vs. 

FL4 

FL2 

vs. 

FL6 

FL4 

vs. 

FL6 

TD4 

vs, 

TD7 

TD4 

vs. 

TDll 

TD7 

vs. 

TDll 

Small  traps  (4.3  cm 
diameter) 

0.37 

0.58** 

0.79*** 

0.21 

0.42* 

0.21 

Large  traps  (11.1  cm 

diameter) 

0,54* 

0.95*** 

1.02*** 

0.40 

0.47 

0.00 

Short  fences  (2  m) 

— 

— 

— 

— 

— 

— 

0.33 

0.50* 

0.17 

Medium  fences  (4  m) 

— 

— 

— 

— 

— 

— 

0.14 

0.69*** 

0.55** 

Long  fences  (6  m) 

— 

— 

— 

— 

— 

— 

0.25 

0.56** 

0.30 

8 m 

0 

c 

XL 

O 


w2H 

c 
m 
m 


4.3  cm  diameter  traps 


ab 

i 


11.1  cm  diameter  traps 


.g  4 

0) 

‘0 

a 2- 

(n 
c 
o 

S oJ 


b 


I 1 1 1 

0 2 4 6 

Fence  length  (m) 

Figures  8-9.-— -Effect  of  fencing  length  on  spider 
species  richness  for:  (8)  small  traps  (4.3  cm  diam- 
eter), or  (9)  large  traps  (11.1  cm  diameter).  Differ- 
ent lower  case  letters  denote  significantly  different 
means  (established  from  post-hoc  tests  on  trans- 
formed data.  Table  4).  Error  bars  are  ± one  standard 
error  of  the  mean. 


creases  in  abundance  and  species  richness  of 
beetles  collected  with  fenced  traps,  however, 
have  been  documented  (Durkis  & Reeves 
1982;  Morrill  et  al.  1990;  Crist  & Wiens 
1995). 

Our  study  revealed  marked  differences  in 
taxonomic  composition  between  fenced  and 
unfenced  traps.  This  may  have  arisen  because 
pitfall  traps  preferentially  sample  species 
moving  actively  across  the  ground  surface. 
Adding  fences  my  skew  this  bias  further  to- 
wards the  most  active  species.  It  will  be  these 
species  most  likely  to  encounter  fences  and, 
by  following  the  fence,  fall  into  the  trap.  For 
example,  SIMPER  analysis  revealed  the  ni- 
codamid  Ambicodamus  marae  made  the  high- 
est contribution  to  the  dissimilarity  between 
fences  and  unfenced  traps.  This  species  had  a 
mean  abundance  of  5.22  across  fenced  traps 
but  was  not  collected  at  all  in  unfenced  traps 
(Table  7).  Given  that  of  the  47  individuals  col- 
lected, 45  were  adult  males,  it  is  likely  that  at 
the  time  of  our  sampling,  males  were  actively 
searching  for  mates  thus  leading  to  high  cap- 
tures in  fenced  traps.  Similar  results  of  spe- 
cies-specific differences  in  catchability  be- 
tween unfenced  traps  and  fenced  traps  have 
been  documented  for  beetles  (Morrill  et  al. 
1990). 

How  does  trap  size  influence  spider 
catchability  for  fenced  and  unfenced 
traps? — Generally,  higher  abundances  and 
more  species  were  collected  as  trap  size  in- 
creased, however,  differences  between  each 


BRENNAN  ET  AL.— DRIFT-FENCE  LENGTH  AND  PITFALL  TRAP  SIZE 


691 


Figures  10-11.- — Ordinations  showing  similarity 

in  spider  community  composition  between  each 
fence  length/trap  size  combination  at  (10)  species 
and  (11)  family  ranks.  TD4  denotes  trap  diameter 
4.3  cm,  TD7  denotes  trap  diameter  7.0  cm,  TDll 
denotes  trap  diameter  11.1  cm,  FLO  denotes  no 
fence,  FL2  denotes  2 m fence,  FL4  denotes  4 m 
fence,  FL6  denotes  6 m fence. 

trap  size  were  not  always  present  (Figs.  3-7). 
Absent  in  the  fenced  2 and  6 m data  subsets, 
but  present  in  the  full  dataset,  were  significant 
differences  between  4.3  versus  7.0  cm  traps, 
and  between  7.0  versus  11.1  cm  traps.  Re- 
moval of  significant  differences  most  likely 
arose  through  a loss  of  power  associated  with 
fewer  replicates.  Greater  captures  from  large 
pitfall  traps  with  fences  compared  to  small  pit- 
fall  traps  with  fences  has  been  found  also  for 
reptiles  (Morton  et  al.  1988). 

For  fenced  traps,  the  primary  factor  influ- 
encing taxonomic  composition  was  trap  size; 
fence  length  had  no  significant  effect.  ANO- 
SIMs  revealed  significant  differences  between 
each  trap  size  for  fenced  traps,  but  no  differ- 
ences between  traps  with  2,  4 or  6 m fences. 
Reasons  behind  differences  in  taxonomic 
composition  between  trap  sizes  for  fenced 
traps  are  not  obvious.  They  arose  from  com- 
bined contribution  of  subtle  differences  in  the 
abundances  of  many  species,  rather  than  a 
limited  few.  Some  species  were  preferentially 
collected  in  smaller  traps.  For  example,  Sal- 
ticidae  Genus  9 sp.  01  was  collected  in  high 
abundance  in  4.3  cm  traps,  intermediate  abun- 


dance in  7.0  cm  traps  and  in  low  abundance 
in  11.1  cm  traps  (Table  9).  Conversely,  other 
species  such  as  Ambicodamus  marae,  were  bi- 
ased against  4.3  cm  traps,  but  didn’t  discrim- 
inate between  7.0  or  11.1  cm  traps.  Finally, 
some  species  were  captured  predominantly  in 
intermediate  sized  7.0  cm  traps  (e.g.  Hesti- 
modema  sp.  02  and  Myrmopopaea  sp.  01). 
Other  species  were  biased  against  this  trap 
size  (e.g.  Salticidae  Genus  3 sp.  02).  We  in- 
terpret these  findings  as  arising  from  species- 
specific  differences  in  behavior  that  preferen- 
tially predisposed  individual  species  to 
capture  (or  prevented  escape)  by  each  individ- 
ual trap  size. 

For  unfenced  traps,  even  for  very  small 
sample  sizes,  trap  diameter  can  have  a major 
influence  on  spider  abundance  and  species 
richness.  Our  earlier  findings  revealed  greater 
captures  with  increasing  trap  size  when  we 
compared  4.3,  7.0,  11.1  and  17.1  cm  diameter 
traps  (Brennan  et  al,  1999).  In  particular,  mean 
abundance  and  species  richness  differed  sig- 
nificantly between  the  three  largest  traps.  For 
other  invertebrates,  size  of  unfenced  traps  can 
also  influence  captures.  Larger  traps  have 
yielded  greater  abundance  and  species  rich- 
ness of  ants  and  beetles  (Luff  1975;  Aben- 
sperg-Traun  & Steven  1995).  However,  for 
both  groups  trap  size  influenced  taxonomic 
composition.  For  example,  small  trap  sizes 
preferentially  sampled  small  beetles  and  large 
traps  were  better  for  large  species  (Luff  1975). 
Similar  results  were  obtained  in  the  present 
study.  Spider  taxonomic  composition  differed 
markedly  between  unfenced  4.3  cm  versus  un- 
fenced 7.0  and  11.1  cm  diameter  traps.  The 
later  trap  sizes  clustered  together  tightly  in  or- 
dinations. 

The  above  finding  highlights  the  difficulties 
of  making  valid  comparisons  between  studies 
using  different  sampling  protocols.  Here  we 
can  but  echo  earlier  calls  for  arachnologists  to 
standardize  sampling  protocols  thereby  per- 
mitting more  valid  comparisons  to  be  made 
(Coddington  et  al.  1991;  Churchill  1993;  New 
1999). 

How  does  fence  length  influence  spider 
catchability  for  fenced  traps? — Increasing 
fence  length  yielded  increased  spider  abun- 
dance plus  the  richness  of  families  and  species 
in  our  full  data  set.  In  fact,  traps  with  6 m 
fences  had  greater  captures  than  those  with  2 
m fences  for  all  of  these  variables.  Greatest 


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THE  JOURNAL  OF  ARACHNOLOGY 


20 


40 


•f*  60 

1 

m 


80 


100 


o 

_J 

o 

o 

_j 

3 

CD 

=J 

3 

3 

3 

3 

C0 

_! 

u. 

u. 

u_ 

u_ 

LL 

U. 

y. 

LL 

LL 

LL 

IL 

u. 

NT 

f— 

h. 

h.. 

Q 

Q 

Q 

Q 

Q 

Q 

Q 

Q 

-f” 

•r’ 

H- 

1- 

p 

H 

H 

H 

H 

H 

H 

Q 

Q 

Q 

f~ 

h- 

H 

no  fences 


fences 


4.3  cm  traps 


7.0  cm  traps 


11.1  cm  traps 


Figure  12.- — Dendrogram  for  hierarchical  clustering  (group-average  linking)  of  similarity  in  spider  spe- 
cies composition  between  each  fence  length/trap  size  combination. 


increases,  however,  occurred  between  un- 
fenced traps  and  those  with  2 m fences  (our 
smallest  length  of  fence).  Given  these  find- 
ings, two  questions  arise.  Firstly,  what  is  the 
minimum  length  of  fence  required  to  derive 
the  initial  rapid  increase  in  captures?  Second- 
ly, at  what  length  of  fence  will  no  additional 
benefit  be  gained  by  adding  more  fence?  The 
former  cannot  be  answered  from  our  dataset. 


We  suggest  future  workers  test  the  effective- 
ness of  fences  over  a wider  range  of  lengths. 
These  should  include  very  short  fences  of  per- 
haps only  10  to  20  cm  (5  to  10  cm  each  side 
of  the  trap).  With  respect  to  the  second  ques- 
tion, our  results  differed  between  data  sets. 

When  fence  length  was  considered  sepa- 
rately in  data  subsets  for  4.3  and  11.1  cm  di- 
ameter traps,  the  rate  of  increase  in  species 


Table  5.—ANOSIM  global  test  results  for  difference  in  species  composition  between  various  combi- 
nations of  trap  diameter  and  fence  lengths.  Bold  text  denotes  statistically  significant  differences  in  taxo- 
nomic composition  at  **  P < 0.01  or  * P < 0.05.  ® denotes  all  possible  permutations  used.  TD4  denotes 
trap  diameter  4.3  cm,  TD7  denotes  trap  diameter  7.0  cm,  TDll  denotes  trap  diameter  11.1  cm,  FLO 
denotes  no  fence,  FL2  denotes  2 m fence,  FL4  denotes  4 m fence,  FL6  denotes  6 m fence. 


Data  set  used 

Factors 

Global  R 

Permutations 

available 

Permuted 
statistics  > 
global  R 

All  trap/fence  combinations 

FLO  vs.  FL2  & FL4  & FL6 

0.871 

220® 

J*Si8 

FLO  vs.  FL2  vs.  FL4  vs.  FL6 

0.309 

15400® 

378* 

TD4  vs.  TD7  vs.  TDll 

0.1 

5775® 

1114 

Fenced  traps  only 

TD4  vs.  TD7  vs.  TDll 

0.712 

280® 

BRENNAN  ET  AL.— DRIFT-FENCE  LENGTH  AND  PITFALL  TRAP  SIZE 


693 


Table  6. — ^Individual  species  contributions  to  the  difference  in  taxonomic  composition  between  fenced 
and  unfenced  traps  (average  dissimilarity  = 66.39%),  from  SIMPER  analysis  of  root  transformed  stan- 
dardized data. 


Species 

Mean  abundance 

Unfenced  Fenced 

Mean 

dissimilarity 

Contribution 

(%) 

Cumulative 

contribution  (%) 

Ambicodamus  marae  Harvey  1995 

0.00  - 

55.22 

4.24 

6.38 

6.38 

Linyphiidae  Genus  02  sp.  02 

1.33 

1.00 

3.96 

5.96 

12.34 

Longepi  woodman  Platnick  2000 

0.00 

3.89 

3.57 

5.38 

17.73 

Supunna  funerea  Simon  1896 

1.33 

0.67 

3.30 

4.97 

22.69 

Anapidae  Genus  01  sp.  02 

0.00 

2.33 

3.04 

4.58 

27.28 

Tasmanoonops  sp.  02 

0.67 

0.44 

3.04 

4.57 

31.85 

Hestimodema  sp.  02 

0.33 

2.89 

2.82 

4.24 

36.10 

Gnaphosidae  Genus  01  sp.  01 

0.67 

1.67 

2.77 

4.17 

40.27 

Elassoctenus  sp.  03 

0.67 

0.22 

2.77 

4.17 

44.44 

Salticidae  Genus  03  sp.  02 

0.67 

4.56 

2.38 

3.58 

48.02 

richness  for  additional  units  of  fence  differed 
(Figs.  8 vs.  9).  The  4.3  cm  diameter  traps  fol- 
lowed the  pattern  noted  previously  in  the  full 
data  set.  Additional  increments  of  fences  in- 
creased the  catch  so  that  traps  with  6 m fences 
had  significantly  more  than  those  with  2 m 
fences.  Conversely,  for  11.1  cm  traps  no  fur- 
ther significant  increase  in  species  richness 
occurred  with  4 or  6 m fencing. 

For  beetles,  increasing  fence  length  yields 
greater  abundance.  Durkis  and  Reeves  (1982) 
compared  unfenced  traps  to  traps  with  fences 
of  0.3,  0.9  or  1.5  m.  They  found  1.5  m fences 
collected  more  beetles  than  traps  with  0.9  m 


fences  and  these  lengths  were  superior  to  0.3 
m fences  or  unfenced  traps  (Durkis  & Reeves 
1982).  Other  authors  report  variable  effects. 
Morrill  et  al.  (1990)  compared  unfenced  traps 
and  traps  with  fences  of  0.05,  0.10  or  0.15  m. 
For  some  carabid  species,  abundance  did  not 
differ  between  fenced  and  unfenced  traps.  For 
other  species,  0.20  m fences  were  superior  to 
0.05  m fences. 

For  vertebrates,  increasing  fence  length  has 

often  been  accompanied  by  increased  cap- 
tures, even  for  very  long  fences  (Bury  & Corn 
1987;  Friend  et  al.  1989;  Hobbs  et  al.  1994). 
Hobbs  et  al.  (1994)  reported  increased  reptile 


Table  7.— -ANOSIM  pairwise  tests  results  for  of  differences  in  species  composition  between  various 
combinations  of  trap  diameter  and  fence  lengths.  ^ denotes  all  possible  permutations  used.  denotes  level 
of  statistical  significance  (P)  was  set  at  0.1  owing  to  the  low  number  of  permutations  available.  Bold  text 
denotes  statistically  significant  differences  in  taxonomic  composition  at  * P = 0.1.  TD4  denotes  trap 
diameter  4.3  cm,  TD7  denotes  trap  diameter  7.0  cm,  TDll  denotes  trap  diameter  11.1  cm,  FLO  denotes 
no  fence,  FL2  denotes  2 m fence,  FL4  denotes  4 m fence,  FL6  denotes  6 m fence. 


Permuted 

Factors  and  pairwise  tests  of  Permutations  statistics  > 

Data  set  used  factor  levels  R statistic  available  R statistic 


All  trap/fence  combinations 


FLO  vs.  FL2  vs.  FL4  vs.  FL6 

FLO  vs.  FL2 

FLO  vs.  FL4 

FLO  vs.  FL6 

FL2  vs.  FL4 

FL2  vs.  FL6 

FL4  vs.  FL6 

TD4  vs.  TD7  vs.  TDll 

TD4  vs.  TD7 

TD4  vs.  TDll 

TD7  vs.  TDll 


0.481 

10"*^ 

2 

0.778 

10"b 

1* 

0.741 

10"b 

1* 

-0.185 

lO^*’ 

8 

0.074 

lO^b 

4 

-0.111 

lOab 

8 

0.741 

lO^b 

1* 

0.926 

IQab 

1* 

0.519 

lO"*^ 

1* 

Fenced  traps  only 


694 


THE  JOURNAL  OF  ARACHNOLOGY 


Table  8. — Individual  species  contributions  to  differences  in  taxonomic  composition  between  different 
trap  sizes  amongst  traps  with  fences,  from  SIMPER  analysis  of  root  transformed  standardized  data.  TD4 
denotes  trap  diameter  4.3  cm,  TD7  denotes  trap  diameter  7.0  cm,  TDll  denotes  trap  diameter  11.1  cm. 


Pairwise 

comparison 

Species 

Mean  abundance 

TD4  TD7  TDll 

Mean 

dissim- 

ilarity 

Contri- 

bution 

(%) 

Cumu- 
lative 
contribu- 
tion (%) 

TD4  vs.  TD7 

Hestimodema  sp.  02 

0.33 

5.67 

— 

3.67 

6.90 

6.90 

(average  dis- 

Gnaphosidae  Genus  01  sp.  01 

3.00 

0.00 

— 

3.60 

6.78 

13.67 

similarity  = 

Lycidas  michaelseni  (Simon 

0.00 

2.33 

— 

2.32 

4.36 

18.03 

53.17%) 

1909) 

Myrmopopaea  sp.  01 

23.00 

14.33 



2.27 

4.27 

22.30 

Salticidae  Genus  03  sp.  02 

4.67 

2.67 

— 

2.26 

4.24 

26.54 

Ambicodamus  marae  Harvey 

1.33 

5.67 

— 

2.17 

4.07 

30.61 

1995 

Elassoctenus  sp.  01 

0.33 

2.00 

1.92 

3.61 

34.22 

Linyphiidae  Genus  02  sp.  02 

0.00 

1.33 

— 

1.90 

3.57 

37.80 

Zodariidae  Genus  01  sp.  02 

0.33 

1.33 

— 

1.80 

3.38 

41.17 

Longepi  woodman  Platnick 

1.33 

4.67 

— 

1.78 

3.35 

44.53 

2000 

Salticidae  Genus  09  sp.  01 

1.00 

0.33 

1.78 

3.35 

47.88 

Opopaea  sp.  01 

1.67 

1.33 

— 

1.52 

2.85 

50.73 

TD4  vs.  TDll 

Anapidae  Genus  01  sp.  02 

4.00 

— 

0.67 

2.74 

5.23 

5.23 

(average  dis- 

Gnaphosidae  Genus  01  sp.  01 

3.00 

— 

2.00 

2.73 

5.21 

10.44 

similarity  = 

Lycidas  michaelseni  (Simon 

0.00 

— 

4.00 

2.71 

5.16 

15.60 

52.39%) 

1909) 

Gnaphosidae  Genus  01  sp.  02 

0.00 

_ 

2.33 

2.14 

4.09 

19.69 

Lycidas  sp.  04 

0.33 

— 

3.67 

1.98 

3.79 

23.48 

Salticidae  Genus  09  sp.  01 

1.00 

— 

0.00 

1.88 

3.59 

27.07 

Linyphiidae  Genus  02  sp.  02 

0.00 

— 

1.67 

1.83 

3.49 

30.56 

Ambicodamus  marae  Harvey 

1.33 

— 

8.67 

1.80 

3.44 

34.00 

1995 

Hestimodema  sp.  02 

0.33 

2.67 

1.77 

3.37 

37.37 

Tasmanoonops  sp.  03 

0.00 

— 

1.33 

1.59 

3.04 

40.41 

Myrmopopaea  sp.  01 

23.0 

— 

29.0 

1.56 

2.98 

43.39 

Tasmanoonops  sp.  02 

0.67 

— 

0.67 

1.35 

2.59 

45.98 

Longepi  woodman  Platnick 

1.33 

— 

5.67 

1.20 

2.30 

48.27 

2000 

Elassoctenus  sp.  01 

0.33 

1.00 

1.19 

2.26 

50.54 

TD7  vs.  TDll 

Gnaphosidae  Genus  01  sp.  02 

— 

0.00 

2.33 

1.98 

4.32 

4.32 

(average  dis- 

Zodariidae Genus  01  sp.  02 

— 

1.33 

0.00 

1.94 

4.24 

8.56 

similarity  = 

Hestimodema  sp.  02 

— 

5.67 

2.67 

1.63 

3.55 

12.11 

45.83%) 

Salticidae  Genus  03  sp.  02 

— 

2.67 

6.33 

1.58 

3.44 

15.55 

Anapidae  Genus  01  sp.  02 

— 

2.33 

0.67 

1.55 

3.39 

18.93 

Elassoctenus  sp.  01 

— 

2.00 

LOO 

1.50 

3.28 

22.22 

Supunna  funerea  Simon  1896 

— 

0.00 

1.33 

1.47 

3.21 

25.43 

Myrmopopaea  sp.  01 

— 

14.33 

29.00 

1.38 

3.01 

28.44 

Gnaphosidae  Genus  01  sp.  01 

— 

0.00 

2.00 

1.35 

2.95 

31.39 

Longepi  woodman  Platnick 

— 

4.67 

5.67 

1.33 

2.90 

34.28 

2000 

Lycidas  michaelseni  (Simon 

2.33 

4.00 

1.29 

2.82 

37.11 

1909) 

Opopaea  sp.  01 

1.33 

2.33 

1.17 

2.54 

39.65 

Gamasomorpha  sp.  02 

— 

0.00 

1.33 

1.08 

2.36 

42.02 

Tasmanoonops  sp.  03 

— 

0.33 

1.33 

1.06 

2.32 

44.34 

Linyphiidae  Genus  02  sp.  02 

— 

1.33 

1.67 

1.04 

2.27 

46.61 

Lampona  brevipes  L.  Koch 

— 

0.67 

0.00 

1.04 

2.26 

48.87 

1872 

Australobus  sp.  01 

— 

1.00 

1.33 

0.99 

2.16 

51.04 

BRENNAN  ET  AL,-=-DRIFT»FENCE  LENGTH  AND  PITFALL  TRAP  SIZE 


695 


TD4FL6 

TD4FL4 

TD4FL2 

TO4FL0 


TD7FL6 

TD7FL4 

TD7FL2 

TD7FL0 


T117FL6 

TD11FL4 


TD11FL2 


TD11FL0 


Figure  13.-=-Smoothed  species  accumulation 
curves  showing  the  number  of  species  likely  to  be 
sampled  with  standardized  number  of  traps  (15 
traps)  for  each  fence  lengtli/trap  size  combination. 
Error  bars  are  ± one  standard  deviation  of  the 
mean.  TD4  denotes  trap  diameter  4.3  cm,  TD7  de- 
notes trap  diameter  7.0  cm,  TDll  denotes  trap  di- 
ameter 1 L 1 cm,  FLO  denotes  no  fence,  FL2  denotes 
2 m fence,  FL4  denotes  4 m fence,  FL6  denotes  6 
m fence.  Curves  are  spread  over  three  graphs  for 
the  purpose  of  clarity. 


3S- 


TO4FL6 


TD4FL4 

TD4FL2 

TO4FL0 


T117FL6 

TD11FL4 


TD11FL2 


TD11FL0 


Figure  14,— -Smoothed  species  accumulation 
curves  showing  the  i lumber  of  species  likely  to  be 
sampled  with  standardized  cumulative  trap  circum- 
ference of  206  cm  for  each  fence  lengthdrap  size 
combination.  Error  bars  are  ± one  standard  devia- 
tion of  the  mean.  TD4  denotes  trap  diameter  4.3 
cm,  TD7  denotes  trap  diameter  7.0  cm,  TDll  de- 
notes trap  diameter  11.1  cm,  FLO  denotes  no  fence, 
FL2  denotes  2 m fence,  FL4  denotes  4 m fence, 
FL6  denotes  6 m fence.  Curves  are  spread  over 
three  graphs  for  the  purpose  of  clarity. 


696 


THE  JOURNAL  OF  ARACHNOLOGY 


TD4FL6 

TD4FL4 

TD4FL2 

TD4FL0 


TD7FL6 


TD7FL4 

TD7FL2 


TD7FL6 


TD7FL4 

TD7FL2 


TD7FL0 


T117FL6 
TD1 1 FL4 


TD11FL2 


TD11FL0 


sampled  with  standardized  cumulative  fence  length 
of  24  m for  all  trap  sizes  of  fenced  traps.  Error  bars 
are  ± one  standard  deviation  of  the  mean.  TD4  de- 
notes trap  diameter  4.3  cm,  TD7  denotes  trap  di- 
ameter 7.0  cm,  TDll  denotes  trap  diameter  11.1 
cm,  FL2  denotes  2 m fence,  FL4  denotes  4 m fence, 
FL6  denotes  6 m fence.  Curves  are  spread  over 
three  graphs  for  the  purpose  of  clarity. 


Figure  16. — Smoothed  species  accumulation  curves 
showing  the  number  of  species  likely  to  be  sampled 
with  standardized  handling  time  of  approximately  23 
minutes  and  50  seconds  for  each  fence  length/trap  size 
combination.  Error  bars  are  ± one  standard  deviation 
of  the  mean.  TD4  denotes  trap  diameter  4.3  cm,  TD7 
denotes  trap  diameter  7.0  cm,  TDll  denotes  trap  di- 
ameter 11.1  cm,  FLO  denotes  no  fence,  FL2  denotes 
2 m fence,  FL4  denotes  4 m fence,  FL6  denotes  6 m 
fence.  Curves  are  spread  over  three  graphs  for  the 
purpose  of  clarity. 


BRENNAN  ET  AL.— DRIFT=FENCE  LENGTH  AND  PITFALL  TRAP  SIZE 


697 


captures  with  66  m as  opposed  to  50  m fences. 
However,  Williams  and  Braun  (1983)  found 
no  difference  in  small  mammal  captures  be= 
tween  traps  with  0.6  or  1.2  m fences. 

Although  not  the  focus  of  this  study,  trap 
location  was  important  for  7.0  cm  diameter 
traps.  A significant  interaction  effect  was 
found  between  FENCE  and  LOCATION  for 
species  richness  (Table  3).  This  result  may 
have  arisen  through  differences  in  habitat 
structure  or  the  influence  of  trap  spacing.  Dif- 
ferences in  trap  arrangement  and  spacing  can 
influence  the  abundance,  species  richness  and 
composition  of  beetles  (Crist  & Wiens  1995; 
Digweed  et  al.  1995;  Ward  et  al.  2001).  The 
role  of  trap  arrangement  and  spacing  for  spi- 
ders should  be  investigated, 

Deteriniiiatioe  of  an  optimum  combiea- 
ticm  of  trap  diameter  and  fence  length,— 
Our  results  show  clearly  that  some  trap  di- 
ameter/feece  length  combinations  are  more 
efficient  than  others.  For  example,  results  for 
a standardized  fence  length  suggest  that  if  a 
total  of  only  24  m of  fence  were  available, 
more  species  might  be  collected  in  12  traps 
with  2 m fences  than  in  four  traps  with  6 m 
fences.  This  finding  is  in  conflict  with  Bury 
and  Corn’s  (1987)  statement  that  “ultimately, 
the  total  amount  of  fence  in  a [forest]  stand  is 
probably  more  important  than  individual 
lengths.”  It  is  important  to  note,  however,  that 
in  our  study  the  best  trap  diameter/fence 
length  combination  often  varied  with  the  ef- 
ficiency criterion  used.  For  handling  time, 
1 L 1 cm  trap  with  a 4 rn  fence  were  best.  That 
said,  uefeeced  traps  often  were  very  similar 
in  efficiency  to  fenced  traps.  This  suggests 
that  at  our  study  site  during  our  sampling  pe- 
riod, when  pitfall  trapping  with  11.1  cm  traps, 
fieldworkers  would  be  equally  justified  dig- 
ging in  just  six  traps  with  a 2 m fence  or  14 
unfeeced  traps.  Given  this  choice,  we  would 
much  prefer  to  dig  in  many  unfeiiced  traps  for 
the  following  reasons.  Firstly,  although  dura- 
tion of  the  tasks  is  similar,  digging  in  many 
uefeeced  traps  requires  much  less  strenuous 
physical  effort.  Secondly,  digging  in  fences 
causes  considerably  more  physical  distur- 
bance aed  alteration  of  habitat  surrounding  the 
trap.  Thirdly,  w^e  suspect  uefericed  traps  re- 
quire less  maintenance.  As  part  of  a two-year 
monitoring  program  of  jarrah  forest  spiders, 
we  have  sampled  at  three  monthly  intervals 
using  fenced  aed  unfeeced  traps.  Fences  have 


needed  repairing  constantly  owing  to  distur- 
bance by  kangaroos  and  feral  pigs.  Branches 
and  twigs  falling  on  fences  also  have  in- 
creased the  time  required  to  maintain  fenced 
traps  in  good  condition.  Fourthly,  fences  may 
potentially  bias  captures  by  hindering  loco- 
motion or  changing  microhabitats  as  litter  and 
debris  accumulates  against  them  more  rapidly 
than  other  areas  surrounding  the  trap.  Conse- 
quently, using  drift-fences  over  many  years 
may  allow  microhabitats  surrounding  traps  to 
change  more  rapidly  than  traps  without  fenc- 
es. For  our  monitoring  program,  any  litter  than 
had  built  up  against  fences  was  redistributed 
a week  prior  to  opening  the  traps.  Finally, 
fences  have  the  potential  to  inhibit  perception 
of  internal  spatial  heterogeneity  within  spider 
communities  v/ithin  a study  site.  Consolidat- 
ing individuals  from  a wider  spatial  area  into 
a single  fenced  trap  removes  patchiness  in  the 
occurrence  of  individuals  that  would  be  evi- 
dent in  multiple  uefenced  traps. 

Could  other  fence  designs  be  more  effi- 
cieet?=The  fenced  traps  we  used  were  single 
pitfall  traps  placed  in  the  middle  of  a straight 
fence.  However,  other  fence  designs  exist.  The 
main  variations  are  multiple  fences  per  trap  or 
multiple  traps  per  fence.  In  the  former,  a com- 
mon design  is  to  erect  a second  fence  perpen- 
dicular to  the  first,  so  that  the  two  fences  form 
a cross  with  the  pitfall  trap  in  the  centre.  Mor- 
rill et  al,  (1990)  found  adding  a second  fence 
yielded  higher  captures  only  for  one  beetle 
species.  Morton  et  al,  (1988)  suspected  that 
adding  a second  fence  was  beneficial  to  in- 
crease reptile  catch,  but  their  results  were  in- 
conclusive, Hobbs  et  al.  (1994)  showed  un- 
equivocally that  adding  a second  fence  did  not 
increase  reptile  captures,  despite  the  extra  la- 
bor aed  length  of  fencing  involved.  That  said, 
the  latter  two  studies  used  multiple  traps  along 
one  or  both  fences. 

With  respect  to  multiple  traps  per  fence  de- 
signs, perhaps  the  most  common  is  a straight 
row  of  three  or  more  pitfall  traps  connected 
by  a single  straight  fence.  The  success  of  this 
design  in  relation  to  multiple  unfenced  traps 
for  spiders  has  been  demonstrated  by  Chur- 
chill (uepub.  data)  aed  was  discussed  previ- 
ously. How  this  trap  design  compares  to  the 
simple  fenced  trap  we  used  is  unknown.  For 
small  mammals,  amphibians  and  reptiles, 
however,  Friend  et  al.  (1989)  found  indepen- 
dent traps  collected  more  animals  than  a mul- 


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THE  JOURNAL  OF  ARACHNOLOGY 


Table  9. — Mean  (±  S.E.)  time  periods  (minutes: seconds)  taken  to  perform  various  pitfall  trapping 
activities  for  different  combinations  of  fence  length/trap  size. 


Activity 

4.3 

0 

7.0 

Trap/fence  combination 
Fence  length  (m) 

Trap  diameter  (cm) 

11.1  4.3 

2 

7.0 

1 

1.1 

Digging  in  traps/ 

fences 

0:40  ± 0:02 

0:40  ± 0:01 

0:44  ± 0:01 

3:01  ± 0:07 

3:16  ± 0:07 

3:11 

± 0:11 

Pouring  solution 

into  traps 

0:10  ± 0:00 

0:11  ± 0:00 

0:14  ± 0:00 

0:10  ± 0:00 

0:11  ± 0:00 

0:14 

± 0:00 

Set  traps 

0:20  ± 0:00 

0:20  ± 0:00 

0:20  ± 0:00 

0:25  ± 0:00 

0:25  ± 0:00 

0:25 

± 0:00 

Collecting  traps 

0:25  ± 0:00 

0:25  ± 0:00 

0:25  ± 0:00 

0:25  ± 0:00 

0:25  ± 0:00 

0:25 

± 0:00 

Total 

1:35  ± 0:02 

1:35  ± 0:01 

1:43  ± 0:01 

4:01  ± 0:07 

4:17  ± 0:07 

4:15 

± 0:11 

tiple  traps  per  fence  design.  They  attributed 
this  to,  firstly,  independent  traps  sampling  a 
wider  range  of  microhabitats  and  home  rang- 
es. Secondly,  animals  altering  their  daily 
movement  patterns  to  avoid  the  fence  during 
periods  when  traps  were  closed.  Consequent- 
ly, when  traps  were  opened,  they  were  less 
susceptible  to  capture.  Another  permutation  of 
the  multiple  traps  per  fence  design  is  two  traps 
at  either  end  of  a fence.  Friend  (1984)  tested 
this  design  against  a fenced  trap  with  a single 
pit  (of  a different  size)  that  herpetofauna  could 
approach  only  from  one  side.  Consequently, 
there  are  confounding  effects  and  we  await  a 
more  rigorous  test.  Theoretically,  however, 
traps  placed  at  either  end  of  fences  may  be 
more  efficient.  There  is  twice  the  probability 
that  an  animal  encountering  the  fence  will  turn 
and  move  towards  a trap,  yet  the  most  time 
consuming  component  of  sampling  (digging 
in  the  fence)  remains  constant.  This  assumes 
that  for  an  animal  encountering  a fence,  the 
probability  of  not  turning  away  before  reach- 
ing the  end  of  the  fence,  is  equal  between 
fencing  types.  For  longer  fences,  the  proba- 
bility of  following  to  the  fence’s  end  may  de- 
cline and  thereby  the  greater  efficiency  of  the 
two-trap  fence  over  the  single-trap  fence. 

Different  fencing  materials  may  also  influ- 
ence efficiency.  To  date,  fences  have  been 
constructed  of  plastic,  metal  roofing  and  flys- 
creee.  Consequently,  considerable  variation 
may  be  expected  in  cost,  longevity,  and  time 
to  construct,  install  plus  maintain  fences.  All 
may  influence  handling  time  efficiency,  par- 
ticularly where  regular  trapping  is  undertaken 
or  if  long  periods  elapse  between  trapping. 


Here  we  used  black  plastic,  purchased  cheaply 
from  a hardware  store  on  a roll.  Although 
metal  roofing  was  readily  available,  it  costs 
more  per  meter,  cannot  be  cut  to  size  easily, 
and  is  bulky  to  transport.  Disadvantages  may 
be  outweighed,  however,  if  metal  fences  last 
longer,  require  less  maintenance  or  facilitate 
greater  captures.  The  performance  of  different 
fence  materials  should  thus  be  investigated. 
When  doing  so  we  advocate  assessing  perfor- 
mance by  a number  of  criteria,  of  which  one 
should  be  maintenance/handling  time. 

Differences  in  fencing  efficiency  may  vary 
also  between  different  grades  of  plastics.  In 
the  monitoring  program  mentioned  previously 
we  have  used  both  100  um  and  200  pm  thick 
plastic.  Longevity  between  thickness  grades 
varies  considerably.  Thicker  fences  deteriorat- 
ed approximately  twice  as  rapidly  as  thinner 
fences.  Thicker  fences  began  to  become  brittle 
and  pieces  of  fence  flaked  off  with  exposure 
to  sunlight  nine  months  after  installation.  Con- 
versely, at  the  end  of  the  monitoring  program, 
most  thinner  fences  did  not  need  replacing. 
This  is  not  to  suggest  that  thinner  fences  did 
not  require  regular  maintenance.  We  estimate 
that  over  the  course  of  monitoring  program, 
even  where  thin  fences  were  initially  installed, 
half  the  fences  were  reinstalled. 

Future  directions«-=“The  results  presented 
here  show  clearly  that  both  trap  size  and  fence 
length  can  play  critical  roles  in  determining 
spider  catch  in  terms  of  abundance,  species 
richness  and  community  composition.  As  such 
comparisons  to  date  between  regions,  time  pe- 
riods or  studies  where  pitfall  trapping  proto- 
cols have  differed  are  tenuous.  Future  devel- 


BRENNAN  ET  AL.-™-DRIFT=FENCE  LENGTH  AND  PITFALL  TRAP  SIZE 


699 


Table  9.“— Extended. 


Trap/fence  combination 
Fence  length  (m) 

4 6 

Trap  diameter  (cm) 


4.3 

7.0 

” 11.1 

4.3 

7.0 

11.1 

5:34  ± 0:14 

5:17  ± 0:17 

5:26  ± 0:10 

8:42  ± 0:14 

8:35  ± 0:16 

8:35  ± 0:17 

0:10  ± 0:00 

0:11  ± 0:00 

0:14  ± 0:00 

0:10  ± 0:00 

0:11  ± 0:00 

0:14  ± 0:00 

0:27  ± 0:00 

0:27  ± 0:00 

0:27  ± 0:00 

0:29  ± 0:01 

0:29  ± 0:00 

0:29  ± 0:00 

0:25  ± 0:00 

0:25  ± 0:00 

0:25  ± 0:00 

0:25  ± 0:00 

0:25  ± 0:00 

0:25  ± 0:00 

6:37  ± 0:14 

6:19  ± 0:17 

6:32  ± 0:10 

9:46  ± 0:15 

9:40  ± 0:16 

9:43  ± 0:17 

opmeets  in  statistical  analysis  may  assist  in 
negotiating  some  of  the  current  plethora  of  bi- 
ases and  limits  to  data  interpretation  where 
protocols  have  differed.  A more  direct  and  po- 
tentially superior  line  of  research,  however,  is 
the  development  of  standardized  sampling 
protocols  for  spiders.  The  limited  resources 
available  to  inventory  biodiversity  require  that 
standardized  sampling  protocols  be  highly  ef- 
ficient. Before  adopting  a standardized  pitfall 
trapping  protocol  for  spiders  it  must  be  firmly 
established  that  the  protocol  is  more  efficient 
than  others  in  a wide  variety  of  habitat  types, 
and  across  differing  temporal  and  spatial 
scales.  Currently  the  data  necessary  for  an  in- 
formed decision  as  to  what  size,  preserving 
solution,  spatial  arrangement,  and  duration  of 
sampling  etc.  to  adopt  for  spiders  is  lacking. 
The  results  presented  here  are  an  important 
step  toward  identifying  the  most  efficient  pro- 
tocols for  trap  size  and  fencing.  Nonetheless, 
studies  with  sufficient  statistical  power  to  de- 
termine the  interplay  of  these  and  other  factors 
in  combination  remain  scarce.  The  elucidation 
of  factors  influencing  pitfall  trap  efficiency 
represents  a priority  area  for  research  and  the 
development  of  a standardized  pitfall  trapping 
protocol  a key  conservation  goal  for  arach- 
eologists. 

ACKNOWLEDGMENTS 

Financial  support  for  this  research  was 
kindly  provided  by  Alcoa  World  Alumina 
Australia,  the  Minerals  and  Energy  Research 
Institute  of  Western  Australia  (MERIWA), 
and  the  Department  of  Environmental  Biology 
at  Curtin  University  of  Technology.  For  field- 


work and  laboratory  assistance  we  thank 
Nicholas  Reygaert.  For  assistance  in  identi- 
fying specimens,  we  thank  Mark  Harvey  and 
Juliaeee  Waldock  (Western  Australian  Muse- 
um), Barbara  Main  (University  of  Western 
Australia),  plus  Robert  Raven  and  Barbara 
Baehr  (Queensland  Museum).  Tracey  Chur- 
chill kindly  permitted  us  to  cite  her  unpub- 
lished data.  Tracey  Churchill,  Mark  Harvey, 
Elisha  Ladhams,  Owen  Nichols,  Erich  Vol- 
scheek  and  Julianne  Waldock,  provided  useful 
discussions  on  many  aspects  of  sampling  with 
pitfall  traps.  For  constructive  criticisms  that 
improved  the  manuscript  we  thank  Thomas 
Crist,  Paula  Cushing,  Robert  Dunn,  Maggie 
Hodge  and  an  anonymous  reviewer.  This  re- 
search was  conducted  whilst  KECB  was  sup- 
ported by  an  Australian  Postgraduate  Award 
and  a MERIWA  student  scholarship.  Access 
to  the  study  site  was  provided  by  Alcoa  World 
Alumina  Australia,  the  Western  Australian 
Department  of  Conservation  and  Land  Man- 
agement, and  the  Western  Australian  Water 
Corporation. 

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Manuscript  received  13  December  2001,  revised  19 
February  2004. 


2005.  The  Journal  of  Arachnology  33:703-710 


MALE  RESIDENCY  AND  MATING  PATTERNS  IN  A 
SUBSOCIAL  SPIDER 


Barrett  A.  Klein ^ Todd  C.  Bukowski^,  and  Leticia  Aviles^  ^:  ^ Department  of 

Entomology,  Forbes  Building,  Room  410,  University  of  Arizona,  Tucson,  AZ  85721 
USA.  E-mail:  pupating@maiLutexas.edu;;  ^Department  of  Ecology  and  Evolutionary 
Biology,  Biological  Science  West,  University  of  Arizona,  Tucson,  Arizona  85721 
USA;  ^Department  of  Zoology,  University  of  British  Columbia,  Vancouver,  BC, 

V6T  1Z4  Canada 

ABSTRACT.  Male  mating  strategies  are  often  deployed  with  regard  to  female  maturity  and  receptivity, 
possibly  in  response  to  sperm  utilization  patterns  on  the  part  of  the  female.  We  examined  the  pattern  of 
male  residency  with  females  during  the  mating  period  of  the  subsocial  spider  Anelosimus  cf.  jucundus 
(Araneae,  Theridiidae).  We  first  examined  patterns  of  male  cohabitation  with  naturally  occurring  penul- 
timate instar  and  adult  females  in  the  field.  Males  were  significantly  more  likely  to  be  found  in  association 
with  adult  females,  rather  than  with  penultimate  instar  females.  Penultimate  instar  and  virgin  adult  females 
of  known  age  were  then  placed  into  the  field  and  monitored  for  residency  by  subsequently  marked  males. 
Males  were,  again,  significantly  more  likely  to  be  found  in  association  with  adult  females,  rather  than 
with  penultimate-instar  females,  although  we  were  unable  to  determine  if  this  pattern  was  due  to  differ- 
ential arrival  or  to  differential  retention  of  males  at  adult  female  web  sites.  Aspects  of  A.  cf,  jucundus 
natural  history,  including  duration  of  male  residency  and  frequency  of  mating  in  the  field,  are  provided 
for  the  first  time.  We  discuss  the  patterns  of  male  residency  in  relation  to  predictions  based  on  sperm 
utilization  patterns  by  female  A,  cf.  jucundus  spiders. 

Keywords:  Anelosimus,  female  maturity,  male  cohabitation,  residency,  sperm  utilization 


Male  reproductive  success  is  largely  deter- 
mined by  the  number  of  mates  males  are  able 
to  access  (Bateman  1948;  Jones,  et  al.  2000). 
In  spiders,  where  males  tend  to  move  around 
in  search  of  females,  a male’s  mating  success 
will  depend  on  his  ability  to  locate  females  of 
the  appropriate  age  and  reproductive  status 
and  to  assess  potential  paternity  success  once 
a female  has  been  located.  When  females  mate 
multiple  times,  sperm  priority  patterns  should 
influence  male  reproductive  strategies  (Austad 
1984;  Eberhard  et  al.  1993).  When  paternity 
is  biased  towards  the  first  male  to  mate,  males 
should  seek  out  and  guard  females  who  are 
approaching  the  final  molt  (Jackson  1980; 
Christenson  & Goist  1979;  Austad  1982;  Toft 
1989;  Watson  1990;  Dodson  & Beck  1993; 
Eberhard  et  al.  1993;  Bukowski  & Christen- 
son 1997;  Bukowski  et  al.  2001;  but  see  Mas- 
umoto  1991).  In  contrast,  males  should  seek 

Current  address:  Dept,  of  Ecology,  Evolution  and 
Behavior,  Section  of  Integrative  Biology,  Univ.  of 
Texas  at  Austin,  Austin,  TX  78712. 


out  already  mature  females  when  paternity  is 
not  biased  with  respect  to  male  mating  order 
(Eberhard  et  al.  1993;  Schneider  1997)  or 
when  paternity  is  biased  towards  the  last  male 
to  mate  (Uhl  1998;  West  & Toft  1999).  In  the 
latter  case,  post-copulatory  guarding  of  fe- 
males is  expected.  We  examined  male  mate- 
finding and  residency  patterns  in  relation  to 
female  maturity  in  Anelosimus  cf.  jucundus,  a 
subsociai  spider  species  in  which,  for  reasons 
we  discuss  below,  we  suspected  sperm  utili- 
zation patterns  to  be  unbiased  with  respect  to 
male  mating  order. 

Anelosimus  cf.  jucundus,  a species  to  be  de- 
scribed shortly  (I.  Agnarsson  in  press),  is  rel- 
atively common  in  riparian  regions  of  south- 
ern Arizona.  Following  a period  of  maternal 
care,  A.  cf.  jucundus  siblings  remain  together 
in  their  natal  nest  until  close  to  sexual  matu- 
ration, communally  capturing  and  feeding  on 
prey.  All  clutchmates  eventually  disperse  and 
establish  individual  webs  at  relatively  short 
distances  from  the  natal  nest  (5  cm“-5  m,  me- 
dian ^ 46  cm;  Powers  & Aviles  2003).  Dis- 


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persal  typically  occurs  during  the  ante-penuL 
timate  and  penultimate  stadia  (Aviles  & 
Gelsey  1998).  Following  dispersal,  males  and 
females  mature  in  their  individual  webs.  AL 
though  both  sexes  mature  during  the  same  sta- 
dium  (Aviles  & Gelsey  1998),  males  do  so  on 
average  nine  days  earlier  than  their  sibling  fe- 
males (Bukowski  & Aviles  2002).  After  mat- 
uration, females  typically  remain  in  the  webs 
where  they  matured  while  males  set  out  in 
search  of  females.  While  the  sex  ratio  in  nests 
prior  to  dispersal  is  even,  postdispersal  sex  ra- 
tios are  significantly  female-biased  (Aviles  & 
Gelsey  1998). 

The  patterns  of  sexual  receptivity  in  A.  cf. 
jucundus  differ  for  males  and  females.  Males 
become  sexually  active  within  approximately 
two  days  following  their  final  molt,  while  fe- 
males become  sexually  receptive  an  average 
of  ten  days  following  their  final  molt  (Bu- 
kowski & Aviles  2002).  The  probability  of  a 
male  courting  a female  appears  to  increase  as 
the  female  gets  older  (Bukowski  & Aviles 
2002). 

Females  readily  remate  under  laboratory 
conditions  and  males  do  not  release  signifi- 
cantly different  numbers  of  sperm  to  virgin 
and  non-virgin  females  (Bukowski  & Aviles, 
unpub.  data,  using  methods  of  Bukowski  et  al. 
2001  to  quantify  sperm).  Given  that  paternity 
patterns  in  spiders  largely  reflect  the  numbers 
of  sperm  released  (Christenson  1990;  Bu- 
kowski & Christenson  1997;  Schneider  et  al. 
2000;  Elgar  et  al.  2000;  Bukowski  et  al. 
2001),  we  predict  that  A.  cf.  jucundus  will 
have  a paternity  pattern  that  is  unbiased  with 
respect  to  male  mating  order.  In  such  a case, 
males  should  preferentially  seek  out  adult 
rather  than  subadult  females.  Here  we  exper- 
imentally examine  this  prediction  and  present 
the  first  natural  history  data  on  mating  fre- 
quency under  field  conditions  in  this  spider 
species. 

METHODS 

We  conducted  our  studies  in  Garden  Can- 
yon, a riparian  area  in  the  Huachuca  Moun- 
tains of  southeastern  Arizona  (31.51°N, 
110.31°W;  1600-2000  m).  Anelosimus  cf.  ju- 
cundus primarily  inhabit  juniper  trees  along- 
side permanent  streams  in  this  area  (Fig.  1). 
Our  study  involved  an  early  phase,  in  which 
we  censused  naturally  occurring  webs  for  pat- 
terns of  male/female  cohabitation,  and  a later. 


experimental  phase,  in  which  we  examined 
male  residency  patterns  in  artificially-estab- 
lished subadult  and  adult  females’  webs. 

Early  census  of  naturally-occurring 
webs. — On  14  and  24  June  2000,  we  exam- 
ined naturally  occurring,  active,  post-natal  dis- 
persal webs  {n  ~ 293)  for  the  presence  of  sub- 
adult and  adult  males  and  females.  We 
identified  new,  active  webs  containing  dis- 
persed individuals  by  the  relative  lack  of  de- 
bris, smaller  size,  and  presence  of  recently 
maintained  capture  threads.  We  recorded  the 
instar  (immature  versus  adult)  and  sexes  of  all 
animals  in  each  web. 

Artificially-established  webs. — On  8 and 
13  July  2000,  we  returned  to  their  collection 
site  27  penultimate-instar  females  and  54 
adult  females  that  had  been  individually  raised 
in  the  laboratory.  These  spiders  had  been  col- 
lected as  penultimate-instar  females  one  to 
two  weeks  earlier,  held  individually  in  125  ml 
or  30  ml  plastic  containers,  and  fed  ad  libitum 
on  house  flies  {Musca  domestica),  walnut  flies 
(Rhagoletis  juglandis),  and  fruit  flies  {Dro- 
sophila melanogaster). 

The  spiders  were  returned  to  a large  patch 
of  naturally  occurring  A.  cf.  jucundus  webs  to 
ensure  the  presence  of  naturally  occurring 
males.  We  placed  individual  females  in  open 
125  ml  containers,  which  we  attached  to 
branches  of  juniper  trees.  We  covered  each 
branch  with  a fine  nylon  mesh  net  to  encour- 
age web-construction  at  the  selected  site  and 
prevent  males  or  predators  from  visiting  until 
initiation  of  the  observation  period  (Fig.  2). 
When  the  nets  were  removed  48  hours  later, 
females  had  usually  expanded  their  webs  from 
the  containers  to  the  surrounding  vegetation, 

Web  sites  (defined  here  as  the  area  within 
approximately  ten  centimeters  of  the  female’s 
web)  were  censused  every  1~2  hours  over  a 
24  hour  period,  every  other  day.  Females  re- 
turned to  the  field  on  8 July  were  censused 
over  a period  of  seven  days,  and  females  re- 
turned to  the  field  on  13  July  were  censused 
over  a period  of  three  days.  During  each  cen- 
sus, females  were  recorded  as  present  or  ab- 
sent and  the  occurrence  of  mating  and  male- 
male  physical  contact  was  monitored. 

We  individually  marked  all  males  that  ap- 
peared at  a female’s  web  site  {n  = 76)  with 
water-based  acrylic  paints  so  that  we  could 
determine  their  duration  of  residency,  occur- 
rences of  mating  and  relocation  distances. 


KLEIN  ET  AL.— MALE  RESIDENCY  AND  MAl'lNG  IN  ANELOSJMUS  705 


Figure  1 . — Juniper  trees  in  the  Huachuca  Mountains  of  Arizona,  where  we  artificially  established  webs 
of  female  A.  cf . jucund us  spiders  in  a community  of  naturally-occurring  conspecifics. 

Figure  2. — Artificially-established  female  web  site,  temporarily  surrounded  by  netting  to  deter  predation 
or  escape  as  she  expanded  her  web  beyond  the  cup  (labeled  “2”  and  attached  to  a juniper  branch). 

Figure  3. — Copulation  (male  on  left,  female  on  right). 

Figure  4. — Following  an  extended  bout  of  male-male  aggression,  this  male  had  tumbled  below  its 
combatant,  who  proceeded  to  court  and  mate  with  the  resident  female. 


First,  each  unmarked  male  was  removed  from 
a female’s  web  site  immediately  upon  detec- 
tion or  following  copulation.  Each  male  was 
uniquely  marked  by  gently  guiding  him  into 
a piece  of  mesh  netting  and  dabbing  acrylic 
paint  onto  his  opisthosoma.  Following  mark- 
ing, the  male  was  returned  to  his  place  of  re- 
moval. Most  males  remained  without  obvious 
behavioral  long  term  effects,  although  six  (of 
82)  males  were  dropped  and  lost,  and  two 
males  were  being  consumed  by  female  resi- 
dents during  the  census  following  each  male’s 
marking. 

Matings  were  defined  as  pairs  in  copula 
with  at  least  one  male  pedipalp  inserted  in  the 
female.  Anelosimus  cf.  juciindus  males  typi- 
cally have  one  insertion  with  each  palp  during 


mating.  Matings  typically  last  approximately 
135  minutes  per  pedipalp,  with  an  interim  of 
35  minutes  between  pedipalps  (Bukowski  & 
Aviles  unpub.  data).  Matings,  in  light  of  their 
lengthy  durations,  were  unlikely  to  have  been 
undetected  during  a day  of  censusing  with  1- 
2 hour  inter-census  periods. 

Statistical  analyses. — For  all  maturity 
analyses,  each  female  was  classified  as  pen- 
ultimate instar  or  adult.  If  seen  at  a web  site 
during  consecutive  census  periods,  a spider 
was  assumed  to  have  remained  for  the  dura- 
tion between  observations.  If  observed  only 
during  a single  census  period,  a spider  was 
considered  to  have  remained  for  one  hour  (for 
duration  study  purposes).  Each  adult  female 
web  site  {n  ~ 54)  was  checked  an  average  of 


706 


THE  JOURNAL  OF  ARACHNOLOGY 


Female  maturity 


Figure  5. — Male  residency  in  relation  to  female 
maturity  in  naturally-occurring  webs.  Number  of 
males  residing  in  each  web  (zero,  one,  two,  or  three 
males)  is  plotted  against  the  number  of  naturally- 
occurring  female  webs  with  respect  to  female  ma- 
turity. These  data  are  the  result  of  an  early  field 
survey. 

30  times  and  each  penultimate-instar  female 
web  site  {n  — 21)  was  checked  an  average  of 
27  times.  The  proportion  of  observations  that 
a female’s  web  site  was  visited  by  a male  and 
the  number  of  different  males  involved  was 
recorded  for  each  female.  Each  female  then 
served  as  a single  observational  unit  for  the 
puipose  of  analyses.  All  analyses  used  data 
from  the  entire  study  period,  except  for  the 
duration  of  male-female  encounters  and  mat- 
ing analyses,  which  used  data  collected  after 
the  first  day  (when  male  marking  began).  Ex- 
cept where  noted,  only  data  concerning  pre- 
sent and  live  spiders  were  analyzed. 

Data  from  the  two  sets  of  animals  (those 
placed  into  the  field  on  8 and  13  July)  were 
combined  when  they  exhibited  no  significant 
differences.  Percentage  data  were  arcsine 
square  root  transformed  prior  to  analysis.  Du- 
ration data,  which  were  non-normally  distrib- 
uted, were  analyzed  using  nonparametric  tests. 
Summary  statistics  of  continuous  variables  are 
reported  as  X ± standard  error  (SE).  Alpha 
was  set  at  0.05  for  all  tests  and  all  tests  are 
two-tailed.  Data  were  analyzed  with  the  JMP 
IN  (version  4.0.3;  SAS  Institute  Inc.  2001) 
computer  package,  or,  in  the  case  of  rates  of 
male  arrival,  with  Systat  (Systat  Software, 
Inc.). 

RESULTS 

Male  residency  in  relation  to  female  ma- 
turity: naturally-occurring  webs. — Male  co- 


habitation with  immature  females  was  rarely 
observed  in  naturally-occurring  A.  cf.  jucun- 
dus  webs  during  our  early  census.  The  webs 
of  adult  females  were  far  more  likely  to  con- 
tain an  adult  male  (42  of  107  females,  39.3%) 
than  were  the  webs  of  penultimate-instar  fe- 
males (5  of  93  females,  5.4%;  - 35.79,  P 

< 0.0001).  Of  those  webs  that  contained 
males,  most  adult  females  {n  = 39)  and  all 
five  penultimate-instar  females  each  contained 
a single  male.  Two  of  the  adult  females  each 
cohabited  with  two  males,  and  the  web  of  one 
adult  female  contained  three  male  visitors 
(Fig.  5).  Since  we  were  interested  in  male  res- 
idency with  females  and  female-female  resi- 
dency was  rare,  four  webs  that  each  contained 
two  adult  females  and  two  webs  that  each 
contained  two  penultimate-instar  females 
were  excluded  from  the  previous  analysis. 

All  penultimate-instar  males  were  found  as 
solitary  individuals  {n  = 48).  In  contrast,  at 
least  as  many  adult  males  were  found  with  a 
female  {n  = 46)  as  without  {n  — 38).  In  one 
additional  case,  three  adult  males  were  found 
together  in  one  web  without  a female. 

Male  residency  in  relation  to  female  ma- 
turity: artificially-established  webs. — Of  the 
females  placed  into  the  field,  many  (47  of  81, 
58.0%)  disappeared  from  their  web  sites  be- 
fore the  study  ended.  The  web  sites  of  adult 
females  were,  again,  far  more  likely  to  contain 
an  adult  male  than  were  the  web  sites  of  pen- 
ultimate-instar females  (27.9  ± 4.3%  versus 
2.4  ± 6.1%  of  the  observations  per  female;  n 
= 36  and  18  females,  respectively;  t^2  ~ 3.41, 
P = 0.0013;  Fig.  6).  Adult  females  also  had 
a greater  number  of  male  cohabitants  per  hour 
(0.37  ± 0.06)  than  did  penultimate-instar  fe- 
males (0.03  ± 0.08;  ^52  = 3.28,  P = 0.0019; 
n = 36  and  18  females,  respectively;  Fig.  7). 
All  but  five  (of  54)  male  visitations  were  by 
new,  unmarked  males.  The  five  exceptions  in- 
cluded one  male  who  returned  to  the  same  fe- 
male after  a 37  hour  absence,  two  males  who 
each  traveled  to  a second  female,  and  one 
male  who  traveled  to  three  different  females. 

Although  males  appeared  to  arrive  to  adult 
female  web  sites  at  twice  the  rate  than  to  sub- 
adult female  web  sites  (to  33  out  of  1 18  avail- 
able adult  females,  or  28%,  versus  6 out  of  43 
available  subadult  females,  or  14%),  this  dif- 
ference was  not  statistically  significant  with 
our  sample  size  (Mantel-Haenzel  — 2.37,  P 
— 0.12,  for  the  comparison  of  numbers  of  new 


KLEIN  ET  AL.— MALE  RESIDENCY  AND  MATING  IN  ANELOSIMUS 


707 


6 


penultimate-instar  adult 


Female  maturity 


Figure  6. — Male  residency  in  relation  to  female 
maturity  in  artificially=established  webs:  percent  of 

field  observations  in  which  at  least  one  male  was 

present  (±  SE). 

Figure  7. — Male  residency  in  relation  to  female 
maturity  in  artificially-established  webs:  mean  num- 
ber of  male  residents  per  hour  (±  SE). 


males  arriving  per  total  females  available  at 
each  of  18  different  census  periods).  Males 
also  tended  to  stay  longer  at  adult  female  web 
sites  (see  next  section),  but  this  effect  ap- 
peared to  reflect  whether  copulation  occurred 
or  not,  rather  than  female  age  per  se. 

Duration  of  male  residency. — Because  of 
the  periods  between  census  days  during  which 
the  nests  were  not  monitored,  we  can  only 
provide  estimates  of  the  minimum  and  maxi- 
mum possible  male  residence  times.  In  cases 
where  male  residence  periods  had  either  al- 
ready been  initiated  when  observations  had 
started  or  had  not  yet  concluded  when  obser- 
vations ended,  we  have  taken  the  period  ac- 
tually observed  as  the  minimum  male  resi- 
dence time.  This  period  plus  the  unobserved 


period  either  before  or  after  the  start  of  a cen- 
sus day,  as  appropriate  to  the  case,  gives  us  a 
maximum  possible  residence  time.  Given 
these  considerations,  the  median  male  resi- 
dence time  we  observed  was  bracketed  be- 
tween a minimum  of  five  and  a maximum  of 
1 1 hours. 

Based  on  our  minimun  male  residence  es- 
timates (period  actually  observed),  males 
spent  more  time  per  visit  with  adult  females 
with  whom  they  mated  than  with  any  other 
females  (median  = 18.5  hours,  versus  5 hours 
for  adults  not  observed  to  mate,  and  3 hours 
for  penultimate-instar  females;  n = 10,  37, 
and  6 visits,  respectively;  ^ 12.1,  2 df,  P 
= 0.002;  Fig.  8).  Post-copulatory  periods 
ranged  from  three  to  33  hours  (ji  = 10),  with 
seven  cases  lasting  seven  hours  or  less.  If 
three  cases  in  which  the  period  had  not  yet 
concluded  when  observations  ended  are  in- 
cluded, a floor  for  the  median  post-copulatory 
period  is  estimated  at  six  hours. 

In  a few  instances,  more  than  one  male 
could  be  observed  at  a female’s  web  site  (Ta- 
ble 1).  Cohabiting  males  engaged  in  agonistic 
interactions,  including  foreleg  tapping  and 
locking  of  chelicerae  and  legs  {n  = three  pairs 
of  males  in  the  presence  of  three  different  fe- 
males). One  battle  sent  a male  tumbling  and 
appearing  temporarily  dead  (Fig.  4),  while  his 
combatant  copulated  with  the  resident  female 
(Fig.  3).  Male-induced  coitus  interruptus,  re- 
sulting in  no  resumption  of  copulation,  was 
also  observed  in  one  case  where  two  males 
were  simultaneously  present  with  a female. 

Mating  frequency. — Nineteen  of  the  36 
adult  females  (52.7%)  were  observed  mating 
with  at  least  one  male  over  the  study  period. 
Eleven  of  these  females  (57.9%)  were  each 
observed  mating  with  a single  male.  The  re- 
maining eight  of  these  females  (42.1%)  were 
each  observed  mating  with  two  males.  The  av- 
erage number  of  males  a female  copulated 
with  over  the  active  observation  period  (an 
average  of  38.8  observation-hours  per  female) 
was  therefore  0.75,  which  corresponds  to  0.47 
males  per  female  per  day,  if  we  assume  a sim- 
ilar mating  rate  during  non-observed  periods, 
or,  more  conservatively,  0.22  males  per  fe- 
male per  day  if  we  assume  that  all  matings 
were  observed  during  the  recorded  period  of 
each  female. 

Some  marked  males  (10  of  76,  13.2%)  were 
observed  at  the  web  sites  of  two  {n  ==  9)  or 


THE  JOURNAL  OF  ARACHNOLOGY 


708 


Female  maturity 


Figure  8. — Estimates  of  the  range  (outermost 
lines  in  each  graph),  25th  and  75th  quantiles  (edge 
of  boxes),  and  medians  (lines  inside  the  boxes)  of 
the  minimum  duration  of  male  residency  (based  on 
period  actually  observed)  with  respect  to  female 
age  and  mating  status.  Males  spent  more  time  per 
visit  with  adult  females  with  whom  they  mated 
(median  = 18.5  hours;  n — 10  visits),  than  with 
adults  with  whom  they  were  not  observed  to  mate 
(median  = 5 hours;  n = 37  visits),  or  with  penul- 
timate-instar females  (median  = 3 hours;  n = 6 
visits). 


three  (n  = 1 ) females.  However,  because 
males  could  not  be  tracked  as  reliably  as  fe- 
males (and  several  of  the  females  were  absent 
or  dead  at  the  time  of  male  visitation),  only 
one  of  these  males  was  actually  observed  to 
mate  more  than  once.  Overall,  ten  of  48 
(20.8%)  visits  by  marked  males  to  adult  fe- 
male web  sites  were  observed  to  result  in  cop- 
ulation (Fig.  8). 

Measurements  of  distances  between  female 
web  sites  that  males  successively  visited 
showed  an  average  travel  distance  of  2.0  ± 
0.4  m (range:  < 1-4  m,  /?  = 11  males)  over 
an  average  of  21.5  ± 4.5  hours  (range:  1 1.5- 
5 1 .0  hours,  n = 11).  Three  of  the  males  each 
traveled  four  meters  in  an  average  32.3  ± 1 1.4 
hours. 

DISCUSSION 

Anelosimus  cf.  jucundiis  males  were  much 
more  likely  to  be  found  on  the  webs  of  adult 
females  than  on  those  of  penultimate-instar  fe- 
males, both  in  a survey  of  free-ranging  spiders 
and  when  females  of  known  age  and  repro- 
ductive history  were  placed  into  the  field. 
Adult  females  also  had  a greater  number  of 
male  residents  per  hour  than  did  penultimate- 
instar  females. 


The  mechanism  responsible  for  these  di- 
vergent residency  patterns  remains  unclear. 
Males  could  preferentially  arrive  at  the  webs 
of  adult  females  or  arrive  equally  at  both  adult 
and  juvenile  female  webs,  but  be  preferential- 
ly retained  by  adult  females.  Our  data  show  a 
nonsignificant  trend  towards  differential  arriv- 
al at  adult  webs  and  significant  retention  when 
copulation  occurs.  Although  a greater  sample 
size  will  be  needed  to  definitely  address  this 
issue,  the  trend  towards  preferential  arrival  at 
adult  female  web  sites  suggests  that  females 
may  be  producing  a distance-acting  signal  or 
cue  guiding  males  to  their  webs.  Distance-act- 
ing pheromones  released  by  females  have 
been  demonstrated  to  attract  males  in  both 
Pardosa  milvina  wolf  spiders  (Searcy  et  al. 
1999)  and  in  Agelenopsis  aperta  desert  spi- 
ders (Papke  et  al.  2001).  If  males  arrive  at  the 
webs  of  adult  and  juveniles  equally,  then  some 
process  associated  with  interaction  with  the 
female  must  influence  duration  of  male  resi- 
dency. 

Nearly  half  of  the  females  observed  mating 
copulated  with  more  than  one  male,  suggest- 
ing that  multiple  mating  by  females  is  com- 
mon in  this  species.  Matings  were  not  pre- 
dictably followed  by  continued  male  residence 
at  the  females’  web  sites  (in  60%  of  the  cases 
the  male  departed  in  six  hours  or  less),  so  pro- 
longed post-copulatory  guarding  appears  to  be 
absent  in  these  spiders.  Male  residency  sub- 
sequent to  copulation  could  simply  involve 
time  spent  by  males  inducting  sperm  into  their 
pedipalps  for  subsequent  matings  or  their  fac- 
ultative use  of  females’  webs  for  food  and 
shelter,  rather  than  a means  of  exploiting  the 
resident  females’  reproductive  biology.  Given 
that  males  differentially  reside  with  adult  fe- 
males, females  multiply  mate,  and  males  do 
not  exhibit  post-copulatory  guarding,  male 
mating  order  may  not  be  an  important  deter- 
minant of  paternity  in  A.  cf.  jucundus. 

At  times,  more  than  one  male  entered  the 
same  adult  female  site.  This  could  result  in 
multiple  matings  by  females  with  different 
resident  males,  or  male-male  aggressive  inter- 
actions, as  described  earlier.  Because  of  the 
scarcity  of  extended  multiple  male  residen- 
cies, aggressive  interactions  may  drive  some 
males  to  search  for  different,  unattended  fe- 
males. 

Many  adult  females  were  observed  mating 
during  the  relatively  short  study  period.  Of 


KLEIN  ET  AL.— MALE  RESIDENCY  AND  MATING  IN  ANELOSIMUS 


709 


Table  1, — Number  and  proportion  of  census  ob- 
servations with  zero,  one,  two,  or  three  males  co- 
habiting with  adult  females  in  their  artificially-es- 
tablished webs.  Multiple  male  residency  at  a given 
female’s  web  was  uncommon.  Calculations  are 
pooled  across  females. 


# males 

# observations 

% observations 

0 

355 

57.1 

1 

211 

> 33.9 

2 

53 

8.5 

3 

3 

0.5 

Total 

622 

100 

those  females,  about  half  were  observed  to 
mate  with  at  least  two  males.  Given  that  fe- 
males become  sexually  receptive  an  average 
of  ten  days  after  the  final  molt  and  cease  sex- 
ual receptivity  after  oviposition  (Bukowski  & 
Aviles  2002),  a total  of  20  days  spans  the  av- 
erage period  of  sexual  receptivity  for  females 
in  this  species.  Assuming  that  a female’s  pro- 
pensity to  mate  does  not  alter  dramatically 
over  the  course  of  these  20  days  and  that  all 
matings  are  considered  to  have  been  observed 
throughout  the  period  of  censusieg,  a female 
may  be  calculated  to  mate  with  an  average  of 
4.4  males  during  her  lifetime  (0.22  males  per 
female  per  day  X 20  days).  This  figure  may 
underestimate  the  number  of  potential  matings 
if  we  assume  that  additional  matings  occurred 
during  the  unobserved  periods.  Alternatively, 
this  figure  may  overestimate  the  number  of 
potential  matings  if  female  receptivity  or  the 
frequency  of  male  visitation  to  females’  web 
sites  diminished  as  the  20-day  female  active 
period  progressed,  although  we  have  no  evi- 
dence negating  or  supporting  either  a dimin- 
ished female  receptivity  or  reduced  male  vis- 
itation over  time.  All  matings  within  census 
days  were  likely  to  have  been  observed  and 
recorded  because  times  between  censuses 
were  shorter  than  the  average  copulation  du- 
ration. Matings  occurring  during  the  much 
longer  period  between  census  days,  on  the 
other  hand,  could  have  been  missed. 

The  male  residency  and  female  mating  pat- 
terns exhibited  by  A.  cf.  jucundus  have  im- 
portant implications  for  the  pattern  of  sperm 
utilization  at  fertilization.  When  the  fertiliza- 
tion pattern  is  biased  towards  first  males, 
males  differentially  cohabit  with  juvenile  fe- 
males approaching  the  final  molt  when  the  fe- 


males first  become  sexually  receptive  (Austad 
1982;  Christenson  & Cohn  1988;  Watson 
1990;  Bukowski  & Christenson  1997;  Bu- 
kowski et  al.  2001).  When  the  fertilization 
pattern  is  biased  towards  last  males,  males 
should  preferentially  seek  out  and  guard  adult 
females  (Uhl  1998;  West  & Toft  1999).  When 
the  sperm  of  two  or  more  males  mix  equally 
within  the  female,  males  should  seek  out  adult 
females  regardless  of  female  age  (Eberhard  et 
ah  1993).  Our  data  suggest  that  A.  cf.  jucun= 
dus  exhibit  either  last  male  precedence  or 
sperm  mixing.  Other  data  on  sperm  release 
patterns  in  this  species,  along  with  no  evi- 
dence of  mate  guarding,  provide  support  for 
sperm  mixing,  since  the  first  and  second  males 
to  mate  with  a female  were  found  to  transfer 
equal  numbers  of  sperm  (Bukowski  & Aviles, 
unpub.  data).  Several  studies  have  shown  that 
when  two  males  mating  with  a female  transfer 
equal  numbers  of  sperm,  the  two  males  typi- 
cally sire  equal  numbers  of  offspring  (Bu- 
kowski & Christenson  1997;  Schneider  et  al. 
2000;  Elgar  et  al.  2000).  If  a male  were  to 
reside  with  a penultimate  instar  female  until 
she  became  sexually  receptive,  he  would  like- 
ly visit  and  mate  with  fewer  females,  siring 
fewer  offspring  than  a male  that  exclusively 
visits  adult  females. 

Understanding  the  role  of  female  maturity, 
mating  receptivity  and  subsequent  sperm  uti- 
lization is  contingent  upon  learning  more 
about  the  natural  history  of  A.  cf.  jucundus 
spiders.  Precisely  determining  male  arrival 
rates  and  residency  durations  relative  to  fe- 
male maturity  could  serve  as  the  next  step  in 
understanding  the  mechanisms  driving  their 
sexual  interactions. 

ACKNOWLEDGMENTS 

We  thank  Sheridan  Stone  and  the  Wildlife 
Management  Office  for  access  to  the  spiders 
of  Garden  Canyon,  and  Natalie  Doerr  and  Ter- 
ry A.  Bukowski  for  helping  with  field  data 
collection.  Asher  Cutter,  Greta  Binford,  Jeff 
Smith,  Eileen  Hebets,  Kim  Powers,  two  anon- 
ymous reviewers  and  the  editors  offered  fruit- 
ful comments  on  drafts  of  this  paper.  Voucher 
specimens  of  both  sexes  reside  within  the  Na- 
tional Museum  of  Natural  History  Spider  Col- 
lection, Washington  D.C.,  USA.  This  research 
was  supported  by  NSF  grant  DEB-9815938  to 
Leticia  Aviles. 


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Manuscript  received  7 October  2003,  revised  30 
June  2004. 


2005.  The  Journal  of  Aracheology  33:711-714 


A REDESCRIPTION  OF  CHRYSSO  NIGRICEPS 
(ARANEAE,  THERIDIIDAE)  WITH 
EVIDENCE  FOR  MATERNAL  CARE 

Jeremy  Miller^’^  and  Ingi  Agearsson^’2,4.  ^Department  of  Entomology,  National 
Museum  of  Natural  History,  NHB=105,  Smithsonian  Institution,  PO  Box  37012, 
Washington,  DC  20013-7012,  U.S.A.;  ^Department  of  Biological  Sciences,  George 
Washington  University,  2023  G Street  NW,  Washington,  D.C.  20052,  USA 

ABSTRACT.  Chrysso  nigriceps  is  redescribed  and  the  male  is  described  for  the  first  time  based  on 
material  from  Colombia.  Evidence  for  maternal  care  of  juveniles  in  Chrysso  is  presented.  This  evidence 
is  consistent  with  predictions  based  on  phylogenetic  analysis  that  maternal  care  is  primitively  present  in 
the  lost  colulus  clade,  the  lineage  containing  all  social  theridiids. 

Keywords:  Chrysso,  evolution  of  sociality,  maternal  care,  taxonomy,  South  America 


Chrysso  nigriceps  (Keyserling  1884)  was 
described  based  on  a female  specimen  from 
Colombia.  In  a revision  of  Chrysso  O.  Pick- 
ard-Cambridge  1882  from  the  Americas,  Levi 
(1957)  redescribed  the  female,  but  to  date  the 
male  remains  mnknown.  Here  we  redescribe  C 
nigriceps  and  provide  a description  of  the 
male.  We  observed  juveniles  of  C.  nigriceps 
cohabitating  in  the  female  web  (Fig.  1),  sug- 
gesting some  degree  of  maternal  care.  Kuetner 
(pers.  comm.)  also  observed  juveniles  in  adult 
webs  of  an  Indonesian  species,  Chrysso  nr.  ar- 
gyrodiformis  (Yaginuma  1952).  To  our  knowl- 
edge, these  observations  represent  the  first  ev- 
idence of  maternal  care  of  juveniles  reported 
in  Chrysso.  Although  preliminary,  our  evi- 
dence for  maternal  care  in  Chrysso  is  consis- 
tent with  Agriarsson’s  (2004)  phylogenetic 
conclusion  that  maternal  care  is  primitively 
present  in  the  subfamily  Theridiinae. 

A growing  body  of  evidence  supports  the 
“maternal  care  route”  hypothesis  to  web  shar- 
ing sociality  (Aviles  1997;  Agnarssoe  2002, 
2004).  It  states  that  social  behavior  evolved 
via  temporal  extension  of  maternal  care  (see 
Kullro.ann  1972;  Aviles  1997  for  reviews). 
Tolerance  among  juveniles  is  maintained  over 
an  increasing  period  of  their  life-span,  cul- 
minating in  permanent  web  sharing  sociality 

^ Current  address:  Department  of  Entomology,  Cal- 
ifornia Academy  of  Science,  875  Howard  Street, 
San  Francisco,  CA  94103,  USA. 

E-mail:  jmiller@Calacademy.org 
Current  address:  Department  of  Botany  and  Zoology, 
The  University  of  British  Columbia,  3529-6270  Uni- 
versity Blvd.,  Vancouver,  BC.  V6T  1Z4,  Canada. 


(quasisociality)  with  extensive  cooperation 
among  adults.  The  optimization  of  maternal 
care  (or  simply  the  brief  coexistence  of  moth- 
er and  young  in  the  web)  on  a phylogenetic 
tree  is  therefore  an  important  step  in  recon- 
structing the  evolutionary  path  from  solitary 
to  social  lifestyle. 

Agnarsson  (2002,  2004)  discussed  the  pro- 
gression from  solitary  lifestyle  to  quasisocial- 
ity in  a phylogenetic  context.  In  his  phytoge- 
ny, maternal  care  optimized  to  the  node 
leading  to  all  instances  of  sociality  {AnelosC 
mus  Simon  1891  plus  Theridiinae,  or  the  “lost 
colulus  clade”,  see  Agnarsson  2004,  fig.  106). 
Based  on  this,  he  predicted  that  maternal  care 
should  be  widespread  within  the  lost  colulus 
clade,  a lineage  containing  hundreds  of  spe- 
cies. However,  Agnarsson  (2004)  pointed  out 
that  the  lack  of  behavioral  data  on  many  key 
taxa  in  the  analysis  limited  the  power  of  this 
argument.  He  noted  that  the  lack  of  evidence 
for  maternal  care  in  many  of  these  species  is 
due  to  a poverty  of  studies  on  lost  colulus 
clade  species  that  might  have  discovered  ma- 
ternal care  in  the  field,  rather  than  failed  at- 
tempts to  document  maternal  care.  Agnars- 
son's  (2004)  phylogeny  of  theridiid  genera 
places  Chrysso  (based  on  an  undescribed  spe- 
cies called  Chrysso  nr.  nigriceps)  in  a key 
phylogenetic  position,  sister  to  the  remaining 
theridiines.  Chrysso  was  scored  as  unknown 
for  maternal  care,  as  were  several  other  basal 
theridiines.  Evidence  for  maternal  care  in 
Chrysso  corroborates  the  hypothesis  that  ma- 
ternal care  is  primitively  present  in  the  lost 
colulus  clade,  and  that  maternal  care  precedes 
sociality  in  evolutionary  time.  Note  that  a mo- 


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lecular  phylogeny  of  theridiids  places  Chrysso 
nr.  nigriceps  in  a clade  with  Helvibis  Keyser- 
ling  1884  and  Theriduia  Emerton  1882,  to- 
gether sister  to  the  remaining  theridiines  (Ar- 
nedo  et  al.  2004).  Maternal  behavior  remains 
to  be  documented  for  Helvibis  and  Theriduia 
and  this  alternative  placement  of  Chiysso  does 
not  alter  the  significance  of  our  finding. 

METHODS 

Illustrations  were  modified  from  digital 
photographs  taken  using  a Nikon  DXM  1200 
digital  camera  mounted  on  a Leica  MZ16  A 
dissecting  microscope.  All  measurements  are 
ill  millimeters  and  were  taken  using  a reticle 
in  a LEICA  MZ  APO  dissecting  microscope. 
For  further  details  on  methods  see  Miller  (in 
press)  and  Agnarsson  (2004).  Material  used  in 
this  study  was  borrowed  from  the  following 
institutions:  The  Natural  History  Museum, 
London  (BMNH),  Museum  of  Comparative 
Zoology,  Harvard  (MCZ),  and  National  Mu- 
seum of  Natural  History,  Smithsonian  Insti- 
tution, Washington,  D.C.  (USNM). 

TAXONOMY 

Family  Theridiidae  Sundevall  1833 
Genus  Cluysso  O.  Pickard-Cambridge  1882 
Chiysso  nigriceps  Keyserling  1884 
Figs.  1-6 

Chrysso  nigriceps  Keyserling  1884:  154,  pL  7,  fig. 
95  [$];  Levi  1957:  65,  figs.  16,  32,  33  [9];  Plat- 
nick  2004.  Holotype  female  from  Bogota,  Co- 
lombia, in  BMNH,  examined. 

Theridion  keyserlingi  Petrunkevitch  1911:  198  (un- 
justified replacement  name  for  C.  nigriceps",  see 
Levi  1957;  Platnick  2004);  Mello-Leitao  1941: 
250;  Roewer  1942:  494. 

Type  material, — Holotype  female:  CO- 
LOMBIA: Cundinainarca:  Bogota,  Keyser- 
ling (BMNH,  BM1890.7.1.8150). 

Other  material  examined, — -COLOMBIA: 
Cundinamarca:  Silvania,  Res.  Agua  Bonita 
(off  Carretera  Sibate — Fusagasuga;  15  km 
from  Sibate),  4°26'N,  74°20'W,  2440-2560  m, 
1 February  1998,  G.  Hormiga  (USNM),  1 $; 
same  data,  J.  Miller  (USNM),  1 $;  La  Calera, 
Cen'o  del  Chocolatero,  ca.  5 km  NE  of  Bogota, 
4°42'N,  73°58'W,  3000-3145  m,  31  January 
1998,  G.  Hormiga,  J.  Miller,  J.  Barriga,  J.C. 
Bello,  A.  Sabagal  (USNM),  1 ? ; Valle  del  Can- 
ca:  Yotoco,  1600  m,  December  1976,  W.  Eber- 
hard  (MCZ,  det.  B.  Opeli),  2 d,  1 9,1  juvenile 
d;  Saladito  above  Cali,  1800  m,  3 January 


1977,  fog  forest,  H.  Levi  (MCZ,  57413),  1 9; 
aniba  de  Saladito,  1800  m (MCZ,  57412),  5 
9,  3 egg  cases;  Saladito,  1800  m,  20  March 
1970  (MCZ,  57417,  det.  Levi),  1 9;  Saladito, 
1800  m [no  date]  (MCZ,  57411),  1 9,  eggs 
and  embryonic  juveniles;  near  Saladito,  12  Oc- 
tober [no  year]  (MCZ,  57418),  4 9,  eggs  and 
embryonic  juveniles;  Cali  [no  date]  (MCZ, 
57414),  1 (5;  near  Pance,  PN.N.  Farallones  de 
Cali,  Res.  Nat.  Hato  Viejo,  3°20'53"N, 
76°40'07"W,  2300  m,  12  February  1998,  G. 
Hormiga  (USNM),  1 S ; Putumayo:  Cauda-Pu- 
tumayo,  road  between  Mocoa  and  Silbundoy, 
ca.  71,500  m [sic],  August  1973,  W.  Eberhard 
(MCZ,  57416,  det.  Levi),  1 9. 

Additional  records, — ECUADOR:  Banor, 
Runtun  Trail,  2000  m,  26  November  1939,  E 
M.  Brown,  1 9 (see  Levi  1957). 

Diagnosis. — Chrysso  nigriceps  differs  from 
most  American  Chrysso  by  the  coloration  of 
the  abdomen,  bright  orange  (light  gray  in  al- 
cohol) with  black  posterior  lobe  (Figs.  1,  2 & 
4).  Females  further  differ  by  the  presence  of 
a trapezoidal  plate  on  the  posterior  margin  of 
the  epigynum  (Fig.  3).  Males  can  be  diag- 
nosed by  the  shape  of  the  median  apophysis 
in  prolateral  view  (Fig.  6). 

Description. — Female  (from  Agua  Bonita, 
Cundinamarca,  Colombia):  Total  length  4.40, 
carapace  length  1.55,  carapace  width  1.29, 
sternum  length  0.88,  sternum  width  0.87.  Car- 
apace dusky  orange,  darker  around  eyes.  Ster- 
num orange.  Chelicerae  orange  with  two  pro- 
marginal teeth.  Palpi  dusky  orange;  palpal 
tibia  with  one  prolateral,  one  retrolateral  tri- 
chobothrium.  Coxae,  trochanters,  and  basal 
half  of  femora  orange;  distal  half  of  femora 
and  distal  leg  segments  dusky  orange.  Leg  I: 
femur  2.71,  patella  0.58,  tibia  1.85,  metatarsus 
2.02,  tarsus  0.95,  total  8.12;  leg  II:  femur  1.87, 
patella  0.50,  tibia  1.09  metatarsus  1.20,  tarsus 
0.73,  total  5.40;  leg  III:  femur  1.28,  patella 
0.42,  tibia  0,70,  metatarsus  0.78,  tarsus  0.58, 
total  3.76;  leg  IV:  femur  2.22,  patella  0.51, 
tibia  1.40,  metatarsus  1.33,  tarsus  0.69,  total 
6.14.  Leg  formula:  1 -4-2-3.  Abdomen  extends 
posteriorly  beyond  spinnerets,  bright  orange 
(light  gray  in  alcohol)  with  black  posterior  tip 
and  two  white  guanine  patches,  posterior 
patch  larger  than  anterior  (Figs.  1,  2).  Colulus 
absent.  Area  between  booklungs  covered  with 
smooth  orange  sternite  continuous  with  epi- 
gynum; spermathecae  separated  by  less  than 
their  width;  epigynum  with  median  trapezoi- 
dal plate  at  posterior  margin  (Fig.  3). 


MILLER  & AGNARSSON— C///?mO  NIGRICEPS 


713 


Figure  1. — Chrysso  nigriceps.  Juvenile  spiders  in  web  with  adult  female,  Agua  Bonita,  Colombia. 


Figures  2-6. — Chrysso  nigriceps.  2,  3.  female;  4-6.  male.  2,  4.  habitus,  lateral  view;  3.  epigynum;  5. 
male  palp,  ventral  view;  6.  median  apophysis,  prolateral  view.  C,  conductor,  E,  embolus,  MA,  median 
apophysis,  ST,  subtegulum,  TTA,  theridiid  tegular  apophysis.  Upper  scale  bar  for  Figs.  2 & 4,  1 mm; 
lower  scale  bar  for  other  figures,  0.5  mm. 


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Male  (from  Hato  Viejo,  Valle  del  Cauca, 
Colombia):  Total  length  2.77,  carapace  length 
1.21,  carapace  width  1.06,  sternum  length 
0.73,  sternum  width  0.70.  Carapace  orange. 
Sternum  orange.  Chelicerae  orange  with  two 
promarginal  teeth.  Palpi  dusky  orange.  Coxae, 
trochanters,  and  basal  half  of  femora  orange; 
distal  half  of  femora  and  distal  leg  segments 
dusky  orange.  Leg  I:  femur  2.43,  patella  0.49, 
tibia  1.76,  metatarsus  1.83,  tarsus  0.91,  total 
7.41;  leg  II:  femur  1.65,  patella  0.37,  tibia 
1.02,  metatarsus  1.09,  tarsus  0.66,  total  4.78; 
leg  III:  femur  1.18,  patella  0.33,  tibia  0.69, 
metatarsus  0.73,  tarsus  0.51,  total  3.43;  leg  IV: 
femur  1.97,  patella  0.41,  tibia  1.28,  metatarsus 
1.24,  tarsus  0.66,  total  5.56.  Leg  formula:  1- 
4-2-3.  Abdomen  extends  posteriorly  slightly 
beyond  spinnerets,  light  gray  (in  alcohol)  with 
black  posterior  tip;  guanine  patches  absent 
(Fig.  4).  Colulus  absent.  Area  between  book- 
lungs  covered  with  smooth  orange  sternite. 
Palp  as  in  Fig.  5;  median  apophysis  diagnostic 
(Fig.  6). 

Distribution. — Colombia  and  Ecuador. 

Remarks. — During  an  expedition  to  Co- 
lombia, Chrysso  nigriceps  was  collected  from 
two  regions,  the  male  from  near  Cali,  females 
near  Bogota.  An  undescribed  Chrysso  species 
was  also  collected  on  this  same  expedition. 
Both  males  and  females  of  this  undescribed 
species  were  collected  from  the  S.F.F.  Iguaque, 
Boyoca,  Colombia.  The  undescribed  species 
was  included  as  the  exemplar  representing 
Chrysso  in  recent  phylogenetic  analyses  of 
theridiid  genera,  where  it  was  referred  to  as 
Chrysso  nr.  nigriceps  (Agnarsson  2004;  Ar- 
nedo  et  al.  2004). 

ACKNOWLEDGMENTS 

Mark  Harvey,  Barbara  Knoflach,  Matjaz 
Kuntner,  and  an  anonymous  reviewer,  provid- 
ed comments  that  helped  improve  the  manu- 
script. Thanks  to  Janet  Beccaloni  (BMNH), 
Jonathan  Coddington  and  Dana  De  Roche 
(USNM),  and  Gonzalo  Giribet  and  Laura  Lei- 
bensperger  (MCZ)  for  the  loan  of  specimens. 
Matjaz  Kuntner  generously  shared  unpub- 
lished data  on  Chrysso  in  Indonesia.  Colom- 
bian field  assistance  provided  by  Jonathan 
Coddington,  Gustavo  Hormiga,  Eduardo  Flor- 
ez, Valeria  Rodriguez,  Dario  Correa,  Javier 
Barriga,  Juan  Carlos  Bello,  Fernando  Fernan- 
dez, Claudia  Medina,  A.  Sabogal,  and  the  In- 
stitute von  Humboldt,  Institute  de  Ciencias 


Naturales.  Institutional  support  was  provided 
by  the  National  Museum  of  Natural  History 
(Smithsonian  Institution)  and  the  George 
Washington  University.  This  work  was  sup- 
ported in  part  by  an  NSF-PEET  (9712353) 
grant  to  Hormiga  and  Coddington  and  the 
USIA  Fulbright  program.  Special  thanks  to 
Cynthia  Zujko. 

LITERATURE  CITED 

Agnarsson,  I.  2002.  On  the  relation  of  sociality  and 
kleptoparasitism  in  theridiid  spiders  (Theridiidae, 
Araneae).  Journal  of  Arachnology  30:181-188. 
Agnarsson,  I.  2004.  Morphological  phylogeny  of 
cobweb  spiders  and  their  relatives  (Araneae,  Ar- 
aneoidea,  Theridiidae).  Zoological  Journal  of  the 
Linnean  Society  141:447-626. 

Arnedo,  M.A.,  J.  Coddington,  I.  Agnarsson,  & R.G. 
Gillespie.  2004.  From  a comb  to  a tree:  Phylo- 
genetic relationships  of  the  comb-footed  spiders 
(Araneae,  Theridiidae)  inferred  from  nuclear  and 
mitochondrial  genes.  Molecular  Phylogenetics 
and  Evolution.  31:225-245. 

Aviles,  L.  1997.  Causes  and  consequences  of  co- 
operation and  permanent-sociality  in  spiders.  Pp. 
476-498.  In  The  Evolution  of  Social  Insects  and 
Arachnids.  (J.C.  Choe  & B.J.  Crespi,  eds.)  Cam- 
bridge University  Press,  Cambridge. 

Keyserling,  E.  1884.  Die  Spinnen  Amerikas.  II. 

Theridiidae.  Niirnberg  1,  222  pp. 

Kullmann,  E.  1972.  Evolution  of  social  behavior  in 
spiders  (Araneae;  Eresidae  and  Theridiidae). 
American  Zoologist  12:419-426. 

Levi,  H.W.  1957.  The  spider  genera  Chrysso  and 
Tidarren  in  America  (Araneae:  Theridiidae). 
Journal  of  the  New  York  Entomological  Society 
63:59-81.  [Date  on  volume  1955;  actually  pub- 
lished in  1957.] 

Mello-Leitao,  C.E  de.  1941.  Catalogo  das  aranhas 
da  Colombia.  Anais  Academia  brasileira  de 
Ciencias  13:233-300. 

Miller,  J.A.  In  press.  Review  of  erigonine  spider 
genera  in  the  Neotropics  (Araneae:  Linyphiidae, 
Erigoninae).  Zoological  Journal  of  the  Linnean 
Society. 

Petrunkevitch  A.  1911.  A synonymic  index-cata- 
logue of  spiders  of  North,  Central  and  South 
America  with  all  adjacent  islands,  Greenland, 
Bermuda,  West  Indies,  Terra  del  Fuego,  Gala- 
pagos, etc.  Bulletin  of  the  American  Museum  of 
Natural  History  29:1-791. 

Platnick,  N.I.  2004.  The  world  spider  catalog,  ver- 
sion 4.5.  American  Museum  of  Natural  History, 
online  at  http://research.amnh.org/entomology/ 
spiders/catalog/index. html 
Roewer,  C.  E 1942.  Katalog  der  Araneae  von  1758 
bis  1940.  Bremen,  1:1-1040. 

Manuscript  received  5 February  2004,  revised  12 
May  2004. 


2005.  The  Journal  of  Arachnology  33:715-718 


A ^SWIMMING’  HETEROPODA  SPECIES 
FROM  BORNEO  (ARANEAE, 
SPARASSIDAE,  HETEROPODINAE) 


Peter  Jager:  Forschungsinstitut  und  Naturmuseum  Senckenberg,  Senckenberganlage 
25,  D~60325  Frankfurt  am  Main,  Germany.  E-mail:  Peter.Jaeger@Senckenberg.de 

ABSTRACT.  Heteropoda  natans  new  species  (Araneae,  Sparassidae,  Heteropodinae)  is  described  from 
Borneo.  Additional  illustrations  of  the  genitalia  of  H.  hosei  (Pocock  1897)  are  provided  for  comparison 
purposes.  The  lectotype  of  H.  hosei  is  designated. 

Keywords:  Sparassidae,  Heteropoda,  taxonomy,  new  species,  Borneo 


The  sparassid  subfamily  Heteropodinae  in- 
cludes eight  genera,  of  which  Heteropoda  La- 
treille  1804  is  by  far  the  most  diverse  with 
about  190  nominal  species  (Jager  2002).  The 
genus  has  not  been  revised  in  recent  times  ex- 
cept for  the  species  from  the  Australian  region 
(Davies  1994). 

In  1998  Satie  Airame  and  Petra  Sierwald 
observed  and  collected  specimens  of  an  un- 
identified Heteropoda  species  in  a lowland 
rainforest  on  Borneo  (Malaysia,  Sabah).  In- 
dividuals were  observed  in  a laboratory  and 
the  hunting  behavior  was  investigated.  Hunt- 
ing on  the  water  surface  could  be  shown  the 
first  time  for  the  family  Sparassidae.  Even 
though  the  observations  were  made  under  ar- 
tificial conditions,  there  is  evidence  that  this 
behavior  also  occurs  in  natural  situations  (Air- 
ame & Sierwald  2000). 

Two  Heteropoda  species  have  been  de- 
scribed previously  from  Borneo:  H.  hosei  Po- 
cock 1897  and  H.  obtusa  Thorell  1890.  After 
comparing  the  new  material  with  type  mate- 
rial and  original  descriptions,  it  appeared  to 
be  a species  new  to  science,  which  is  de- 
scribed below.  Conspecifity  of  H.  obtusa  with 
the  here  described  new  species  can  be  exclud- 
ed by  the  distinctly  smaller  size  of  H.  obtusa 
(ca.  14.5  mm  body  length:  Thorell  1890).  As 
H.  hosei  could  be  confused  with  the  new  spe- 
cies due  to  similar  size,  it  is  diagnosed  and 
illustrated  below. 

METHODS 

Specimens  are  deposited  in  the  Field  Mu- 
seum of  Natural  History  Chicago,  USA 
(FMNH),  Forschungsinstitut  und  Naturmu- 


seum Senckenberg,  Germany  (SMF)  and  the 
Natural  History  Museum  London,  England 
(BMNH).  Format  and  style  of  description  as 
well  as  treatment  of  female  genitalia  follow 
Davies  (1994)  and  Jager  (2000).  Measure- 
ments are  expressed  in  millimeters.  Measure- 
ments of  appendages  are  listed  as:  total  length 
(femur,  patella,  tibia,  metatarsus,  tarsus).  Aris- 
ing points  of  tegular  parts  (i.e.  embolus,  con- 
ductor) are  described  for  the  left  palp  in  a ven- 
tral view. 

Abbreviations.  ALE  = anterior  lateral  eyes, 
AME  = anterior  median  eyes,  AW  ==  anterior 
width  of  dorsal  shield  of  prosoma,  CH  = clyp- 
eus  height,  FE  = femur,  MT  ==  metatarsus,  OL 
= opisthosoma  length,  OW  = opisthosoma 
width,  PA  = patella,  PH  — height  of  dorsal 
shield  of  prosoma,  PJ  xx  ==  serial  number  of 
Sparassidae  examined  by  Peter  Jager,  PL  = 
length  of  dorsal  shield  of  prosoma,  PLE  = 
posterior  lateral  eyes,  PME  = posterior  me- 
dian eyes,  PP  ==  palpus,  PW  ~ width  of  dorsal 
shield  of  prosoma,  RTA  = retrolateral  tibal 
apophysis,  TA  = tarsus,  TI  = tibia,  I/II/III/IV 
” leg  I,  etc. 

TAXONOMY 

Family  Sparassidae  Bertkau  1872 
Genus  Heteropoda  Latreille  1804 
Heteropoda  natans  new  species 
(Figs.  1-7) 

Types. — Male  holotype  (PJ  1173),  female 
paratype  (PJ  1174):  Malaysia,  Borneo,  Sabah, 
Kinabalu  Park,  near  Poring,  Hot  Springs, 
Lowland  Rainforest,  stream  edges,  6°03'N, 
116°42'E,  Airame  & Sierwald  leg.  IV-VL1998 


715 


716 


THE  JOURNAL  OF  ARACHNOLOGY 


Figures  1-7. — Heteropoda  natans  new  species:  1 — 2.  left  male  palp;  1.  ventral  view;  2.  retrolateral 
view;  3.  left  male  bulb,  prolateral  view;  4.  RTA,  retrolateral  view;  5.  epigyne,  ventral  view;  6.  vulva, 
dorsal  view;  7,  schematic  course  of  internal  duct  system.  Scale  bars  = 1 mm. 


(FMNH  18975,  18972).  Male  paratype  (PJ 
1786):  Malaysia,  Borneo,  Sabah,  Kinabalu 
Park,  near  Poring  Hot  Springs.  6°03'N, 
116°42'E,  along  river,  600m,  Heteropoda 
male,  R Sierwaid  det.  1998  (SMF).  Female 
paratype  (PJ  1785):  same  data,  Heteropoda  fe- 
male, R Sierwaid  det.  1998  (SMF). 

Etymology* — The  specific  name  refers  to 
the  ability  of  this  species  to  hunt  on  the  water 
surface  and  to  dive  and  hide  under  water  (Lat- 
in: natans  = swimming),  adjective. 

Diagnosis* — Tip  of  conductor  divided  into 
two  parts  as  in  //.  squamacea  Wang  1990 
from  southern  China  (see  Wang  1990:  figs.  6, 
7),  but  male  dorsal  RTA  of  H.  natans  with  a 
distinct  protrusion  between  dorsal  and  ventral 
part  (Fig.  4).  Retrolateral  margin  of  conductor 
undulating.  Females  with  slightly  rectangular 
epigynal  field,  this  with  distinct  anterior 
bands.  Lateral  lobes  not  touching  each  other. 
Median  septum  anteriorly  trapezoid.  Sperma- 
thecae  almost  as  large  as  anterior  coils  of  cop- 
ulatory  ducts. 

Description* — Male  holotype  (PJ  1173): 


PL  10.6,  PW  10.2,  AW  4.6,  PH  2.6,  OL  10.5, 
OW  6.8.  Eyes:  AME  0.51,  ALE  0.71,  PME 
0.56,  PLE  0.71,  AME- AME  0.30,  AME- ALE 
0.08,  PME-PME  0.42,  PME-PLE  0.66,  AME- 
PME  0.52,  ALE-PLE  0.53,  CH  AME  0.98, 
CH  ALE  0.77.  Leg  formula:  2143,  spination: 
PP  131,101,2120,  FE  LII  323,  III  333,  IV  331, 
PA  101,  TI  LII  2326,  III  2226,  IV  2126,  MT 
LII  1014,  III  2014,  IV  3036.  Leg  measure- 
ments: PP  17.4  (5.9,  2.6,  3.4,  -,  5.5),  I 70.8 
(18.5,  6.5,  21.1,  19.6,  5.1),  II  82.2  (22.0,  6.7, 
24.3,  23.7,  5.5),  III  62.4  (17.6,  5.9,  18.5,  16.3, 
4.1),  IV  69.9  (19.6,  5.5,  19.6,  20.5,  4.7). 

Chelicerae  with  5-6  posterior  teeth.  Orga- 
nization of  palpal  structures  simple,  i.e,  em- 
bolus arising  in  a 6-o'clock-position  on  the 
tegulum,  following  a semi-circular  path.  Con- 
ductor arising  in  a 9:30-o'clock-position  on 
the  tegulum.  Sperm  duct  shaped  like  broad  ‘S' 
across  the  tegulum. 

Color:  Reddish-brown  to  brown  with  dark 
markings,  made  up  of  short  dark  hairs.  Che- 
licerae reddish-brown  with  three  longitudinal 
bands.  Prosoma  with  dark  radial  markings  and 


JAGER— NEW  HETEROPODA  FROM  BORNEO 

a white  ‘V’ -shaped  line,  consisting  of  white 
short  hairs,  running  along  the  suture  between 
head  and  thoracical  region.  Sternum,  gnatho- 
coxae,  labium,  ventral  coxae  and  trochanter 
pale  brown  without  markings.  Opisthosoma 
covered  with  dark  hairs.  Ventral  opisthosoma 
with  a light  yellowish-brown  median  band. 

Female  paratype  (PJ  1174):  PL  14.9,  PW 

13.2,  AW  6.5,  PH  4.1,  OL  19.2,  OW  12.6. 
Eyes:  AME  0.47,  ALE  0.78,  PME  0.63,  PLE 
0.77,  AME-AME  0.57,  AME-ALE  0.20, 
PME-PME  0.66,  PME-PLE  0.86,  AME-PME 
0.77,  ALE-PLE  0.80,  CH  AME  1.40,  CH 
ALE  1.12.  Leg  formula:  2413,  spination:  PP 
131,101,2(1)121,1014(3),  FE  I-II  323,  III  333, 
IV  331,  PA  101,  TI I 21(2)26,  II-IV  2126,  MT 
I-II  1014,  III  2014,  IV  3036.  Palpal  claw  with 
8 teeth.  Leg  measurements:  PP  22.9  (6.7,  3.2, 

5.2,  7.8),  I 71.9  (20.1,  7.4,  21.2,  18.5,  4.7), 
II  79.3  (22.7,  7.9,  23.5,  20.2,  5.0),  III  65.6 
(19.5,  7.1,  18.7,  16.2,  4.1),  IV  75.4  (21.1,  7.0, 

21.5,  20.7,  5.1). 

Chelicerae  with  5 posterior  teeth.  Lateral 
lobes  of  epigyne  broad  tongue-shaped,  cov- 
ering mainly  posterior  parts  of  the  median 
septum.  Anterior  bands  of  epigynal  field  frag- 
mented. Spermathecae  separated  from  each 
other  by  one  of  their  diameters.  Slit  sense  or- 
gans separated  2.5-4  times  of  their  length 
from  epigynal  field  (Fig.  5). 

Color:  As  in  male,  but  generally  darker  (i.e. 
reddish-brown).  Prosoma  and  opisthosoma 
covered  continously  with  dark  hairs,  without 
any  pattern. 

Variation. — Male  paratype  (PJ  1786):  PL 

11.6,  OL  12.  l \ female  paratype  (PJ  1785):  PL 

13.7,  OL  12.4. 

Distribution. — Only  known  from  the  type 
locality. 

Biology, — Observations  on  the  biology  of 
Heteropoda  natans  were  made  and  published 
by  Airame  & Sierwald  (2000).  Specimens 
were  found  sitting  at  the  edge  of  streams.  One 
specimen  was  observed  jumping  into  the  wa- 
ter and  diving.  In  the  laboratory,  feeding  ex- 
periments showed  that  individuals  of  H.  na- 
tans monitor  for  prey  by  holding  their 
pedipalps  and  the  first  two  pairs  of  legs  in  the 
water.  From  the  prey  offered  to  the  spiders 
(cockroaches,  fish,  large  and  small  tadpoles) 
only  tadpoles  were  rejected  under  laboratory 
conditions.  In  these  experiments  cockroaches 
were  the  preferred  prey. 


717 


Figures  8-10. — Heteropoda  hosei  Pocock  1897: 
8.  epigyne,  ventral  view;  9.  vulva,  dorsal  view;  10. 
schematic  course  of  internal  duct  system.  Scale  bar 
= 1 mm. 


Heteropoda  hosei  Pocock  1897 
(Figs.  8-10) 

Heteropoda  hosei  Pocock  1897:  614,  figs.  2 1-2 la; 
1 female  syntype  (PJ  1765):  Malaysia,  Sarawak, 
purchased  E.  Gerrara,  (BMNH  1894.9.19.11-31). 
Examined  and  herewith  designated  as  lectotype 
(see  Remarks  below). 

Diagnosis. — Epigynal  field  roughly  trape- 
zoid with  short  anterior  bands,  these  neither 
fragmented  nor  separated  from  the  field.  Me- 
dian septum  covered  only  on  its  margins  by 
lateral  lobes.  Posterior  margin  of  median  sep- 
tum distinctly  separated  from  the  epigastric 
furrow.  Spermathecae  separated  from  each 
other  by  at  least  1.5  times  their  diameters,  ex- 
tending laterally  beyond  the  first  windings  of 
the  internal  duct  system. 

Description. — PL  10.0.  Slit  sense  organs 
separated  by  their  length  from  the  epigynal 
field  (Fig.  8).  For  further  details  see  Pocock 
(1897). 


718 


THE  JOURNAL  OF  ARACHNOLOGY 


Distribution. — Only  known  from  the  type 
locality  (Sarawak). 

Remarks. — Pocock  (1897)  mentioned  two 
female  specimens  in  his  original  description, 
one  from  Baram  River  in  Borneo  and  one 
from  Sarawak.  These  have  to  be  considered 
syntypes.  In  the  BMNH  only  one  series  of  H. 
hosei  was  found.  It  comprises  three  adult  fe- 
males and  one  subadult  female  from  Sarawak. 
One  adult  female  is  labelled  as  type,  matches 
with  the  original  description  (the  other  sped- 
mens  are  smaller  and  probably  added  later  to 
the  vial)  and  is  considered  belonging  to  the 
syntype  series.  The  other  syntype  was  not 
found  and  its  whereabouts  remain  unkown.  To 
support  stability  the  only  located  syntype  (PJ 
1765)  is  herewith  designated  as  lectotype. 

ACKNOWLEDGMENTS 

Parts  of  this  research  arose  from  a visit  to  the 
BMNH,  which  was  sponsored  by  the  European 
Community  (Access  to  Research  Infrastructure 
action  of  the  Improving  Human  Potential  Pro- 
gramme: London — SYS-RESOURCE  pro- 
gram). Thanks  go  to  Satie  Airame  and  Petra 
Sierwald  (both  Chicago)  for  collecting  and  pro- 
viding the  specimens  and  to  an  anonymous  ref- 
eree and  Mark  Harvey  for  improving  the  man- 
uscript with  helpful  comments. 


LITERATURE  CITED 

Airame,  S.  & P.  Sierwald.  2000.  Hunting  and  feed- 
ing behavior  of  one  Heteropoda  species  in  low- 
land rainforest  on  Borneo  (Araneae,  Sparassi- 
dae).  Journal  of  Arachnology  28(2):25 1-253. 

Davies,  V.T  1994.  The  huntsman  spiders  Hetero- 
poda Latreille  and  Yiinthi  gen.  nov.  (Araneae: 
Heteropodidae)  in  Australia.  Memoirs  of  the 
Queensland  Museum  35(1):75-122. 

lager,  P.  2000.  Two  new  heteropodine  genera  from 
southern  continental  Asia  (Araneae:  Sparassi- 
dae).  Acta  Arachnologica  49(1):61-71. 

lager,  P.  2002.  Heteropodinae:  transfers  and  syn- 
onymies (Arachnida:  Araneae:  Sparassidae). 
Acta  Arachnologica  51(1):33-61. 

Pocock,  R.I.  1897.  Spinnen  (Araneae).  In  Ergebnis- 
se  einer  zoologischen  Forschungsreise  in  den 
Molukken  und  Borneo.  (Kiikenthal,  W.  ed.).  Ab- 
handlungen  der  Senckenbergischen  Naturfor- 
schenden  Gesellschaft  33(4):59 1-629. 

Thorell,  T.  1890.  Diagnoses  Aranearum  aliquot  no- 
varum  in  Indo-Malesia  inventarum.  Annali  del 
Museo  Civico  di  Storia  Naturale  di  Genova  (2) 
10:132-172. 

Wang,  J.-F.  1990.  Six  new  species  of  the  spiders  of 
the  genus  Heteropoda  from  China  (Araneae: 
Heteropodidae).  Sichuan  Journal  of  Zoology 
9(3):7-ll. 

Manuscript  received  11  February  2004,  revised  4 
May  2004. 


2005.  The  Journal  of  Arachnology  33:719-725 


THREE  NEW  SPECIES  OF  SOLIFUGAE  FROM  NORTH 
AMERICA  AND  A DESCRIPTION  OF  THE  FEMALE 
OF  BRANCHIA  BREVIS  (ARACHNIDA,  SOLIFUGAE) 


Jack  O.  Brookhart  and  Paula  E.  Cushing:  Department  of  Zoology,  Denver  Museum 
of  Nature  & Science,  2001  Colorado  Blvd.,  Denver,  Colorado  80205-5798,  USA. 
E-mail:  joipbroo@comcast.net 

ABSTRACT.  Three  new  species  of  Solifugae  are  described:  Eremobates  paleta  from  Mexico,  is  a 
member  of  the  Eremobates  scaber  species  group;  Eremobates  inkopaensis  from  California,  U.S.A.,  is  a 
member  of  the  Eremobates  palpisetulosus  group;  and  Eremochelis  albaventralis  from  Mexico  is  tentatively 
placed  in  the  Eremochelis  bilobatus  group.  The  female  of  Branchia  brevis  Muma  from  Texas,  U.S.A.  is 
described  for  the  first  time. 

Keywords!  Solpugida,  species  description,  taxonomy,  camel  spider,  sun  spider,  wind  scorpion 


New  species  of  solifugids  are  being  discov- 
ered  each  year  as  a result  of  re-examination 
of  museum  material  and  newly  collected  ma- 
terial being  sent  in  for  identification.  These 
new  species  are  beginning  to  shed  some  light 
on  the  phylogenetic  relationships  among  spe- 
cies and  between  species-groups  (Brookhart  & 
Cushing  2002,  2004).  Herein  we  describe 
three  new  species  in  the  family  Eremobatidae 
and  provide  a description  of  the  female  of 
Branchia  brevis  Muma  1951  from  the  family 
Ammotrechidae . 

Using  the  methods  of  Muma  (1951), 
Brookhart  & Muma  (1981,  1987),  Muma  & 
Brookhart  (1988)  and  Brookhart  & Cushing 
(2002,  2004)  we  measured  length  of  palpus, 
leg  I,  leg  IV,  length  and  width  of  chelicera  and 
propeltidium,  length  and  width  of  fondal 
notch  when  present,  width  of  base  of  fixed 
finger,  and  length  and  width  of  female  genital 
operculum.  Abbreviations  used  to  indicate 
various  cheliceral  structures  are  as  follows:  FF 
= fixed  finger;  MF  — movable  finger;  PT 
primary  tooth;  AT  = anterior  tooth;  MT  = 
medial  tooth;  IT  = intermediate  tooth;  MST 
= mesal  tooth.  All  measurements  are  in  mil- 
limeters. 

The  number,  shape  and  relative  length  of 
ctenidia  to  succeeding  tergite  was  noted. 
Counts  were  made  of  palpal  papillae.  Color  of 
palpus,  legs  I,  II,  III,  IV  and  general  overall 
color  especially  that  of  the  propeltidium  was 
recorded.  The  shape  of  the  female  genital 


operculum  especially  the  medial  margin  was 
observed  using  the  terminology  of  Brookhart 
& Cushing  (2004). 

Ratios  used  previously  by  Muma  (1951, 
1970,  1989),  Brookhart  & Muma  (1981, 
1987),  Muma  & Brookhart  (1988),  and 
Brookhart  & Cushing  (2002)  were  computed. 
These  ratios  are  as  follows:  A/CP:  the  sum  of 
the  lengths  of  palpus,  leg  I,  and  leg  IV  divided 
by  the  sum  of  length  of  chelicera  and  propel- 
tidium indicating  length  of  appendages  in  re- 
lation to  body  size.  The  larger  the  number,  the 
longer  legged  is  the  species.  CL/CW:  chelic- 
eral length  divided  by  cheliceral  width.  FL/ 
FW  indicates  whether  the  cheliceral  fondal 
notch  is  longer  or  wider.  Longer  is  defined  as 
the  anterior  to  posterior  axis  and  width  is  de- 
fined as  the  dorsal  to  ventral  axis.  PL/PW 
compares  propeltidium  length  to  width.  FW/ 
FFW  diagnoses  the  size  of  fondal  notch  com- 
pared to  the  thickness  of  fixed  finger.  CW/ 
FFW  is  used  to  indicate  whether  the  fixed 
cheliceral  finger  is  thin  or  robust  in  relation  to 
the  size  of  the  chelicera.  This  is  a useful  ratio 
when  there  is  no  fondal  notch.  GOL/GOW 
demonstrates  the  relative  size  of  the  female 
genital  operculum  in  terms  of  length  and 
width.  Abbreviations  for  collections  are  as  fol- 
lows: DMNS  = Denver  Museum  of  Nature  & 
Science,  Denver,  Colorado;  EMEC  = Essig 
Museum  of  Entomology,  University  of  Cali- 
fornia at  Berkeley,  Berkeley,  California; 
FSCA  = Florida  State  Collection  of  Arthro- 


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THE  JOURNAL  OF  ARACHNOLOGY 


pods,  Gainesville,  Florida;  SDMC  = San  Di- 
ego Natural  History  Museum,  San  Diego,  Cal- 
ifornia. 

SYSTEMATICS 

Family  Eremobatidae  Kraepelin  1901 

Subfamily  Eremobatinae  Kraepelin  1901 
Genus  Eremobates  Banks  1900 
Eremobates  paleta  new  species 
Figs.  1-5 

Material  examined. — Holotype  male  from 
2.5  km  S.  of  El  Salto  (23°28'N,  105°13'W), 
Durango  Province,  Mexico,  4 August  1986, 
D.K.  Faulkner  (SDMC). 

Etymology. — From  the  Spanish  for  trowel, 
paleta,  which  refers  to  the  shape  of  the  four 
ctenidia.  To  be  treated  as  a noun  in  apposition. 

Diagnosis. — This  new  species  is  placed  in 
the  Eremobates  scaber  group  based  on  the 
notch  on  the  posterior  aspect  of  the  male  fixed 
finger  when  viewed  dorsally.  The  four  trowel- 
shaped ctenidia  as  well  as  the  combination  of 
coloration  and  “crimped”  male  fixed  finger 
distinguishes  it  from  other  members  of  the  Er- 
emobates scaber  group. 

Description. — Male  holotype:  total  length 
20,  chelicera  length  2.5,  chelicera  width  2.5, 
propeltidium  length  3.5,  propeltidium  width 
4.8,  palpus  length  16,  first  leg  length  17, 
fourth  leg  length  20.  Ratios:  A/CP  8.8,  CL/ 
CW  2.24,  PL/PW  0.73,  FL/FW  1.0,  CW/FFW 
5.0. 

Overall  coloration  lemon  yellow  with  dusky 
purplish-brown  markings  on  anterior  edge  of 
propeltidium  and  ocular  area  (Fig.  1),  violet- 
brown  on  apical  tip  of  palpal  tarsus  (Fig.  2). 
All  legs  lemon  yellow,  abdomen  dark  violet 
brown  dorsally,  lighter  violet  brown  ventrally, 
pleura  a light  violet.  Malleoli  white.  Chelic- 
eral  fixed  finger  “crimped”  in  mesal  view 
without  teeth,  movable  finger  with  large  PT, 
smaller  AT  with  no  cleft,  posterior  IT  on  PT, 
MST  medium  in  size.  “Crimped”  fixed  finger 
defined  in  Brookhart  & Cushing  (2004)  and 
shown  as  a recurved  dorsal  edge  of  fixed  fin- 
ger in  Fig.  3.  Fondal  notch  equal  in  length  to 
width.  Fondal  teeth  graded  I,  III,  II,  IV  ectally 
and  mesally  (Figs.  3 & 4),  Mesoventral 
groove  typical  of  the  group,  narrow,  deep, 
ending  in  a cup-like  depression  beneath  the 
origins  of  flagellum  complex.  Flagellum  com- 
plex typical  of  Eremobates  group  with  apical 
plumose  bristle  large,  flattened,  occupying  ap- 


proximately 90%  of  mesoventral  groove.  Pal- 
pus with  40  rounded  papillae  on  the  apical, 
ventral  region  of  palpus  (Fig.  2).  Four  short, 
trowel  shaped  ctenidia  (Fig.  5). 

Remarks. — The  only  valid  recorded  mem- 
ber of  the  scaber  group  from  Mexico  is  Ere- 
mobates legalis  Harvey  2002  which  is  known 
from  the  female  type  only  and  has  no  type 
locality.  Vasquez-Rojas’s  (1981,  1995)  re- 
cords of  Eremobates  zinni  Muma  1951  and 
Eremobates  ctenidiellus  Muma  1951  appear  to 
be  in  error  based  on  our  recent  studies  (Brook- 
hart  & Cushing  2004).  Eremobates  paleta 
does  not  appear  to  be  related  to  E.  legalis 
based  on  coloration.  Gavino  (pers.  comm.)  is 
also  describing  a new  scaber  species  from  the 
Baja  region  of  Mexico.  The  “crimped”  aspect 
of  the  fixed  finger  is  unusual  for  a species  in 
the  southern  regions  of  North  America 
(Brookhart  & Cushing  2004). 

Eremobates  inkopaensis  new  species 
Figs.  6-9 

Material  examined. — Male  holotype.  In 
Ko  Pah  Valley,  Meyer  Gorge  (32°43'N, 
116°02'W),  Imperial  County,  California, 
U.S.A.,  14  March  1982,  pitfall  trap,  J.  Berrian 
(SDMC).  Female  allotype  from  same  site,  pit- 
fall  trap,  17  April  1982,  J.  Berrian  (SDMC). 
Paratypes:  U.S.A.:  California:  6 males  and  1 
female  from  same  site  locality  by  same  col- 
lector between  4 March- 17  April  1982  (5 
male  paratypes  in  SDMC,  1 male  and  1 fe- 
male in  DMNS). 

Etymology. — Refers  to  the  type  locality.  In 
Ko  Pah  Valley. 

Diagnosis. — This  member  of  the  Eremo- 
bates palpisetulosus  group  is  a member  of  the 
kraepelini  series  as  defined  by  Muma  & 
Brookhart  (1988).  It  is  the  only  member  of 
this  group  without  ctenidia.  Most  members  of 
this  series  are  pale  but  have  some  dusky  to 
dusky  purple  markings.  Eremobates  inko- 
paensis is  entirely  pale  in  both  the  male  and 
female. 

Description. — Male  holotype:  total  length 
21,  cheliceral  length  5.4,  cheliceral  width  2.2, 
propeltidium  length  2.6,  propeltidium  width 

5.2,  palpus  length  14,  first  leg  length  16, 
fourth  leg  length  27.  Ratios:  A/CP  7.04,  CL/ 
CW  2.6,  PL/PW  0.5,  FL/FW  1.0,  CW/FFW 

5.2.  Coloration  cream  yellow  in  all  aspects  of 
chelicera,  propeltidium  and  appendages.  Mal- 
leoli white.  Cheliceral  FF  with  low,  incon- 


BROOKHART  & CUSHING— THREE  NEW  SPECIES  OF  SOLIFUGAE 


721 


5 


Figures  1-5. — Eremobates  paleta  new  species.  1-5.  Male  holotype.  1.  Male  propeltidium,  dorsal  view; 
2.  Male  palpus,  ventral  view;  3.  Male  right  chelicera,  ectal  view;  4.  Male  right  chelicera,  mesal  view;  5. 
Male  fourth  abdominal  segment  showing  ctenidia,  ventral  view.  Scale  bars  = 1 mm. 


spicuous  ridge  on  basal  aspect  of  FF.  No  teeth 

ventrally.  MF  with  large  PT  but  only  a low 
ridge  anteriorally,  small  posterior  IT  separate 
from  PT,  tiny  AT,  MST  absent  (some  para- 
types  have  tiny  MST).  Fondal  teeth  graded  I, 
III,  II,  IV.  Fondal  notch  equal  length  to  width. 
Mesoventral  groove  deep,  median  in  position 
expanding  ventrally  near  the  tip  (Figs.  6 & 7). 
Flagellum  complex  typical  of  group,  no  cte- 
nidia, no  palpal  papillae.  Male  paratypes  (6): 


total  length  20-26,  cheliceral  length  5. 5-6.4, 
cheliceral  width  2. 2-2. 9,  propeltidum  length 
23-3.1,  propeltidium  width  4.4-4. 9,  palpus 
length  17.5-22.0,  first  leg  length  16.0-18.0, 
fourth  leg  length  22.0-29.0.  Ratios:  A/CP 
6.5-8.0,  CL/CW  2.2-2.9,  PL/PW  0.52-0.67, 
FL/FW  0.7-1. 0,  CW/FFW  4.2-4.8. 

Female  allotype:  total  length  22,  cheliceral 
length  6.2,  cheliceral  width  2.2,  propeltidium 
length  2.1,  propeltidum  width  3.9,  palpus 


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THE  JOURNAL  OF  ARACHNOLOGY 


Figures  6-9. — Eremobates  inkopaensis  new  species.  6-7.  Male  holotype.  6.  Male  right  chelicera,  ectal 
view;  7.  Male  right  chelicera,  mesal  view.  8-9.  Female  allotype.  8.  Female  right  chelicera,  ectal  view;  9. 
Female  genital  operculum,  ventral  view.  Scale  bar  = 1 mm. 


16.5,  first  leg  length  12.5,  fourth  leg  length 
21.0.  Ratios:  A/CP  4.3,  CL/CW  2.8,  PL/PW 
0.74  GOL/GOW  0.82.  Coloration  is  the  same 
as  the  males.  Chelicera  typical  of  the  group, 
FF  with  large  PT  and  MT,  smaller  AT,  two  IT 
between  PT  and  MT,  one  IT  between  IT  and 
AT,  MF  with  large  PT  and  medium  AT,  two 
smaller  IT,  MST  absent  (Fig.  8).  Genital  oper- 
cula  with  broad  anterior  arms,  recurved  me- 
dial margin,  short,  curved  wings,  posterior 
margin  straight  (Fig.  9).  The  allotype  but  not 
the  paratype  with  four  tiny,  thin  ctenidia.  Fe- 
male paratype  (J):  total  length  31,  cheliceral 
length  6.8,  cheliceral  width  2.2,  propeltidium 
length  3.7,  propeltidium  width  5.5,  palpus 
length  19.5,  first  leg  length  16.5,  fourth  leg 
length  26.0.  Ratios:  A/CP  5.96,  CL/CW  2.6, 
PL/PW  0.65,  GOL/GOW  0.76. 

Remarks. — The  nine  specimens  of  Ere- 
mobates inkopahensis  were  collected  in  mid- 
March  to  early  April  indicating  an  early  ma- 
turity. Eremobates  gracilidens  Muma  1951  is 
also  found  in  southern  California  in  Inyo  and 
San  Bernardino  counties.  The  two  females  are 
shorter  legged  then  E.  gracilidens  based  on 
the  A/CP  ratio.  The  genital  opercula  are  typ- 


ical of  the  group  although  the  anterior  arms 
are  broader  than  in  other  members  of  this 
group. 

Genus  Eremochelis  Roewer  1934 

Eremochelis  albaventralis  new  species 
Figs.  10-17 

Material  examined. — Holotype  male,  7 
km  WSW  of  Juchitepec  (19°06^N,  98°52'W), 
Mexico  State,  Mexico,  24  August  1987,  J. 
Doyen  (CAS).  Paratypes:  Mexico:  Mexico 
State:  1 male,  same  collection  data  as  holo- 
type (CAS);  1 male,  same  collection  data  as 
holotype  (DMNS). 

Etymology. — Refers  to  the  contrasting 
white  underside  of  the  species. 

Diagnosis. — This  species  is  distinguished 
from  Eremochelis  rossi  Muma  1987  on  the 
basis  of  coloration,  shape  of  fixed  finger,  and 
ctenidial  number  and  shape. 

Description. — Male  holotype:  total  length 
14,  cheliceral  length  3.3,  cheliceral  width  1.3, 
propeltidium  length  1.5,  propeltidium  width 
2.3,  palpus  length  13.5,  first  leg  length  10.0, 
fourth  leg  length  14.0.  Ratios:  A/CP  7.8,  CL/ 
CW  2.5,  PL/PW  0.43,  no  fond,  CW/FFW  2.6. 


BROOKHART  & CUSHING— THREE  NEW  SPECIES  OF  SOLIFUGAE 


723 


17 

Figures  10-17.- — Eremochelis  albaventralis  new  species.  10-14.  Male  holotype.  10.  Male  right  chelic- 
era,  ectal  view;  11.  Male  right  chelicera,  mesal  view;  12.  Male  propeltidium,  dorsal  view;  13.  Male  right 
palpus,  dorsal  view;  14.  Male  right  palpus,  ventral  view.  15.  Male  paratype,  ventral  view  showing  everted 
suctorial  organ.  16-17.  Male  holotype.  16.  Male  abdomen,  ectal  view;  17.  Male  fourth  abdominal  segment 
showing  ctenidia.  Vertical  scale  line  = 1 mm  for  10,  11,  12,  16,  & 17.  Horizontal  scale  line  = 1 mm  for 
13,  14,  & 15. 


Metatarsus/tarsus  ratio  4.2.  Male  paratypes 
(2):  total  length  13-15,  cheliceral  length  3.4- 
3.6,  cheliceral  width  1.3-1. 6,  propeltidum 
length  1. 9-2.0,  propeltidium  width  23-2 J , 
palpus  length  13.0-16.0,  first  leg  length  10.0- 


11.0,  fourth  leg  length  14.0-17.0.  Ratios:  AJ 
CP  6.2-7.0,  CL/CW  2.25-2.40,  PL/PW  0.75- 
0.80,  no  fond,  CW/FFW  2.6-3.2.  Metatarsus/ 
tarsus  ratio  4.25-4.50.  Coloration  in  alcohol  a 
blotchy,  vibrant  violet  brown  on  the  dorsal  as- 


724  THE  JOURNAL  OF  ARACHNOLOGY 


Figures  18-20. — Branchia  brevis  female.  18.  Female  right  chelicera,  ectal  view;  19.  Female  right  che- 
licera,  mesal  view;  20.  Female  genital  operculum,  ventral  view.  Scale  line  = 1 mm. 


pect  of  most  of  palpus  (Fig.  13),  legs  I,  II,  III, 
IV  and  most  of  the  propeltidum  except  for  a 
thin  linear  area  of  creamy  yellow  on  the  me- 
dian sector  (Fig.  12).  Entire  ventral  aspect 
white  including  palpus  (Fig.  14).  Abdomen 
more  lightly  colored  with  distinct  patches  on 
the  ectal  regions  (Fig.  16).  Chelicera  with  3 
lighter  stripes  ectally  of  the  same  color  (Fig. 
10).  Malleoli  white.  Cheliceral  FF  with  no 
teeth  or  denticles,  blade  shaped  with  a circular 
region  where  you  would  normally  find  the 
fondal  notch.  Small  ventral  cup  anteriorly  ex- 
tending to  a broad,  shallow  mesoventral 
groove.  MF  with  large  PT  and  a cusp-like 
structure  for  an  AT;  small  IT  on  the  PT;  no 
MST  (Figs.  10  & 11).  Flagella  complex  of 
tubular  to  slightly  striate  bristles.  No  scopula, 
seven  short,  needle-like  ctenidia  (Fig.  17).  The 
everted  palpal  suctorial  organ  is  shown  in  Fig. 
15. 

Remarks. — This  species  is  tentatively 
placed  in  the  Eremochelis  bilobatus  group  but 
clearly  needs  to  be  part  of  a new  group  which 
would  include  E.  albaventralis,  E.  rossi 
Muma  1987,  E.  cochiseae  Muma  1989,  E. 
kerni  Muma  1989  and  possibly  the  two  mem- 
bers of  the  E.  andreasana  group,  E.  andreas- 
ana  Muma  1962  and  E,  larrea  Muma  1962. 


This  distinction  is  based  mainly  on  the  unique 
shape  of  the  male  chelicera. 

Family  Ammotrechidae  Roewer  1934 
Subfamily  Saronominae  Roewer  1934 
Genus  Branchia  Muma  1951 
Branchia  brevis  Muma  1951 
Figs.  18-20 

Branchia  brevis  Muma  1951:  137-138,  figs.  311, 

312;  Harvey  2003:  208  (full  synonymy). 

Type  specimen. — Holotype  male,  Edin- 
burgh, Hidalgo  County,  Texas,  U.S.A. 
(26°irN,  98°06'W),  15  March  1939,  S.  Mu- 
laik  (AMNH). 

Material  examined. — U.S.A.:  Texas: 
Webb  County:  19  c3,  8 9,  57.1  km  NW  of 
Laredo  (27°34'N,  99°30'W),  Rt.  83,  under 
cow  pies,  21  April  1980,  M.H.  Muma 
(FSCA);  2 d,  1 9,  same  collection  data 
(DMNS). 

Description. — Eemales  (5):  Length  16.0- 
18.5,  cheliceral  length  2. 8-3. 3,  cheliceral 
width  1.1 -1.2,  propeltidium  length  1. 8-2.1, 
propeltidium  width  1.9-2. 3,  palpus  length 
5.0-7. 0,  first  leg  length  4. 0-5.0,  fourth  leg 
length  11.5-12.5.  Ratios:  A/CP  4.45-4.53, 
PL/PW  0.9,  GOL/GOW  0.85-0.92. 

Overall  coloration  in  alcohol  pale  creamy 


BROOKHART  & CUSHING— THREE  NEW  SPECIES  OF  SOLIFUGAE 


725 


yellow;  ocular  area  pale;  palpus  with  splotchy 

brown  violet  on  tarsus  and  apical  two  thirds 
of  metatarsus;  other  appendages  creamy  yel- 
low; abdomen  dusky  yellow  dorsally  and  very 
pale  ventrally.  Fixed  finger  typical  of  the 
group  with  equally  sized  PT,  MT  and  AT;  one 
small  IT  between  PT  and  MT,  MST  absent; 
FT  graded  II,  I ectally  and  III  mesally  (Figs. 
18  & 19).  No  ctenidia,  no  palpal  papillae. 
Genital  operculum  typical  of  the  group  (Fig. 
20). 

Remarks. — -Muma  (1951)  described  the 
male  of  Branchia  brevis  from  Hidalgo  Texas, 
U.S.A.  but  did  not  describe  a female  allotype 
(Muma  1951,  1962,  1970,  1989).  One  of  the 
authors  (JOB)  has  in  his  personal  collection 
two  males  and  a female  from  57.1  km  north- 
west of  Laredo,  Texas  labeled  '"Branchia 
brevipes'’  with  the  Muma  identifying  label. 
There  is  no  record  of  this  species.  The  FSCA 
also  has  five  vials  containing  nineteen  males 
and  eight  females  of  Muma’s  material  from 
the  same  site  collected  on  the  same  day  la- 
beled "Branchia  brevipes'\  Examination  of 
the  male  holotype  as  well  as  the  above  ma- 
terial determined  all  these  specimens  to  be 
Brancia  brevis  Muma.  These  are  included  in 
the  material  examined. 

ACKNOWLEDGMENTS 

We  would  like  to  thank  Lorenzo  Prendini 
(AMNH);  Cheryl  Barr  (EMEC);  Paisley  Cato 
and  Jim  Berrian  (SDMC);  and  G.B.  Edwards 
(FSCA)  for  loaning  the  specimens  used  in  this 
study.  This  project  was  partially  supported  by 
National  Science  Foundation  grant  DBI- 
0346378  awarded  to  PEC. 

LITERATURE  CITED 

Brookhart,  J.O.  & RE.  Cushing.  2002.  New  species 
of  Eremobatidae  (Arachnida,  Solifugae)  from 
North  America.  Journal  of  Arachnology  30:84- 
97. 

Brookhart,  J.O.  & RE,  Cushing.  2004.  The  system- 
atics  of  the  Eremobates  scaber  species-group 
(Solifugae,  Eremobatidae).  Journal  of  Arachnol- 
ogy 32:284-312. 

Brookhart,  J.O.  & M.H.  Muma.  1981.  The  pallipes 


species-group  of  Eremobates  Banks  (Solpugida: 
Arachnida).  Florida  Entomologist  64:283-308. 

Brookhart,  J.O.  & M.H.  Muma.  1987.  Arenotherus, 
a new  genus  of  Eremobatidae  (Solpugida)  in  the 
United  States.  Rrinted  for  the  authors  by  Cherry 
Creek  High  School  Rrint  Shop,  Englewood,  Col- 
orado. 

Harvey,  M.S.  2002.  Nomenclatural  notes  on  Soli- 
fugae, Amblypygi,  Uropygi  and  Araneae  (Arach- 
nida). Records  of  the  Western  Australian  Muse- 
um 20:449-459. 

Harvey,  M.S.  2003.  Catalogue  of  the  Smaller 
Arachnid  Orders  of  the  World:  Amblypygi,  Uro- 
pygi, Schizomida,  Ralpigradi,  Ricinulei  and  So- 
lifugae. CSIRO  Rublishing,  Melbourne. 

Muma,  M.H.  1951.  The  arachnid  order  Solpugida 
in  the  United  States.  Bulletin  of  the  American 
Museum  of  Natural  History  97:35-141. 

Muma,  M.H.  1962.  The  arachnid  order  Solpugida 
in  the  United  States,  supplement  1,  American 
Museum  Novitates  2092:1-44. 

Muma,  M.H.  1970.  A synoptic  review  of  North 
American,  Central  American  and  West  Indian 
Solpugida  (Arthropoda:  Arachnida):  Arthropods 
of  Florida  and  Neighboring  Land  Areas  5:1-62. 

Muma,  M.H.  1989.  New  species  and  records  of  Sol- 
pugida (Arachnida)  from  the  United  States.  Rri- 
vately  published  by  the  author  by  Douglas  Rrint 
Shop.  Rp.  1-50. 

Muma,  M.H.  & J.O.  Brookhart.  1988.  The  Eremo- 
bates palpisetulosus  species-group  (Solpugida: 
Eremobatidae)  in  the  United  States.  Rublished 
for  the  authors  by  the  Cherry  Creek  High  School 
print  shop. 

Roewer,  C.F.  1934.  Solifugae,  Ralpigradi.  Vol. 
5(IV)(4)(4-5).  Rp.  481-723.  In  Klassen  und  Ord- 
nungen  des  Tierreichs.  5:  Arthropoda.  IV:  Arach- 
noidea  (Bronn,  H.G.,  Ed.),  Akademische  Ver- 
lagsgesellschaft  M.B.H.,  Leipzig. 

Vazquez-Rojas,  I.M.  1981.  Solifugos  de  Mexico 
(Arachnida:  Solifugae).  Universidad  Nacional 
Autonoma  de  Mexico,  Facultad  de  Ciencias, 
Mexico  (D.F.)  Rp.  1-78.  Bachelor  of  Science 
Thesis.  Unpublished. 

Vazquez-Rojas,  I.M.  1995.  Los  aracnidos  de  Mex- 
ico parte  1:  Ricinulei,  Amblypygi,  Solifugae, 
Ralpigradi,  Schizomida,  Uropygi.  Dugesiana  2: 

15-17. 

Manuscript  received  17  December  2003,  revised  17 
June  2004. 


2005.  The  Journal  of  Arachnology  33:726-734 


VISUAL  ACUITY  OF  THE  SHEET- WEB  BUILDING  SPIDER 
BADUMNA  INSIGNIS  (ARANEAE,  DESIDAE) 


Christofer  J.  Clemente,  Kellie  A.  McMaster,  Liz  Fox,  Lisa  Meldrum^, 

Barbara  York  Main  and  Tom  Stewart:  School  of  Animal  Biology,  University  of 
Western  Australia,  Crawley,  Western  Australia,  6009. 

ABSTRACT.  Visual  acuity  in  the  sheet- web  building  spider  Badumna  insignis  (L.  Koch  1872)  (Araneae, 
Desidae)  was  examined  in  relation  to  its  microhabitat.  We  examined,  using  histological  techniques,  the 
major  structural  and  functional  features  of  the  visual  systems,  including  external  and  internal  ocular  or- 
ganizations, resolution,  sensitivity,  focal  lengths  and  the  field  of  view  for  each  eye.  Badumna  insignis 
showed  little  differentiation  in  its  ocular  arrangement  from  the  presumed  ancestral  condition  in  spiders, 
with  poor  visual  acuity  and  a small  field  of  view.  Resolution  and  sensitivity  were  low,  particularly  in  the 
secondary  eyes.  The  AM  eyes  were  enhanced  showing  larger  fields  of  view  and  higher  sensitivity,  resem- 
bling that  of  nocturnal  uloborids.  These  eyes  appear  adapted  for  close-range  recognition,  due  to  short- 
range  focus  and  good  visual  overlap. 

Keywords^  Corneal  eye,  vision,  field  of  view,  sheet-web 


Spiders  are  renowned  for  their  effective  and 
complex  visual  systems  (Land  1985).  The 
primitive  eye  arrangement  of  spiders,  as  hy- 
pothesized by  Homann  (1971),  consists  of  two 
transverse  rows  each  containing  four  eyes. 
The  first  row  consists  of  the  anterior  median 
(AM)  eyes  in  the  middle  and  the  anterior  lat- 
eral (AL)  eyes  on  the  periphery.  Similarly,  the 
posterior  eyes  are  grouped  into  posterior  me- 
dian (PM)  eyes  and  posterior  lateral  (PL)  eyes. 
However,  deviations  from  this  pattern  are 
common  in  extant  species.  The  eyes  of  spiders 
often  form  three  or  four  rows  and  certain  pairs 
of  eyes  may  become  specialized  and  enlarged, 
while  other  pairs  may  become  reduced  or  lost 
(Homann  1971;  Comstock  1948).  The  visual 
capacity  of  spiders  varies  according  to  the 
size,  shape,  internal  arrangement  and  position 
of  the  visual  field  of  the  eyes  (Forster  1979; 
Foelix  1982;  Opell  & Cushing  1986;  Opell  & 
Ware  1987;  Land  & Barth  1992). 

Visual  acuity  is  a combination  of  many  as- 
pects of  the  visual  system  such  as  field  of 
view,  focal  length,  resolution  and  sensitivity. 
The  external  placement  and  internal  arrange- 
ment determine  the  field  of  view  of  each  eye 
(Land  1985).  Forward-facing  binocular  vision 
is  a product  of  overlapping  visual  fields,  and 
is  necessary  for  good  distance  judgment.  The 

' Deceased. 


distance  over  which  an  eye  can  focus  upon  an 
object  is  determined  by  the  focal  length  of  its 
lens  (Homann  1971).  This  ranges  from  38.01 
p.m  in  the  AL  eyes  of  the  uloborid  Hyptiotes 
cavatus  (Hentz  1847)  (although  this  eye  ap- 
pears to  be  vestigial;  Opell  & Ware  1987),  to 
448  p.m  in  the  PM  eyes  of  the  ctenid  Cupien- 
nius  salei  (Keyserling  1877)  (Land  & Barth 
1992).  Sensitivity,  or  the  ability  to  see  in  low 
light  levels  varies,  generally  in  relation  to  the 
light  conditions  under  which  each  species  op- 
erates (Opell  & Ware  1987).  The  number  of 
visual  cells  (rhabdomeres)  within  the  retina 
determines  the  quality  of  image  resolution 
(Foelix  1982).  Small  numbers  of  rhabdomeres 
in  the  retina,  such  as  10-20  in  some  eyes  of 
the  ochyroceratid  Speocera  (Berland  1914), 
detect  little  more  than  movement  (Homann 
1971).  In  contrast,  the  PM  eyes  of  the  wolf 
spider  Lycoi'a  tarantula  (Linnaeus  1758),  con- 
tain about  5470  rhabdomeres  and  would  thus 
have  greater  image  resolution  (Kovoor  et  al. 
1992). 

Visual  acuity  in  a spider  is  often  related  to 
the  microhabitat  that  it  occupies,  or  the  type 
of  prey  and  method  of  capture  (Forster  1979; 
Rovner  1993;  Schmid  1998;  Ortega-Escobar 
& Munoz-Cuevas  1999).  However,  much  of 
the  literature  is  limited  to  spiders  in  relatively 
few  microhabitat  types,  such  as  salticids,  ac- 


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CLEMENTE  ET  AL.— VISUAL  ACUITY  IN  BADUMNA  INSIGNIS 


111 


tively-hunting  jumping  predators  (Land  1969; 
Forster  1979;  Harland  & Jackson  2000  2002; 
Parker  & Hegedus  2003);  lycosids,  ground 
dwelling  sit-and-wait  predators  (Lizotte  & 
Rovner  1988;  Land  & Barth  1992;  Rovner 
1993;  Persons  & Uetz  1996,  1998;  Grusch  et 
al.  1997;  Schmid  1998;  Ortega-Escobar  & 
Munoz-Cuevas  1999;  Dacke  et  al.  2001);  ulo- 
borids,  orb  web  or  single  line  web  building 
spiders  (Opell  & Cushing  1986;  Opell  & Ware 
1987;  Opell  1988)  and  Deinopis  subrufa  (L. 
Koch  1879),  a net  casting  spider  (Blest  & 
Land  1977).  Few  studies  have  focused  on  vi- 
sual acuity  in  a sheet-web  building  spider. 

We  examined  the  focal  length,  resolution, 
sensitivity  and  field  of  view  in  Badumna  in- 
signis  (Koch  1872),  which  builds  an  asym- 
metrical sheet- web  that  extends  from  a tubular 
retreat  and  is  attached  to  a substrate.  The  web 
consists  of  many  pairs  of  parallel  support  lines 
overlain  with  zigzag  threads  of  cribellate  silk 
that  function  to  entangle  prey  (Main  1976; 
Opell  1999).  The  sheet- web  of  B.  insignis 
both  defines  the  individual’s  foraging  patch 
and  provides  some  shelter  from  predators.  Vi- 
brations on  the  web  can  also  be  used  to  rec- 
ognize the  identity  of  an  object  (Suter  1978; 
Barth  1982;  Masters  et  al.  1986;  Herberstein 
et  al.  1998).  In  natural  situations  B.  insignis 
builds  its  web  under  the  shelter  of  logs,  loose 
bark  of  trees,  rocks,  cliffs  and  stones,  prefer- 
ring dry  positions  (Main  1964).  However  its 
opportunistic  nature  has  allowed  it  to  take  ad- 
vantage of  areas  settled  by  humans,  where  it 
is  quite  common  around  houses,  sheds,  win- 
dow-sills, under  eaves  and  rafters,  boxes  and 
outdoor  furniture  (Main  2001). 

METHODS 

Twenty  adult  female  specimens  of  Badum- 
na insignis  (L.  Koch  1872)  were  collected 
over  a period  of  three  weeks  during  February 
2001,  within  the  grounds  of  The  University  of 
Western  Australia. 

External  ocular  organization. — ^Three  ex- 
ternal features  were  measured  on  each  speci- 
men: total  eye  width  (TEW),  total  eye  depth 
(TED)  and  eye  diameters  (Fig.  1).  These  mea- 
surements may  be  influenced  by  both  orien- 
tation of  the  lens  and  the  amount  of  tissue 
devoted  to  each  eye  type.  Measurements  were 
taken  under  a binocular  dissecting  microscope 
with  an  ocular  micrometer.  Since  all  the  ex- 
ternal features  correlated  significantly  with 


Figure  1. — External  measurements  taken  on  B. 
insignis;  AM  = anterior  median  eyes;  AL  = ante- 
rior lateral  eyes;  PM  = posterior  median  eyes;  PL 
= posterior  lateral  eyes;  TED  = total  eye  diameter; 
TEW  = total  eye  width;  IS  = interocular  space. 


carapace  length  (with  the  exception  of  the  di- 
ameter of  the  PM  eyes  P = 0.054),  values 
were  standardized  for  the  animals’  size  by  di- 
viding each  measurement  by  the  carapace 
length.  Repeated  measures  ANOVA  with  one 
within  subject  factor  and  no  between  subject 
factors,  and  Student-Newman-Keuls  post-hoc 
tests,  were  used  to  determine  significant  dif- 
ferences in  the  relative  eye  diameters. 

Internal  ocular  organization. — Three 
specimens  of  B.  insignis  were  killed,  using 
CO2  gas,  and  the  cephalathorax  trimmed  to  a 
small  block  of  tissue  and  fixed  in  Karnovsky’s 
fixative  for  72  hours.  Specimens  were  then 
washed  and  further  trimmed  down  in  spider 
saline  (scorpion  saline  excluding  the  CaCl2; 
Zwicky  1968)  and  placed  in  phosphate  buffer 
prior  to  being  embedded  in  araldite/procure. 
Longitudinal  and  transverse  sections  (1  p.m 
thick)  were  cut  using  an  LKB  ultratome  and 
a diamond  knife.  Sections  were  mounted  on 
slides  and  stained  with  toluidine  blue.  These 
sections  were  used  to  determine  the  internal 
ocular  organization  and  to  measure  resolution, 
sensitivity  and  field  of  view  of  individual 
eyes. 

Resolution. — The  numbers  of  axons  exit- 
ing each  eye  were  counted  from  sections  cut 
using  the  same  methods  as  for  internal  ocular 
organization.  Resolution  is  dependent  upon 
the  number  of  photoreceptors,  or  rhabdomeric 
cells  per  eye.  The  higher  the  density  of  cells 
the  finer  the  resolution  of  an  image  (Land 
1985).  The  number  of  nerve  axons  exiting  a 


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THE  JOURNAL  OF  ARACHNOLOGY 


spider’s  eye  is  in  a 1:1  ratio  with  the  number 
of  photoreceptors  (Uehara  & Uehara  1996). 

Focal  length, — The  focal  length  of  each 
lens  was  determined  using  the  ‘hanging  drop’ 
method  described  in  Homann  (1928)  and 
Land  (1985).  The  lens,  along  with  a small  pro- 
portion of  the  surrounding  cuticle,  was  dis- 
sected from  the  head  and  stored  in  spider  sa- 
line. After  being  cleared  of  excess  tissue  in 
warm,  dilute  sodium  hydroxide,  the  lens  was 
suspended  in  a drop  of  spider  saline  from  the 
underside  of  a cover  slip.  Using  a microscope, 
the  image  through  the  lens  was  then  viewed, 
targeting  an  object  of  known  size  (o).  The  dis- 
tance between  the  lens  and  the  object  was  then 
measured  using  callipers  (|x).  The  size  of  the 
image  (i)  was  determined,  and  the  focal  length 
was  calculated,  using  the  formula  described 
by  Opell  & Ware  (1987:  Table  1).  For  each 
lens  type  an  average  of  the  values  measured 
was  determined.  Repeated  measures  ANOVA, 
with  one  within  subject  factor  (eye)  and  no 
between  subject  factors,  with  a Tukey/Kramer 
post-hoc  test,  was  used  to  determine  differ- 
ences between  the  focal  lengths  of  the  differ- 
ent eyes. 

Sensitivity. — Sensitivity  (/-number),  or  the 
eye’s  ability  to  admit  light,  was  calculated  us- 
ing values  for  focal  length  (F)  and  the  diam- 
eter of  the  retina  (d),  measured  from  the  ex- 
tremities of  the  rhabdomeres  in  each  species 
(Opell  & Ware  1987).  The  resulting /-number 
is  inversely  related  to  the  eyes  ability  to  admit 
light  (Land  1985).  Focal  lengths  were  deter- 
mined by  the  above  methods  and  retinal  di- 
ameters were  determined  by  taking  measure- 
ments from  slides  obtained  using  methods 
described  for  internal  ocular  organization. 
These  values  were  then  entered  into  the  sen- 
sitivity equation  outlined  in  Opell  & Ware 
(1987:  Table  1). 

Field  of  view. — Histological  investigation 
revealed  B.  insignis  has  a ‘canoe  shaped’  ta- 
petum,  which  reflects  light  at  an  acute  angle 
making  it  impossible  to  determine  the  field  of 
view  using  ophthalmoscopy  (Land  1985). 
Therefore,  the  visual  field  was  determined  us- 
ing physical  measurements  of  the  lens  and  the 
surrounding  retinal  hemisphere.  To  determine 
the  field  of  view,  the  size  and  orientation  of 
the  visual  angle  were  determined  according  to 
methods  comparable  to  those  used  on  ulobor- 
ids  by  Opell  & Cushing  (1986)  and  Opell  & 
Ware  (1987).  Two  deviations  from  these  meth- 


Figure  2. — Diagrammatic  section  of  the  second- 
ary eye  of  B. insignis.  nl  = front  nodal  point;  n2  = 
rear  nodal  point;  Cl  = center  of  curvature  of  front 
of  lens;  C2  = center  of  curvature  of  the  rear  of  lens; 
PI  = front  principal  plane;  P2  = rear  principal 
plane;  P.A.  = principal  axis;  T = tapetum;  V.A.  = 
visual  axis. 


ods  were  employed.  Measurements  from  fron- 
tal sections  rather  than  sagittal  sections  were 
used  and  the  tapetal  periphery  was  taken  to 
represent  the  limits  of  the  visual  cells  and 
therefore  define  the  width  of  the  retina. 

Size  of  visual  angle. — To  ascertain  the  field 
of  view  of  each  eye,  the  angle  at  which  light 
can  enter  to  activate  visual  cells  must  be  cal- 
culated; this  is  the  visual  angle.  The  visual 
angle  of  B.  insignis  was  determined  mathe- 
matically using  measurements  taken  from  sec- 
tions of  the  eye  (Fig.  2).  A simple  lens  has 
two  centers  and  two  radii  of  curvature,  one 
for  both  the  front  surface  and  the  rear  surface 
of  the  lens.  The  line  joining  the  two  centers 
is  the  principal  axis  of  the  lens.  The  refractive 
index  of  each  lens  was  required  to  calculate 
the  front  and  rear  principal  planes  (Fig.  2),  and 
was  determined  using  measured  focal  length 
in  conjunction  with  the  radii  of  curvature  of 
each  lens  (Table  1).  This  index  was  then  used 
to  calculate  the  principal  planes  (Table  1).  The 
refractive  index  of  air  was  assumed  to  be  1.00 
and  the  refractive  index  of  spider  saline  was 
assumed  to  be  1.33  (Land  1969).  Drawings 
were  made  of  each  lens  and  its  retinal  hemi- 
sphere with  the  principal  axis,  principal  planes 
and  nodal  points  added  to  the  reconstruction 
(Fig.  2).  The  rear  nodal  point  was  calculated 
by  measuring  the  focal  length  forward  from 
the  retinal  hemisphere  along  the  principal 
axis.  The  front  nodal  point  was  then  calculat- 
ed since  the  distance  between  the  front  and 


CLEMENTE  ET  AL.— VISUAL  ACUITY  IN  BADUMNA  INSIGNIS 


729 


rear  nodal  points  along  the  principal  axis 
equates  to  the  distance  between  the  principal 
planes. 

To  determine  the  visual  angle  of  each  eye, 

sections  from  the  frontal  plane  were  used. 
Lines  were  drawn  from  the  peripheral  retinal 
cells  in  front  of  the  tapetum  to  the  rear  nodal 
point  and  the  angle  these  lines  made  with  the 
principal  axis  was  measured.  An  inverted  pro- 
jection of  this  angle  from  the  front  nodal  point 
produced  the  eye’s  visual  field  (Fig.  2).  A line 
bisecting  this  field  represents  the  visual  axis. 
To  plot  the  visual  field  around  the  visual  axis, 
the  angle  made  with  the  principal  axis  was 
measured. 

Orientation  of  visual  angle.— To  accurate- 
ly plot  visual  fields,  the  relative  positions  of 
each  eye  must  be  known,  therefore  the  prin- 
cipal axis  must  be  determined  relative  to  both 
its  frontal  and  sagittal  planes.  The  former  was 
determined  by  placing  the  specimen  under  a 
dissecting  microscope  attached  to  a digital 
camera.  A line  was  drawn  to  bisect  the  spec- 
imen along  the  midline.  A second  line  was 
drawn  along  the  points  where  the  lens  merged 
with  the  spider’s  carapace,  through  the  widest 
part  of  the  eye’s  ellipse.  A third  line  was  then 
drawn  through  the  center  of  the  eye  and  per- 
pendicular to  the  second  line  drawn.  The  an- 
gle this  line  made  with  the  midline  of  the  car- 
apace was  recorded,  and  represented  the  eye’s 
frontal  orientation  relative  to  the  sagittal 
plane.  To  determine  the  eye’s  sagittal  orien- 
tation, a similar  method  to  above  was  em- 
ployed in  which  the  spider  was  placed  on  its 
side  and  a similar  set  of  angles  was  created  to 
measure  the  angle  of  the  principal  axis  relative 
to  the  frontal  plane. 

Total  visual  arc,  the  angle  of  the  principal 
plane  and  the  visual  angle  were  used  to  plot 
fields  of  view  for  B.  insignis  by  moving  the 
principal  axis  relative  to  the  center  of  a geo- 
logical stereonet  accounting  for  the  deviations 
from  the  sagittal  and  frontal  planes.  Visual 
fields  were  produced  using  the  visual  axis  as 
a central  point,  around  which  the  angle  of  the 
visual  arc  was  plotted. 

Uniformity  of  refractive  index.^ — The  re- 
fractive index  of  each  lens  was  required  to 
calculate  the  size  of  the  visual  angle.  The 
methods  used  in  this  study  to  evaluate  refrac- 
tive index  in  B.  insignis  require  that  at  least 
two  specimens  be  used;  one  to  determine  the 
eye’s  focal  length  and  one  to  determine  the 


lens’s  physical  properties.  To  reduce  error  that 
may  result  from  using  two  specimens,  mean 
measurements  of  focal  length  for  each  eye 
type  were  used,  thereby  accounting  for  pos- 
sible differences  in  focal  lengths  between  the 
two  specimens. 

Representative  specimens  from  the  study 
population  have  been  deposited  in  the  Western 
Australian  Museum.  Slide  preparations  are 
held  in  the  Zoology  Building,  School  of  An- 
imal Biology,  University  of  Western  Australia. 

RESULTS 

External  ocular  organization. — The  eyes 
of  B.  insignis  were  widely  spaced  along  the 
carapace  but  not  deeply  set  (TEW  = 36.69  ± 
0.61,  TED  = 13.06  ± 0.42,  n = 20).  Diam- 
eters of  the  eyes  are  shown  in  Table  2.  There 
was  a significant  difference  in  the  sizes  of  the 
four  different  types  of  eyes  for  B,  insignis 
(Fi9,3  ^ 15.0,  P < 0.001).  The  PL  eyes  were 
significantly  larger  than  all  others,  while  both 
pairs  of  anterior  eyes  and  both  pairs  of  medial 
eyes  were  similar  in  size. 

Internal  ocular  organization. — -The  AM 
eyes  (Fig.  3)  display  a typical  bi-convex  lens 
formed  by  a visible  thickening  of  the  cuticular 
layer.  The  lens  is  separated  from  the  retina  by 
a layer  of  columnar  vitreous  cells.  The  retina 
is  composed  of  visual  cells  and  pigment  cells. 
The  most  anterior  portion  of  the  visual  cell, 
which  contains  the  rhabdomeres,  borders  the 
vitreous  layer  and  the  nuclei  lie  below. 

In  the  secondary  eyes  the  boundary  sepa- 
rating the  rhabdomeres  from  the  visual  cells 
is  marked  by  the  tapetum.  In  B.  insignis,  a 
'canoe-shape’  tapetum,  characteristic  of  most 
species  in  the  amaurobioid  clade  (Homann 
1971;  Land  1985)  was  found  (Fig.  4).  The  vi- 
sual cells  in  these  eyes  bend  around  the  ta- 
petum, exiting  through  the  opening  between 
the  adjacent  tapetal  plates.  In  the  eyes  of  B. 
insignis,  one  discrete  nerve  bundle  was  found 
to  emerge  from  each  eye. 

Resolution. — The  optic  nerves  from  all 
four  pairs  of  eyes  of  B.  insignis  were  found 
grouped  together,  surrounded  by  muscle  along 
the  midline  of  the  prosoma.  Identification  of 
the  eye  from  which  each  of  the  six  nerve  bun- 
dles originated,  was  possible  by  observing  the 
arrival  sequence  (within  the  slides)  of  each 
nerve  bundle  and  the  direction  from  which  it 
originated.  The  number  of  nerve  axons  (indi- 
cating resolution;  Table  2)  found  in  B.  insignis 


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THE  JOURNAL  OF  ARACHNOLOGY 


Table  1 . — Equations  used  in  histological  methods. 


Focal  length  (P): 

i 

o 

u 

i 

F = -u 
o 

F 

Refractive  index  {n)\ 

^ = (« - 1) 

1 ^ 1 d{n  — 1) 

n 

r, 

r,  r2  nr,r2 

U 

Power  of  lens  surface  (P): 

An 

Front:  P,  = — 

An 

Rear:  — — 


d 

An 


Equivalent  power  (P^): 

Pe  = P^+  Pi-  -P^Pi 
n 


Principal  planes  {VH)\ 

d Pj 

Front:  = - X 

n P, 


Rear: 


d P, 

Vi^i  = - X 

n Pe 


Nodal  points  (N): 

Determined  by  plotting  /-number  (sensitivity): 


F 

d 


image  length 

object  length 

object  and  eye  separation 

focal  length 

refractive  index 
radius  of  outer  curvature 
radius  of  inner  curvature 
lens  thickness 

the  difference  in  the  refractive  index  of  the 
front  lens  and  air  or  the  rear  lens  and  the  bodi- 
ly fluids 

radius  of  outer  curvature 
radius  of  inner  curvature 


front  surface  power 
rear  surface  power 
lens  thickness 
refractive  index 

lens  thickness 
refractive  index 
front  surface  power 
rear  surface  power 
equivalent  power 


front  nodal  point 
rear  nodal  point 
focal  length 
pigment  ring  diameter 


Figures  3-4. — 3.  Primary  eye  of  B.  insignis;  4.  Secondary  eye  of  B.  insignis. 


CLEMENTE  ET  AL.— VISUAL  ACUITY  IN  BADUMNA  INSIGNIS 


731 


Table  2. — Summary  of  parameters  measured  for  eyes  of  B.  insignis.  Values  shown  are  mean  values  ± 
standard  error  (where  calculated).  Values  for  resolution  are  the  mean  of  the  left  and  right  eye. 


Eye 

Eye  diameters 

(as  % of  carapace) 
n = 20 

Resolution 

(#  nerve  axons) 

n = 1 

Resolution 
(#  nerve  axons/ 
visual  angle)  n = \ 

Focal  Length  (jxm) 
n = 2 

Sensitivity 
(1 //-number) 
n = 1 

AM 

4.78  ± 0.15 

328 

3.5 

233.60  ± 17.74 

0.86 

AL 

4.99  ± 0.16 

96 

3.1 

209.26  ± 2.58 

0.37 

PM 

4.31  ± 0.14 

119 

3.2 

210.26  ± 7.68 

0.46 

PL 

5.71  ± 0.21 

102 

4.3 

198.06  ± 4.38 

0.34 

was  greatest  for  the  AM  eyes,  followed  in  or- 
der by  the  PL,  PM,  and  AL  eyes.  To  compare 
the  density  of  visual  cells  the  number  of  nerve 
axons  was  divided  by  the  size  of  the  visual 
angle.  All  eyes  were  similar  in  density,  being 
slightly  greater  in  the  PL,  followed  in  order 
by  the  AM,  PM  and  AL  eyes  (Table  2).  This 
suggests  that  the  retinal  cell  number  in  the 
AM  eyes  only  maintains  the  resolution  of 
these  eyes,  given  their  larger  visual  angle,  and 
does  not  increase  their  resolution. 

Focal  length. — The  eyes  of  B.  insignis  dis- 
played no  significant  differences  in  focal 
length  (Fi3  = 3.1,  P = 0.191;  Table  2). 

Sensitivity.— Calculated  /-numbers  for  B. 
insignis  were  relatively  high  (demonstrating  a 
low  amount  of  sensitivity;  Table  2).  The  high- 
est sensitivity  in  B.  insignis  was  found  in  the 
AM  eyes,  which  showed  a considerably  lower 
/-number  than  all  other  eyes  in  this  species. 
The  remaining  AL,  PL,  and  PM  eyes  had  sim- 
ilar low  sensitivities  (Table  2). 

Field  of  view. — Table  3 provides  values 
used  to  calculate  the  field  of  view  for  B.  in- 
signis. The  AM  eyes  showed  the  greatest  field 
of  view,  covering  130°  along  the  horizontal 
meridian  (Figs.  5 & 6).  They  also  had  a large 
degree  of  forward  facing  overlap,  extending 
55°  above  and  below  the  horizontal,  and  hav- 
ing a maximum  overlap  of  66°  on  the  hori- 
zontal meridian.  Both  sets  of  posterior  eyes 
and  the  AL  eyes  have  small  visual  fields  (less 
than  40°  horizontally  or  vertically)  that  show 
no  overlap  (Figs.  5 & 6).  Both  pairs  of  pos- 
terior eyes  are  directed  50°  above  horizontal, 
with  the  PM  eyes  directed  anteriorly  and  the 
PL  eyes  laterally. 

DISCUSSION 

Badumna  insignis  has  two  rows  of  four 
eyes,  reminiscent  of  a primitive  external  or- 
ganization (Homann  1971),  with  all  eyes 


showing  little  histological  differentiation,  or 
differences  in  diameter,  resolution  or  focal 
length.  The  AM  eyes  were  the  most  special- 
ized, with  the  greatest  sensitivity,  the  largest 
field  of  view  and  were  the  only  eyes  to  display 
binocular  overlap.  None  of  the  eyes  of  B.  in- 
signis displayed  the  long  distance  vision  or 
resolution  used  for  detecting  prey  at  a dis- 
tance. 

However,  there  is  a tradeoff  between  reso- 
lution and  sensitivity  due  to  physical  restric- 
tions of  eye  size  (Blest  & Land  1977).  The 
visual  system  of  B.  insignis  seems  to  be  se- 
lected for  sensitivity  rather  than  resolution,  as 
the  resolution  is  low,  even  for  web-building 
spiders.  The  orb  weaver  Argiope  amoena  (L. 
Koch  1878)  typically  has  400-500  optical 
nerve  axons  exiting  the  AM  eyes  (Uehara  et 
al.  1977),  which  is  greater  than  the  resolution 
found  in  B.  insignis. 

The  sensitivity  of  the  secondary  eyes  in  B. 
insignis  (2.16-2.97)  is  far  less  than  that  of  the 
nocturnally  active  web  building  uloborids, 
whose  /-number  ranges  from  0.88-1.70 
(Opell  & Ware  1987).  Instead,  they  more 
closely  reflect  those  of  the  visually  hunting 
diurnal  jumping  spiders,  which  have  /-num- 
bers ranging  from  2.68-5.90  (Foelix  1982; 
Land  1969).  This  suggests  that  B.  insignis  uti- 
lize their  secondary  eyes  under  higher  light 
levels.  Badumna  insignis  is  occasionally  ac- 
tive during  the  day  (Henderson  & Elgar  1999) 
thus,  the  secondary  eyes  may  be  utilized  dur- 
ing these  periods.  Conversely  the  /-number  of 
the  AM  eyes  of  B.  insignis  resembles  that  of 
the  nocturnal  uloborids  and  appears  more  suit- 
able for  its  typical  nocturnal  habit.  This  com- 
bination of  sensitivities  may  allow  B.  insignis 
to  be  a more  versatile  hunter,  predominately 
active  in  low  light-levels,  but  capable  of  tak- 
ing advantage  of  occasional  daylight  oppor- 
tunities. 


732 


THE  JOURNAL  OF  ARACHNOLOGY 


Ventral  gone  eye's  field  of  view  Posterior 

B[Two  eyes 
Hlhree  eyes 


Figures  5-6. — Fields  of  view  for  B.  insignis:  5.  Anterior  view;  6.  Dorsal  view.  AM  = anterior  median 
eyes;  AL  = anterior  lateral  eyes;  PM  = posterior  median  eyes;  PL  = posterior  lateral. 


However,  the  lack  of  binocular  vision  dis- 
played by  any  of  the  secondary  eyes  would 
restrict  depth  perception  and  therefore  limit 
the  use  of  these  eyes  in  prey  capture.  The  pos- 
sible function  of  the  secondary  eyes  remains 
unclear.  With  such  small  fields  of  view  it  is 
unlikely  they  would  be  useful  in  prey  detec- 
tion. These  secondary  eyes  may  be  used  for 
distinguishing  light  levels  to  control  circadian 
rhythms  (Uehara  et  al.  1994),  or  act  simply  as 
wide  angle  detectors  of  movement.  Converse- 
ly, the  AM  eyes  with  their  large  forward  fac- 
ing fields  of  view  and  large  area  of  binocular 
vision,  would  play  an  important  role  in  rec- 


ognition and  judgement  of  distance  to  the  en- 
tangled prey. 

The  web  increases  the  perceptive  area  of  a 
spider  (Peters  & Pfreundt  1986)  and  evidence 
suggests  spiders  can  determine  the  identity  of 
an  object  in  the  web  by  the  vibrations  it  cre- 
ates (Suter  1978;  Barth  1982;  Masters  et  al. 
1986;  Herberstein  et  al.  1998).  Coupled  with 
its  poor  visual  acuity,  this  suggests  that  B.  in- 
signis relies  on  its  web  rather  than  its  eyes  for 
prey  detection.  The  web  of  B.  insignis  also 
acts  to  entangle  and  ensnare  prey,  and  so  also 
plays  a significant  role  in  prey  capture. 

The  relatively  unspecialized  visual  system 


Table  3. — Ocular  properties  and  measurements  used  to  calculate  and  plot  fields  of  view  for  Badumna 

insignis. 


Visual 

Lens  Pigment  axis 


thick- 

Radius of 

Refrac- 

ring 

Total 

Visual  axis 

Visual 

from 

ness 

curvature 

tive 

diameter 

num- 

visual 

from 

axis  from 

sagittal 

Eye 

(irm) 

(rl/r2,  |jLm) 

index 

(|xm) 

ber 

angle 

physical  axis 

frontal  plane 

plane 

AM 

184.7 

142.7/107.8 

1.31 

200.8 

1.16 

93° 

8°  right  of  right 
eye 

0° 

9° 

AL 

129.0 

126.9/108.2 

1.32 

87.4 

2.67 

32° 

6°  right  of  right 

eye 

33°  ventral 

o 

o 

PM 

109.4 

108.3/98.5 

1.28 

97.5 

2.16 

37° 

19°  right  of  right 

eye 

38°  dorsal 

33° 

PL 

91.5 

112.3/97.8 

1.29 

33.3 

2.97 

24° 

1°  right  of  right 
eye 

44°  dorsal 

'-O 

o 

CLEMENTE  ET  AL.— VISUAL  ACUITY  IN  BADUMNA  INSIGNIS 


733 


of  B,  insignis  may  be  attributed  to  the  utili- 
zation of  the  web.  As  well  as  functioning  to 
ensnare  prey,  a web  can  also  be  protective.  A 
complete  field  of  view  is  not  essential  as  the 
web  warns  the  spider  of  some  potential  threats 
and  provides  a hidden  retreat.  The  web  essen- 
tially functions  to  increase  the  perceptive  area 
for  prey  capture  and  may  act  in  place  of  a 
highly  developed  visual  system.  However,  B. 
insignis  still  requires  a system  for  recognizing 
whether  an  object  within  the  web  is  predator 
or  prey.  The  araneophagic  spider  Lampona  cy~ 
lindrata  (L.  Koch  1866)  (Araneae  Lamponi- 
dae)  is  commonly  known  to  prey  upon  Bad- 
umna  insignis  (Hickman  1967;  Main,  pers 
obs).  The  eyes  of  B.  insignis  appear  adapted 
for  close  range  recognition,  due  to  the  short- 
range  focus  and  good  depth  perception  of  the 
AM  eyes.  Thus  the  visual  system  operates  to 
inform  B.  insignis  of  the  distance  to  an  object 
and  whether  to  attack  or  retreat. 

ACKNOWLEDGEMENTS 

We  are  grateful  to  the  following  people 
from  the  School  of  Animal  Biology,  Univer- 
sity of  Western  Australia:  Professor  Lyn  Bea- 
zley,  for  specialist  information  on  optic 
nerves;  Wally  Gibb,  for  advice  on  collection 
of  specimens;  Phil  Runham,  for  help  with  ex- 
perimental methods  and  general  advice.  We 
would  also  like  to  thank  the  reviewers  for 
their  time  and  helpful  comments  on  this  man- 
uscript. 

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Manuscript  received  10  June  2004,  revised  28  No- 
vember 2004. 


2005=  The  Journal  of  Arachnology  33:735-744 


A NEW  SPECIES  OF  BOTHRIURUS  FROM  BRAZIL 
(SCORPIONES,  BOTHRIURIDAE) 


Camilo  Ivan  Mattoni^  and  Luis  Eduardo  Acosta:  Catedra  de  Diversidad  Animal  I, 
Facultad  de  Ciencias  Exactas,  Fisicas  y Naturales,  Universidad  Nacional  de  Cordoba, 
Av.  Velez  Sarsfield  299,  X5000JJC  Cordoba,  Argentina.  E-mail:  cmattoni@com. 
uncor.edu 

ABSTRACT.  A new  species  of  scorpion  from  southern  Brazil,  Bothriurus  pora,  is  described.  The  hem- 
ispermatophore  of  this  speqies  is  unique  within  the  genus,  displaying  a highly  developed  and  extremely 
complex  capsular  region.  External  morphology  and  shape  of  the  sperm  packages  show  a close  relationship 
with  the  Bothriurus  bonariensis  species  group. 

RESUMEN.  Se  describe  una  nueva  especie  de  escorpion  del  sur  del  Brazil,  Bothriurus  pora.  El  hemies- 
permatoforo  de  esta  especie  presenta  caracteres  unicos  en  el  genero,  con  una  region  capsular  muy  desa- 
rrollada  y extremadamente  compleja.  Su  morfologia  externa  y la  forma  general  de  sus  paquetes  esper- 
maticos  demuestran  una  relacion  cercana  con  el  grupo  de  especies  Bothriurus  bonariensis. 

Keywords:  Scorpiones,  Bothriuridae,  Bothriurus,  bonariensis  group,  taxonomy,  Brazil,  Neotropics 


The  genus  Bothriurus  Peters  1861  (Scor- 
piones, Bothriuridae)  comprises  small  to  me- 
dium-sized scorpions,  distributed  over  a large 
part  of  South  America  (Argentina,  Chile,  Uru- 
guay, Bolivia,  Paraguay,  southern  Peru,  and 
from  southern  to  northwestern  Brazil)  in  di- 
verse habitats  including  deserts,  steppes,  dry 
forests,  mountains,  savannas  and  rainforests 
(Maury  1979,  1982;  Lourengo  & Maury  1979; 
Acosta  & Ochoa  2002;  Mattoni  2003).  The 
genus  currently  contains  36  valid  nominal 
species  (Lowe  & Fet  2000;  Mattoni  2002a, 
2002b,  2002c;  Ojanguren  Affilastro  2002, 
2003),  although  the  actual  number  should 
reach  around  45  (Mattoni  2003),  making  it  the 
most  diverse  genus  of  Bothriuridae.  Bothriu- 
rus species  are  presently  placed  in  13  species 
groups,  characterized  by  both  somatic  and 
genitalic  characters  (Maury  1979,  1982,  1984; 
Lourengo  & Maury  1979;  Maury  & Acosta 
1993;  Mattoni  2002b).  These  “groups”  show 
considerable  internal  uniformity,  and  some 
may  be  monophyletic  (Acosta  & Peretti  1998; 
Mattoni  2003).  Although  a previous  analysis 
(Prendini  2000,  2003)  questioned  the  mono- 

‘ Current  address:  Department  of  Invertebrate  Zo- 
ology, American  Museum  of  Natural  History,  79th 
St.  at  Central  Park  West,  New  York,  NY  10024 
USA.  E-mail:  emattoni@amnh.org 


phyly  of  Bothriurus,  a more  recent  phyloge- 
netic analysis  demonstrates,  albeit  with  weak 
support,  that  Bothriurus  is  monophyletic 
(Mattoni  2003). 

During  the  course  of  a larger  revision  of 
Bothriurus,  a single  Bothriurus  male  that 
could  not  be  assigned  to  any  of  the  known 
species  groups,  was  discovered  in  the  collec- 
tion of  the  Instituto  Butantan,  Sao  Paolo,  Bra- 
zil. Its  external  morphology  suggested  a close 
relationship  to  the  bonariensis  group  (Maury 
& Acosta  1993;  Ojanguren  Affilastro  2003), 
but  the  complex  morphology  of  its  hemisper- 
matophore  was  unlike  any  other  species  of 
Bothriurus.  The  specimen  is  described  below 
as  B.  pora  new  species. 

METHODS 

Terminology  for  general  morphology  fol- 
lows that  of  Stahnke  (1970),  except  for  the 
pedipalp  (Francke  1977)  and  metasomal  cari- 
nae  (Prendini  2000,  2003),  trichobothrial  no- 
menclature (Vachon  1974)  and  pedipalp  seg- 
mentation (Sissom  1990).  The  nomenclature 
of  the  hemispermatophore  is  based  on  San 
Martin  (1963,  1965),  Peretti  (1992)  and  Mau- 
ry & Acosta  (1993);  we  maintained  the  ab- 
breviations derived  from  the  names  in  Span- 
ish, since  they  were  widely  used  in  the 
literature.  Carinae  of  metasomal  segments  are 


735 


736 


THE  JOURNAL  OF  ARACHNOLOGY 


Figures  1-4. — Bothriurus  pora  new  species,  holotype  male  (IBSP-SC);  1.  Metasomal  segment  V and 
telson,  lateral  view;  2.  Metasomal  segment  V,  ventral  view;  3-4.  Right  pedipalp  chela;  3.  Ventrointernal 
view;  4.  External  view.  Scale  bar  = 1 mm. 


abbreviated  as  follows:  Dsm  = dorsal  sub- 
median; Dl  = dorsal  lateral;  Lsm  = lateral 
supramedian;  Lm  = lateral  median;  Li  = lat- 
eral inframedian;  Vl  = ventral  lateral;  VsM  == 
ventral  submedian;  Vm  = ventral  median.  He- 
mispermatophore  structures:  L = lamina;  c.d. 
— distal  crest  of  lamina;  r.f.  — frontal  fold; 
c.f.  = frontal  crest;  Rb.  = basal  portion;  Li. 
= internal  lobe  of  capsule;  Lb.  = basal  lobe 
of  capsule;  Le.  — external  lobe  of  capsule;  c.c. 

capsular  concavity;  r.b.  = basal  fold.  The 
material  examined  are  deposited  at  Institute 
Butantan,  Sao  Paulo,  Brazil  (IBSP-SC);  Ca- 
tedra  de  Diversidad  Animal  I,  Facultad  de 
Ciencias  Exactas,  Fisicas  y Naturales,  Univer- 
sidad  Nacional  de  Cordoba,  Argentina  (CDA); 
Museu  de  Ciencias  Naturais,  Fundagao  Zoo- 
botanica  do  Rio  Grande  do  Sul,  Porto  Alegre, 
Brazil  (MCN);  and  Museu  de  Zoologia  da 
Universidade  de  Sao  Paulo,  Brazil  (MZUSP). 
All  measurements  are  in  mm  and  were  taken 
using  an  ocular  micrometer.  Illustrations  were 
produced  using  a Leica  MSS  stereomicro- 
scope and  camera  lucida. 

Bothriurus  pora  new  species 
Figs.  1-16,  23 

? Bothriurus  bonariensis:  Brazuna  & Roller,  1998: 

1 (probable  misidentification). 


Type. — Holotype  male,  BRAZIL:  Estado 
de  Mato  Grosso  do  Sul:  Ponta  Pora  (22°32'S, 
55°43'W),  652  m,  13  December  1966,  N.RV. 
Salvaeno  (IBSP-SC  937). 

Etymology. — The  species  name  is  a noun 
in  apposition  taken  from  the  type  localiy. 

Diagnosis. — In  terms  of  external  morphol- 
ogy, B.  pora  appears  most  closely  related  to 
the  bonariensis  group:  B.  bonariensis  (C.L. 
Koch  1842),  B.  chacoensis  Maury  & Acosta 
1993,  and  B.  jesuita  Ojanguren  Affilastro 
2003.  All  of  these  species  share  a similar  ar- 
rangement of  the  ventral  carinae  of  metasomal 
segment  V.  However,  subtle  differences  exist. 
In  B.  bonariensis,  the  Vl  and  VsM  carinae  are 
almost  connected  medially  (Figs.  19,  20), 
whereas  in  the  other  species  they  are  not  com- 
pletely fused,  leaving  a small  median  gap;  the 
most  distal  granules  of  the  Vm  carina  (slightly 
more  developed)  are  placed  in  that  space.  The 
ventral  surface  of  segment  V is  noticeably 
granular  in  B.  pora  (Fig.  2),  compared  with 
other  species  of  the  bonariensis  group,  in 
which  it  is  smooth  (Fig.  20).  The  Dsm  carinae 
of  the  metasomal  segments  I to  IV  are  more 
weakly  developed  in  the  bonariensis  group 
(represented  only  by  terminal  granules). 


MATTONI  & ACOSTA— W BOTHRIURUS  FROM  BRAZIL 


737 


5 


6 


7 


8 


Figures  5-8. — Bothriurus  pora  new  species,  holotype  male  (IBSP~SC);  5.  Right  pedipalp  femur,  dorsal 
view;  6“8.  Right  pedipalp  patella;  6.  Dorsal  view;  7.  External  view;  8.  Ventral  view.  Scale  bar  = 1 mm. 


whereas  in  B.  pora  they  are  granular  through- 
out.  Bothriurus  pora  shares  with  the  bonarien- 
sis  group  a robust  habitus  and  dark  coloration. 
Another  important  similarity  is  the  pro- 
nounced dorsal  gland  of  the  male  telson, 
which  occupies  the  entire  dorsal  surface  of  the 
vesicle.  However,  in  the  bonariensis  group, 
the  gland  is  contained  in  a large  depression 
which  is  absent  in  B.  pora.  The  chaetotaxy  of 
the  metasoma  is  quite  similar  between  the  spe- 
cies of  the  bonariensis  group  and  B.  pora 
(Figs.  15-18),  however,  the  latter  shows  a pair 
of  ventromedian  chetae  on  Segment  III  that  is 
absent  in  the  bonariensis  group. 

In  spite  of  many  external  similarities,  the 
hemispermatophore  of  B.  pora  is  markedly 
different.  The  hemispermatophore  of  B.  pora 
is  unique  in  Bothriurus,  presenting  characters 
not  previously  observed  in  other  bothriurid 
species  (Figs.  9-13).  The  lamina  exhibits  a 
well  developed  r.f.  and  c.f.,  and  a curved  in- 
ternal crest.  The  lobe  region  is  extremely 
complex,  with  Lb.  elongated  and  concave, 
bearing  partitions  in  its  dorsal  surface.  In  the 
bonariensis  group,  the  lamina  is  more  elon- 
gated, with  c.f.  much  more  extended,  and  Lb. 
larger  and  triangular  in  shape  (Figs.  21,  22). 
A feature  shared  by  both  B.  pora  and  the  B. 
bonariensis  species  group  is  the  general  mor- 
phology of  the  sperm  packages  (as  preserved 
in  80%  ethanol),  which  display  a strongly 
gnarled,  helicoidal  anterior  region  (Peretti  & 


Battan-Horenstein  2003).  In  B.  pora,  however, 
the  degree  of  torsion  is  less  marked  than  in 
the  bonariensis  group. 

Several  robust  synapomorphies  (e.g.,  shape 
and  size  of  spiracles,  shape  of  sperm  pack- 
ages, position  of  Et3  trichobothria  on  chela) 
suggest  that  B.  pora  is  the  sister  taxon  of  the 
bonariensis  species  group  (Mattoni  2003). 
Also  the  bonariensis  species  group  is  sup- 
ported by  several  synapomorphies:  the  large 
depression  on  the  dorsal  surface  of  the  telson, 
the  hemispermatophore  (similar  in  all  the  spe- 
cies of  the  group),  and  the  pigmentation  pat- 
tern of  the  ventral  face  of  the  metasoma  (with 
two  lateral  stripes)  (Mattoni  2003).  However, 
the  hemispermatophore  of  B.  pora  is  clearly 
divergent,  with  many  unique  charactes  not 
previously  observed  in  the  family  Bothriuri- 
dae  (see,  e.g.,  Maury  1980).  The  structure  of 
the  basal  lobe,  which  bears  thin  dorsal  walls, 
raises  questions  about  its  function,  as  this  part 
enters  the  female  atrium  during  sperm  transfer 
(Peretti  1992). 

The  helicoidal  end  of  the  sperm  package  in 
B.  pora  and  the  three  species  of  the  bonarien- 
sis group,  has  not  been  recorded  in  other  Both- 
riurus species,  or  in  any  other  bothriurid  (Pe- 
retti & Battan-Horenstein  2003;  Mattoni 
2003).  The  shape  observed  in  B.  pora,  with  a 
slightly  helicoidal  end,  might  represent  an  in- 
termediate condition  between  the  marked  he- 
licoid in  the  bonariensis  group  and  the  straight 


738 


THE  JOURNAL  OF  ARACHNOLOGY 


Figures  9-14. — Bothriurus  pora  new  species,  holotype  male  (IBSP-SC);  9-13.  Right  hemispermatop- 
hore;  9.  External  view;  10.  Internal  view;  11.  Frontal  view;  12-13.  Detail  of  basal  lobe;  12.  Dorsal  view; 
13.  Laterointernal  view;  14.  Sperm  package.  Scale  bars  = 1 mm  (Figs.  9-11);  0.5  mm  (Figs.  12-13);  50 
|jLm  (Fig.  14). 


condition  of  all  remaining  Bothriurus  species 
(Mattoni  2003).  Similarly,  the  morphology  of 
the  front  crest  (c.f.)  of  the  hemispermatophore 
in  B.  pora  resembles  that  observed  in  the  bo- 
nariensis  group,  which  display  a plain  front 
surface  and  undulated  edge,  though  much  less 
strongly  developed. 

Since  the  bonariensis  group  is  longely  de- 
fined through  its  characteristic  hemisperma- 
tophore morphology,  we  are  convinced  that  is 
not  advisable  to  include  B.  pora  as  a member 
of  this  group,  maintaining  it  just  as  its  sister 
taxon. 

Description. — Coloration:  In  general, 
brown  to  orange-brown,  with  patches  of  dark 
brown  pigmentation.  Carapace  brown,  densely 
pigmented  near  the  median  ocelli,  and  extend- 
ed laterally;  transverse  spot  on  anterior  mar- 
gin, posterolateral  margins  reticulate.  Tergites 


almost  completely  and  diffusely  pigmented, 
more  densely  on  the  pretergites  and  the  pos- 
terior edge;  submedian  areas  with  small,  ir- 
regular clear  dots  inside  the  pigmented  area. 
Legs  yellowish,  densely  spotted  prolaterally 
and  retrolaterally;  tarsi  depigmented.  Coxa, 
genital  operculum  and  pectines  faintly  reticu- 
late. Chelicerae  yellowish,  with  very  faint 
spots  dorsally,  forming  longitudinal  stripes 
that  reunite  transversely  at  the  base  of  the  fin- 
gers. Pedipalp  patella  and  femur  with  numer- 
ous spots  dorsally;  chela  with  longitudinal 
stripes  externally,  joining  transversely  near  the 
base  of  the  fingers.  Sternites  broadly  pig- 
mented, increasing  in  intensity  from  sternite  I- 
V.  Metasoma  dark  orange-brown.  Segments  I- 
IV  each  with  a wide  diffuse  subtriangular  spot 
dorsally,  and  a transverse  spot  on  the  posterior 
border;  segment  V with  a pale  spot  of  retie- 


MATTONI  & ACOSTA— W BOTHRIURUS  FROM  BRAZIL 


739 


Figures  15-18. — Distribution  of  macrosetae  on  metasoma  (carinae  schematic,  not  to  scale);  15-16. 
Bothriurus  pora  new  species,  holotype  male  (IBSP-SC);  15.  Lateral  view;  16.  Ventral  view.  17-18.  Both- 
riurus  bonariensis  group;  17.  Lateral  view;  18.  Ventral  view  (the  pair  of  setae  in  black  is  absent  in  B. 
bonariensis). 


ulate,  diffuse  pigment,  proximally.  Lateral 
surfaces  diffusely  reticulate,  reticulations 
merging  ventrolaterally.  Ventral  surface  with 
three  longitudinal  stripes  (median  weaker) 
uniting  in  distal  half  or  one  third  of  each  seg- 
ment. Telson  reddish  brown,  almost  depig- 
mented,  but  with  a narrow,  longitudinal,  me- 
dian line  ventrally;  and  a wide  yellow  area 
ventrally. 

Morphology:  Medium-sized  scorpion  of  ro- 
bust habitus.  Total  length:  38.11  mm  (detailed 
measurements:  Table  1).  Carapace  and  tergites 
very  finely  and  evenly  granular,  giving  matt 
appearance.  Carapace:  three  pairs  of  lateral 
ocelli;  ocular  tubercle  prominent,  median 
ocelli  separated  by  one  diameter;  anterior 
margin  with  weak  median  notch,  anterior  me- 
dian and  anterior  marginal  furrows  only  weak- 
ly developed;  median  ocular  furrow  present, 
lateral  ocular  furrows  weak,  median  and  pos- 


teromedian furrows  strong,  with  a depressed 
area  in  between,  posterior  transverse  furrows 
absent,  posterolateral  furrows  well  developed. 
Tergites  LVI  acarinate,  VII  with  four  short  ca- 
rinae in  the  posterior  quarter,  two  submedian 
and  two  lateral,  with  scattered  granules  in  be- 
tween. Sternites  acarinate,  smooth;  spiracles 
elongated  and  narrow.  Carinae  of  metasomal 
segments  I-IV:  Dsm  entire,  formed  by  low 
granules,  the  distal  one  more  strongly  devel- 
oped; Dl  present  in  the  posterior  half  of  seg- 
ments I and  IV,  and  the  posterior  fifth  of  seg- 
ments II  and  III;  surface  between  Dsm  and  Dl 
with  scattered  granules;  Li  vestigial  in  poste- 
rior third  of  segments  I and  II,  absent  on  III 
and  IV;  Vl  and  VsM  absent.  Carinae  of  me- 
tasomal segment  V:  Dl  only  present  in  pos- 
terior third,  very  weak;  Lm  absent;  area  be- 
tween Dl  and  Vl  with  small,  scattered 
granules,  more  abundant  in  posterior  half;  Vl 


740 


THE  JOURNAL  OF  ARACHNOLOGY 


Table  L — Measurements  (mm)  of  the  holotype 
male  of  Bothriurus  pora  new  species. 


Total  length 

38.11 

Carapace 

length 

5.63 

anterior  width 

3.34 

Mesosoma 

length 

9.37 

Metasoma 

length 

23.21 

segment  I,  length 

2.27 

width 

3.87 

segment  II,  length 

2.73 

width 

3.67 

segment  III,  length 

3.07 

width 

3.60 

segment  IV,  length 

3.80 

width 

3.60 

segment  V,  length 

5.00 

width 

3.47 

height 

2.93 

Telson 

length 

6.34 

width 

2.93 

height 

2.07 

aculeus,  length 

1.67 

Pedipalp 

total  length 

14.63 

femur,  length 

3.54 

width 

1.60 

patella,  length 

3.87 

width 

1.73 

chela,  length 

7.22 

width 

2.60 

height 

3.74 

movable  finger,  length 

3.87 

limited  to  posterior  quarter,  and  connected 
with  oblique  VsM,  together  forming  an  open 
arc;  Vm  present  in  posterior  half,  with  a pair 
of  accessory  submedian  granules  posteriorly; 
area  posterior  to  the  Vl+Vsm  arc  slightly  de- 
pressed, with  small  granules;  surface  anterior 
to  the  Vl+Vsm  arc  finely  granular,  granules 
more  abundant  posteriorly.  Metasomal  macro- 
setae  as  in  Figs.  15  & 16.  Telson:  vesicle  oval, 
ventral  surface  granular,  with  larger  granules 
towards  proximal  third;  dorsal  surface  smooth 
and  not  depressed,  with  a wide  glandular  area 
almost  covering  the  dorsal  surface.  Chelicer- 
ae:  one  subdistal  tooth  on  movable  finger; 
ventral  surface  of  hand  and  movable  finger 
covered  with  abundant,  fine  setae.  Pedipalps. 
Femur  with  three  carinae  comprising  blunt 
granules;  dorsointernal  carina  restricted  to 
proximal  half,  with  sparse  granules  distally; 
dorsoexternal  carina  well  developed,  becom- 
ing obsolete  towards  distal  quarter;  ventroin- 
ternal  carina  present  in  proximal  half,  weak- 
ening distally;  dorsal  and  internal  surface  with 


abundant  scattered  granules,  ventral  surface 
with  only  a few  small  granules,  external  sur- 
face smooth.  Patella  with  two  weak  vestigial 
carinae,  dorsointernal  and  ventrointemal,  each 
represented  by  only  one  proximal  granule. 
Chela  robust,  acarinate,  surface  almost 
smooth,  with  only  a few  small  granules  be- 
hind base  of  fixed  finger;  a strong  conical 
apophysis  evident  near  base  of  movable  fin- 
ger, internally,  slightly  curved  dorsally,  with  a 
slight  depression  internally.  Trichobothrial 
pattern  type  C,  neobothriotaxic  major,  with  the 
following  segment  totals:  femur  3 (1  ^i;  1 /;  1 
e),  patella  19  (2  d\  1 /;  13  e;  3 v)  and  chela 
27  (17  manus,  with  5 V ; 6 fixed  finger);  chela: 
Esb  near  to  Eb2  and  Eb^,  Etj  aligned  with  Est. 
Sternum  slitlike,  represented  by  a narrow 
transversal  plate.  Genital  operculum  loosely 
joined  together  along  the  anterior  one-fourth 
of  their  length,  isosceles  triangle  shaped,  with 
the  more  acute  angle  towards  posterior.  Num- 
ber of  pectinal  teeth:  19-19.  Hemispermatop- 
hore:  heavily  sclerotized;  L.  large  and  straight, 
narrowing  medially;  c.d.  strong,  divided  by  a 
transverse  crest  (terminally  curved,  basally 
straight,  parallel  to  the  axis  of  L.);  r.f.  well 
developed  on  external  surface  of  L.,  long  and 
curved,  enlarging  towards  base  of  L.;  con- 
necting to  a short  c.f.,  which  extends  from 
dorsal  limit  of  P.b.  to  basal  quarter  of  L.  (c.f. 
straight  basally  and  slightly  sinuous  on  the  ter- 
minal edge;  front  surface  plain);  on  the  inte- 
rior side  of  L.,  a small  curved  crest  is  present; 
P.b.  wide,  slightly  longer  than  L.;  r.b.  well 
developed,  sinuous;  lobe  region  large,  highly 
complex,  occupying  superior  half  of  P.b.;  Lb. 
laminar,  elongated  and  concave,  with  a spat- 
ulate  end;  on  its  anterior  half,  two  thin  dorsal 
trabeculae  (one  transverse,  the  other  longitu- 
dinal) present;  interior  portion  of  l.i.  large;  l.e. 
with  well  developed  c.c.  Sperm  packages 
(preserved  in  80%  ethanol):  ‘‘head”  portion 
visible  by  refringence  as  a darker  area  on  the 
anterior  third  of  the  package,  helicoidal  in 
shape;  medially  corrugated;  “tail”  straight, 
becoming  acute  posteriorly,  showing  small 
granulations  (some  packages  stick  to  each  oth- 
er at  this  point). 

Distribution. — Only  known  from  the  type 
locality,  in  the  southernmost  part  of  the  Ce- 
rrado  Biogeographic  Province  (SE  Brazil).  A 
record  of  B.  bonariensis  from  the  urban  area 
of  Campo  Grande,  Mato  Grosso  do  Sul  (Bra- 
zuna  & Koller  1998)  is  probably  referable  to 


MATTONI  & ACOSTA— W BOTHRIURUS  FROM  BRAZIL 


741 


Figures  19-22. — Bothriurus  bonariensis,  male  from  Toledo,  Cordoba  (CDA);  19.  Metasomal  segment 
V and  telson,  lateral  view;  20.  Metasomal  segment  V,  ventral  view;  21-22.  Left  hemispermatophore;  21. 
Internal  view;  22.  External  view.  Scale  bars  = 1 mm  (Figs.  19-20);  0.5  mm  (Figs.  21-22). 


B.  pora.  The  single  known  record  of  B.  pora 

is  allopatric  with  respect  to  the  known  distri- 
bution of  the  bonariensis  group,  all  compo- 
nent species  of  which  are  also  allopatric  with 
one  another  (Fig.  23).  Bothriurus  bonariensis 
inhabits  the  Pampeae  Biogeographic  Province 
and  a large  portion  of  the  “Espinal”  Province 
(as  defined  by  Cabrera  & Willink  1980), 
whereas  B.  chacoensis  is  almost  restricted  to 
the  western  district  of  the  Chacoan  Province 
(Maury  1973;  Maury  & Acosta  1993;  Acosta 
& Maury  1998).  Bothriurus  jesuita,  the  sister 
species  of  B.  chacoensis  (Ojanguren-Affilastro 
2003;  Mattoni  2003),  has  a very  similar  he- 
mispermatophore morphology  (a  filament  at 
the  end  of  the  basal  lobe  of  the  right  hemis- 
permatophore), and  occurs  in  northeast  Ar- 
gentina and  southern  Brazil  (Maury  & Acosta 
1993;  Ojanguren-Affilastro  2003).  The  type 
locality  of  B.  pora  is  in  the  Sierra  Amambai, 
almost  on  the  southeast  border  of  the  state 


Mato  Grosso  do  Sul  (close  to  the  boundary 
with  Paraguay).  This  locality  lies  in  the  Ce- 
rrado  Biogeographic  Province  (Cabrera  & Wi- 
llink 1973). 

We  believe  that  the  material  cited  by  Bra- 
zuna  & Koller  (1998)  as  B.  bonariensis  from 
Campo  Grande  (Mato  Grosso  do  Sul)  should 
be  referred  to  B.  pora  instead,  taking  into  ac- 
count that  Campo  Grande  is  close  to  Ponta 
Pora,  on  the  slopes  of  the  Sierra  Maracaju  (a 
geographical  extension  of  the  Sierra  Amam- 
bai). The  fairly  well  known  range  of  B.  bo- 
nariensis is  distant  from  both  of  these  sites 
(Fig.  23),  and  the  habitats  occupied  by  this 
species  are  very  different  to  the  Cerrado. 

The  pattern  of  allopatric  distribution  among 
these  four  related  species  is  shown  by  several 
other  Bothriurus  species  groups,  e.g.,  the 
prospicuus  group  (Mattoni  & Acosta  1997; 
Acosta  & Peretti  1998;  Ojanguren  Affilastro 
2002;  Mattoni  2003),  the  vittatus  group  (Mat- 


742 


THE  JOURNAL  OF  ARACHNOLOGY 


Figure  23. — Distribution  map  of  Bothriurus  pora  new  species  (type  locality:  black  dot;  probable  ad= 
ditional  locality:  ?)  and  the  Bothriurus  bonariensis  group  (B.  bonariensis,  squares;  B.  chacoensis,  stars, 
and  B.  jesuita,  triangles). 


toni  2002a,  2002b,  2002c),  and  the  patagoni- 
cus  group  (Mattoni  & Acosta,  unpub.  data). 
The  distribution  of  B.  pora  and  the  bonarien- 
sis group  is  congruent  with  the  hypothesised 
relationships  of  the  Cerrado  with  the  Chaco, 
in  a putative  Taunistic  corridor’  for  scorpions 
(‘corridor  B’  of  Lourengo  1994).  Moreover, 
the  araguayae  group,  a probable  sister  group 
of  the  clade  comprising  B.  pora  and  the  bo- 
nariensis group  (Mattoni  2003),  shows  a com- 
plementary pattern.  The  araguayae  group  is 
mainly  distributed  towards  the  center  and 
north  of  the  Cerrado,  with  one  species  inhab- 
iting humid  forests  in  the  northern  sector  of 
the  Argentine  province  of  Misiones  and  the 
southwest  part  of  Parana  State,  Brazil  (Lou- 
rengo  & Maury  1979;  Mattoni  2003). 

Additional  material  examined  (bonarien- 
sis group). — Bothriurus  bonariensis:  BRA- 


ZIL: Estado  do  Rio  Grande  do  Sul:  1 9 , Novo 
Hamburgo  [24°4U09"S,  51°08'03"W],  22  No- 
vember 1965,  C.  Valle  (MZUSP  8682;  22);  1 
d,  Porto  Alegre  [30°02'09''S,  51°12'03"W],  14 
March  1957,  C.  Schneider  (MCN  0098);  1 ju- 
venile, same  locality,  1 April  1957,  E.H.  Buc- 
kup  (MCN  0105);  1 d,  Pavaela  44,  Viamao 
[30°05'09"S,  5r02'04"W],  25  November  1956, 
M.  Palova  (MCN  0061);  1 juvenile,  Ipanema, 
Porto  Alegre  [30°08'10"S,  5ri3'49"W],  24 
September  1956,  M.  Palova  (MCN  0043);  1 
juvenile,  Ponta  Grossa,  Porto  Alegre  [30°02'S, 
51°12'W],  21-26  June  1945,  M.P  Godoi 
(MZUSP  13.736);  1 juvenile,  same  locality 
and  collector,  1 June  1946  (MZUSP);  4 9, 
same  locality  and  collector,  cultivated  land, 
rocks,  23  February  1945  (MZUSP  16.115);  6 
d,  Guaiba  [30°06'50"S,  5ri9'04"W],  27  Feb- 
ruary 1975,  H.A.  Gastal  (MCN  0007);  2 d. 


MATTONI  & ACOSTA— W BOTHRIURUS  FROM  BRAZIL 


743 


same  locality  and  collector,  5 February  1975 
(MCN  0028);  1 juvenile,  Belem  Novo 
[30°12'10"S,  5ri0'04"W],  4 June  1946,  M.R 
Godoi  (MZUSP  13.733);  1 d,  Sao  Leopoldo 
[29M6'05"S,  51°09'08"W],  15  November 
1965,  C.  Valle  (MZUSP);  3 d,  Quarai 
[30°23'09"S,  56°27'03"W],  February  1963, 
J.W.  Thome  (MCN  0019);  1 juvenile,  Barra 
do  Quarai  [30°23'S,  56°27'W],  20  February 
1974  (MZUSP);  1 juvenile,  km  211,  Pelotas 
[3r46'S,  52°20'W],  28  July  1965,  Exped. 
CDZ  (MZUSP).  ARGENTINA:  Provincia  de 
Cordoba:  5 d,  1 juvenile,  Toledo,  1 km  road 
to  Cordoba  [3r34'S,  64°0rW],  24  January 
1987,  L.  Acosta  (CDA  000.101).  URUGUAY: 
Departamento  Tacuarembo:  1 juvenile,  Ta- 
cuarembo  [3r44'S,  55°59'W],  7 March  1944, 
E.  Mullin-Diaz  (MZUSP  8710). 

Bothriurus  chacoensis:  ARGENTINA: 
Provincia  de  Cordoba:  6 d,  2 ?,  3 juveniles, 
Eufrasio  Loza,  3 km  to  Gutenberg  [29°56'S, 
63°35'W],  20  February  1987,  L.  Acosta,  A. 
Peretti  (CDA  000.103). 

Bothriurus  jesuita:  ARGENTINA:  Provin- 
cia de  Misiones:  1 d,  Campo  San  Juan,  37 
km  N Posadas  by  route  N°  12  [27°20'S, 
55°38'W],  21  January  1991,  G.  Flores  (CDA 
000.102). 

ACKNOWLEDGMENTS 

We  are  grateful  to  curators  of  the  following 
institutions  for  the  loan  of  specimens  and  for 
allowing  access  to  their  collections:  Erika 
Buckup  (MCN),  Denise  Candido  (IBSP)  and 
Ricardo  Pinto-da~Rocha  (MZUSP).  CIM  is  es- 
pecially indebted  to  Candido  and  Pinto-da-Ro- 
cha  for  their  help,  collaboration  and  company 
during  his  visit  to  Sao  Paulo.  We  thank  Lo- 
renzo Prendini  (American  Museum  of  Natural 
History),  Alfredo  Peretti  and  Moira  Battan- 
Horenstein  (Catedra  de  Diversidad  Animal  I, 
Universidad  Nacional  de  Cordoba)  for  sharing 
unpublished  information.  This  contribution  is 
part  of  the  Doctoral  Thesis  of  CIM,  carried 
out  at  Universidad  Nacional  de  Cordoba  (Ar- 
gentina), under  advice  of  LEA.  Research  par- 
tially supported  by  a grant  of  the  University’s 
Secretaria  de  Ciencia  y Tecnologia  (Secyt)  to 
LEA,  and  a Postgraduate  grant  from  CONI- 
CET  (Consejo  Nacional  de  Investigaciones 
Cientificas  y Tecnicas,  Argentina)  to  CIM. 
LEA  is  researcher  of  CONICET. 


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Mattoni,  C.I.  2003.  Patrones  evolutivos  en  el  genero 
Bothriurus  (Scorpiones,  Bothriuridae):  analisis 
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Maury,  E.A.  1982.  Dos  Bothriurus  del  nordeste 
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with  the  paraxial  organ  and  the  presence  of 
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Manuscript  received  2 June  2004,  revised  20  Sep- 
tember 2004. 


2005.  The  Journal  of  Arachnology  33:745-752 


DIEL  ACTIVITY  PATTERNS  AND  MICROSPATIAL 
DISTRIBUTION  OF  THE  HARVESTMAN 
PHALANGIUM  OPILIO  (OPILIONES,  PHALANGHDAE) 

IN  SOYBEANS 


Cora  M,  Allard  and  Kenneth  V.  Yeargan:  Department  of  Entomology,  University  of 

Kentucky,  S-225  Ag  Science  North,  Lexington,  KY  40506  USA.  E-mail: 
cmallarcL22  @ hotmail  .com 

ABSTRACT.  Phalangium  opilio  L.  is  a polyphagous  predator  frequently  found  in  agricultural  habitats. 
Although  the  potential  importance  of  P.  opilio^  feeding  on  pests  has  been  recognized,  little  is  known 
about  its  activity  patterns  or  its  within-plant  distribution  in  crops.  We  determined  diel  activity  patterns 
and  microspatial  distribution  in  small,  fenced  arenas  in  soybean  fields.  The  fenced  arenas  allowed  us  to 
track  known  numbers  of  particular  size  categories  of  P.  opilio  for  each  24  h trial.  Phalangium  opilio  were 
separated  into  the  following  categories  based  on  body  size  and  sex:  medium-sized  nymphs,  large-sized 
nymphs,  adult  females  and  adult  males.  Medium-sized  nymphs  occupy  the  bottom  and  middle  portions  of 
plants  regardless  of  time  of  day;  they  remain  still  during  the  day,  but  they  exhibit  leg  palpating  behavior 
from  21:00-01:00  h.  Large-sized  nymphs  rest  in  the  bottom  and  middle  portions  of  plants  during  the  day, 
but  they  walk  and  palpate  on  the  ground  from  21:00-01:00  h.  Adult  females  rest  in  the  bottom,  middle 
and  top  portions  of  plants  during  the  day,  and  they  walk  and  palpate  on  the  ground  from  21:00-01:00  h. 
Adult  males  remain  stationary  in  the  bottom,  middle  and  top  portions  of  plants  during  the  day,  but  they 
walk  on  the  ground  from  21:00-04:00  h. 

Keywords!  Predator,  behavior,  microhabitat  separation 


The  microspatial  distribution  and  diel  activ- 
ity patterns  of  predators  in  crops  affect  the 
prey  they  encounter,  which  potentially  affects 
their  value  in  biological  control.  When  differ- 
ent instars  of  the  same  species  separate  their 
location  and  activities  spatially  and  temporal- 
ly, the  separation  may  reduce  cannibalism 
and/or  intraspecific  competition  for  resources. 
All  these  factors  have  the  potential  to  affect 
the  population  dynamics  of  arthropod  species 
in  agricultural  systems.  Predatory  members  of 
the  group  Opiliones  are  sometimes  overlooked 
in  crops.  One  such  predator  is  Phalangium  op- 
ilio L.  1758.  We  studied  P.  opilio'^  micro- 
spatial distribution  and  diel  activity  because  of 
its  potential  importance  in  biological  control 
of  soybean  pests  (Anderson  1996;  Pfannen- 
stiel  & Yeargan  2002). 

Microhabitat  separation  of  different  life 
stages  is  seen  in  some  Opiliones.  For  example, 
Mitopus  morio  (Fabricius  1799)  exhibits  ver- 
tical stratification,  with  late  iestars  found  at 
high  vegetation  strata  (Adams  1984).  Vertical 
distribution  of  P.  opilio  is  believed  to  vary 


among  habitats.  When  sparse  shrub  cover  is 
present,  88%  of  P.  opilio  are  found  in  shrubs 
and  brushy  vegetation,  but  with  dense  cover, 
the  highest  percentage  of  P.  opilio  is  found  on 
the  ground  layer  (Edgar  1980).  Cloudsley- 
Thompson  (1968)  also  observed  P.  opilio  to 
primarily  inhabit  low  vegetation  or  grass  and 
other  herbaceous  plants,  but  he  stated  that  the 
early  instars  only  occur  on  the  ground.  Several 
hypotheses  have  been  presented  to  explain  mi- 
crohabitat separation  in  Opiliones.  Opilionids 
may  be  found  on  vegetation  to  eliminate  com- 
petition with  strict  ground  predators  (Halaj  & 
Cady  2000).  It  also  has  been  hypothesized  that 
the  vertical  expansion  of  the  distribution  of 
late  instars  is  due  to  the  need  for  larger  prey, 
more  moving  space,  mating,  and/or  different 
temperature  and  humidity  requirements  (San- 
key  1949;  Todd  1949).  Not  all  individuals 
abandon  the  ground;  Williams  (1962)  found 
individuals  of  the  same  species  and  instar  both 
in  pitfall  traps  and  on  vegetation.  Based  on 
those  results,  Williams  hypothesized  opilion- 
ids may  expand  their  microhabitat  distribution 


745 


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without  completely  abandoning  the  ground. 
However,  it  is  possible  that  Williams’  (1962) 
results  reflected  diel  movement,  not  microhab- 
itat separation. 

Opiliones  generally  are  nocturnal  (Sankey 
1949;  Todd  1949;  Phillipson  1960;  Williams 
1962;  Edgar  & Yuan  1969).  The  increase  in 
activity  at  night  may  be  attributed  to  de- 
creased light  intensity,  increased  relative  hu- 
midity and  decreased  temperatures  (Todd 
1949).  Pfannenstiel  & Yeargan  (2002),  who 
observed  predation  events  on  Helicoverpa  zea 
(Boddie  1850)  eggs  in  soybean  fields  at  3 h 
intervals  during  24  h cycles,  found  that  all  ob- 
served events  of  predation  by  Phalangiidae 
occurred  at  night.  Although  P.  opilio  occa- 
sionally is  active  under  diurnal  conditions,  in- 
dividuals exhibit  90%  of  their  total  activity 
between  1800-0600  h (Edgar  & Yuan  1969; 
Edgar  1980). 

Phalangium  opilio  is  known  to  feed,  pri- 
marily nocturnally,  upon  a variety  of  arthro- 
pod pests.  In  Kentucky,  this  predator  appears 
to  overwinter  in  the  egg  stage  and  undergo 
three  generations  per  year  (Newton  & Yeargan 
2002),  with  the  second  generation  being  the 
most  relevant  to  predation  in  soybean  (due  to 
seasonal  timing  of  this  annual  crop),  where  it 
feeds  on  H.  zea  eggs  (Pfannenstiel  & Yeargan 
2002).  Other  aspects  of  its  ecology  relevant  to 
its  role  in  soybean  fields  are  poorly  known, 
including  its  diet  breadth,  its  spatial  distribu- 
tion in  large  fields,  its  within-plant/epigeal 
distribution  and  its  diel  activity  patterns.  We 
investigated  the  diel  activity  patterns  and  mi- 
crospatial  distribution  of  P.  opilio  for  nymphal 
instars  three  through  seven  and  both  adult  sex- 
es. 

METHODS 

This  study  was  done  during  the  summers  of 
2001  and  2002  at  the  University  of  Ken- 
tucky’s North  Farm  near  Lexington,  KY.  In 
each  year,  three  small  plots  (1  m of  soybean 
row  per  plot)  were  established  within  a 0.6  ha 
field  of  soybeans.  The  soybean  variety  used  in 
both  years  was  Asgrow  4702  and  planting  oc- 
curred on  1 May  2001  and  20  May  2002.  Each 
1 m plot  was  surrounded  by  a fence  of  gal- 
vanized sheet  metal  (20  cm  tall,  0,5  m from 
plants  on  either  side  of  fence);  preliminary 
studies  showed  P.  opilio  could  not  scale  this 
fence.  In  both  years,  the  entire  soybean  field 
was  treated  at  planting  with  recommended 


rates  of  conventional  pre-emergence  herbi- 
cides (alachlor,  metribuzin  and  chlorimuron 
ethyl)  and  was  subsequently  treated  once 
(2002)  or  twice  (2001)  with  the  post-emer- 
gence herbicide  glyphosate  for  additional 
weed  control.  Post-emergence  herbicide  treat- 
ments occurred  several  weeks  before  trials  be- 
gan. No  insecticides  were  applied  during  ei- 
ther year.  Trials  were  conducted  weekly  from 
23  July-9  September  2001  and  from  7-24  Au- 
gust 2002. 

Phalangium  opilio  were  collected  in  the 
field  no  more  than  5 d prior  to  the  trial  dates. 
Individuals  were  taken  to  the  laboratory,  mea- 
sured and/or  sexed  in  order  to  be  placed  in  a 
category  (described  below),  and  provided  with 
food  (i.e.,  //.  zea  eggs  and  cornmeal/bacon 
diet)  and  water;  food  was  removed  24  h prior 
to  the  initiation  of  observations  and  individ- 
uals were  marked  with  a small  dot  of  paint  12 
h prior  to  the  initiation  of  field  observations. 
In  the  laboratory,  individuals  were  kept  in  8.5 
X 8.5  cm  (diam  X ht)  containers  in  incubators 
at  24  ± 1 °C  (15:9  L:D)  with  high  humidity 
via  open  water  containers  on  the  floor  of  the 
incubators.  Prior  to  the  initiation  of  trials,  field 
arenas  were  checked  for  naturally  occurring 
opilionids  that  were  removed  when  found.  No 
opilionid  species  other  than  P.  opilio  were  en- 
countered in  this  study.  No  other  potential 
prey  were  removed  from  or  added  to  an  arena. 
Three  arenas  were  monitored  on  each  date.  In 
each  arena,  three  field  collected  P.  opilio  of 
the  same  category  marked  with  pink  fluores- 
cent, water-based  paint  (Apple  Barrel  Colors, 
Plaid  Enterprises,  Inc.)  were  introduced  si- 
multaneously on  the  ground  in  the  center  of 
an  arena  1 h before  observations  began.  There 
is  no  accurate  morphological  indicator  for  sex 
or  instar  in  P.  opilio  nymphs;  therefore,  size 
categories  (hereafter  referred  to  as  P.  opilio 
categories)  based  on  cephalothorax  width 
were  used  (after  Newton  & Yeargan  2002). 
Small  nymphs  were  less  than  1.0  mm,  medi- 
um nymphs  ranged  from  1.0-1. 5 mm,  and 
large  nymphs  were  greater  than  1.5  mm  in 
cephalothorax  width.  Adults  were  discrimi- 
nated from  nymphs  based  on  the  presence  or 
absence  of  a genital  opening  beneath  the  oper- 
culum (Sankey  & Savory  1974)  and  adult 
males  and  females  were  identified  based  on 
the  presence  or  absence  of  the  sexually  di- 
morphic horns  on  the  distal  segment  of  male 
chelicerae  (Sankey  & Savory  1974). 


ALLARD  & YEARGAN—ACTIVITY  PATTERNS  OF  PHALANGIUM  OPILIO 


747 


During  the  trials,  5 min  observations  were 
made  at  each  arena  at  20  min  intervals  for  1 
h at  approximately:  1200,  1500,  1800,  2100, 
0000,  0300  and  0600  h (EDT).  A red  light 
filter,  which  minimized  disturbance  to  the  an- 
imals, was  used  to  make  nocturnal  observa- 
tions and  an  ultraviolet  light  was  used  to  lo- 
cate individuals  only  if  they  could  not  be 
found  with  the  red  light.  The  ultraviolet  light 
was  used  for  —10%  of  the  observations.  Dur- 
ing each  observation,  the  location  of  individ- 
uals (i.e.,  on  ground  or  plant;  if  on  plant,  bot- 
tom, middle,  or  top  third  of  the  plant,  and 
exterior  or  interior  portion  of  the  plant)  and 
the  behavior  of  individuals  (i.e.,  walking, 
grooming,  feeding,  stationary,  palpating, 
drinking)  were  recorded.  Exterior  and  interior 
portions  of  the  plants  were  differentiated 
based  on  whether  or  not  the  view  of  the  ob- 
server was  obstructed  by  other  plant  parts 
(i.e.,  if  an  opilionid  was  on  a plant  part  that 
had  no  other  plant  part  between  it  and  the  ob- 
server, it  was  recorded  as  being  on  the  exte- 
rior). For  the  purposes  of  this  study,  palpating 
behavior  is  defined  as  the  movement  of  the 
sensory  legs  (i.e.,  the  long  second  pair)  in  a 
slow  tapping  motion  on  the  surrounding  sub- 
strate. All  behaviors  recorded  were  mutually 
exclusive,  and  only  the  first  observation  of  an 
individual  was  recorded  within  each  5 min  ob- 
servation period. 

Each  trial  consisted  of  three  individuals  ob- 
served in  a field  arena  for  24  h.  In  2001,  the 
following  number  of  trials  were  conducted: 
small-sized  nymphs  {n  ~ 1),  medium-sized 
nymphs  {n  = 6),  large-sized  nymphs  {n  = 4), 
adult  females  {n  — 5),  and  adult  males  {n  = 
5).  In  2002,  the  following  number  of  trials 
were  conducted:  medium-sized  nymphs  {n  = 
1),  large- sized  nymphs  {n  — 3),  adult  females 
{n  ^ 2),  and  adult  males  {n  = 2).  Small 
nymphs  were  excluded  from  the  study  after 
the  first  trial  due  to  the  difficulty  in  seeing  the 
nymphs,  due  in  part  to  their  tendency  to  hide 
in  tiny  crevices.  The  combined  years  yielded 
seven  trial  dates  for  all  P.  opilio  categories 
excluding  small.  After  each  trial  date,  all  in- 
dividuals were  removed  from  the  arenas  and 
nymphs  were  reared  in  the  laboratory  until 
maturity  for  positive  identification  to  species. 
Individuals  were  not  always  found  at  the  time 
of  observations,  but  all  individuals  were  re- 
covered at  the  end  of  each  trial.  Voucher  spec- 
imens were  placed  in  the  arthropod  collection 


of  the  Department  of  Entomology  at  the  Uni- 
versity of  Kentucky. 

Statistical  analysis. — In  order  to  analyze 
the  microspatial  distribution  and  behaviors  for 
the  different  nymphal  and  adult  P.  opilio  cat- 
egories, proportions  were  calculated  for  each 
set  of  three  individuals  during  each  1 h ob- 
servation period.  There  was  a maximum  of 
nine  observations  per  arena  per  hour  (i.e., 
three  individuals  times  three  visits  = the  de- 
nominator for  calculating  proportions).  These 
proportions  reflected  the  frequency  of  obser- 
vations of  P.  opilio  at  a particular  place 
(ground,  bottom  of  plant,  middle  of  plant,  top 
of  plant)  or  engaged  in  a particular  behavior 
(stationary,  walking,  feeding,  palpating,  drink- 
ing). 

Category  X time  interactions  were  exam- 
ined to  determine  if  different  P.  opilio  cate- 
gories (medium-sized  nymphs,  large-sized 
nymphs,  adult  males  and  adult  females)  were 
at  different  locations  at  different  times  of  the 
day  and  if  they  exhibited  different  behaviors. 
Because  the  ANOVA  assumptions  of  homo- 
geneity of  variances  and  normality  of  the  var- 
iables were  not  met,  even  after  several  trans- 
formations, we  used  profile  analysis,  which 
can  be  performed  with  both  parametric  and 
non-parametric  statistics  to  test  for  the  cate- 
gory X time  interactions  (Ende  1993).  To 
compute  a profile  analysis  the  response  vari- 
able (i.e.,  percentage  of  time  per  hour)  was 
subtracted  between  repeated  measures  and 
tested  for  differences  among  P.  opilio  cate- 
gories on  the  resulting  variable.  The  new  var- 
iables did  not  meet  the  ANOVA  assumptions; 
therefore,  the  non-parametric  Kruskal-Wallis 
ANOVA  (Siegel  & Castellan  1988)  was  used 
to  test  for  differences  among  P.  opilio  cate- 
gories with  the  new  (subtracted)  variables. 
There  were  seven  time  periods.  Six  new  var- 
iables were  calculated  for  the  profile  analysis 
performed  on  each  location  and  behavior. 
Each  variable  was  derived  by  subtracting  the 
response  variable  (i.e.,  percentage  of  time  per 
hour)  of  every  time  period  from  the  response 
at  one  arbitrarily  selected  time  period  (i.e.,  00: 
00  h).  Thus,  the  first  variable  for  profile  anal- 
ysis was  00:00  minus  03:00  h,  the  second  was 
00:00  minus  06:00  h,  and  so  on.  This  allowed 
interactions  to  be  detected  and  showed  which 
time  periods  had  a larger  change  in  location 
or  behavior.  Therefore,  we  tested  for  signifi- 
cance of  six  variables,  four  locations  and  five 


748 


THE  JOURNAL  OF  ARACHNOLOGY 


Ground  r - Mid'l"  To^- 


Figure  1 . — Percentage  of  observations  (mean  ± SE)  for  all  Phalangium  opilio  categories  on  the  ground, 
in  the  bottom,  in  the  middle,  and  in  the  top  portions  of  soybean  plants  during  diurnal  (not  shaded)  and 
nocturnal  (shaded)  hours. 


behaviors,  for  a total  of  6 X (4+5)  = 54  tests. 
Because  significance  of  the  overall  category 
X time  interaction  could  not  be  tested  as  it  is 
done  in  repeated  measures  ANOVA,  the  cri- 
terion to  decide  whether  there  was  an  overall 
significant  interaction  for  each  category  and 
location  or  behavior  was  whether  a combined 
probability  test  (Fisher's  meta- analysis;  Sokal 
& Rohlf  1995)  across  the  six  tests  was  sig- 
nificant. The  resulting  value  is  compared  with 
the  chi-square  distribution  with  twice  as  many 
degrees  of  freedom  as  number  of  tests  per- 
formed (in  this  case  2X6=  12  d.f.). 

To  test  if,  at  different  heights,  the  different 
P,  opilio  categories  were  more  likely  located 
on  the  exterior  or  in  the  interior  part  of  the 
plant,  a logistic  regression  analysis  was  used. 
The  response  variable  was  interior  or  exterior 
on  the  plant,  which  were  coded  as  0 and  1 
respectively.  For  this  analysis  the  data  for  all 
time  periods  were  pooled  and  the  frequency 
at  which  individuals  were  on  the  interior  or 
exterior  of  the  plant  at  every  height  was  in- 
cluded in  the  model  by  using  the  FREQ  state- 


ment in  the  SAS  LOGISTIC  procedure  (Alli- 
son 1999).  For  graphical  purposes,  the 
percentage  of  time  per  hour  in  which  individ- 
uals were  exterior  at  every  height  was  aver- 
aged across  individuals.  A significant  catego- 
ry X height  interaction  in  the  logistic 
regression  indicates  that  there  is  spatial  seg- 
regation in  relation  to  exterior  and  interior 
portions  of  the  plant  and  that  it  is  different  at 
different  heights. 

RESULTS 

There  was  a significant  category  X time  in- 
teraction for  all  vertical  strata  (i.e.,  ground, 
bottom,  middle  and  top)  indicating  that  dif- 
ferent P.  opilio  categories  were  at  different 
strata  at  different  times  (Fig.  1;  Table  1).  All 
P.  opilio  categories,  excluding  medium-sized 
nymphs  (which  remained  on  the  plants), 
moved  to  the  ground  at  nightfall,  21:00  h, 
where  they  remained  until  03:00  h.  Males 
were  on  the  ground  significantly  more  than  the 
females,  and  large  nymphs  and  males  re- 
mained on  the  ground  in  the  03:00  h when  the 


ALLARD  & YEARGAN—ACTIVITY  PATTERNS  OF  PHALANGIUM  OPILIO 


749 


Stationary 


Walking 


Palpating 


Figure  2.--"“Percentage  of  observations  (mean  ± SE)  for  all  Phalangium  opilio  categories  that  were 
stationary,  walking,  and  palpating  in  soybean  plots  during  diurnal  (not  shaded)  and  nocturnal  (shaded) 
hours. 


females  and  large  nymphs  returned  to  the 

plants  (Fig.  1).  For  the  majority  of  the  day  all 
P.  opilio  categories  were  found  on  the  plants. 
During  this  time,  all  P.  opilio  categories  were 
recorded  in  the  bottom  and  middle  portions  of 
the  plants;  however,  small  percentages  of 
males  and  females  were  recorded  in  the  top 
portion  of  the  plants  during  the  15:00  and  18: 
00  h,  respectively.  Medium-sized  nymphs  re- 
mained on  the  bottom  and  middle  portions  of 
the  plants  at  night.  Early  in  the  morning  there 
was  an  increase  in  large  nymph  and  female 
observations  in  the  middle  portions  of  the 
plants.  A substantial  percentage  of  the  females 
was  found  on  the  top  portion  of  the  plants 


only  during  03:00  h,  followed  by  males  at  06: 
00  h. 

There  also  were  significant  category  X time 
interactions  for  the  following  behaviors:  sta- 
tionary, walking,  and  leg  palpating  (Fig.  2;  Ta- 
ble 1).  Drinking,  feeding  and  grooming  were 
excluded  because  there  were  only  a few  re- 
corded observations.  Only  a single  case  of 
predation  was  observed,  namely  a large  im- 
mature individual  feeding  on  an  immature 
leafhopper  (Hemiptera,  Cicadellidae)  on  a 
soybean  plant.  The  majority  of  all  P.  opilio 
categories  were  stationary  during  the  day  but 
stationary  behavior  was  less  common  in  the 
nocturnal  hours.  Virtually  no  walking  behav- 


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THE  JOURNAL  OF  ARACHNOLOGY 


Table  1 . — Results  from  the  Kruskal- Wallis  ANOVA  by  ranks  for  the  overall  response  of  size  and  gender 
categories  (average  across  time)  of  Phalangium  opilio  to  heights  on  soybean  plants  and  behaviors.  Pal- 
pating = leg  palpating. 


Ground 

Bottom 

Middle 

Top 

Time  periods 

H 

P 

H 

P 

H 

P 

H 

P 

0000  minus  0300  h 

5.738 

0.125 

5.564 

0.135 

5.738 

0.125 

8.287 

0.041 

0000  minus  0600  h 

37.052 

<0.001 

9.396 

0.025 

12.908 

0.005 

13.782 

0.003 

0000  minus  1200  h 

16.835 

0.001 

7.745 

0.052 

2.883 

0.410 

3.418 

0.332 

0000  minus  1500  h 

27.552 

<0.001 

4.358 

0.225 

13.443 

0.004 

6.985 

0.072 

0000  minus  1800  h 

33.475 

<0.001 

5.872 

0.118 

12.923 

0.005 

7.069 

0.070 

0000  minus  2100  h 

1.308 

0.727 

4.811 

0.186 

4.047 

0.256 

2.491 

0.477 

Combined  test 

<0.001 

0.006 

<0.001 

0.001 

Stationary 

Walking 

Feeding 

Palpating 

Drinking 

Time  periods 

H 

P 

H 

P 

H 

P 

H 

P 

H 

P 

0000  minus  0300  h 

5.509 

0.138 

6.691 

0.083 

8.326 

0.040 

11.239 

0.011 

1.166 

0.761 

0000  minus  0600  h 

10.667 

0.014 

15.569 

0.001 

7.822 

0.050 

8.889 

0.031 

1.911 

0.591 

0000  minus  1200  h 

10.008 

0.019 

18.396 

<0.001 

8.854 

0.031 

10.568 

0.014 

1.911 

0.591 

0000  minus  1500  h 

12.740 

0.005 

19.336 

<0.001 

7.965 

0.047 

12.290 

0.007 

1.911 

0.591 

0000  minus  1800  h 

8.951 

0.030 

18.334 

<0.001 

8.854 

0.031 

10.218 

0.017 

1.911 

0.591 

0000  minus  2100  h 

0.932 

0.818 

1.096 

0.778 

4.179 

0.243 

6.406 

0.094 

0.538 

0.911 

Combined  test 

0.000 

<0.001 

0.000 

<0.001 

0.960 

ior  was  exhibited  during  the  day,  but  with 
nightfall  there  was  a large  increase  in  walking 
behavior  for  males  and  females  and  a small 
increase  for  nymphs.  Males  and  females  ex- 
hibited walking  behavior  from  nightfall 
through  the  midnight  hour,  and  males  contin- 
ued walking  through  the  early  morning,  03:00 
h,  while  female  walking  decreased.  None  of 
the  P.  opilio  categories  exhibited  leg  palpating 
during  the  day.  Large  nymphs  showed  a peak 
in  leg  palpating  during  the  midnight  hour,  and 
medium  nymphs  exhibited  a small  amount  of 
leg  palpating  from  nightfall  through  the  mid- 
night hour.  Females  exhibited  leg  palpating  at 
night,  and  males  showed  a small  peak  in  leg 
palpating  at  03:00  h but  not  at  any  other  time. 

The  percentage  of  P.  opilio  categories 
found  on  the  exterior,  as  opposed  to  the  inte- 
rior, of  plants  varied  with  height  on  the  plant 
and  P.  opilio  category.  Some  P.  opilio  cate- 
gories tended  to  be  on  the  exterior  or  on  the 
interior  of  the  plant  at  a relatively  different 
rate  from  each  other  at  different  heights.  The 
full  logistic  regression  model  was  highly  sig- 
nificant (x^ii  = 157.3,  P < 0.001).  Both  the 
category  (x^3  = 21.2,  P < 0.001)  and  the 
height  (x\  = 31.8,  P < 0.001)  effects  were 
significant,  as  well  as  the  interaction  term  be- 
tween them  (x^6  “ 27.2,  P < 0.001).  In  the 


bottom  portion  of  the  plants,  all  P.  opilio  cat- 
egories tended  to  stay  in  the  interior  of  the 
plant.  In  the  middle  portion  of  the  plant,  some 
individuals  were  found  on  the  exterior,  with 
the  notable  exception  of  large  nymphs,  which 
were  almost  exclusively  found  in  the  interior. 
Except  for  adult  males,  individuals  of  all  other 
categories  were  found  on  the  exterior  more 
frequently  in  the  top  portion  of  the  plant  than 
in  either  of  the  other  two  plant  strata  (Fig.  3). 

DISCUSSION 

Nymphal  P.  opilio  were  somewhat  more  re- 
stricted than  adult  P.  opilio  in  their  micros- 
patial  distribution.  Although  distribution  of 
adult  males  and  females  changed  over  the  diel 
cycle,  they  were  found  on  the  ground  and  in 
all  plant  strata.  Large  nymphs,  however,  were 
seldom  found  in  the  top  portion  of  plants.  Me- 
dium nymphs  appeared  to  be  even  more  re- 
stricted, primarily  occurring  on  the  middle  and 
lower  portions  of  plants.  The  restricted  distri- 
bution of  nymphs  may  reduce  encounters  with 
adult  P.  opilio. 

Phalangium  opilio  became  active  with  the 
onset  of  nightfall  (21:00  h).  At  this  time  all 
P.  opilio,  excluding  the  medium-sized 
nymphs,  moved  to  the  ground.  Medium-sized 
nymphs  might  suffer  higher  predation  risks 


ALLARD  & YEARGAN— ACTIVITY  PATTERNS  OF  PHALANGIUM  OPILIO 


751 


Figure  3. — Percentage  of  observations  (mean  ± 
SE)  for  all  Phalangium  opilio  categories  that  were 
on  the  exterior  of  soybean  plants  as  opposed  to  the 
interior  of  the  plants  at  different  heights. 

from  other  nocturnal  ground  predators,  as  well 
as  larger  P,  opilio,  which  may  account  for 
their  tendency  to  remain  in  the  vegetation. 
While  on  the  ground,  P.  opilio  remains  active. 
Males  spent  most  of  their  time  walking  and 
little  time  palpating.  Females  also  spent  con- 


siderable time  walking  on  the  ground  but  also 
spent  time  palpating.  Nymphs  spent  less  time 
walking  than  adults,  with  medium  nymphs 
walking  the  least  of  all  P.  opilio  categories. 
Adult  females  and  nymphs  engaged  in  pal- 
pating behavior  more  frequently  than  did  adult 
males. 

If  palpating  is  a foraging  strategy  in  this 
species,  it  is  not  surprising  that  females  and 
nymphs  were  observed  palpating  more  than 
males.  Adult  females  need  nutrients  to  invest 
in  reproduction,  and  nymphs  need  nutrients 
for  development,  while  adult  males  presum- 
ably need  less  nutrients.  It  might  be  expected 
that  adult  males  would  spend  more  time  walk- 
ing in  search  of  female  mates.  Females  lay 
eggs  in  the  soil,  so  the  marked  tendency  for 
males  to  spend  more  time  walking  on  the 
ground  (Fig.  1)  may  increase  their  likelihood 
of  encountering  females  there. 

Since  P.  opilio  is  known  to  feed  on  H.  zea 
eggs  in  soybean  fields  (Anderson  1996;  New- 
ton & Yeargan  2001;  Pfannenstiel  & Yeargan 
2002),  it  is  worthwhile  to  consider  the  mi- 
crospatial  distribution  of  P.  opilio  compared 
to  that  of  H.  zea  eggs  in  soybean.  Terry  et  al. 
(1987)  observed  that  H.  zea  oviposited 
throughout  the  vertical  strata  of  soybean 
plants,  with  approximately  70%  of  the  eggs 
being  laid  on  main-stem  leaves.  Hillhouse  & 
Pitre  (1976)  reported  that  the  upper  and  mid- 
dle thirds  of  the  soybean  plants  were  preferred 
for  oviposition  compared  to  the  lower  third. 
The  microspatial  distribution  of  P.  opilio  does 
overlap  with  the  distribution  of  H.  zea  eggs. 

Knowledge  of  the  distribution  and  behavior 
of  P.  opilio  is  important  in  assessing  its  po- 
tential impact  on  arthropod  pests  in  soybean 
systems.  Its  stage-specific  activity  patterns 
and  distributions  may  affect  reproductive  op- 
portunities, intraspecific  competition,  canni- 
balism, and  potential  encounters  with  prey 
species. 

ACKNOWLEDGMENTS 

The  authors  thank  Jordi  Moya-Lorano  for 
his  statistical  advice.  The  authors  also  thank 
Kenneth  Haynes  and  Janet  Lensing  for  re- 
viewing an  earlier  version  of  the  manuscript. 
This  investigation  (paper  no.  04-08-049)  was 
conducted  in  connection  with  a project  of  the 
Kentucky  Agricultural  Experiment  Station. 


752 


THE  JOURNAL  OF  ARACHNOLOGY 


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Environmental  Entomology  31:232-241. 

Phillipson,  J.  1960.  A contribution  to  the  feeding 
biology  of  Mitopus  morio  (E)  (Phalangida).  Jour- 
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Sankey,  J.H.P.  1949.  British  harvest-spiders.  Essex 
Naturalist  28:181-191. 

Sankey,  J.H.P.  & T.H.  Savory.  1974.  British  har- 
vestmen. Synopsis  of  the  British  Fauna,  No.  4. 
Academic  Press,  London. 

SAS  Institute.  2000.  Software  release  8.0.  Cary, 
North  Carolina. 

Siegel,  S.  & N.J.  Castellan.  1988.  Non-parametric 
statistics  for  the  behavioral  sciences.  McGraw- 
Hill  International  Editions,  New  York. 

Sokal,  R.R.  & EJ.  Rohlf.  1995.  Biometry:  the  Prin- 
ciples and  Practice  of  Statistics  in  Biological  Re- 
search. W.H.  Freeman,  New  York. 

Terry,  I.,  J.R.  Bradley,Jr.  & J.W.  Van  Duyn.  1987. 
With-in  plant  distribution  of  Heliothis  zea  (Bod- 
die)  (Lepidoptera:  Noctuidae)  eggs  on  soybeans. 
Environmental  Entomology  16:625-629. 

Todd,  V.  1949.  The  habits  and  ecology  of  the  Brit- 
ish harvestmen  (Arachnida,  Opiliones),  with  spe- 
cial reference  to  those  of  Oxford  District.  Journal 
of  Animal  Ecology  18:209-229. 

Williams,  G.  1962.  Seasonal  and  diurnal  activity  of 
harvestmen  (Phalangida)  and  spiders  (Araneae) 
in  contrasted  habitats.  Journal  of  Animal  Ecolo- 
gy 31:23-42. 

Manuscript  received  24  March  2004,  revised  9 July 
2004. 


2005.  The  Journal  of  Arachnology  33:753-757 


IDENTITY  AND  PLACEMENT  OF  SPECIES  OF  THE 

ORB  WEAVER  GENUS  ALCIMOSPHENUS 

(ARANEAE,  TETRAGNATHIDAE) 


Herbert  W.  Levi:  Museum  of  Comparative  Zoology,  Harvard  University,  26  Oxford 
Street,  Cambridge,  Massachusetts  02138-2902,  U.S.A.  E-mail:  levi@fas.harvard.edu 

ABSTRACT.  Species  placed  in  the  genus  Alcimosphenus  are  examined.  Alcimosphenus  licinus  Simon 
1895  is  redescribed  and  validated.  Alcimosphenus  bifurcatus,  A.  rufoniger,  A.  boringuenae,  Acusilas 
rufonigra  and  A.  r.  maculata  are  placed  in  synonymy.  Alcimosphenus  rubripleuris  Mello-Leitao  is  trans- 
ferred to  Leucauge  and  redescribed. 

Keywords:  Greater  Antilles,  species  placement,  Tetragnathidae 


When  consulted  about  the  correct  specific 
name  for  species  within  the  genus  Alcimos- 
phenus Simon  1895,  the  common,  orange-red 
orb  weaving  spider  of  the  Greater  Antilles,  I 
found  two  specific  names  listed  in  Roewer 
(1942),  and  six  in  the  World  Spider  Catalog 
(Platnick  2004).  Simon’s  (1895)  Latin  descrip- 
tion of  the  genus  is  short  and  indicates  that 
specimens  of  A.  licinus  Simon  1895  from  Ja- 
maica and  Santa  Dominica  may  come  with  a 
forked  posterior  tip.  In  1910,  Petrunkevitch 
described  A,  bifurcatus  from  Jamaica  but  in- 
dicated that  they  were  immature  and  smaller 
in  size  than  A.  licinus  Simon.  The  name  A. 
bifurcatus  suggests  forked,  and  it  may  be  as- 
sumed that  the  name  referred  to  specimens 
with  a forked  tail  rather  than  a simple  tail. 
That  the  species  has  a forked  tail  is  confirmed 
in  Petrunkevitch’s  (1930)  key  to  Puerto  Rican 
tetragnathids,  which  separates  the  two  species, 
A.  licinus  with  a pointed  tail  from  A.  bifur- 
catus with  a forked  tail.  Again  only  immatures 
of  A.  bifurcatus  were  found,  with  forked  tails, 
this  time  one  from  Mayaguez,  Puerto  Rico.  In 
the  same  year  Franganillo  Balboa  described  a 
species  from  Cuba  placed  in  Acusilas  Simon 
1895  (Araneidae).  Later  Franganillo  (1936), 
placed  it  in  Alcimosphenus,  presumably  not 
having  seen  Petrunkevitch ’s  descriptions;  it 
differed  from  A.  licinus,  having  only  a single 
tip.  Although  no  male  had  been  collected  pre- 
viously, Archer  (1951)  placed  Alcimosphenus 
into  the  Araneidae  close  to  Arachnura  based 
on  the  description  of  a male  in  his  collection 
(without  locality).  He  later  (Archer  1958)  re- 
ferred to  the  described  male  as  coming  from 


South  America  (no  locality).  Mello-Leitao 
(1947)  described  A.  rubripleurus  from  the 
state  of  Parana,  Brazil.  (It  is  often  difficult  to 
associate  tetragnathids  males  with  females 
even  when  collected  close  to  the  collecting 
site  of  the  female,  and  examination  of  the 
Mello-Leitao  specimen,  which  I examined, 
showed  that  it  belongs  in  Leucauge  White 
1841).  In  1958  Archer  reported  finding  a ma- 
ture female  of  A.  bifurcatus,  at  last,  from  Har- 
dwar  Gap  in  Jamaica.  He  illustrated,  poorly, 
its  epigynum  and  that  of  A.  licinus.  Later  in 
1965,  Archer  found  a female  in  Puerto  Rico, 
with  a barely  visible  tail  division  and  slightly 
different  epigynal  proportions  and  gave  it  a 
new  name,  A.  borinquenae. 

Having  now  examined  the  original  speci- 
mens of  A.  licinus,  apparently  the  first  time 
they  have  been  examined  since  Simon,  I 
found  them  to  come  from  Jamaica,  and  all 
eight  syntypes  have  forked  tails  (Figs.  1,  3). 
Two  syntypes  of  A.  rufonigra  Franganillo 
1930  from  Cuba  exist,  each  showing  the  sin- 
gle tip.  Archer’s  male,  belonging  to  the 
AMNH,  was  unavailable  (presumably  lost?), 
but  judging  from  the  description  of  the  palpus, 
the  primitive  illustration,  and  its  presumably 
red  color  and  tail,  it  was  a species  of  Alpaida 
O.R-Cambridge  1889. 

Simon,  like  many  other  19*  century  au- 
thors, did  not  mark  specimens  as  types  and 
did  not  indicate  the  date  collected  on  his  la- 
bels. When  borrowing  from  the  Simon  collec- 
tion one  can  only  hope  that  the  original  spec- 
imens, the  types,  have  been  sent.  Scharff 
(pers.  comm.)  indicates  that  in  examining  the 


753 


754 


THE  JOURNAL  OF  ARACHNOLOGY 


catalog  of  the  Paris  collection,  he  found  that 
specimens  exist  other  than  the  ones  examined. 

On  examining  the  contents  of  the  28  vials 
of  Alcimosphenus  of  the  MCZ  collection, 
many  with  several  specimens,  I found  that 
some  are  with  a forked  tail  tip,  some  with  a 
single  tip.  The  forked  tail  specimens  came 
mostly  from  Jamaica,  but  one  immature  was 
from  Cuba;  Petrunkevitch  (1930)  had  one 
from  Puerto  Rico.  There  is  considerable  geo- 
graphic variation  of  the  proportions  of  the  epi- 
gynum,  the  black  patches,  and  the  tail  shape, 
but  I find  it  difficult  to  separate  specimens  into 
different  species  using  the  epigynum.  No 
males  have  ever  been  found,  although  I 
searched  unsuccessfully  for  males  in  Puerto 
Rico  and  the  collections  of  the  American  Mu- 
seum. 

Both  Leucauge  and  Alcimosphenus  differ 
from  all  other  tetragnathids  by  having  two 
parallel  rows  of  trichobothria  on  the  fourth  fe- 
mur, which  appears  to  represent  a synapo- 
morphy.  Alcimosphenus  differs  from  Leucau- 
ge by  having  the  anterior  eye  row  straight; 
whereas  Leucauge  has  the  anterior  eye  row 
recurved  (Simon  1895).  According  to  Pe- 
trunkevitch (1930),  Alcimosphenus  differs  by 
having  the  abdomen  red  and  legs  short;  in 
Leucauge  the  abdomen  is  not  red  and  the  legs 
are  longer.  Alcimosphenus  belongs  in  the  fam- 
ily Tetragnathidae,  judging  by  the  shape  of  the 
endites  (Fig.  4)  and  its  superficial  similarity  to 
Leucauge,  and  had  always  been  placed  in  Te- 
tragnathidae before  Archer  (1951). 

Griswold  et  al.  (1998)  and  Hormiga  et  al. 
(1995)  in  their  cladistic  studies  separate  Ara- 
neidae  from  other  araneoid  families  including 
Tetragnathidae  by  loss  of  the  aciniform  brush 
of  the  posterior  median  spinnerets,  the  periph- 
eral position  of  the  spigot  of  the  cylindrical 
gland  on  the  posterior  lateral  spinnerets  and 
the  use  of  the  inner  leg  tap  of  the  first  leg  used 
to  determine  the  next  point  of  attachment  of 
the  viscid  web  spiral.  Tetragnathidae,  in  turn, 
is  separated  from  other  araneoid  families  by 
the  conductor  that  wraps  around  the  embolus, 
the  presence  of  an  embolus-tegulum  mem- 
brane and  the  loss  of  the  median  apophysis  of 
the  male  palpus.  All  characters  are  considered 
sy  napomorphies . 

Abbreviations  for  museums  where  types  are 
deposited:  AMNH,  American  Museum  of 
Natural  History,  New  York;  lESC,  Instituto  de 
Ecologia  y Sistematica,  La  Habana,  Cuba; 


MCZ,  Museum  of  Comparative  Zoology, 
Cambridge;  MHNC,  Museu  de  Historia  Nat- 
ural “Capao  da  Imbuia”,  Curitiba,  Brazil; 
MNHN,  Museum  National  d’Histoire  Natu- 
relle,  Paris;  YPM,  Peabody  Museum,  Yale 
University,  New  Haven. 

TAXONOMY 

Family  Tetragnathidae  Menge  1866 
Genus  Alcimosphenus  Simon  1895 
Alcimosphenus  Simon  1895:  931. 

Type  species. — Alcimosphenus  licinus  Si- 
mon 1895,  by  monotypy. 

Description. — As  the  genus  has  now  be- 
come monotypic,  the  species  description  can 
be  used. 

Alcimosphenus  licinus  Simon  1895 
Figs.  1-7 

Alcimosphenus  licinus  Simon  1895:  931;  Simon 
1897:  871;  Petrunkevitch  1910:210;  Petrunkev- 
itch 1930:263,  figs.  115,  116;  Roewer  1942:999; 
Platnick  2004. 

Alcimosphenus  bifurcatus  Petrunkevitch  1910:211, 
plate  21,  fig.  8;  Petrunkevitch  1930:264,  figs. 
1 17,  1 18;  Roewer  1942:998;  Platnick  2004.  NEW 
SYNONYMY 

Acusilas  rufonigra  Franganillo  Balboa,  1930:70. 
NEW  SYNONYMY 

Acusilas  rufonigra  maculata  Franganillo  Balboa 
1930:70.  NEW  SYNONYMY 
Alcimosphenus  rufoniger:  Franganillo  Balboa  1936: 

87,  fig.  42;  Platnick  2004. 

Alcimosphenus  boringuenae  Archer,  1965:131,  fig. 
4;  Platnick  2004.  NEW  SYNONYMY. 

Type  specimens. — Alcimosphenus  licinus: 
4 female,  4 immature  syntypes,  Jamaica 
(MNHN,  no.  15818),  examined.  [Syntypes 
originally  from  Jamaica  and  Santa  Dominica.] 
Alcimosphenus  bifurcatus:  immature  holo- 
type.  Port  Antonio  and  Castleton,  Jamaica 
(YPM),  not  examined. 

Acusilas  rufonigra:  2 female  syntypes, 
Loma  del  Gato,  Sierra  Maestra,  Cuba  (lESC), 
examined. 

Acusilas  rufonigra  maculata:  1 specimen, 
Loma  del  Gato,  Sierra  Maestra,  Cuba  (depos- 
itory unknown),  not  examined. 

Alcimosphenus  boringuenae:  female  holo- 
type,  Collazo  Falls,  east  of  Sebastian,  Puerto 
Rico  (AMNH),  examined. 

Other  specimens  examined. — Specimens 
from  Cuba,  Hispaniola,  Jamaica,  Puerto  Rico, 
St  Croix  and  Montserrat  were  examined.  Si- 


LEVI— IDENTITY  OF  ALCIMOSPHENUS 


155 


Figures.  1-10. — Alcimosphenus  licinus  Simon.  1.  Carapace  and  abdomen,  dorsal;  2.  Abdomen,  lateral;  3. 
Abdomen,  ventral;  4.  Labium  and  endites;  5-7.  Epigynum;  5.  Ventral;  6.  Posterior;  7.  Ventral,  cleared.  8- 
10.  Leucauge  rubripleurus  (Mello-Leitao).  8.  Carapace  and  abdomen,  dorsal;  9.  Abdomen,  ventral;  10. 
Epigynum,  ventral.  Scale  lines,  1.0  mm;  of  genitalia  0.1  mm;  Fig.  4 = 0.5  mm. 


mon  (1897)  recorded  this  species  from  St  Vin- 
cent and  Trinidad. 

Description*— (syntype  of  A.  lici- 
nus from  Jamaica):  Carapace  orange,  chelic- 
erae,  labium,  endites,  sternum,  coxae  orange. 
Legs  black.  Abdomen  orange  with  black 
patches  (Figs.  1-3).  Carapace  flat  with  two 
curved  thoracic  grooves  (Fig.  1).  Labium  wid- 
er than  long,  with  large  lip,  endites  longer 
than  wide,  distally  swollen,  much  wider  than 


at  base  (Fig.  4).  Posterior  eye  row  straight. 
Eyes  small  and  subequal.  Lateral  eyes  adja- 
cent to  each  other.  Total  length  9 mm.  Cara- 
pace 2.6  mm  long,  2.5  wide  in  thoracic  region, 
1.5  wide  in  cephalic  area.  First  femur  3.3  mm, 
patella  and  tibia  4.1,  metatarsus  3.5,  tarsus 
1.2.  Second  patella  and  tibia  3.3  mm,  third 
1.8.  Fourth  femur  3.6  mm,  patella  and  tibia 
3.0,  metatarsus  2.8,  tarsus  1.0. 

Variation. — The  size  of  adult  females  is  6- 


756 


THE  JOURNAL  OF  ARACHNOLOGY 


10  mm  total  length.  The  illustrations  were 
made  from  a female  syntype  of  A.  iicinus  from 
Jamaica,  Fig.  7 from  several  non-type  speci- 
mens. The  internal  genitalia  are  lightly  scler- 
otized  and  no  structures  are  distinctly  visible. 

The  forked  tail  (Figs.  1,  3)  is  found  in  Ja- 
maica specimens,  although  some  from  Jamai- 
ca have  a pointed  tail.  Puerto  Rican  specimens 
available  have  a median  groove  at  the  tip.  One 
immature  specimen  from  Cuba  had  a forked 
tail  and  one  small  specimen  from  Jamaica  had 
the  tips  facing  in  opposite  directions. 

The  most  marked  specimens,  with  dorsal, 
lateral  and  ventral  marks  came  from  Jamaica; 
those  from  other  islands  generally  had  lateral 
black  patches  and  black  tail  but  lacked  dorsal 
and  ventral  marks.  The  Cuban  syntypes  of  A. 
rufoniger  have  a dorsal  black  patch  on  the  ab- 
domen. The  Puerto  Rican  specimens  have  a 
wider  abdomen  and  shorter  tail  and  appeared 
better  fed. 

The  differences  in  epigynal  proportions  be- 
tween specimens  with  forked  and  pointed  tails 
reported  by  Archer  were  not  found,  but  Puerto 
Rican  specimens  had  the  sides  of  the  epigyn- 
um  slightly  shorter  in  length  than  in  speci- 
mens from  other  islands.  Unlike  other  tetrag- 
nathids,  the  spermathecae  are  not  sclerotized 
and  are  indistinct  in  the  cleared  epigynum 
(Fig.  7). 

Relationships. — The  shape  of  carapace 
(Fig.  1)  and  that  of  the  abdomen  (Figs.  1-3) 
and  the  rows  of  trichobothria  on  the  fourth 
femur  suggests  a close  relationship  with  Leu- 
cauge. 

Note. — Acusilas  rufonigra  maculata  differs 
by  the  black  pattern  on  the  abdomen.  Fran- 
ganillo  Balboa  does  not  report  on  this  form 
again  in  his  more  comprehensive  paper  on  Cu- 
ban spiders  (Franganillo  Balboa  1936). 

Genus  Leucauge  White  1841 
Leucauge  rubripleurus  (Mello-Leitao  1947) 
NEW  COMBINATION 
Figs.  8-10 

Alcimosphenus  rubripleura  Mello-Leitao  1947:239, 

figs.  6,  7. 

Type  specimens. — Female  lectotype  (here 
designated),  two  female  paralectotypes,  Rio 
de  Areia,  Parana,  Brazil  (MHNC,  no.  2521- 
2523),  examined.  A lectotype  was  designated 
because  the  epigyna  of  the  syntypes  differed 
slightly. 

Description. — Female  (lectotype):  Cara- 


pace and  chelicerae  light  yellow.  Labium  and 
endites  gray,  sternum  grayish  orange-brown. 
Legs  yellowish  with  distal  ends  of  femora 
gray.  Abdomen  gray  with  two  pairs  of  black 
patches  and  patches  of  silver  dorsally  (Fig,  8) 
and  ventrally  (Fig.  9).  The  gray  areas  are  pre- 
sumed to  have  been  red  when  described  by 
Mello-Leitao  (1947). 

Posterior  median  eyes  slightly  larger  than 
others,  which  are  subequal.  Anterior  median 
eyes  0.9  diameters  apart,  1.3  diameters  from 
laterals.  Posterior  eyes  0.9  diameters  apart,  1.2 
from  laterals.  Total  length  5.2  mm.  Carapace 
1.7  mm  long,  1.7  wide.  First  femur  3.9  mm, 
patella  and  tibia  4.5,  metatarsus  3.4,  tarsus 
1.1.  Second  patella  and  tibia  3.2  mm,  third, 

I. 4,  fourth  2.2. 

This  species  has  an  epigynum  that  is  su- 
perficially similar  to  that  of  Alcimosphenus  lb 
cinus  (Fig.  10).  The  preserved  specimen  has 
gray,  silver  and  black  markings  on  the  abdo- 
men. 

It  is  placed  here  in  Leucauge  because  it 
lacks  the  Alcimosphenus  tail  and  the  abdomen 
appears  similar  to  that  of  other  Leucauge  spe- 
cies (Figs.  8,  9);  also  the  legs  are  relatively 
longer  than  those  of  Alcimosphenus. 

ACKNOWLEDGMENTS 

Brian  Farrell  suggested  that  I check  on  the 
specific  name  of  Alcimosphenus.  The  museum 
specimens  were  made  available  for  study  by 
L.E  de  Armas,  Havana;  Bittencourt,  S.  de  Fa- 
tima Caron,  Curitiba;  the  late  W.J.  Gertsch  and 

J. A.L.  Cooke,  New  York;  C.  Rollard,  Paris. 
Lorna  Levi  and  Laura  Leibensperger  reword- 
ed parts  of  the  manuscript.  I also  thank  the 
editor,  and  the  reviewers  G.  Hormiga,  and  N. 
Scharff  for  their  helpful  comments. 

LITERATURE  CITED 

Archer,  A.E  1951.  Studies  in  the  orbweaving  spi- 
ders (Argiopidae)  1.  American  Museum  Novita- 

tes  1487:1-52. 

Archer,  A.E  1958.  Studies  in  the  orbweaving  spi- 
ders (Argiopidae)  4.  American  Museum  Novita- 
tes  1922:1-21. 

Archer,  A.E  1965.  Nuevos  Argiopidos  (Aranas)  de 
las  Antillas.  Caribbean  Journal  of  Science  5: 
129-133. 

Franganillo  Balboa,  P.  1930.  Aracnidos  de  Cuba. 

Institute  Nacional  de  Investigaciones  cientfficas. 
Habana  1:47-99. 

Franganillo  Balboa,  P.  1936.  Los  Aracnidos  de 
Cuba  Hasta  1936.  La  Habana,  183  pp. 

Griswold,  C.E.,  J.A.,  Coddington,  G.  Hormiga  & 


LEVI— IDENTITY  OF  ALCIMOSPHENUS 


151 


N.  Scharff.  1998.  Phylogeny  of  the  orb=web 

building  spiders  (Araneae,  Orbiculariae:  Deino- 
poidea,  Araneoidea).  Zoological  Journal  of  the 
Linnean  Society  123:1-99. 

Hormiga,  G.,  W.G.  Eberhard  & J.A.  Coddington. 
1995.  Web-construction  behaviour  in  Australian 
Phonognatha  and  phylogeny  of  nephiline  and  the 
tetragnathid  spiders  (Araneae:  Tetragnathidae). 
Australian  Journal  of  Zoology  43:313-364 
Mello-Leitao,  C.F.  de  1947.  Aranhas  do  Parana  e 
Santa  Catarina  das  Cole^oes  do  Museu  Paran- 
aense.  Arquivos  do  Museu  Paranaense  6:231- 
304. 

Petrunkevitch,  A.  1910.  Some  new  or  little  known 
American  spiders.  Annals  of  the  New  York 
Academy  of  Sciences  19:205-224. 
Petrunkevitch,  A.  1930.  The  spiders  of  Porto  Rico. 


Transactions  of  the  Connecticut  Academy  of  Arts 
and  Sciences  30:1-355. 

Platnick,  N.I.  2004.  The  World  Spider  Catalog,  Ver- 
sion 5.0.  American  Museum  of  Natural  History, 
on  line  at  http://research.amnh.org/entomology/ 
spiders/catalog/index. html 
Roewer,  C.F.  1942.  Katalog  der  Araneae  von  1758 
bis  1940.  Vol.  1.  Kommissions-Verlag  von  “Na- 
tura”,  Bremen. 

Simon,  E.  1895.  Histoire  Naturelle  des  Araignees. 
Vol.  1,  fasc.  4,  Pp.  761-1084.  Libraire  Encyclo- 

pedique  de  Roret,  Paris. 

Simon,  E.  1897.  On  the  spiders  of  the  Island  of  St. 
Vincent.  Proceedings  of  the  Zoological  Society 
of  London  1897:860-890. 

Manuscript  received  16  March  2004,  revised  24 
August  2004. 


2005.  The  Journal  of  Arachnology  33:758-766 


DEVELOPMENT  AND  LIFE  TABLES  OF  LOXOSCELES 
INTERMEDIA  MELLO-LEITAO  1934  (ARANEAE,  SICARIIDAE) 

Marta  L.  Fischer:  Departamento  de  Biologia,  CCBS,  Pontificia  Universidade 

Catolica  do  Parana.  Nucleo  de  Estudos  do  Comportamento  Animal.  Av.  Silva  Jardim, 
1664/1  lOECEP  80250-200-Curitiba,  Parana,  Brazil.  E-mail:  marta.fischer@pucpr.br 

Joao  Vasconcellos-Neto:  Departamento  de  Zoologia,  Instituto  de  Biologia — 

Universidade  Estadual  de  Campinas — UNICAMP — C.R  6109 — Campinas,  Sao  Paulo, 
Brazil.  CEP  13083-970,  Brasil. 

ABSTRACT.  Loxosceles  intermedia  is  a medically  important  species  that  is  abundant  in  Curitiba,  Parana 
State,  Brazil.  Knowledge  of  the  postembryonic  development  of  this  species  is  fundamental  for  preventing 
bites  by  this  species  and  for  controlling  its  population  size.  In  this  report,  postembryonic  development  {n 
= 212  spiderlings)  was  studied  in  the  laboratory  under  ambient  conditions  of  temperature  and  humidity 
with  a standardized  diet.  The  average  duration  of  development  (from  emergence  from  the  egg  sac  to 
maturity)  was  356  ± 33  days  {n  = 189;  range  = 213-455).  Spiders  matured  after  5‘^-8'^  molt,  although 
most  individuals  matured  after  7“’  molt.  The  sex  ratio  was  1:1.  The  mortality  in  the  laboratory  was  low, 
most  pronounced  in  the  4*  and  5‘^  instars  and  was  associated  mainly  with  molting.  The  longevity  of 
females  (1176  ± 478  days)  was  significantly  longer  than  it  was  for  males  (557  ± 88.6  days).  The  abun- 
dance of  L.  intermedia  in  Curitiba,  city  in  the  southern  part  of  Brazil,  is  related  to  aspects  of  its  life  cycle, 
since  a slow  growth,  low  mortality,  and  greater  longevity  enhance  the  reproductive  potential  of  the  species. 

Keywords:  Loxoscelism,  life  cycle,  ontogeny,  longevity 


The  genus  Loxosceles  consists  of  venomous 
species  of  medical  importance  that  are  widely 
distributed  through  different  parts  of  the 
world.  The  venom  of  these  species,  which 
contains  powerful  cytotoxins,  necrotoxins  and 
hemotoxins  (Gertsch  1967),  together  with  the 
tendency  of  many  species  to  form  large  pop- 
ulations in  urban  areas,  close  to  human  con- 
structions, has  made  these  spiders  a public 
health  problem  in  Chile  (Schenone  et  al.  1970: 
L.  laeta  (Nicolet  1849))  and  in  the  city  of  Cur- 
itiba, a city  in  the  southern  part  of  Brazil  and 
capital  state  of  Parana  (Ribeiro  et  al.  1993:  L. 
intermedia  and  L.  laeta).  Knowledge  of  the 
postembryonic  development  of  this  species  is 
fundamental  in  management  programs  to  min- 
imize bites  by  these  spiders  and  to  control 
their  population  size.  Postembryonic  devel- 
opment has  been  described  for  L.  laeta  (Ga- 
liano  1967;  Galiano  & Hall  1973),  L.  reclusa 
Gertsch  & Mulaik  1940  (Hite  et  al.  1966;  Hor- 
ner & Stewart  1967),  L.  gaucho  Gertsch  1967 
(Rinaldi  et  al.  1997)  and  L.  hirsuta  Mello-Lei- 
tao  1931  (Fischer  & Marques  da  Silva  2001). 
Biicherl  (1961)  provided  some  data  on  the 


nymphal  period  of  L.  rufipes  (Lucas  1834)  and 
L.  rufescens  (Dufour  1820)  which,  according 
to  Gertsch  (1967),  are  L.  laeta  and  L.  gaucho, 
respectively.  Lowrie  (1980,  1987)  studied  the 
influence  of  diet  on  the  development  of  L.  lae- 
ta. The  number  of  molts  required  to  reach  ma- 
turity can  vary  within  a species  due  to  endog- 
enous and  exogenous  factors,  however  it  is 
waited  that  there  is  relationship  with  final 
body  size  (Foelix  1996).  The  maturation  also 
may  be  correlated  to  the  reproductive  system 
in  which  the  species  is  inserted  as  haplogynae 
and  entelegynae  spiders  (Schneider  1997).  In 
the  same  way,  the  difference  between  males 
and  females  in  the  use  of  resource  of  energy 
can  be  due  the  ecological  role  of  each  sex 
(Gary  2001). 

In  Brazil,  cases  of  loxoscelism  are  frequent 
in  the  south  and  southeast  of  the  country,  es- 
pecially in  the  state  of  Parana.  The  city  of 
Curitiba  registers  the  largest  number  of  spider 
bites  by  Loxosceles,  with  hundreds  of  bites 
each  year.  Two  species,  L.  intermedia  and  L. 
laeta  are  found  in  the  urban  area.  Loxosceles 
intermedia,  found  in  the  south  and  southeast 


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of  Brazil,  is  abundant  and  is  more  common 
than  L.  laeta,  the  more  cosmopolitan  species 
(90%  and  10%  of  occurrences  in  Curitiba,  re- 
spectively) (Fischer  1994).  This  distribution 
raises  the  question  about  what  factors  favor 
an  increase  in  the  population  size  of  the  pre- 
dominant species.  In  this  study,  we  examined 
the  postembryonic  development  and  longevity 
of  L.  intermedia  fed  a standardized  diet  under 
ambient  conditions  of  temperature  and  humid- 
ity. 

The  ontogeny  of  spiders  is  divided  into 
three  main  periods:  embryonic  (egg  fertilized 
until  the  establishment  in  the  shape  of  spider 
body),  larval  (prelarva  and  larva  unable  to 
feed)  and  eympho-imaginal  (nymphs  or  ju- 
veniles self-sufficient).  Postembryonic  devel- 
opment within  the  egg  sac  begins  with  rupture 
of  the  chorion  (hatching)  and  ends  with  the 
first  nymphal  molt,  after  which  the  spiderlings 
emerge  from  the  egg  sac  (Foelix  1996).  The 
terminology  used,  based  on  Foelix  (1996), 
was  the  following: 

Within  egg  sac  emergence  from  egg  sac 

Fertilization  Emerge  as  2nd  instar 

Eggs  hatch  by  opening  (mobile  stage) 

of  egg  membranes 
Immobile  stages 
(=lst  instar) 

First  true  molt  to 
2nd  instar 

instars  or  nymphal  instars  ->  adult 

series  of  molts  Sexual 

maturity 

For  this  study,  we  use  the  term  “instar”  as 
each  stage  between  molts,  starting  with  the 
first  instar,  which,  along  with  the  first  true 
molt,  occurs  inside  the  egg  sac.  Maturity  is 
reported  both  as  time  from  oviposition  (egg 
sac  construction)  to  the  maturing  molt  and 
also  as  emergence  from  the  egg  sac  to  matur- 
ing molt.  In  addition,  we  report  on  a measure 
of  growth  ratio,  which  in  this  study  is  defined 
as  the  size  of  a structure  divided  by  its  size  in 
the  preceding  instar. 

METHODS 

Postembryonic  development.— The  spi- 
ders studied  {n  = 212)  were  from  four  egg 
sacs  built  by  spiders  in  the  laboratory.  The 
spiderlings  were  reared  and  maintained  until 
death.  The  females  {n  = 4)  from  which  the 
spiderlings  were  obtained  had  already  been  in- 


after  5 molts  after  6 molts  after  7 molts  after  8 molts 
Maturity 


Figure  1. — Relative  frequency  of  Loxosceles  in- 
termedia females  and  males  reaching  maturity  after 
the  5*,  6*,  1'-^,  and  8*  molts.  The  female  and  male 
frequencies  were  compared  using  G-test.  * = P < 
0.05;  ns  = not  significant. 

seminated  when  collected  in  houses  at  differ- 
ent locations  in  Curitiba  (lat.  25°25'48"S  and 
long.  49°16'15"W).  The  spiders  were  collected 
in  March  and  June  of  1994. 

Following  their  emergence  from  the  egg 
sac,  the  spiderlings  were  housed  individually 
in  1 20  ml  plastic  containers  (diameter  of  base 
4.8  cm)  and,  from  the  4^^  instar  onwards,  were 
maintained  in  350  ml  plastic  containers  (di- 
ameter of  base,  6 cm),  before  finally  being 
transferred  to  750  ml  plastic  containers  (di- 
ameter of  base,  8 cm)  at  adult.  All  containers 
were  lined  with  a double  sheet  of  paper,  which 
provided  a substratum  for  locomotion,  web 
fixation,  refuge,  attachment,  and  ecdysis.  The 
spiders  were  maintained  under  ambient  con- 
ditions of  temperature,  humidity,  and  lumi- 
nosity. The  air  temperature  and  relative  hu- 
midity were  monitored  daily  using  a 
hydrothermograph.  During  the  study,  the 
monthly  average  temperature  was  21.4  ± 2.3 
°C  {n  = 19;  range  = 16.2-24.7),  and  the  av- 
erage monthly  humidity  was  73.9  ± 11.4%  {n 
~ 19;  range  = 57.8-95.7).  Moistened  cotton 
was  supplied  weekly.  Juveniles  up  to  the  4'*^ 
instar  were  fed  a standardized  diet  consisting 
of  larval  and  adult  Drosophila  melanogaster. 
After  the  4*  instar  the  spiderlings  were  fed 
Tenebrio  molitor  larvae.  Two  fruit  flies  or  two 
mealworm  larvae  were  supplied  twice  a week. 

The  exuvia  from  the  molt  to  the  2"^  instar 
from  four  egg  sacs  were  kept  dry  and  were 
measured  using  an  ocular  micrometer.  Four- 
teen exuvia  (from  first  molt)  and  20  exuvia 
from  the  to  the  8^^  molt  (10  females  and 


Growth  ratio  (mm) 


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1.9 

— Growth  ratio  of  female  cephalohorax  width  P 

1 .8  - Growth  ratio  of  male  cephalohorax  width 


1.7 


1.6 

1.5 

1.4 

13 


1.2 


1.1,  ^ ^ ^ ^ ^ ^ 

II  III  IV  V VI  VII  VIII 


Instar 

Figure  2. — Growth  ratio  of  the  cephalothorax  width  in  successive  instars  of  Loxosceles  intermedia  male 
and  female  (e.g.,  value  of  carapace  width  for  instar  III/  value  for  carapace  width  for  instar  II).  The  average 
ratios  for  each  instar  were  compared  using  the  Mann-Whitney  U test.  The  letters  (lowercase  for  females 
and  uppercase  for  males)  indicate  significantly  different  averages  {P  < 0.05). 


10  males)  were  examined.  The  sequential  exu- 
via  from  all  but  the  first  molt  were  always 
from  the  same  individuals.  A thin  microscope 
slide  was  placed  on  the  exuvium  to  obtain 
measurements  in  the  same  plane.  Cephalotho- 
rax width  was  used  to  compare  the  growth 
ratios  of  instars  and  adults  (Huxley  1924; 
Hangstrum  1971;  Gary  2001).  The  length  of 
tibia  I was  used  as  parameter  for  leg  growth, 
since  total  length  of  the  leg  could  be  affected 
by  loss  of  the  tarsus.  To  compare  the  size  of 
adults  that  reached  maturity  with  an  additional 
instar,  and  to  assess  whether  other  body  struc- 
tures grew  differently  in  males  and  females 
during  postembryonic  development,  addition- 
al parameters  were  measured,  including  the 
length  of  the  femur,  tibia,  metatarsus  and  tar- 
sus of  all  legs  and  the  femur,  tibia  and  tarsus 
of  the  palp,  the  width  and  length  of  the  ster- 


num and  chelicerae,  and  the  length  of  the 
cephalothorax,  labium  and  maxilla. 

In  adult  females,  the  orange  coloration  of 
the  sclerotized  regions  of  the  seminal  recep- 
tacles is  visible  with  maturity.  However,  ma- 
turity was  only  confirmed  after  insemination. 
The  development  of  the  palpal  organs,  which 
are  characteristic  of  mature  males,  was  appar- 
ent only  after  maturation.  The  fresh  weight  of 
mature  females  {n  ^ 86)  and  males  {n  57) 
was  measured  to  the  nearest  0.1  mg. 

Statistical  analyses. — G-tests  were  used  to 
compare  the  maturation  rates  of  the  different 
instars  and  the  sex  ratios.  Since  the  data  were 
not  normally  distributed  (Shapiro-Wilks  W 
test),  the  non-parametric  Kruskal- Wallis  (H 
test)  were  used  to  compare  the  average  period 
between  successive  ecdysis  and  the  average 
growth  ratio  of  the  different  morphological 


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761 


Instar 

Figure  3. -—Growth  ratio  of  tibia  I length  in  successive  instars  of  male  and  female  Loxosceles  intermedia 
(e.g.  value  of  tibia  I length  for  instar  Ill/value  for  tibia  I length  for  instar  II).  The  average  ratios  for  each 
instar  were  compared  using  the  Mann-Whitney  U test.  The  letters  (lowercase  for  females  and  uppercase 
for  males)  indicate  significantly  different  averages  {P  < 0.05). 


structures.  The  Mann- Whitney  U test  was 
used  to  compare  the  average  interval  between 

molts,  the  growth  ratios,  spider  weights,  and 
the  longevity  of  males  and  females,  and  of 
spiders  that  reached  the  maturity  after  7 and 
8 molts. 

Voucher  specimens  are  deposited  in  arach- 
nological  collection  Dra.  Vera  Regina  von 
Eicksted  in  session  of  poisonous  arthropods  of 
Imunologic  Production  and  Research  Center 
(SESA-PR). 

RESULTS 

Number  of  molts  and  instars. — -Females 

matured  after  5-8  molts  whereas  males  ma- 
tured after  6-8  molts  (Fig.  1).  In  both  males 
and  females,  the  highest  frequency  of  maturity 
was  after  molt  (females:  G-test  = 44;  P < 
0.001;  df  - 3;  males:  G-test  - 42;  P < 0.001; 
df  = 2).  The  frequency  of  maturation  after 
6^*^,  and  8‘^  molts  was  different  between 
males  and  females  {G-test  ~ 10,5;  P < 0.05; 


df  ==  3).  The  highest  frequency  of  maturity 
after  molt  was  observed  in  females,  and 
after  7^^  and  8*  molt  in  males  (Fig.  1). 

Duration  of  stages  or  instars. — There  was 
no  pattern  of  increasing  or  decreasing  the  du- 
ration of  the  interval  between  molts  during  de- 
velopment. However,  the  duration  of  the  in- 
stars was  different  in  females  (//  ^ 380;  P < 
0.001)  and  males  {H  = 423.2;  P < 0.001)  (Ta- 
ble 1)  in  the  4*  to  8‘^  instars  (for  instar,  U 
- 28530.5;  P < 0.001;  and  instar  U = 
2215;  P < 0.01).  The  time  (days)  until  adult- 
hood was  not  significantly  different  between 
males  and  females  {U  ^ 3334.5;  P ==  0.15) 
(Table  2). 

Growth. — A comparison  of  the  growth  ra- 
tio of  the  cephalothorax  width  showed  the 
same  pattern  between  males  and  females  (Fig. 
2).  A growth  ration  of  1.5  shows  that  the  car- 
apace width  was  l,5x  greater  in  one  instar 
than  the  previous  instar.  The  growth  ratio  de- 
creased with  each  instar  until  the  VIII  instar. 


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Table  1. — Duration  (days)  of  Loxosceles  intermedia  nymphal  instars.  The  different  letters  indicate  av- 
erages that  are  significantly  different  {P  < 0.05;  Mann-Whitney  U test). 


Total  Females  Males 


Instars 

n 

Mean  ± SD 

Range 

U 

n 

Mean  ± SD 

Range 

U 

n 

Mean  ± SD 

Range 

U 

II 

212 

41.1  ± 

7.8 

25-64 

a 

88 

40.1  ± 7.6 

25-64 

a 

101 

41.5  ± 

8.2 

29-64 

a 

III 

211 

31  ± 

6.2 

14-57 

b 

88 

31.6  ± 6.5 

14-50 

b 

101 

30.3  ± 

5.4 

19-57 

b 

IV 

210 

46.9  ± 

22 

14-198 

c 

88 

48.1  ± 27 

16-198 

c 

101 

44.2  ± 

15 

14-105 

a 

V 

200 

99.5  ± 

31.8 

39-170 

d 

88 

108.5  ± 32 

49-167 

d 

101 

91.3  ± 

30 

39-162 

c 

VI 

192 

74  ± 

20 

36-188 

e 

87 

75.4  ± 21.3 

36-144 

e 

101 

73.2  ± 

18.4 

50-188 

d 

VII 

164 

70.1  ± 

18.8 

39-200 

e 

72 

64.7  ± 13.7 

39-91 

f 

91 

72.3  ± 

12.9 

43-104 

d 

VIII 

23 

61.5  ± 

14 

45-84 

f 

8 

60.5  ± 9.8 

45-75 

f 

16 

61.2  ± 

49 

45-84 

e 

when  it  increased  markedly.  Likewise  there 
was  no  difference  in  the  growth  ratio  of  the 
tibia  I length  when  males  and  females  were 
compared  (Fig.  3).  The  biggest  change  in  the 
growth  ratio  of  tibia  I occurred  between  in- 
stars  II  and  III. 

The  cephalothorax  width  did  not  differ 
among  females  that  matured  after  and  8'^ 
instars  {U  = 20\  P = 0.7)  (Table  3).  Tibial 
length  (II  and  III)  increased  between  7^*’  and 
instars  {U  = 13.5;  P < 0.01  and  U = 16; 
P < 0.05).  In  males  that  reached  maturity  after 
8'^  instar,  both  the  cephalothorax  width  {U  = 
0.1;  P < 0.001)  and  tibial  length  of  all  legs 
(I:  t/  = 14;  F < 0.01;  II:  U = 18;  F < 0.05; 
III:  U = 17.5;  F < 0.01;  IV:  U = 9.5;  F < 
0.0001)  were  significantly  greater  than  in 
males  that  matured  after  the  7^^  instar  (Table 
3).  The  cephalothorax  width  did  not  differ  be- 
tween males  and  females  that  reached  matu- 
rity after  and  8'^  instars.  However,  the  tibial 
length  was  longer  in  males  in  both  situations 
(Table  3). 

The  average  weight  of  adult  females  was 
127.4  ± 5.03  mg  {n  = 86;  range  = 30-240) 
and  that  of  adult  males  was  68.6  ± 23.7  mg 
{n  = 57;  range  = 10-=  110).  Females  were 
thus  significantly  heavier  than  males  {U  = 
649.5;  F < 0.001).  The  weight  of  females  that 


reached  maturity  after  7“^  instar  was  not  dif- 
ferent from  that  of  females  that  reached  ma- 
turity after  8‘^  instar  {U  = 163.5;  F = 0.58). 
In  contrast,  males  that  reached  maturity  after 
8^*^  instar  were  heavier  than  those  that  reached 
maturity  after  1'-^  instar  {U  = 42;  F < 0.01). 

Sex  ratio. — Of  the  212  spiderlings  studied 
until  death,  41.5%  {n  = 88)  were  female, 
47.6%  {n  = 104)  were  male,  and  10.8%  {n  = 
20)  died  before  reaching  maturity.  Of  the  four 
egg  sacs  studied,  in  two  there  were  more 
males  than  females,  but  this  difference  was 
significant  in  only  one  egg  sac. 

Longevity. — Loxosceles  intermedia  reared 
in  the  laboratory  had  a low  overall  mortality 
rate.  Mortality  which  was  greatest  in  the  4‘^ 
and  5^^^  instars  and  was  associated  mainly  with 
molting  (immediately  prior  to  ecdysis).  The 
spiders  sometimes  remained  attached  to  the 
old  exoskeleton  and  died  1-4  days  after  molt- 
ing. The  initial  instars  had  the  greater  life  ex- 
pectancies (ex),  which  then  decreased  during 
development  (Table  4). 

Adult  longevity  and  total  longevity  post 
emergence  was  significantly  greater  in  fe- 
males than  in  males  {U  = 589.5;  F < 0.001 
and  U = 527;  F < 0.001)  (Table  5).  The  time 
required  for  growth  from  oviposition  to  the 
adult  stage  increased  with  the  number  of  ec- 


Table  2. — Loxosceles  intermedia  maturation  times. 


Total 

Female 

Male 

Time  (days) 

n 

Mean  ± SD 

Range 

n 

Mean  ± SD 

Range 

n 

Mean  ± SD 

Range 

Oviposition  to 

189 

409  ± 33 

269-506 

88 

404  ± 56 

112-506 

101 

410  ± 46 

269-744 

maturity 
Emergence  of 

189 

356  ± 33 

213-455 

88 

359  ± 35.7 

241-455 

101 

354.7  ± 31.1 

258-431 

egg  sac  to 
maturity 


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763 


Table  3. -“Average  tibia  I length  (mm)  and  cephalothorax  width  (mm)  in  successive  instars  of  male  and 
female  Loxosceles  intermedia  (sample  size  and  range  in  parentheses).  The  averages  were  compared  using 
the  Mann-Whitney  U test.  The  letters  indicate  significantly  different  averages  {P  < 0.05). 


Cephalothorax 


Tibia  I 

Mean  ± SD 

U 

Tibia  II 

Mean  ± SD 

U 

Tibia  III 

Mean  ± SD 

U 

Tibia  IV 

Mean  ± SD 

U 

width 

Mean  ± SD 

U 

Male  instar 

5.9  ± 0.6 

a 

7.0  ± 0.8 

a 

d 

+1 

00 

•4 

a 

5.4  ± 0.62 

a 

3.0  ± 0.3 

a 

VII 

(10;  4.7-6.9) 

(10;5.9-8.4) 

(10;  4.1-5.6) 

(10;  4.7-6.3) 

(10;  2.4-3.3) 

Male  instar 

6.6  ± 0.6 

b 

9.3  ± 0.5 

b 

5.2  ± 0.1 

b 

6.3  ± 0.2 

b 

3.8  ± 0.2 

b 

VIII 

(10;  5. 1-7.5) 

(10;  8.1-9.7) 

(10;  5-5.3) 

(10;  5.6-6.4) 

(10;  3.4-3.9) 

Female  instar 

4.3  ± 0.7 

c 

4.7  ± 0.8 

c 

3.4  ± 0.6 

c 

4.4  ± 0.7 

c 

3.1  ± 0.3 

a 

VII 

(10;  3.1-5.3) 

(10;  3.4-5.6) 

(10;  2.3-4.4) 

(10;  3.4-5.6) 

(10;  2.5-3.6) 

Female  instar 

5.2  ± 0.9 

c 

6.5  ± 1.8 

d 

4.3  ± 0.8 

d 

5 ± 0.6 

c 

3.5  ± 0.45 

ab 

VIII 

(8;  4.5-6.6) 

(8;  5.2-9.4) 

(8;  3.6-5.9) 

(8;  4.4-5.9) 

(8;  3. 1-4.4) 

dysis  required  for  the  spider  to  reach  maturity 
(females:  H = 24.5;  P < 0.001  and  males:  H 
= 31.2;  P < 0.001).  However,  the  longevity 
as  adults  and  the  total  longevity  were  unrelat- 
ed to  number  of  molts  (Table  6). 

DISCUSSION 

The  present  study  is  an  important  reference 
on  the  basic  biology  of  L.  intermedia.  In  ad- 
dition to  serving  as  a beech  mark  for  experi- 
mental studies,  the  data  may  be  important  in 
the  preparation  of  management  plans  for  the 
species.  The  observation  of  the  212  spiders  for 
more  than  six  years  allowed  the  characteriza- 
tion of  the  postembryoeic  development  evi- 
dencing long  time  to  maturity,  similar  growth 
of  different  parts  of  the  body  in  males  and 
females,  similar  proportion  of  the  sexes,  little 
mortality  and  long-lived  spiders  in  spite  of 
their  small  size. 

Variations  in  final  body  size  of  the  Loxos- 
celes species  (Gertsch  1967)  reflect  the  differ- 

Tabie  4. — -Life  table  of  Loxosceles  intermedia 
reared  in  the  laboratory  (k  “ number  of  survivors 
at  the  start  of  the  instar;  d,,  = number  of  deaths  in 
the  interval  x and  x + 1;  = mortality  rate;  ^ 

average  life  expectancy  for  an  individual  alive  at 
the  beginning  of  the  interval;  ==  average  number 
of  individuals  alive  in  the  interval  x and  x + 1;  T^ 
= individuals  for  unit  of  time). 


lestar 

1. 

d. 

fix 

e. 

L. 

T 

-*■  X 

II 

164 

1 

0.006 

5.18 

163.5 

847 

III 

163 

1 

0.006 

4.21 

162.5 

683 

IV 

162 

10 

0.006 

3.32 

157 

521 

V 

152 

6 

0.66 

2.44 

149 

364 

VI 

146 

4 

0.41 

1.49 

144 

215 

VII 

142 

142 

1 

1.01 

71 

144 

ent  number  of  molts  required  to  reach  matu- 
rity (Foelix  1996),  Although  the  standardized 
number  of  molts  in  L.  intermedia  was  seven, 
this  number  could  be  smaller  or  greater.  The 
variation  of  up  to  four  molts  occur  in  L.  in- 
termedia, L.  laeta  (Galiano  1967;  Lowrie 

1987)  and  L.  gaucho  (Rinaldi  et  al.  1997),  and 
the  variation  of  only  two  molts  in  L.  hirsuta 
(Fischer  & Marques  da  Silva  2001),  L.  reclusa 
(Horner  & Stewart  1967)  and  L,  rufipes  (Del- 
gado 1966).  Although  L.  intermedia  has  the 
same  number  of  molts  or  more  than  other  spe- 
cies, this  species  required  more  time  to  reach 
maturity  (7  molts;  357  days)  compared  to  L. 
laeta  {6-9  molts;  315.3  days)  (Galiano  1967) 
and  L.  reclusa  (7  molts;  303.3)  (Hite  et  al. 
1966);  L.  rufipes  {3-A  molts;  357  days)  (Del- 
gado 1966)  had  smaller  number  of  molts  but 
required  the  same  time  as  L.  intermedia. 

The  maturation  period  and  the  number  of 
molts  until  maturity  can  vary  within  the  same 
species  when  spiders  are  maintained  in  differ- 
ent conditions.  In  spiders,  this  variation  is  at- 
tributed to  the  feeding  regime  (Turnbull  1962, 
1965;  Levy  1970),  temperature  (Downes 

1988) ,  predation  of  infertile  eggs  by  spider- 
lings  within  the  egg  sac  (Galiano  1967;  Val- 
erio 1974)  and  genetic  variation  (Muniappan 
& Chada  1970;  Wise  1976;  Downes  1987). 
For  Loxosceles  the  time  and  number  of  molts 
was  attributed  to  the  amount  and  composition 
of  food  (Lowrie  1980,  1987;  L.  laeta),  tem- 
perature during  development  (Horner  & Stew- 
art 1967;  L.  reclusa)  and  season  when  the  egg 
sac  was  deposited  (Hite  et  al.  1966;  L.  laeta). 

The  maturation  also  may  be  correlated  to 
the  mating  system,  which  is  in  turn  influenced 
by  spermathecal  morphology  and  the  pattern 


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THE  JOURNAL  OF  ARACHNOLOGY 


Table  5. — Average  longevity  (days)  of  female  and  male  Loxosceles  intermedia  reared  in  the  laboratory. 
The  values  are  the  mean  ± SD.  The  number  of  spiders  and  the  range  are  shown  in  parentheses. 


Total 

Female 

Male 

Longevity  as  adults  (last  molt  to  death) 

493.7  ± 455 

816.9  ± 478.1 

202  ± 92 

(175;  0-181) 

(83;  124-1810) 

(92;  0-483) 

Longevity  total  (emergence  from  egg  sac 

850.6  ± 455.8 

1176  ± 478 

557  ± 88.6 

to  death) 

(175;  368-2195) 

(83;  465-2195) 

(92;  368-795) 

of  use  of  stored  sperm  (Schneider  1997).  In 
species  in  which  the  sperm  package  deposited 
first  will  also  be.  the  first  to  leave  the  sper- 
mathecae  (conduit  spermathecae),  the  males 
should  reach  maturity  before  females,  and 
should  compete  for  a mate,  guarding  the  fe- 
males in  order  to  maximize  their  fertilization 
rates.  In  this  system  (strong  male-male  com- 
petition) a larger  body  size  for  males  is  im- 
portant. In  Loxosceles,  there  is  a single  open- 
ing to  the  spermathecae  (Gertsch  1967; 
Fischer  1994)  and  the  spiders  are  considered 
haplogynae  since  the  copulatory  duct  also 
serves  as  the  fertilization  duct  (Foelix  1996). 
Such  species  are  considered  to  have  last  male 
priority,  since  the  sperm  deposited  last  in  the 
spermathecae  will  be  the  first  to  reach  the 
eggs  (Schneider  1997).  Hence,  the  males 
reach  maturity  at  the  same  time  as  the  female, 
as  observed  in  L.  intermedia  (this  study)  and 
L.  gaucho  (Rinaldi  et  al.  1997),  or  a little  later, 
as  in  L.  laeta  (Galiano  1967;  Galiano  & Hall 
1973;  Lowrie  1980,  1987)  and  L.  hirsuta  (Fi- 
scher & Marques  da  Silva  2001).  Experimen- 
tal studies  should  be  conducted  with  other 
Loxosceles  to  confirm  this  trend. 

The  linear  growth  of  different  parts  of  the 
body  (e.g.  cephalothorax  width  and  abdomen 
length)  means  that  there  was  no  difference  in 
the  allocation  of  resources  to  specific  body 
parts,  also  shown  by  Gary  (2001)  for  males 
and  females  of  Linyphia  triangularis  (Clerck 
1757)  (Linyphiidae).  Although  the  abdomen 
of  L.  intermedia  was  not  measured  here,  the 
existence  of  resource  allocation  is  seen  in  the 
larger  weight  of  the  females,  and  the  longer 
walking  legs  of  the  males.  The  female  prob- 
ably uses  energy  resources  for  egg  production, 
while  males  have  a more  wandering  lifestyle 
(mate-searching  in  adult  life)  and  maximize 
mating  with  a larger  number  of  females.  On 
the  other  hand,  the  similar  size  of  the  cepha- 
lothorax width  may  indicate  that  there  is  in- 
traspecific competition  in  both  sexes,  selecting 


the  largest  size.  A larger  size  in  females  would 
favor  a greater  production  of  eggs,  while  in 
males  a larger  size  would  be  important  for 
competition  during  mating  opportunities  and 
possibly  for  fighting. 

The  long  time  to  maturity  and  the  similar 
growth  of  different  parts  of  the  body  in  males 
and  females  indicate  that  rapid  growth  mech- 
anisms do  not  exist  in  L.  intermedia.  The  rap- 
id growth  registered  in  Nephila  clavipes  (Lin- 
naeus 1767)  (Tetragnathidae)  has  ecological 
costs  (increase  in  mortality)  that  are  related  to 
the  risk  of  predation  and  parasitism  (associ- 
ated with  increased  foraging),  and  an  inherent 
physiological  cost  because  of  the  high  food 
consumption  (Higgins  & Rankin  2001). 

The  lack  of  difference  in  the  body  size  of 
juvenile  male  and  female  L.  intermedia  has 
also  been  observed  in  L.  gaucho  (Rinaldi  et 
al.  1997)  and  L.  laeta  (Galiano  1967).  Ac- 
cording to  Galiano  (1967),  instar  VI  was  the 
earliest  age  for  accurate  recognition  of  the 
sexes.  Again,  this  pattern  is  evidence  of  a sim- 
ilar allocation  of  energy  resources  during  de- 
velopment in  order  to  produce  adults  of  sim- 
ilar body  sizes  (cephalothorax  width). 
Although  a larger  size  benefits  both  sexes,  the 
additional  molt  was  significant  only  for  male 
L.  intermedia  and  L.  hirsuta  (Fischer  & 
Marques  da  Silva  2001)  and  reflected  advan- 
tages in  the  accumulation  of  energy  (Wheeler 
et  al.  1990).  In  females  an  8'^  molt  probably 
does  not  influence  the  reproductive  potential 
since  body  weight  and  size  did  not  differ. 

There  was  little  mortality  during  develop- 
ment of  L.  intermedia  and  L.  hirsuta  (Fischer 
& Marques  da  Silva  2001).  The  correlation 
between  deaths  and  molting  (before,  during  or 
after)  indicates  that  this  is  a time  of  great 
stress  and  a very  vulnerable  phase  in  the  life 
history  of  spiders  (Galiano  1967,  L.  laeta; 
Turnbull  1965,  Agelenidae;  Nuessly  & Goe- 
den  1984,  Diguetidae;  Downes  1993,  Amau- 
robidae).  According  to  Galiano  (1967),  the  de- 


FISCHER  & VASCONCELLOS-NETO— DEVELOPMENT  OF  LOXOSCELES  INTERMEDIA 


765 


Table  6. — Time  (days)  from  emergence  to  adult  hood,  adult  longevity,  and  longevity  after  emergence 
of  female  and  male  L.  intermedia  that  reached  maturity  after  5th,  6th,  7th,  and  8th  instar.  The  values  are 
the  mean  ± SD.  The  number  of  spiders  and  the  range  are  shown  in  parentheses.  The  averages  were 
compared  using  the  Mann- Whitney  U test.  The  letters  indicate  significantly  different  averages  {P  < 0.05). 


Instar 

Time  to  maturity 

Females 

Adult  longevity 

Total  longevity 

Time  to  maturity 

Males 

Adult  longevity 

Total  longevity 

V 

258  ± 24 

321  ± 68 

579  ± 43.8 

— 

— 



(4;  241-275)  a 

(4;  273-369)  a 

(4;  548-610)  a 

VI 

334  ± 42.2 

1045  ± 400 

1385  ± 396 

306  ± 39.7 

242  ± 120 

547  ± 100 

(16;  263-192)  b 

(16;  128-1577)  ab 

(16;  465-1894)  ab 

(7;  261-367)  a 

(7;  146-461)  a 

(7;  45-729)  a 

VII 

365.3  ± 27 

779  ± 482 

1143  ± 482 

354  ± 23.5 

199  ± 91 

554  ± 88 

(62;  271-435)  c 

(62;  124-1810)  ac 

(62;  495-2195) b 

(77;  258-403)  b 

(77;  2-483)  a 

(77;  368-795)  a 

VIII 

382.4  ± 14.3 

825  ± 520 

1204  ± 511 

387  ± 22.6 

197  ± 89 

585  ± 91 

(8;  363-405)  d 

(8;  18-1558)  a 

(8;  568-1935)  ab 

(15;  331-431) c 

(15;  0-293)  a 

(15;  368-705)  a 

lay  in  growth  and  the  difficulty  in  molting 
results  from  an  increase  in  the  time  between 
successive  feedings.  Higgins  & Rankin  (2001) 
observed  that  spiders  fed  large  amounts  of 
food  were  more  likely  to  die  at  or  immediately 
before  the  next  molt. 

The  abundance  of  L.  intermedia  in  Curitiba 
is  associated  with  aspects  of  this  species’  life 
cycle.  The  long  period  until  maturity  is 
reached  results  in  large  body  size  and  a low 
mortality  rate.  The  fertilization  of  a larger 
number  of  females  by  males  is  favored  by  the 
greater  longevity  and  larger  body  of  the 
males.  Likewise,  the  life  span  of  up  to  five 
years  in  adult  females  maximizes  their  repro- 
ductive potential  by  allowing  than  to  be  fer- 
tilized by  successive  generations  of  males. 

ACKNOWLEDGMENTS 

The  authors  thank  Prof.  Dr.  Luis  Amilton 
Foerster,  Dra.  Sylvia  Lucas  and  Dra.  Gail 
Stratton  for  their  comments  and  help  in  pre- 
paring this  manuscript  and  Liliani  Tiepolo  and 
Claudia  Staudacher  for  supplying  the  females 
of  L.  intermedia.  This  paper  was  suported  by 
Curso  de  Pos-Graduagao  em  Zoologia-— Univ- 
ersidade  Federal  do  Parana— ^UEPR  and 
CAPES.  J.  Vasconcellos-Neto  was  supported 
by  a grant  from  Conselho  Nacional  de  Desen- 
volvimento  Cientffico  e Tecnologico  (CNPq, 
grant  no.  300539/94-0)  and  BIOTA/FA- 
PESP — The  Biodiversity  Virtual  Institute  Pro- 
gram (grant  no.  99/05446-8). 

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Manuscript  received  9 June  2003,  revised  23  Oc- 
tober 2004. 


2005.  The  Journal  of  Arachnology  33:767-775 


MATE  CHOICE  AND  SEXUAL  CONFLICT  IN  THE  SIZE 
DIMORPHIC  WATER  SPIDER  ARGYRONETA  AQUATICA 
(ARANEAE,  ARGYRONETIDAE) 


Dolores  Schiitz^’^  and  Michael  Taborsky^’^:  ^Konrad  Lorenz  Institut  fur 
Vergleichende  Verhaltensforschung  (KLIVV),  Austrian  Academy  of  Sciences, 
SavoyenstraBe  la,  1160  Wien,  Austria;  ^Department  of  Behavioural  Ecology, 
University  of  Bern,  Wohlenstr.  50a,  3032  Hinterkappelen,  Switzerland.  E-mail: 
MichaeLTaborsky@esh.unibe.ch. 

ABSTRACT.  Argyroneta  aquatica  is  the  only  spider  that  spends  its  entire  life  under  water,  and  is  one 
of  the  few  spiders  in  which  males  are  larger  than  females.  In  this  paper  we  investigated  size  dependent 
mate  choice  to  clarify  whether  intersexual  selection  may  be  partly  responsible  for  the  reversed  sexual  size 
dimorphism  (SSD)  in  A.  aquatica.  We  found  that  females  that  only  copulated  once  could  produce  up  to 
six  viable  egg  sacs,  although  the  number  of  offspring  decreased  with  each  egg  sac  produced.  Males  are 
the  more  active  sex  in  mate  acquisition  and  females  prefer  large  males  as  mating  partners.  However, 
females  fled  more  often  from  males  larger  than  their  own  size  (SSD  >1)  than  from  relatively  smaller 
males  (SSD  < 1),  although  small  males  approached  females  more  often  than  large  males  did.  We  found 
that  males  of  A.  aquatica  may  cannibalize  females,  which  to  our  knowledge  is  the  first  account  of  such 
reversed  sexual  cannibalism  in  spiders.  The  extent  of  SSD  (m  > f)  determined  the  likelihood  of  females 
being  cannibalized.  Apparently,  avoidance  behavior  of  females  towards  the  preferred,  large  mating  partners 
is  related  to  the  higher  risk  of  being  cannibalized.  In  A.  aquatica,  intersexual  selection  may  stabilize  male 
size  at  an  optimum  instead  of  directionally  selecting  for  large  body  size. 

Keywords*  Sexual  size  dimorphism,  SSD,  sexual  cannibalism 


In  most  web-building  spiders,  females  are 
larger  than  males  (Vollrath  1980;  Head  1995). 
Recent  studies  suggest  that  selection  pressures 
on  male  locomotory  ability  greatly  influence 
optimal  male  body  size.  For  terrestrial  spiders, 
small  male  size  has  often  been  explained  by 
mobility  advantages  (Foelix  1992).  In  some 
species,  males  are  even  able  to  balloon,  sim- 
ilar to  young  spiderlings  (Foelix  1992).  Re- 
cently, Moya-Larano  et  al.  (2002)  proposed, 
with  help  of  a simple  biomechanical  model, 
that  smaller  males  are  favored  in  species  in 
which  the  male  must  climb  to  reach  females 
in  high  habitat  patches.  They  argued  that  the 
constraint  imposed  by  gravity  on  climbing 
males  is  a selective  factor  in  determining  male 
dwarfism  (Moya-Larano  et  al.  2002).  In  the 
water  spider  Argyroneta  aquatica  Clerck 
1757,  however,  males  are  larger  than  females 
and  larger  males  have  mobility  advantages 
over  smaller  ones  when  moving  under  water 
(Schutz  & Taborsky  2003).  Since  the  water 

^ Corresponding  author. 


spider  spends  its  entire  life  under  water,  large 
body  size  is  favored  in  this  species  more  in 
males,  the  more  mobile  sex,  than  in  females 

Mate  choice  and  male-male  competi- 
tion.— There  is  evidence  that  female  choice 
mechanisms  may  influence  the  evolution  of 
male  body  size  in  some  spiders.  Elgar  et  al. 
(2000)  demonstrated  that  females  used  can- 
nibalism to  choose  their  preferred  mates  in  the 
orb-web  spider  Argiope  keyserlingi  Simon 
1895,  in  which  mature  males  are  much  small- 
er than  mature  females.  Females  that  copulat- 
ed with  relatively  smaller  males  delayed  sex- 
ual cannibalism  and  prolonged  the  duration  of 
copulation.  Consequently,  small  males  fertil- 
ized more  eggs  than  large  ones  (Elgar  et  al. 
2000).  In  the  desert  spider,  Agelenopsis  aperta 
Koch  1837,  a species  in  which  males  and  fe- 
males are  approximately  the  same  size  at  ma- 
turity, heavy  males  were  more  likely  to  be  ac- 
cepted by  females  (Singer  & Riechert  1995). 

Intrasexual  competition  between  males  may 
also  influence  optimal  body  size  in  spider 
males.  In  some  sheet- web  spiders  (Linyphi- 


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THE  JOURNAL  OF  ARACHNOLOGY 


idae),  where  males  are  larger  than  females,  the 
reversed  sexual  size  dimorphism  (SSD)  prob- 
ably depends  on  strong  intrasexual  selection 
through  male-male  competition  for  mating  op- 
portunities (Lang  2001).  In  contrast,  male 
dwarfism  may  be  the  result  of  reduced  intra- 
sexual competition  (Vollrath  & Parker  1997). 
For  example  in  Nephila  spp.,  in  which  males 
suffer  a much  greater  mortality  risk  than  fe- 
males due  to  active  mate  search  and  a higher 
mobility,  intrasexual  competition  between 
males  is  strongly  reduced  and  males  are  much 
smaller  than  females  (Vollrath  & Parker 

1997) . 

Sexual  conflict. — Mating  patterns  are  often 
characterized  by  conflicts  of  interest  between 
the  sexes.  Such  conflicts  may  exist  over  the 
frequency  of  mating  or  the  degree  of  parental 
investment  (Warner  et  ah  1995;  Henson  & 
Warner  1997;  Schneider  & Lubin  1998;  John- 
son 2001).  Since  in  spiders,  males  do  not  pro- 
vide parental  care  and  females  can  usually  fer- 
tilize more  than  one  clutch  with  a single 
copulation,  the  main  conflict  between  the  sex- 
es in  spider  reproduction  should  be  about  the 
frequency  of  mating  (Schneider  & Lubin 

1998) . 

Both  sexes  are  selected  to  prevail  in  this 
conflict  (Henson  & Warner  1997;  Shine  et  al. 
2000;  Eberhard  2002).  In  spiders,  males  may 
force  copulations  (Schneider  & Lubin  1998) 
or  develop  adaptations  that  prevent  the  sperm 
of  rival  males  from  fertilizing  the  eggs  of  the 
female  (sperm  competition,  Schneider  & El- 
gar 2001).  Females  may  reduce  receptivity  af- 
ter one  mating,  they  may  respond  aggressively 
towards  approaching  males,  or  they  may  have 
structures  that  enhance  their  control  over  mat- 
ing (Schneider  & Lubin  1998).  Sexual  conflict 
in  spiders  can  even  result  in  the  death  of  one 
partner,  usually  when  a female  cannibalizes  a 
male  after,  during  or  even  before  mating  (An- 
drade 1996;  Schneider  & Lubin  1996;  Schnei- 
der & Lubin  1998;  Elgar  et  al.  2000). 

The  reversed  SSD  in  the  water  spider  may 
lead  to  a different  outcome  of  sexual  conflict 
with  respect  to  rates  of  mating  when  the  water 
spider  is  compared  to  other  spiders.  Due  to 
their  relatively  large  size  it  may  be  easier  for 
A.  aquatica  males  to  overcome  resistance  of 
the  female,  and  female  cannibalism  of  males 
may  be  difficult. 

The  study  species. — Argyroneta  aquatica 
(Clerck  1757)  is  a solitary,  aquatic  spider 


(Heinzberger  1974)  distributed  in  northern 
and  middle  Europe,  in  Siberia  up  to  62°  lati- 
tude north,  and  in  central  Asia  (Crome  1951). 
It  is  active  mainly  during  the  night  (Stadler 
1917;  Heinzberger  1974;  Masumoto  et  al. 
1998)  and  shows  specific  adaptations  to  the 
life  under  water.  For  digesting  their  prey, 
molting,  copulating,  depositing  eggs  and  rais- 
ing offspring,  males  and  females  separately 
construct  air  bells  under  water,  which  are  usu- 
ally built  between  water  plants  and  fixed  with 
spider  thread  to  plants  or  stones  (Wesenberg- 
Lund  1939;  Heinzberger  1974).  The  abdomen 
and  legs  bear  hairs  that  keep  an  air  bubble 
around  the  body  to  help  transport  air  from  the 
surface  down  to  the  air  bell,  and  to  breathe 
under  water  (Ehlers  1939).  Adult  males  were 
significantly  larger  (males:  3.8  ± 0.67  mm, 
females:  3.2  ± 0.29  mm,  mean  ± SD)  and 
heavier  (males:  0.15  ± 0.08  g,  females:  0.10 
± 0.039  g)  than  females  (data  in  Schiitz  & 
Taborsky  2003). 

Water  spiders  appear  to  suffer  from  certain 
constraints  from  their  life  under  water  (En- 
gelhardt  1989).  Argyroneta  aquatica  is  not  a 
good  diver  as  it  struggles  hard  to  compensate 
for  buoyancy  when  moving  under  water 
(Schollmeyer  1913).  Males  are  more  mobile 
than  females.  They  rove  around  more  often, 
actively  searching  for  females  and  catching 
their  prey  mainly  by  active  hunting  (Crome 
1951).  Females  spend  most  of  the  time  inside 
their  air  bell,  where  they  also  raise  their 
broods.  They  are  ambush  predators  catching 
prey  mainly  when  detecting  vibrations  caused 
by  prey  touching  the  underwater  net,  which 
surrounds  their  air  bell.  Thus,  males  and  fe- 
males have  different  “life  styles”,  which  may 
select  for  different  body  sizes  (Schutz  & Ta- 
borsky 2003). 

In  a previous  study  we  found  that  A.  aqua- 
tica males  (i.e.  the  more  mobile  sex)  are  better 
divers  than  females,  as  measured  by  the  ver- 
tical diving  ability  in  a 1000  ml  glass  cylinder 
with  and  without  structures  to  grasp.  It  is  pos- 
sible that  ecological  constraints  select  for  a 
body  size  that  is  optimal  for  underwater  lo- 
comotion in  males  much  more  than  in  fe- 
males. We  further  found  that  females  built 
larger  air  bells  than  males  and  that  air  bells 
size  correlated  with  body  size  in  females,  but 
not  so  in  males.  Thus  female  size  may  be  lim- 
ited by  the  costs  of  building  air  bells  (Schutz 
& Taborsky  2003).  In  the  present  study,  we 


SCHIJTZ  & TABORSKY— SEXUAL  CONFLICT  IN  THE  WATER  SPIDER 


769 


investigated  how  this  unusual  direction  of 
SSD  relates  to  mate  choice  and  sexual  conflict 
in  A.  aquatica.  Do  females  choose  mates  ac- 
cording to  size,  and  do  males  compete  for  ac= 
cess  to  females? 

METHODS 

Study  subjects. — ^All  spiders  used  for  this 
study  were  wild  caught  animals  from  four  ad- 
jacent populations  near  Vienna,  Austria,  or 
their  offspring.  In  1999  and  2000  we  collected 
more  than  160  water  spiders  (45  adult  fe- 
males, 35  adult  males  and  >80  subadults) 
with  small  fishing  nets  and  kept  each  adult 
spider  isolated  in  a glass  Jan  Whole  broods 
and  smaller  subadults  were  held  in  groups  in 
small  aquaria,  and  all  spiders  were  fed  twice 
a week  with  living  Assellus  aquaticus  or  Gam- 
mams  pulex.  The  prey  also  survived  very  well 
in  the  small  aquaria,  so  that  the  spiders  had 
access  to  ad  libitum  quantities  of  living  food. 
For  each  spider,  we  determined  the  cephalo- 
thorax  width  as  a measure  of  body  size  (see 
Foelix  1992;  Lang  2001).  After  we  could  de- 
termine the  sex  of  subadult  spiders,  we  mea- 
sured their  cephalothorax  width  when  they 
were  mature.  Voucher  specimens  (two  fe- 
males) have  been  deposited  in  the  Natural 
History  Museum  of  Berne. 

Due  to  very  dense  aquatic  vegetation  in  the 
field  it  was  impossible  to  observe  the  water 
spiders’  behavior  there  and  to  measure  popu- 
lation parameters  such  as  longevity  of  males 
and  females,  sex  ratios  or  spider  aii.d  nest  den- 
sities. From  continuous  size  monitoring  of  in- 
dividual spiders  that  were  born  in  the  lab 
(cephalothorax  width),  we  found  that  under 
standardized  conditions,  females  grew  faster 
than  males.  After  200  days,  females  were  sig- 
nificantly heavier  than  males  (T-test,  T = 
2.226,  P - 0.035,  n = 13  males  and  15  fe- 
males). Lab  born  females  survived  signifi- 
cantly longer  than  lab  born  males  (T-test,  T = 
2.226,  P = 0.035,  males:  358.9  ± 72.9  days, 
mean  ± SD,  « = 13,  females:  479.7  ± 84.6 
days,  n = 15).  In  the  field,  females  and  males 
that  are  born  late  in  the  season  have  probably 
two  mating  seasons,  with  females  laying  sev- 
eral clutches  per  season.  Much  about  the  life 
history  of  this  species  remains  unknown  be- 
cause of  the  difficulties  of  studying  them  in 
their  natural  habitat. 

Typical  mating  behavior.- — We  observed 
over  50  pairings  of  the  water  spider  in  a va- 


riety of  settings  in  the  laboratory,  and  from 
these  observations  have  developed  a general 
description  of  a “typicaF’  mating. 

Number  of  young  produced  in  successive 
broods  after  one  copulation. — To  find  out 
whether  females  need  to  copulate  repeatedly 
to  fertilize  subsequent  clutches,  we  took  31 
females  that  had  matured  in  the  lab  (and  thus 
we  knew  they  were  virgins),  mated  them  in 
the  lab,  then  held  the  females  separately  in 
glass  jars  for  one  year,  and  counted  all  off- 
spring in  successive  egg  sacs. 

Mate  choice  and  male-male  competition 
experinients,-=“Iii  a mate  choice  experiment 
in  the  lab  we  studied  which  sex  is  more  active 
in  mate  acquisition  and  whether  either  sex 
chooses  particular  individuals  as  mating  part- 
ners. In  a male-male  competition  experiment 
we  tested  whether  males  compete  for  access 
to  females  and  whether  sexual  cannibalism 
occurs  and  depends  on  the  direction  and  ex- 
tent of  SSD.  The  test  females  were  mature  and 
had  laid  three  successive  egg  sacs  without 
copulating  in  between  before  they  were  used 
in  these  experiments.  They  were  kept  in  2 liter 
holding  tanks  before  and  between  experiments 
for  at  least  three  weeks  to  ensure  that  they 
were  ready  to  mate  at  the  beginning  of  each 
experiment.  Each  female  was  used  in  both  ex- 
periments, with  a different  partner  in  each  ex- 
periment. Each  male  was  tested  twice  in  both 
experiments,  with  at  least  two  weeks  between 
trials. 

For  both  experiments,  the  bottom  of  each 
10  liter  tank  was  covered  with  Scm  of  small 
gravel  (grain  size  ^ 2mm),  and  tee  one-leaf 
plants  {Cryptocoryne  sp.)  were  put  in  a row 
in  the  front  part  of  the  tank,  so  that  the  spiders 
had  the  opportunity  to  build  a diving  bell  be- 
tween two  plants  or  between  one  plant  and  the 
glass  wall  of  the  tank.  The  whole  tank  was 
videotaped,  and  the  behavior  of  the  spiders 
was  recorded  with  a time  lapse  recorder  so 
that  48  h were  condensed  into  three  h,  and 
recorded  on  a 180  min  video  tape. 

In  the  mate  choice  experiment,  we  tested 
for  behavioral  differences  (i)  between  males 
and  females,  (ii)  between  large  and  small 
males  and  (iii)  of  males  towards  large  and 
small  females.  In  20  replicates,  half  of  the  test 
females  were  presented  first  with  a small  male 
for  two  days  and  then  with  a large  male  for 
two  days;  in  the  other  ten  females  the  se- 
quence was  reversed.  Large  males  were  on  av- 


770 


THE  JOURNAL  OF  ARACHNOLOGY 


erage  4.6  ± 0.5  mm  (cephalothorax  width, 
mean  ± SD,  range:  4.05-5.8  mm),  small 
males  3.5  ± 0.35  mm  (range:  2.95-3.91  mm), 
and  females  3.2  ± 0.26  mm  (range:  2.71-4.24 
mm).  Each  mate  choice  trial  lasted  for  four 
days,  in  which  the  female  was  together  with 
either  of  the  two  males  for  two  days  each. 

The  video  recordings  were  analyzed  in  two 
ways:  (A)  Instantaneous  time  sampling:  in  the 
first  hour  and  then  every  fourth  hour  of  the 
experiment,  we  noted  every  five  minutes  reaU 
time  whether  the  male  and  female  are  togeth- 
er, either  inside  or  outside  of  the  female  air 
bell.  From  this  we  calculated  the  percent  of 
time  each  pair  stays  together  during  48  hours 
and  compared  these  times  between  large  and 
small  males.  For  females  we  also  noted 
whether  they  built  an  egg  sac.  (B)  Continuous 
recording:  during  the  whole  experimental  pe- 
riod we  continually  recorded  which  spider  ap- 
proached the  other,  fled  from  the  other,  and 
which  spider  cannibalized  the  other.  For  each 
spider  we  calculated  the  frequency  of  ap- 
proaching and  fleeing  within  48  hours,  and 
compared  these  frequencies  between  (i)  males 
and  females,  (ii)  smaller  and  larger  males,  and 
(iii)  males  towards  the  larger  and  towards  the 
smaller  females.  We  also  analyzed  whether  fe- 
males fled  more  often  or  spent  more  time  to- 
gether with  either  of  the  two  males.  From  14 
videos  we  could  analyze  the  hrst  experimental 
pairing  of  the  female  with  a male,  and  from 
12  of  these  14  videos  we  were  able  to  analyze 
the  experimental  pairing  of  the  female  also 
with  the  second  male. 

We  noted  the  location  of  each  spider  twice 
a day  (between  10.00-11.00  and  between 
17.00-18.00)  in  the  mate  choice  experiment, 
whether  a male  and  female  were  together, 
whether  they  showed  courtship  behavior  (e.g., 
the  male  chasing  the  female  outside  of  the  bell 
or  both  spiders  swimming  around  until  they 
meet  again  in  the  bell)  or  mating  behavior  (i.e. 
copulations  or  when  the  two  spiders  are  in  an 
entangled  position),  and  whether  females  built 
egg  sacs.  When  the  female  courted,  mated  or 
built  an  egg  sac  only  with  one  male,  we  in- 
terpreted this  as  “preference”  for  this  male. 
When  a female  showed  any  such  preference 
with  the  first  male  on  days  1 and  2,  we  left 
her  in  the  tank  to  observe  encounters  with  the 
second  male  on  days  3 and  4,  and  to  see 
whether  females  re-mate  in  dependence  of  the 
relative  sizes  of  the  two  partners. 


In  the  male-male  competition  experiment, 
two  differently- sized  males  were  released  in 
one  tank  on  the  first  day  and  kept  together  for 
two  days.  For  the  following  two  days  a female 
was  added.  Sixteen  replicates  were  performed 
each  with  different  individuals.  The  daily  re- 
cordings were  similar  to  the  female  choice  ex- 
periments, and  we  analyzed  whether  females 
preferred  to  copulate  with  either  of  the  two 
males. 

We  analyzed  aggressive  behavior  between 
males  and  whether  cannibalism  (intra-  and  in- 
tersexual)  occurred.  If  it  happened,  we  ana- 
lyzed whether  its  occurrence  depended  on  the 
degree  and  direction  of  SSD.  For  this  we 
pooled  the  data  from  the  mate  choice  and 
male-male  competition  experiments.  From  the 
mate  choice  experiment  we  included  the  cases 
in  this  analysis  in  which  the  female  was  com- 
bined with  the  larger  of  the  two  males  {n  = 
20).  In  the  male-male  competition  experi- 
ments the  females  were  together  with  two 
males  simultaneously.  We  only  included  the 
SSDs  between  the  female  and  the  larger  male 
in  this  analysis  {n  = 16),  because  due  to  the 
male-female  size  difference  only  the  larger 
males  were  candidates  for  sexual  cannibalism. 

Statistics. — Data  distributions  were  tested 
for  normality  (Kolmogorov-Smirnoff  one- 
sample  tests,  P > 0.1).  Non-parametric  statis- 
tics were  used  if  significant  differences  from 
normal  distributions  were  found  {P  < 0.1), 
and  when  the  sample  size  was  too  low  to  test 
reliably  for  normality.  Otherwise  we  used 
parametric  statistics.  All  tests  were  two-tailed. 

RESULTS 

Typical  mating  behavior. — A typical  mat- 
ing in  A.  aquatica  starts  with  the  male  ap- 
proaching the  female  in  her  living  bell  (see 
also  Braun  1931).  Once  in  the  bell,  the  male 
chases  the  female  out  of  the  bell  and  both  spi- 
ders swim  around  for  a short  while  until  they 
meet  again  in  the  bell,  a behavior  called 
“courtship  swimming”.  Once  they  are  back  in 
the  bell,  the  female  accepts  the  male,  they 
chase  each  other  around  the  air  bell  and  after 
a short  period  they  start  copulating.  Copula- 
tion takes  place  in  the  female’s  living  bell, 
where  the  male  transfers  the  sperm  to  the  fe- 
male, and  the  spiders  remain  in  an  entangled 
position  for  some  seconds.  Copulations  take 
place  several  times,  and  after  the  last  one  the 
pair  remains  together  in  the  bell  for  some  min- 


SCHUTZ  & TABORSKY— SEXUAL  CONFLICT  IN  THE  WATER  SPIDER 


771 


140 


o 

CO 

C/) 

120 

D) 

Ui 

0 

100 

0 

Q. 

m 

80 

c 

‘k- 

Q. 

60 

O 

4— 

40 

o 

0 

20 

E 

3 

0 

Z 

N = 26 


26  24 


6 

10 


100 


3 4 

Egg  sac 


Figure  1. — Number  of  spiderlings  per  egg  sac 
produced  in  successive  egg  sacs  by  Argyroneta 
aquatica  without  copulation  between  successive 

broods  (dots)  and  with  copulation  after  the  third  egg 
sac  was  produced  (triangles,  means  and  standard 
deviations). 


m 


f m f 

Approaching  Fleeing 

Figure  2. — Frequency  of  approaching  and  fleeing 
from  each  other  in  males  and  females  during  48 
hours  (means  and  standard  deviations). 


utes,  while  the  female  starts  building  an  egg 
sac  (see  also  Braun  1931).  Producing  an  egg 
sac  took  a few  hours.  The  female  cares  for  the 
brood  alone  (27  ± 2,61  days  in  the  first 
broods  of  each  female  in  this  study,  n = 23; 
see  also  Hamburger  1910;  Stadler  1917;  Cro- 
me  1951).  When  the  female  does  not  accept 
the  male,  she  tries  to  chase  the  male  out  of 
her  bell,  but  often  looses  the  conflict  by  loos- 
ing her  bell  and  sometimes  even  her  life  (see 
below),  and  then  the  male  stays  in  the  bell. 

Number  of  young  produced  in  successive 
broods  after  one  copulation. — Of  the  31  fe- 
males that  were  known  to  have  mated  only 
once,  26  produced  at  least  three  successive 
egg  sacs.  A few  females  produced  up  to  six 
egg  sacs  while  they  were  isolated  in  single 
glass  jars  for  a year.  The  number  of  spider- 
lings  per  egg  sac  decreased  significantly  with 
increasing  egg  sac  number  (Spearman  corre- 
lation, r = “”0.943,  P = 0.005,  n = 6,  Fig. 
1).  A pairwise  comparison  of  the  numbers  of 
spiderlings  per  egg  sac  in  the  first  and  second 
egg  sacs  revealed  that  females  raised  signifi- 
cantly more  young  in  the  first  eggs  sac  than 
in  the  second  (paired  T-test,  T ~ 5.611,  n = 
26  females,  P = 0.001).  Females  that  copu- 
lated a second  time  after  producing  the  third 
egg  sac  produced  significantly  more  offspring 


in  the  fourth  egg  sac  (Mann-Whitney-U-test, 
Z - -2.284,  « = 6 + 10,  P - 0.022)  and  in 
the  fifth  egg  sac  (Mann-Whitney-U-test,  Z = 
—2.263,  n ~ 3 + 6,  P = 0,024)  than  females 
that  did  not  copulate  after  the  third  egg  sac 
(see  Fig.  1). 

Mate  choice  and  male-male  competition 
experiments. — (i)  Differences  between  males 
and  females:  In  order  to  assure  data  indepen- 
dence, for  this  analysis  we  only  included  the 
first  experimental  pairing  of  the  female  with 
either  of  the  two  males  in  the  mate  choice 
experiments.  Males  approached  females  more 
often  than  vice  versa  (Paired  t-test,  T = 3.064, 
df  = 13,  P = 0.009,  Fig.  2),  and  females  fled 
more  often  from  males  than  vice  versa  (Paired 
t-test,  T - -4.017,  df  - 13,  P - 0.001,  Fig. 
2). 

(ii)  Behavior  of  large  and  small  males  to- 
wards females:  In  the  first  experimental  pair- 
ing of  each  female  with  a male  in  the  mate 
choice  experiments,  small  males  approached 

the  female  more  often  than  large  males  did 
(Pearson  correlation,  r “ —0.624,  n = 14,  P 
= 0.017,  Fig.  3). 

(Hi)  Male  behavior  towards  females  of  dif- 
ferent sizes:  We  tested  with  pairwise  compar- 
isons whether  males  behaved  differently  to- 
wards large  and  small  females  when  they  were 
tested  with  differently  sized  partners.  There 


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THE  JOURNAL  OF  ARACHNOLOGY 


Male  size  (mm) 

Figure  3. — Frequency  of  approaches  of  males  of 

different  sizes  to  the  test  female. 


was  no  difference  in  the  behaviors  measured 
(Wilcoxon  tests,  n = 11,  all  P > 0.15,  see 
methods  for  behaviors). 

In  three  instances,  females  mated  with  both 
males.  From  20  females  in  the  mate  choice 
experiments,  10  showed  a preference  because 
they  performed  reproductive  behavior,  i.e. 
courtship  behavior  {n  = 4),  mating  behavior 
{n  = 3)  or  egg  sac  building  {n  = 3)  with  only 
one  of  the  two  males.  Nine  females  did  not 
show  a preference  (Fig.  4;  one  female  was 
killed  during  the  experiment),  because  they 
performed  reproductive  behavior  with  both  {n 
— 3)  or  with  neither  of  the  males  {n  = 6). 
When  the  tesLfemales  preferred  one  male, 
they  showed  reproductive  activity  with  the 
larger  of  the  two  males  (Binomial  test,  n = 
10,  P = 0.002),  despite  the  fact  that  small 
males  approached  females  more  often  than 
large  males  (see  above).  In  both  cases  in 
which  a female  showed  reproductive  behavior 
with  the  smaller  male  first,  she  repeated  this 
with  the  larger  male,  but  in  only  one  of  six 
cases  when  a female  showed  reproductive  be- 
havior with  a larger  male  first,  did  she  again 
show  reproductive  behavior  with  the  smaller 
male. 

In  the  male-male  competition  experiment, 
when  two  differently  sized  males  and  one  fe- 
male were  combined  in  one  tank  on  days  three 
and  four,  the  larger  male  copulated  with  the 
female  five  times,  but  the  smaller  male  never 
copulated  with  the  female  (Fisher’s  exact  test, 
0.05  < P <0.1). 


Observed  courtship  behavior,  mating  behavior 
or  egg  sac  building  of  the  female  with 


Number  of  females 

Figure  4. — Number  of  females  courting,  mating 
or  building  an  egg  sac  with  only  the  large  male, 
only  the  small  male  or  both  males. 


In  mate  choice  experiments  with  SSD  > 1 
(male:female,  males  1.28  ±0.13  times  larger 
than  females,  n = 22)  females  fled  more  often 
from  the  males  than  in  experiments  with  SSD 
< 1 (males  = 0.85  ± 0.03  times  female  size, 
n — 3;  Mann-Whitney-U-test,  Z — —2.174,  P 
= 0.03,  Fig.  5).  We  found  no  significant  dif- 
ferences in  the  percent  of  time  females  spent 
together  with  the  larger  or  smaller  males  (Wil- 
coxon matched-pairs  signed-ranks  test,  Z = 

0.0,  n ~ \2,  P = 1.0),  either  inside  the  air  bell 
(Wilcoxon  test,  Z = —0.677,  n = 12,  P = 
0.498),  or  outside  of  it  (Wilcoxon  test,  Z = 
-0.7,  n = 12,  P = 0.944). 

Cannibalism  occurred  in  two  of  40  pairings 
in  the  mate  choice  experiments.  In  one  of  the 
20  pairings  where  the  female  was  together 
with  the  larger  of  the  two  males,  the  male 
killed  the  female.  This  was  in  the  experiment 
with  the  highest  SSD  (m:f)  among  all  exper- 
iments (SSD  ~ 1.72:1).  In  the  replicate  in 
which  the  largest  of  all  test  females  was  com- 
bined with  the  smaller  of  the  two  males  as- 
signed to  her,  the  female  killed  this  male  (SSD  i 
= 0.87:1).  Video  analysis  revealed  that  when 
one  spider  killed  another  one,  the  killer  ate  the 
victim  thereafter. 

Male-male  competition  experiments  re- 
vealed that  aggression  between  males  was 
very  high.  During  the  days  one  and  two  of 
these  experiments,  when  two  differently  sized 
males  were  kept  in  one  tank  without  a female, 
in  three  out  of  16  experiments,  aggression  re- 


SCHUTZ  & TABORSKY— SEXUAL  CONFLICT  IN  THE  WATER  SPIDER 


773 


suited  in  the  death  of  the  smaller  male  (= 
18.75%).  There  was  no  significant  difference 
in  the  size  disparity  between  the  two  males  in 
cases  with  or  without  cannibalism  (Mane- 
Whitney-U-test,  Z = -1.144,  n = 3 + 13,  P 
= 0.296). 

On  days  three  and  four  of  the  male^male 
competition  experiments,  when  two  different- 
ly sized  males  and  one  female  were  kept  in 
one  tank,  the  larger  male  killed  the  female  in 
three  trials  and  the  larger  male  killed  the 
smaller  male  in  one  trial.  It  never  happened 
that  a female  killed  a male  in  the  male-male 
competition  experiments,  or  that  the  smaller 
male  killed  another  spider. 

By  comparing  the  cases  in  which  male  can- 
nibalism of  females  occurred  with  those  in 
which  this  did  not  happen,  the  extent  of  SSD 
(m  > f)  was  greater  when  cannibalism  oc- 
curred (Mann-Whitney-U-test,  Z = —2.074,  n 
= 4 + 22,  F = 0.037,  see  Fig.  6). 


50.0  n 


I ^ 40.0  - 


o -6 

o ® 

C CO 

SE 

cr  0) 

0)  JO 


0.0 


m >f  m <f 

Figure  5.- — Frequency  of  fleeing  in  females  when 
the  male  is  larger  (m  > f)  or  smaller  (m  < f)  than 
the  female  (medians  and  quartiles). 


DISCUSSION 

Our  results  show  that,  although  the  number 
of  offspring  per  egg  sac  decreased,  females 
that  only  copulated  once  could  produce  up  to 
six  viable  clutches.  Test  females  that  copulat- 
ed a second  time  after  producing  three  suc- 
cessive egg  sacs  had  a higher  reproductive 
success  in  their  fourth  and  fifth  clutches  than 
females  that  did  not  copulate  again.  This  sug- 
gests that  sperm  depletion  occurs  in  females 
and  shows  that  it  is  to  the  females’  advantage 
to  mate  repeatedly  when  producing  a series  of 
clutches. 

Our  experiments  suggest  that  in  addition  to 
the  natural  selection  acting  on  sexual  dimor- 
phism (Schiitz  & Taborsky  2003),  both  inter- 
and  intrasexual  selection  mechanisms  may  be 
involved  in  the  evolution  of  large  male  size  in 
A.  aquatica.  As  is  usual  in  spiders  (Foelix 
1992),  A.  aquatica  males  are  more  mobile  and 
they  are  the  more  active  partners  in  mate  ac- 
quisition. In  controlled  experiments  they  ap- 
proached the  females  more  often  than  vice 
versa,  and  females  fled  from  males  more  often 
than  vice  versa.  Females  chose  large  males 
preferably  as  mating  partners.  Since  small 
males  approached  females  more  often  than 
large  males  did,  female  preference  for  large 
males  cannot  be  due  to  a lack  of  contact  with 
small  males.  Males  did  not  show  a preference 
for  females  of  a certain  size. 

Aggression  between  males  was  very  high 


and  sometimes  resulted  in  the  death  of  the 
smaller  male.  These  results  suggest  that  in 
males,  large  size  is  favored  by  intersexual  and 
intrasexual  selection  mechanisms  in  A.  aqua- 
tica. Males  are  also  the  better  divers  in  this 
spider,  so  the  necessity  of  moving  under  water 
efficiently  appears  to  be  an  important  deter- 
minant of  large  male  body  size  as  well 
(Schiitz  & Taborsky  2003). 

In  terrestrial  spiders,  often  small  males  have 
locomotor  advantages  over  larger  males  (e.g. 
see  Moya-Larano  et  al.  2002),  i.e.  natural  se- 
lection acts  against  sexual  selection,  which  is 
a minor  selective  force  in  some  spider  species 
(see  Vollrath  & Parker  1997).  Therefore,  the 
difference  in  locomotor  advantages  of  differ- 
ently sized  males  on  land  and  under  water, 
together  with  ietra-  and  intersexual  selection 
mechanisms,  may  explain  the  reversed  SSD  of 
the  water  spider  in  comparison  to  many  ter- 
restrial spiders.  In  females,  large  size  is  fa- 
vored by  fecundity  selection,  but  female  size 
is  apparently  limited  by  the  high  costs  of 
building  air  bells  under  water  (Schiitz  & Ta- 
borsky 2003).  This  may  be  an  additional  cause 
of  the  reversed  SSD  in  water  spiders. 

Sexual  conflict  was  very  obvious  in  our  ex- 
periments and  sexual  contact  sometimes  re- 
sulted in  the  death  of  the  female.  To  our 
knowledge,  this  reversed  sexual  cannibalism 
(i.e.  males  cannibalizing  females)  has  not 
been  reported  before  in  any  spider  species.  In 


774 


THE  JOURNAL  OF  ARACHNOLOGY 


YES  NO 
Cannibalism 

Figure  6. — Median  SSDs  when  the  male  canni- 
balized the  female  and  when  it  did  not  (medians 
and  quartiles). 


A,  aquatica,  the  extent  of  SSD  determined  the 
likelihood  of  females  to  be  cannibalized.  The 
SSD  was  greater  in  cases  when  the  male  can- 
nibalized the  female  than  when  he  did  not. 

There  are  two  main  hypotheses  to  explain 
female  cannibalism  in  spiders  (see  Johnson 
2001;  Schneider  & Elgar  2002).  The  adaptive 
nutritional-advantage  hypothesis  postulates 
that  sexual  cannibalism  is  an  economic,  adap- 
tive foraging  strategy  on  the  part  of  the  adult 
female  (Newman  & Elgar  1991;  Schneider  & 
Elgar  2002).  The  aggressive-spillover  hypoth- 
esis postulates  that  precopulatory  sexual  can- 
nibalism is  misplaced  aggression  favored  in 
previous  life  history  phases  (Amqvist  & Hen- 
riksson  1997;  Schneider  & Elgar  2002),  so  it 
would  be  neutral  or  maladaptive.  It  is  con- 
ceivable that  these  hypotheses  could  explain 
male  cannibalism  as  well,  even  though  the  po- 
tential benefits  appear  to  be  smaller  for  males 
than  for  females.  However,  our  results  do  not 
allow  us  to  distinguish  between  these  hypoth- 
eses for  the  explanation  of  sexual  cannibalism 
in  A.  aquatica.  In  our  experiments  large  males 
killed  smaller  females  and  small  males,  ap- 
parently dependent  mainly  on  the  direction 
and  extent  of  the  size  difference.  Sexual  can- 
nibalism in  A.  aquatica  seems  to  follow  the 
simple  rule  “Large  eats  Small”. 

An  aspect  of  particular  interest  is  the  ob- 


served preference  of  females  for  large  males, 
despite  the  risk  of  cannibalism.  There  is  an 
apparent  conflict  between  attraction  and 
avoidance  as  females  often  flee  from  large 
males.  Sexual  cannibalism  by  otherwise  pre- 
ferred, large  males  might  select  for  large  fe- 
male size,  in  addition  to  fecundity  selection. 
However,  female  size  is  apparently  limited  by 
the  energetically  costly  and  risky  air  bell 
building  and  maintenance,  which  is  size  de- 
pendent in  females  but  not  in  males  (Schiitz 
& Taborsky  2003). 

In  contrast  to  other  species,  mate  choice  in 
A.  aquatica  may  select  for  an  “optimal  male 
size”  instead  of  directional  selection  for  large 
size.  Usually,  natural  selection  constrains  SSD 
against  the  action  of  sexual  selection  by  lim- 
iting the  evolution  of  extreme  body  size  in  one 
of  the  two  sexes.  For  example,  a comparative 
study  of  North  American  passerines  suggested 
that  sexual  selection  for  increased  male  size  is 
balanced  by  energetic  constraints  of  paternal 
care  (Hughes  & Hughes  1986;  see  also  Ca- 
bana et  al.  1982;  Saether  et  al.  1986;  Joensson 
& Alerstam  1990).  In  A.  aquatica  intersexual 
selection  may  stabilize  male  size  without  a 
necessary  limitation  imposed  by  natural  selec- 
tion, with  sexual  cannibalism  being  the  con- 
straining factor. 

ACKNOWLEDGMENTS 

We  thank  Thomas  Drapela  for  his  help  with 
the  experiments,  and  Thomas  Drapela,  Nicole 
Madlener  and  Katinka  Maurer  for  their  help 
in  analyzing  the  videos,  Karin  Donnerbaum, 
Katharina  Peer,  Michaela  Ritzmeier  and  Eva 
Skubic  helped  to  collect  the  spiders  from  var- 
ious field  locations,  and  Franz  Bratter  helped 
to  take  care  of  the  spiders  in  the  lab.  The  pro- 
ject was  funded  by  the  Jubilaumsfonds  der 
Stadt  Wien  fiir  die  Osterreichische  Akademie 
der  Wissenschaften,  project  number  STI  0040. 

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Vollrath,  E & G.  Parker.  1997.  Giant  female  or 
dwarf  male  spiders?  Nature  385:687. 

Warner,  R.R.,  D.Y.  Shapiro,  A.  Marcanato,  & C.W. 
Petersen.  1995.  Sexual  conflict:  males  with  high- 
est mating  success  convey  the  lowest  fertilization 
benefits  to  females.  Proceedings  of  the  Royal  So- 
ciety London  B.  262:135-139 

Wesenberg-Lund,  C.  1939.  Biologie  der  SiiBwasser- 

tiere.  Springer  Verlag.  Wien. 

Manuscript  received  9 September  2003,  revised  1 
November  2004. 


2005.  The  Journal  of  Arachnology  33:776-784 


MOLECULAR  INSIGHTS  INTO  THE  BIOGEOGRAPHY  AND 

SPECIES  STATUS  OF  NEW  ZEALAND’S  ENDEMIC 
LATRODECTUS  SPIDER  SPECIES;  L.  KATIPO  AND 
L.  ATRITUS  (ARANEAE,  THERIDHDAE) 


James  W.  Griffiths^,  Adrian  M.  Paterson  and  Cor  J.  Vink^’^:  Ecology  & 
Entomology  Group,  PO  Box  84,  Lincoln  University,  New  Zealand.  E-mail: 
cor,  vink@arachnology.org 

ABSTRACT.  New  Zealand’s  endemic  sand  dune  Latrodectus  widow  spider  species,  L.  katipo  and  L. 
atritus,  possess  behavioral  and  physiological  attributes  likely  to  promote  dispersal  over  large  distances. 
Morphological,  physiological  and  behavioral  similarities  between  L.  katipo  and  L.  hasselti,  an  Australian 
endemic,  suggest  gene  flow  may  occur  across  the  Tasman  Sea.  In  this  study  we  examine  intraspecific  and 
interspecific  genetic  relationships  within  the  NDl  gene  region  between  L.  katipo,  L.  atritus,  L.  hasselti 
and  L.  hesperus  to  assess  whether  the  genetic  evidence  supports  current  taxonomic  species  designations. 
We  found  low  interspecific  pairwise  distances  among  L.  katipo  and  L.  atritus  populations,  suggesting 
either  introgression,  incomplete  lineage  sorting,  or  that  the  current  taxonomic  distinction  between  the  two 
species  may  be  invalid.  Parsimony  and  maximum  likelihood  analyses  were  inconclusive  as  to  the  rela- 
tionships between  the  New  Zealand  Latrodectus  species  and  the  Australian  L.  hasselti.  Low  pairwise 
distances  between  L.  hasselti  and  the  New  Zealand  widow  fauna  indicated  that  L.  katipo  and  L.  atritus 
were  not  present  in  New  Zealand  before  the  fragmentation  of  Gondwana. 

Keywords:  Latrodectus,  New  Zealand,  Australia,  dispersal,  molecular  phylogenetics 


New  Zealand’s  endemic  Latrodectus  Wal- 
ckenaer  1805  fauna  is  considered  to  comprise 
two  endemic  species,  L.  katipo  Powell  1870 
and  L.  atritus  Urquhart  1890  (Forster  & For- 
ster 1999),  Latrodectus  atritus  was  originally 
described  as  a subspecies  of  L.  katipo  (Ur- 
quhart 1890)  and  was  proposed  as  a subspe- 
cies of  L.  hasselti  Thorell  1870  by  Parrott 
(1948),  and  a junior  synonym  of  L.  mactans 
(Fabricius  1775)  by  Levi  (1959).  McCutcheon 
(1976)  and  Forster  & Kingsford  (1983)  argued 
that  L.  atritus  is  a separate  species  to  L.  katipo 
and  Forster  (1995)  elevated  L.  atritus  to  spe- 
cies but  did  not  provide  any  taxonomic  justi- 
fication. The  only  reported  morphological  dif- 
ference between  L.  atritus  and  L.  katipo  is 
coloration,  which  is  usually  unreliable  for  sep- 
arating spider  species  but  can  be  useful  in  sep- 

^ Current  address:  Department  of  Conservation, 
East  Coast/Hawke’s  Bay  Conservancy,  PO  Box 
668,  Gisborne,  New  Zealand. 

2 Current  address:  Department  of  Biology,  San  Di- 
ego State  University,  San  Diego,  CA  92182-4614, 
USA. 

^ Corresponding  author. 


arating  Latrodectus  species  (McCrone  & Levi 
1964).  Latrodectus  atritus  females  do  not 
have  the  red  median  stripe  on  the  dorsal  sur- 
face of  the  abdomen  that  L.  katipo  has  (Mc- 
Cutcheon 1976;  Forster  & Kingsford  1983; 
Forster  & Forster  1999)  and  the  males  of  the 
two  species  have  slight  differences  in  color 
(Forster  & Kingsford  1983).  Forster  & Kings- 
ford (1983)  also  reported  differences  between 
the  species  in  the  time  it  took  for  spiderlings 
to  emerge  from  the  eggsac.  Forster  & Forster 
(1999)  noted  that  L.  atritus  eggs  and  spider- 
lings  need  higher  temperatures  than  L.  katipo 
and  they  also  stated  that  “laboratory  studies 
show  that  they  do  not  generally  crossmate  but 
when  they  do,  the  eggs  are  infertile”  but  no 
data  was  included  in  the  publication  to  support 
this.  Both  New  Zealand  species  inhabit  coastal 
dune  systems  and  commonly  build  webs  in 
low  growing  plants  and  driftwood  or  flotsam. 
Although  the  niches  occupied  by  L.  katipo  and 
L.  atritus  are  similar,  their  known  distributions 
are  distinct.  Latrodectus  katipo  inhabits  coast- 
al dunes  in  the  northern  half  of  South  Island 
and  the  southern  half  of  North  Island,  whereas 


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GRIFFITHS  ET  AL.— GENETICS  OF  NEW  ZEALAND  lATRODECTUS  SPECIES 


777 


L.  atritus  inhabits  coastal  dunes  in  the  north- 
ern half  of  North  Island.  There  is  an  overlap 
in  the  species’  distributions  in  Taranaki  on  the 
west  coast  of  North  Island  (Forster  & Forster 
1999)  and  in  Hawkes’  Bay  on  the  east  coast 
North  Island. 

Discriminating  between  Latrodectus  spe- 
cies using  morphology  has  always  been  prob- 
lematic (Levi  1983)  and  the  distinction  be- 
tween L.  katipo  and  the  Australian  L.  hasselti 
is  minimal.  There  is  no  difference  between  the 
male  pedipalp  and  female  external  and  inter- 
nal genitalia  of  the  two  species  (Parrott  1948; 
Levi  1959)  but  that  is  often  the  case  in  Lat- 
rodectus (Levi  1983).  Forster  & Forster 
(1999)  state  that  the  most  definitive  morpho- 
logical character  that  separates  the  two  species 
is  the  dense  covering  of  short,  fine  hairs  on 
the  body  of  L.  katipo  compared  to  the  long 
fine  hairs  and  stouter  short  hairs  on  L.  hasselti. 
Latrodectus  hasselti  females  are  usually  larg- 
er, their  webs  are  stronger  and  usually  yellow- 
ish in  color  (Forster  & Forster  1999)  and  this 
species  performs  a stereotyped  behavior  of 
sexual  cannibalism  (Forster  1992).  Laboratory 
studies  examining  interspecific  interactions 
have  shown  that  L,  hasselti  females  will  not 
mate  with  L.  katipo  males  (Forster  1992, 
1995).  However,  in  their  phylogenetic  study 
of  Latrodectus,  Garb  et  aL  (2004)  found  that 
L.  katipo  and  L.  hasselti  were  closely  related 
(4.9%  uiicorrected  divergence  in  a 428  bp  sec- 
tion of  the  mitochondrial  gene  cytochrome  ox- 
idase subunit  I (COI)). 

Recent  research  demonstrates  that  L,  katipo 
and  L.  atritus  are  probably  good  dispersers. 
Spiderlings  of  both  species  are  able  to  dis- 
perse by  ballooning  and  adult  females  may  be 
able  to  disperse  on  driftwood  at  sea  under  op- 
timal conditions  (Griffiths  2002).  It  is  uncer- 
tain how  far  L.  katipo,  L.  atritus,  or  L.  hasselti 
could  disperse  by  these  means,  but  other  bal- 
looning spider  species  have  been  recorded 
landing  on  ships  up  to  300  km  from  land 
(Gertsch  1979),  indicating  that  ballooning  spi- 
ders may  travel  substantial  distances.  Further- 
more, spiders  recorded  from  driftwood  and 
flotsam  at  sea,  suggest  that  water-borne  spi- 
ders could  also  disperse  over  large  distances 
(Foelix  1996)  and  adult  L.  hasselti  can  survive 
more  than  300  days  without  food  (Forster  & 
Kavale  1989).  This  evidence  may  explain  why 
L.  katipo  and  L.  atritus  distributions  span  nu- 
merous geographic  barriers  such  as  headlands. 


estuaries,  rivers  and  areas  of  open  sea  (<30 
km)  and  may  account  for  morphological, 
physiological  and  molecular  similarities  be- 
tween the  New  Zealand  Latrodectus  fauna  and 
L.  hasselti,  which  is  considered  endemic  to 
Australia  (Parrott  1948;  Levi  1959;  Forster  & 
Kingsford  1983;  Garb  et  al.  2004).  As  yet, 
however,  the  influence  dispersal  may  have  had 
on  the  biogeography  of  L,  katipo  and  L.  atri- 
tus has  not  been  investigated.  Moreover,  be- 
havioral, morphological,  physiological  and 
molecular  similarities  between  L.  katipo  and 
the  Australian  endemic,  L.  hasselti,  have  not 
been  adequately  explained. 

In  this  paper,  we  examine  intraspecific  and 
interspecific  genetic  relationships  within  the 
NADH  dehydrogenase  subunit  1 (NDl)  mi- 
tochondrial gene  region  between  L.  katipo,  L. 
atritus,  L.  hasselti  and  L.  hesperus  Chamber- 
lin & Me  1935  (all  part  of  the  strongly  sup- 
ported "'mactans  clade”  in  Garb  et  al.  2004) 
to  assess  the  degree  of  separation  between  the 
New  Zealand  and  Australian  Latrodectus  spe- 
cies and  whether  genetic  evidence  supports 
current  taxonomic  species  designations.  The 
NDl  gene  region  was  chosen  because  it  is  fast 
evolving  and  has  been  successfully  used  to  ex- 
amine genetic  differences  between  spider  spe- 
cies and  populations  (Hedin  1997a,  1997b; 
Masta  2000;  Johaeeesee  et  al.  2002;  Maddi- 
son  & Hedin  2003;  Masta  & Maddisoe  2002; 
Vink  & Paterson  2003). 

METHODS 

Adult  female  L.  katipo  and  L.  atritus  were 
collected  from  eight  sites  around  New  Zea- 
land (Fig.  1)  and  were  stored  in  95-100% 
EtOH  at  ““80  °C  to  maintain  high  quality 
DNA.  Voucher  specimens  are  stored  at  the 
Ecology  and  Entomology  Group,  Research 
Collection,  Lincoln  University,  New  Zealand. 
Specimens  were  collected  from  sites  that  were 
selected  throughout  the  distributions  of  both 
species.  One  specimen  per  population  of  L. 
katipo  was  collected  from  Kaitorete  Spit 
(43°50'S,  172°3rE)  and  Waikuku  Beach 
(43°17'S,  172"43^E),  Canterbury,  from  Fare- 
well Spit  (40°30'S,  172°48'E),  Golden  Bay 
and  from  Flat  Point  (41°28'S,  175°37'E)  and 
Herbertville  (40°29'S,  176°37'E)  on  the  east 
coast  of  the  lower  North  Island  (Fig.  1).  One 
specimen  per  population  of  L.  atritus  was  col- 
lected from  Houpoto  (37°58'S,  177°33'E), 
Rarawa  (34°44'S,  173°05'E)  and  Opoutere 


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THE  JOURNAL  OF  ARACHNOLOGY 


(37°24'S,  175°56'E)  in  the  upper  North  Island 
(Fig.  1).  Latrodectus  hasselti  were  collected 
from  Myalup,  Western  Australia  (33°06'S, 
115°4UE)  and  Brisbane,  Queensland 
(27°27'S,  153°02).  A specimen  of  L.  hesperus, 
intercepted  by  the  New  Zealand  Ministry  of 
Agriculture  and  Forestry  on  table  grapes  from 
California,  LFSA  was  used  as  an  outgroup.  Al- 
though L.  hesperus  is  common  throughout 
western  North  America  (Chamberlin  & Ivie 
1935;  Levi  1983),  the  identification  of  the  L. 
hesperus  specimen  is  tentative  as  a second, 
undescribed  Latrodectus  species  is  reported  to 
be  present  in  California  (see  Levi  1983)  and 
the  taxonomic  differences  between  the  two 
species  are  unknown.  The  entire  front  leg  and 
hind  leg  from  one  side  of  each  specimen  were 
removed  and  washed  in  sterile  deionized,  dis- 
tilled water  to  remove  excess  alcohol.  Geno- 
mic DNA  was  extracted  from  samples  using 
a proteinase-K  digestion  and  high  salt  precip- 
itation method  (White  et  al.  1990).  The  DNA 
was  suspended  in  1:20  TE  (lOmM  Tris,  ImM 
EDTA,  pH  8.0). 

The  first  half  (—420  bp)  of  the  mitochon- 
drial NDl  gene  region  was  amplified  from  di- 
luted genomics  in  25  jxl  PCR  reactions  using 
the  primers  Nl-J- 12261  and  TLl-N-12718 
(Hedin  1997a).  Each  25  pi  reaction  contained 
1 X Taq  buffer,  1 mM  dNTPs,  2 pM  MgCl2, 
0.4pM  of  each  primer,  1.25  units  Taq  DNA 
polymerase  (Roche),  and  1 pi  diluted  genomic 
DNA.  Amplification  took  place  in  a Gene- 
Amp®  2400  Thermocycler  and  included  an 
initial  denaturation  of  4 min.  at  94  °C  fol- 
lowed by  40  cycles  of  40  s at  94  °C,  40  s at 
45  °C,  40  s at  72  °C  and  a final  extension  of 
5 min.  at  72  °C.  The  resulting  PCR  product 
was  purified  by  precipitation  with  50  pi  of 
isopropanol  and  25  pi  NH4AC  (2.5M)  to  re- 
move excess  salts  and  primers.  Purified  ds- 
DNA  samples  were  washed  in  70%  EtOH  and 
suspended  in  6 pi  of  sterile  deionized,  dis- 
tilled water.  All  dsDNA  samples  were  subse- 
quently sent  to  the  Waikato  DNA  Sequencing 
Facility  where  they  were  sequenced  in  both 
directions. 

DNA  sequences  were  aligned  against  a 
complementary-strand  sequence  in  DNA- 
MAN  (version  4.02),  and  checked  against 
hard  copy  chromatograms  by  eye.  Corrections 
were  made  where  necessary.  The  possibility 
of  pseudogenes  and  polymerase  errors  were 
eliminated  by  the  translation  of  the  sequences 


to  amino  acids  and  no  stop  codons  or  frame- 
shifts  were  found.  A multiple  alignment  of  all 
sequences  was  compiled  in  CLUSTALX 
(Thompson  et  al.  1997)  and  imported  into 
PAUP*  4.0b  10  (Swofford  2002)  for  analysis. 

Data  were  analyzed  as  unordered  characters 
using  parsimony  with  the  exhaustive  option 
selected.  Bootstrap  values  (Felsenstein  1985) 
for  monophyletic  groups  were  calculated  us- 
ing the  branch  and  bound  search  option  in 
PAUP*.  Model  test  version  3.06  (Posada  & 
Crandall  1998)  was  used  to  select  the  maxi- 
mum likelihood  parameters  and  the  HKY  + 
F model  (Hasegawa  et  al.  1985)  was  used  to 
estimate  the  maximum  likelihood  tree.  The 
branch  and  bound  option  was  selected  in 
PAUP*  for  the  maximum  likelihood  analysis 
and  branches  were  collapsed  creating  polyto- 
mies  if  the  branch  length  was  < le-08.  Boot- 
strap values  for  the  maximum  likelihood  tree 
were  calculated  using  a heuristic  search 
(10000  replicates).  Base  frequency  calcula- 
tions, transition/transversion  ratios,  number  of 
variable  sites  and  the  conversion  of  nucleo- 
tides to  amino  acids  were  conducted  using 
MEGA  version  2.1  (Kumar  et  al  2001). 

In  addition  to  the  molecular  work,  22  spec- 
imens of  L.  katipo  and  L.  atritus  from  collec- 
tions at  the  Museum  of  New  Zealand,  Otago 
Museum,  Auckland  Museum  and  Lincoln 
University  Entomology  Research  Museum 
were  examined  for  differences  in  male  and  fe- 
male genitalia. 

RESULTS 

The  nucleotide  composition  was  G (gua- 
nine) depauperate  (29%  A,  22%  C,  10%  G, 
39%  T),  which  is  similar  to  that  of  the  spider 
family  Nesticidae  (Hedin  1997a),  a sister  fam- 
ily of  Theridiidae  (Griswold  et  al,  1998).  Se- 
quence data  were  deposited  in  GenBank  (Ben- 
son et  al.  2002),  accession  numbers 
AY383604-AY383614. 

The  largest  interspecific  pairwise  distance 
between  L.  katipo,  L.  atritus  and  L.  hasselti 
was  1.95  %,  whereas  the  smallest  pairwise 
distance  between  the  Australasian  specimens 
and  L.  hesperus  was  21.41  % (Table  2).  In 
contrast,  the  largest  intraspecific  pairwise  dis- 
tance between  L.  katipo  specimens  was  0.97 
%,  which  was  the  same  as  the  largest  pairwise 
distance  between  L.  katipo  and  L.  atritus  0.97 
% and  greater  than  the  largest  pairwise  dis- 


GRIFFITHS  ET  AL.— GENETICS  OF  NEW  ZEALAND  LATRODECTUS  SPECIES 


779 


tance  between  L.  atritus  specimens  0.73  %,  or 
L.  hasseiti  specimens  0.00  % (Table  2). 

Three  haplotypes  of  L.  katipo  occurred 
among  the  specimens  sampled.  The  L.  katipo 


specimens  from  Herbertville  and  Flat  Point 
had  identical  NDl  sequences  as  did  the  spec- 
imens from  Farewell  Spit  and  Wiakuku.  There 
were  three  haplotypes  of  L.  atritus  and  all 


780 


THE  JOURNAL  OF  ARACHNOLOGY 


Table  1. — Base  frequencies,  transition/transversion  ratios  and  number  of  variable  sites  at  each  codon 
position. 


Position  1 

Position  2 

Position  3 

Base  frequencies  % 

T 32.8,  C 18.4, 

T 44.9,  C 21.3, 

T 40.1,  C 26.4, 

A 36.0,  G 12.7 

A 21.9,  G 11.9 

A 28.7,  G 4.7 

Transition/transversion  ratio  % 

3.5 

1.3 

1.6 

Variable  sites  including  L.  hesperus 

16 

7 

68 

Variable  sites  excluding  L.  hesperus 

1 

0 

10 

three  specimens  had  different  sequences.  The 
NDl  sequences  of  both  L.  hasselti  specimens 
were  identical.  Ninety-oee  nucleotides  varied 
among  the  four  Latrodectus  species  but  only 
1 1 sites  varied  between  the  L.  katipo,  L.  atri- 
tus  and  L.  hasselti  specimens.  Table  1 lists  the 
base  frequencies  by  base  position,  transition/ 
transversion  ratios  and  number  of  variable 
sites  at  each  position. 

Fourteen  of  the  137  amino  acids  coded  for 
by  the  NDl  sequence  were  variable.  Only  two 
were  variable  within  L.  katipo,  L.  atritus  and 
L.  hasselti.  There  were  three  Australasian  hap- 
lotypes.  The  two  L.  hasselti  specimens  formed 
one  haplotype.  Latrodectus  katipo  from  Flat 
Point,  Herbertville  and  Kiatorete  Spit  had 
identical  amino  acids.  The  third  amino  acid 
haplotype  consisted  of  L.  katipo  from  Fare- 
well Spit  and  Waikuku  and  L.  atritus  from 
Houpoto,  Rarawa  and  Opoutere. 

Parsimony  analysis  yielded  12  equally  par- 
simonious trees,  97  steps  long  with  a consis- 
tency index,  excluding  uninformative  charac- 
ters, of  0.714  and  a retention  index  of  0.714. 
Of  the  411  characters  included,  91  were  var- 
iable of  which  four  were  parsimony  informa- 
tive. There  was  no  consensus  among  the  12 
trees.  Maximum  likelihood  analysis  yielded  1 
tree  with  a score  of  —In  883.451.  The  likeli- 
hood tree  (Fig.  2)  had  an  identical  topology 
to  one  of  the  12  most  parsimonious  trees. 
There  was  no  bootstrap  support  for  any  of  the 
clades  in  the  parsimony  analysis  and  only 
very  weak  bootstrap  support  in  the  maximum 
likelihood  trees  (not  shown  on  Fig.  2);  59% 
for  a clade  containing  Queensland  and  West- 
ern Australia,  Farewell  Spit  and  Waikuku, 
Houpoto,  Opoutere,  Rarawa,  and  Kiatorete 
Spit  and  52%  for  the  clade  containing  Fare- 
well Spit  and  Waikuku,  Houpoto,  Opoutere, 
and  Rarawa. 

There  were  no  differences  in  the  structure 
of  the  sclerites  of  the  male  pedipalpal  bulb  or 


the  sclerites  of  the  female  external  epigyee  of 
the  22  museum  specimens  of  L.  katipo  and  L. 
atritus  examined. 

DISCUSSION 

Although  too  few  genetic  samples  were  col- 
lected to  gain  a definitive  view  on  intra-spe- 
cific gene  flow  between  L.  katipo  and  L.  atrh 
tus  populations,  an  indication  can  be  inferred 
from  the  results.  The  maximum  interspecific 
pairwise  distance  among  L.  katipo  and  L.  atri- 
tus populations  was  0.97%,  which  was  smaller 
than  most  pairwise  distances  found  in  the 
NDl  gene  region  between  Nesticus  spp.  pop- 
ulations (Hedin  1997a).  Although  compari- 
sons between  genera  are  not  ideal,  Nesticus  is 
in  a sister  family  to  Latrodectus  so  some  in- 
ference may  be  drawn.  Low  intraspecific  pair- 
wise distances  among  L.  katipo  and  L.  atritus 
populations,  therefore,  indicate  that  popula- 
tions from  which  genetic  samples  were  col- 
lected may  not  be  genetically  isolated  or  they 
have  not  yet  undergone  complete  lineage  sort- 
ing. 

Both  maximum  likelihood  and  parsimony 
analyses  revealed  that  these  taxa  were  para- 
phyletic.  In  addition  to  this,  none  of  the  22 
museum  specimens  of  L.  katipo  and  L.  atritus 
examined  were  found  to  differ  in  male  and 
female  genitalia.  However,  marked  differences 
between  L.  katipo  and  L.  atritus  coloration 
and  distribution  (McCutcheon  1976;  Forster  & 
Kingsford  1983;  Forster  & Forster  1999)  offer 
support  for  the  current  taxonomic  designation 
of  these  species.  Latrodectus  are  unusual 
amongst  spiders  in  that  their  coloration  ap- 
pears to  be  more  useful  than  genitalia  in  sep- 
arating species  (Levi  1983).  It  is  possible  that 
although  L,  katipo  and  L.  atritus  have  not 
been  observed  mating,  this  does  not  preclude 
the  possibility  that  these  species  may  inter- 
breed. Moreover,  if  color  variation  between 
the  species  were  related  to  an  environmental 


GRIFFITHS  ET  AL.— GENETICS  OF  NEW  ZEALAND  LATRODECTUS  SPECIES 


781 


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variable,  such  as  temperature,  differences  in 
morphology  and  distribution  may  be  ex- 
plained. However,  we  have  only  data  from  one 
mitochondrial  gene  region  and  the  genetic  dif- 
ferences between  L.  katipo  and  L.  atritus  may 
be  due  either  to  gene  flow  or  incomplete  lin- 
eage sorting.  The  validity  of  the  species  status 
of  L.  katipo  and  L.  atritus  could  be  further 
explored  by  the  sequencing  of  more  popula- 
tions with  NDl,  sequencing  with  other  mito- 
chondrial genes  (e.g.,  COI,  which  showed 
over  three  times  more  sequence  divergence 
between  L.  katipo  and  L.  hasselti  than  NDl: 
see  Garb  et  al.  2004)  or  nuclear  gene  introns, 
the  screening  of  micro  satellites  and/or  detailed 
morphological  examinations  for  other  possible 
characters,  especially  including  the  mixed 
populations  of  the  two  species  mentioned  by 
Forster  & Forster  (1999).  It  would  also  be 
worth  repeating  the  rearing  experiments  re- 
ported by  Forster  & Kingsford  (1983)  and 
Forster  & Forster  (1999)  with  large  replicates. 
Until  further  work  is  undertaken  L.  katipo  and 
L.  atritus  should  be  regarded  as  separate  spe- 
cies. 

Forster  (1995)  postulated  that  the  New  Zea- 
land widow  fauna  had  been  genetically  iso- 
lated from  L.  hasselti  since  the  fragmentation 
of  Gondwana  60-80  mya  (Hayes  & Ringis 
1973).  If  Forster’s  (1995)  hypothesis  is  true 
and  L.  hasselti  and  the  New  Zealand  fauna 
have  been  isolated  from  one  another  for  at 
least  60  my,  the  maximum  pairwise  distance 
(1.95%)  between  the  L.  hasselti  and  the  New 
Zealand  widow  fauna  suggests  a rate  of 
change  the  NDl  sequence  of  0.0325%  per 
million  years,  which  is  70  times  slower  than 
mitochondrial  sequence  divergence  reported 
in  other  arthropods  (Brower  1994).  Forster 
(1995)  had  also  suggested  that  all  Latrodectus 
species  had  a common  theridiid  ancestor  be- 
fore the  break  up  of  Pangea  400  mya  (Stevens 
1985),  which  would  predate  the  earliest 
known  Araneoidea  fossil  (Selden  1989)  by 
270  my  and  the  earliest  spider  fossil  (Shear  et 
al.  1989)  by  20  my.  Much  of  the  present  day 
distribution  of  Latrodectus  is  likely  to  be  due 
to  dispersal  events  (Garb  et  al.  2004)  and  the 
low  genetic  divergence  between  L.  hasselti,  L. 
katipo  and  L.  atritus  in  this  study  and  between 
L.  hasselti  and  L.  katipo  in  Garb  et  al.  (2004) 
suggests  that  Latrodectus  was  not  present  on 
New  Zealand  when  it  separated  from  Gond- 
wana 60-80  mya.  This  assertion  is  supported 


782 


THE  JOURNAL  OF  ARACHNOLOGY 


0.01  substitutions/site 

— L katipo  - Farewell  Spit  & Waikuku 


L.  atritus  - Rarawa 


L atritus  ~ Opoutere 


L atritus  - Houpoto 


L katipo  - Kaitorete  Spit 


L katipo  - Herbertviile  & Flat  Point 


L.  hasselti  - Western  Australia  & Queensland 


L.  hesperus 


1 .55  substitutions/site 

Figure  2. — Maximum  likelihood  tree,  which  has  identical  topology  to  one  of  the  12  equally  parsimo- 
nious trees.  Note  the  long  branch  of  L.  hesperus.  There  was  not  bootstrap  support  over  60%  in  the 
maximum  likelihood  analysis  and  none  over  50%  in  the  parsimony  analysis. 


by  growing  evidence  that  the  New  Zealand 
spider  fauna  has  been,  and  continues  to  be, 
influenced  by  the  arrival  of  spiders  from  Aus- 
tralia (Vink  & Sirvid  2000;  Vink  et  al.  2002; 
Vink  & Paterson  2003).  Given  that  suitable  L. 
katipo  and  L.  atritus  habitat  has  probably  been 
present  in  New  Zealand  for  a long  time  (Ste- 
vens et  al.  1988)  and  that  the  genetic  evidence 
indicates  L.  hasselti  is  a good  disperser,  it 
seems  unlikely  that  L,  katipo  and  L.  atritus  are 
recent  arrivals  to  New  Zealand.  In  the  absence 
of  datable  fossil  records,  however,  it  is  un- 
likely that  the  time  L.  katipo  and  L.  atritus 
arrived  in  New  Zealand  will  be  precisely 
known.  Overall,  this  lack  of  evidence  for  iso- 
lation between  Australia  and  New  Zealand 
since  the  Gondwanan  break-up  agrees  with 
other  recent  studies  of  other  New  Zealand 
taxa,  such  as  podocarp  trees  (Pole  1994),  gal- 
axiid  fish  (Waters  et  al.  2000),  hepialid  moths 
(Brown  et  al.  1999)  and  various  flightless  in- 
sects (Trewick  2000). 

It  is  possible  some  gene  flow  may  occur,  or 


has  occurred  until  recently  between  Australian 
and  New  Zealand  Latrodectus  populations. 
Greater  intraspecific  variation  found  among 
populations  of  L.  katipo  or  L.  atritus  than  be- 
tween the  Australian  specimens  might  have 
resulted  from  periods  of  glaciation  or  rising 
sea  levels  that  restricted  gene  flow  between  L. 
katipo  or  L.  atritus  populations  in  New  Zea- 
land, but  are  unlikely  to  have  affected  L.  has- 
selti (Stevens  1985;  Stevens  et  al.  1988;  Nich- 
ols 2001;  Trewick  2001).  Moreover,  Raven 
(1992)  and  Main  (1992)  suggested  that  L.  has- 
selti may  have  only  recently  been  introduced 
to  eastern  Australia  from  South  Australia, 
which  would  explain  the  lack  of  genetic  var- 
iation between  the  L.  hasselti  specimens. 

Although  the  NDl  mitochondrial  gene  re- 
gion has  previously  been  used  to  examine  in- 
tra-specific variation  between  spider  popula- 
tions (Hedin  1997a;  Hedin  1997b;  Masta 
2000;  Johannesen  et  al.  2002;  Maddison  & 
Hedin  2003;  Masta  & Maddison  2002),  this 
gene  region  did  not  evolve  fast  enough  to  pro- 


GRIFFITHS  ET  AL.— GENETICS  OF  NEW  ZEALAND  LATRODECTUS  SPECIES 


783 


vide  the  definition  required  to  examine  gene 
flow  between  populations  of  L.  katipo,  L.  atri- 
tus  or  L.  hasselti.  Moreover,  the  low  number 
of  samples  examined  in  this  project  also  made 
it  difficult  to  gain  a definitive  view  of  intra- 
specific gene  flow.  These  problems  might  be 
overcome  if  sequence  data  from  other  faster 
evolving  mitochondrial  gene  regions,  such  as 
COI  (see  Garb  et  al.  2004),  or  microsatellites 
were  used  and  more  samples  were  examined. 

ACKNOWLEDGMENTS 

Thanks  to  Charlie  Chambers  for  collecting 
assistance.  We  are  grateful  to  Ding  Johnson 
for  collecting  L.  hasselti  from  Western  Aus- 
tralia, to  Robert  Raven  (Queensland  Museum) 
for  providing  L.  hasselti  from  Queensland, 
and  to  David  Voice  (Ministry  of  Agriculture 
and  Forestry)  for  providing  the  L.  hesperus 
specimen.  We  thank  Phil  Sirvid  (Museum  of 
New  Zealand),  Brian  Patrick  (Otago  Museum) 
and  John  Early  (Auckland  Museum)  for  the 
loan  of  specimens.  This  research  was  made 
possible  by  funding  from  the  Department  of 
Conservation  and  the  Soil  Plant  and  Ecolog- 
ical Sciences  Division,  Lincoln  University. 

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Manuscript  received  5 May  2004,  revised  1 August 
2004. 


2005.  The  Journal  of  Arachnology  33:785-796 


REVISION  OF  THE  SPIDER  GENUS  HESYDRUS 

(ARANEAE,  LYCOSOIDEA,  TRECHALEIDAE) 

James  E.  Carico:  School  of  Sciences,  Lynchburg  College,  1501  Lakeside  Drive, 
Lynchburg,  Virginia  24501  USA.  E-mail:  carico@lynchburg.edu 

ABSTRACT.  Hesydrus  palustris  Simon  and  H.  habilis  (O.R-Cambridge)  are  redescribed.  Four  new 
species  are  described:  H.  caripito,  H.  yacuiba  and  H.  chanchamayo  are  described  only  from  females,  and 
H.  canar  from  both  male  and  female  specimens.  Hesydrus  monticola  Chamberlin  is  a junior  synonym  of 
H.  palustris.  Hesydrus  bucculentus  Simon  is  a senior  synonym  of  Trechalea  cezariana  Mello-Leitao. 
Hesydrus  estebanensis  Simon  is  transferred  to  the  genus  Enna  O.R-Cambridge.  Hesydrus  ornatus  Mello- 
Leitao  and  H.  bivittatus  Mello-Leitao,  known  only  from  unidentifiable  spiderling  holotypes,  are  regarded 
as  nomina  dubia.  Coincidence  of  geographic  distributions  of  Hesydrus  and  Trechalea  are  noted. 

Keywords!  New  species,  taxonomy.  South  America,  Central  America 


This  revision  of  the  genus  Hesydrus  Simon 
1898  is  included  in  a series  of  studies  of  tre- 
chaleid  genera  initiated  by  the  recognition  of 
the  validity  of  the  family  (Carico  1986)  and 
subsequently  followed  by  a redefinition  of  the 
family  and  revision  of  its  type  genus,  Tre- 
chalea Thorell  1869  (Carico  1993).  Other 
genera  under  study  include  Syntrechalea  ER- 
Cambridge  1902,  Dossenus  Simon  1898,  Dy- 
rines  Simon  1903,  Enna  O.R-Cambridge  1897 
and  Paradossenus  ER-Cambridge  1903,  along 
with  new  genera  (Carico  2005). 

Members  of  the  genus  Hesydrus  share  the 
trechaleid  habitat,  which  place  them  among 
rocks  and  around  stream  margins.  The  egg  sac 
is  a typical,  flattened,  bivalve  disc  (Carico 
1993,  fig.  6)  which  is  carried  on  the  spinnerets 
and  provides  a transportation  platform  for  spi- 
derling s after  their  emergence.  Like  members 
of  the  genus  Trechalea,  the  egg  sac  is  attached 
permanently  to  the  spinnerets  at  a single  lo- 
cation, but  unlike  the  former,  in  which  the  at- 
tachment is  in  the  center  of  the  upper  valve, 
Hesydrus  always  makes  the  attachment  dis- 
tinctly off-center. 

A comparison  of  the  distributions  of  species 
within  this  genus  and  with  species  of  Tre- 
chalea reveals  notable  similarities  throughout 
Central  and  South  America.  In  particular, 
there  is  an  apparent  sympatry  of  particular 
species  from  each  genus  into  comparable  and 
identifiable  geographic  subregions.  Therefore, 
the  same  geographic  isolating  mechanisms 
may  be  affecting  the  radiation  of  both  genera. 


This  is  not  surprising  in  that  the  habitat  pref- 
erences are  apparently  very  similar.  An  ex- 
ample is  the  observation  that  both  H.  canar 
new  species  and  T.  longitarsis  (C.L.  Koch 
1848)  are  limited  to  the  coastal  river  drainages 
of  Reru,  Ecuador  and  Colombia,  while  H.  pal- 
ustris Simon  1898  along  with  both  T.  mccon- 
nelli  Rocock  1900  and  T.  paucispina  Capo- 
riacco  1947  are  found  in  the  tributaries  of  the 
Amazon  River.  The  common  feature  that  sep- 
arates the  species  cluster  in  the  West  from 
those  in  the  East  is  the  barrier  afforded  by  the 
Andean  continental  divide.  An  interesting  ex- 
ception, however,  is  the  occurrence  of  a single 
collection  of  H.  palustris  in  the  Canal  Zone 
of  Ranama.  The  latter,  if  not  due  to  collection 
mislabeling  or  introduction,  suggests  that  this 
species  has  extended  its  range  from  the  Racific 
coastal  drainages  of  South  America  into  Pan- 
ama. Another  geographic  coincidence  is  the 
occurrence  of  both  H.  habilis  O.R-Cambridge 
1896  and  T.  extensa  ER-Cambridge  1902  in 
Central  America  between  the  isthmuses  of  Te- 
huantepec and  Ranama  which  clearly  suggests 
that  the  Ranamanian  lowlands  is  a barrier  sep- 
arating them  from  species  in  South  America 
while  Tehuantepec  limits  range  extensions 
northward.  The  nomenclature  of  the  genitalia 
and  other  anatomical  features  follow  Carico 
(1993  [after  Sierwald  1989,  1990]).  The  struc- 
ture of  both  the  male  palpus  and  female  gen- 
italia in  Hesydrus  have  the  same  basic  config- 
urations as  that  of  Trechalea  (Carico  1993, 
figs.  7-10).  Because  of  its  rigidity  and  resis- 


785 


786 


THE  JOURNAL  OF  ARACHNOLOGY 


tance  to  distortion,  carapace  length  is  empha= 
sized  as  an  index  of  body  size,  particularly  in 
the  discussions  of  variation.  Measurements 
and  figure  scales  are  in  millimeters. 

Specimens  examined  during  this  study  are 
lodged  in  the  following  museums:  American 
Museum  of  Natural  History,  New  York 
(AMNH);  California  Academy  of  Sciences, 
San  Francisco  (CAS);  Field  Museum  of  NaU 
ural  History,  Chicago  (FMNH);  J.E.  Carico 
collection  (JEC);  Museo  Argentino  de  Cien- 
cias  Naturales,  Buenos  Aires  (MACN);  Mu- 
seum of  Comparative  Zoology,  Harvard 
(MCZ);  via  Museu  Equitoriano  de  Ciencias 
Naturales,  Quito,  Ecuador  (MECN);  Museo  de 
la  Universidad  Nacional  de  La  Plata  (MLP); 
Museu  Nacional,  Universidade  Federal  do  Rio 
de  Janeiro  (MNRJ);  Museum  National 
d’Histoire  Naturelle,  Paris  (MNHN);  Univer- 
sity of  Costa  Rica,  San  Jose  (UCR);  and  Yale 
Peabody  Museum,  New  Haven  (YPM). 

Since  the  general  anatomy  and  color  pattern 
within  species  in  Hesydrus  are  quite  similar, 
the  best  characters  used  to  distinguish  species 
are  details  of  the  genitalia.  Because  of  the  lack 
of  representative  series,  it  is  difficult  to  ascer- 
tain in  many  cases  whether  some  of  the  gen- 
italic  characters  represent  a range  of  variation 
within  a species  or  indicate  species-level  di- 
vergence. Of  particular  concern  is  a number 
of  singleton  females  representing  widely  di- 
vergent locations  within  the  Amazon  River 
basin.  Although  there  are  small,  but  notable, 
differences  in  the  genitalic  characters,  I have 
elected  to  be  conservative  in  the  nomenclature 
for  the  present  in  light  of  the  possibility  that 
future  collecting  in  the  area  will  provide  a ba- 
sis for  decisions.  If,  however,  there  are  well- 
known  geographic  features  serving  as  barriers 
between  species  that  coincide  with  characters, 
then  the  latter  are  assumed  to  be  of  value  in 
distinguishing  species. 

Transfer  of  Hesydrus  species  to  other 
genera. — The  apparent  holotype  of  Hesydrus 
bucculentus  Simon  1898  is  a large  antepen- 
ultimate male  (carapace  length,  7.3)  of  Tre~ 
chalea  cezariana  Mello-Leitao  1931.  Tre- 
chalea  bucculenta  (Simon  1898)  is  therefore 
a senior  synonym  (NEW  SYNONYMY,  NEW 
COMBINATION).  This  conclusion  is  based 
upon  a careful  anatomical  examination  and 
the  consideration  that  the  three  possible  Bra- 
zilian locations  for  the  locality  on  the  speci- 
men label,  “Thelezopolis  [Theresopolis?]” 


Figure  1. — Dorsal  pattern  of  Hesydrus  palustris 

male. 


are  at  22°25'S/42°58'W,  27°05'S/5ri2'W  or 
30°05'S/42°58'W,  all  of  which  are  within  the 
geographical  range  for  Simon’s  species.  In  his 
short  description,  Simon  indicates  the  type  is 
a female  from  “Brasilia”  (Brazil)  and  the 
specimen  examined,  # 8537,  has  the  label 
probably  written  by  him. 

The  holotype  of  H.  estebanensis  Simon 
1898  is  actually  a species  of  Enna  and  this 
species  is  therefore  transferred  to  that  genus 
{Enna  estebanensis  (Simon  1898)  NEW 
COMBINATION].  Its  taxonomic  placement 
within  the  latter  genus,  however,  is  not  yet 
determined. 

Genus  Hesydrus  Simon  1898 
Hesydrus  Simon  1898b:305.  1898b:315  (Pisauri- 
dae);  Roewer  1954:137  (Pisauridae);  Bonnet 


CARICO— REVISION  OF  GENUS  HESYDRUS 

1957:2182  (Pisauridae);  Lehtinen  1967:372 
(transferred  to  Dolomedidae);  Brignoli  1983:461, 
465  (Dolomedidae);  Carico  1986:305  (transferred 
to  Trechaleidae);  Sierwald  1990:8  C'Trechalea 
genus-group”);  Carico  1993:226  (Trechaleidae); 
Sierwald  1993:63  (Trechaleidae);  Platnick  2004 
(Trechaleidae). 

Type  species. — Hesydrus  palustris  Simon 
1898a  by  original  designation. 

Diagnosis. — Leg  I is  always  shorter  than  II 
and  IV  and  approximately  equal  to  the  length 
of  IIL  Both  the  tarsi  and  the  distal  half  of  the 
metatarsi  are  flexible.  Chelicerae  of  adult 
males  are  enlarged  frontally,  glabrous  and 
without  distinct  lateral  carinae.  Pairs  of  ven- 
tral macrosetae  on  the  venter  in  all  known 
species  is:  1-4,  II-4,  III-3  and  IV-3. 

Description. — Carapace  moderately  low, 
cephalic  area  not  distinct,  AE  row  straight  or 
slightly  recurved.  Each  basal  segment  of  male 
chelicera  swollen  anteriorly  and  without  a dis- 
tinct Carina:  promarginal  teeth  three  with  cen- 
ter one  largest,  three  retromarginal  teeth 
sometimes  with  a small  gap  between  the  prox- 
imal two.  Leg  formula  generally  (IV-II)-(I- 
III),  tarsus  and  distal  half  of  metatarsi  flexible, 
all  claws  dentate,  paired  marcosetae  1-4,  II-4, 
IIL3,  IV-3. 

Male  palpal  bulb  (Fig.  2)  with  median 
apophysis  (ma)  with  distal,  sickle-shaped  dor- 
sal division  (dd)  narrow,  tapered,  with  tip  con- 
spicuous, and  directed  variably  distad  or  lat- 
erad,  the  ventral  division  (vd)  acute  distally; 
retrolateral  tibial  apophysis  (rta)  arising  dis- 
tally and  laterally  from  near  the  ventro-distal 
rim  (vr)  with  ectal  division  (ecd)  spatulate, 
and  ental  division  (end)  partly  surrounded  by 
ventral  cymbio-tibial  membrane  (vcm);  tibial 
(vr)  of  ventral  protuberance  (vp)  folded  over 
to  create  a depression  in  the  vcm.  The  epi- 
gynum  externally  a slightly  convex  plate,  with 
an  elongated  medial  scape;  internally  (Fig.  5) 
on  either  side,  partially  attached  stalked  sper- 
mathecum  with  head  (hs)  slightly  larger  than 
stalk  and  free  from  other  components;  a single 
diverticulum  arising  from  a large  common 
chamber  (probably  enlarged  portion  of  copu- 
latory  duct),  both  copulatory  duct  (cd)  and 
fertilization  duct  (fd)  arising  from  this  com- 
mon chamber. 

Distribution. — Widespread  from  Guate- 
mala southward  to  northern  Argentina  (Figs. 
6,  11). 

Nomina  dubia. — The  following  two  spe- 


787 


Figures  2-5.— Genitalia  of  Hesydrus  palustris.  2, 

3.  right  palpus;  2.  ventral  view,  3.  retrolateral  view; 

4,  5.  female  genitalia;  4.  ventral  view,  5.  dorsal 
view.  Apparent  difference  in  scale  in  4 & 5 is  due 
to  viewing  at  different  tilt  angles  of  this  thick  struc- 
ture. (c  = cymbium,  cd  = copulatory  duct,  dd  = 
dorsal  division,  ecd  = ectal  division,  end  = ental 
division,  fd  = fertilization  duct,  hs  = head  of  sper- 
mathecum,  ma  = median  apophysis,  rta  = retrola- 
teral tibial  apophysis,  s = spermathecum,  t = te- 
gulum,  St  = subtegulum,  vcm  = ventral 
cymbio-tibial  membrane,  vd  = ventral  division,  vp 
= ventral  protuberance,  vr  = ventro-distal  rim.) 

cies  described  in  Hesydrus  are  considered  un- 
identifiable with  any  adult  of  any  recognizable 
species: 

Hesydrus  ornatus  Mello-Leitao  1941.  Ho- 
lotype  juvenile  no.  14667,  Yala,  Jujuy,  Argen- 
tina, M.  Biraben,  MLP,  examined.  The  speci- 
men is  a small  spiderling  with  a carapace 
length  of  1.7  mm  and  no  legs  attached.  There 
are  only  a few  loose  leg  fragments  but  no  tarsi 
present. 

Hesydrus  bivittatus  Mello-Leitao  1941.  Ho- 
lotype  juvenile  no.  14666,  Salta,  Salta,  Argen- 
tina, M.  Biraben,  MLP,  examined.  The  speci- 
men is  a small  spiderling  with  a carapace 
length  of  1.16  mm  but  with  all  legs  attached 
except  for  one. 


788 


THE  JOURNAL  OF  ARACHNOLOGY 


Figure  6. — Distribution  of  species  of  Hesydrus  in 
South  America. 


Both  these  similar  specimens  are  very  small 
juveniles  and  are  in  poor  condition.  The  legs 
show  generalized  features  of  lycosoids  but 
have  no  specific  features  of  Hesydrus.  The 
only  features  that  are  clear  enough  for  prac- 
tical  analysis  are  the  eye  pattern  and  what  can 
be  discerned  from  remnants  of  the  dorsal  pat- 
tern. The  eye  pattern  is  general  for  trechaleids 
and  pisaurids,  but  also  for  the  rather  atypical 
lycosid  genus,  Aglaoctenus.  In  some  pisaurids 
I have  found  that  there  may  be  a significant 
shift  of  the  relative  positions  of  eyes  and  pro- 
portions of  some  body  parts  during  the  tran- 
sition of  spiderling  to  adult,  a significant  fac- 
tor to  consider  when  identifying  spiderlings  in 
these  lycosoid  families.  The  median  dorsal 
bands  of  the  abdomen  of  both  specimens  are 
unknown  in  any  recognized  species,  but  then 
it  is  not  unusual  for  spiderling  coloration  to 
be  different  from  that  of  later  juveniles  and 
adults.  Therefore,  until  a detailed  comparative 
study  can  be  made  on  juveniles  of  known  spe- 
cies of  these  wide-ranging  families,  it  is  not 
possible  to  determine  the  status  of  these  spec- 
imens. Since  it  is  not  useful  to  base  a taxon- 
omy on  such  uncertainty,  I have  not  consid- 
ered these  two  species  further  in  the 
nomenclature  of  species  in  Hesydrus. 

Hesydrus  palustris  Simon  1898 

Figs.  1-6 

Hesydrus  palustris  Simon  1898a:20;  Simon  1898b: 

305;  FO.R-Cambridge  1903:165,  plate  15,  figs. 

22-25;  Roewer  1954:137;  Bonnet  1957:2182; 

Platnick  2004. 

Trechalea  monticola  Chamberlin  1916:276,  277, 


plate  23,  fig.  1;  Roewer  1954:143;  Bonnet  1959: 
4679.  NEW  SYNONYMY. 

Hesydrus  monticola  (Chamberlin):  Carico  1993: 
237;  Platnick  2004. 

Type  material. — Hesydrus  palustris:  lec- 
totype  male  (present  designation),  1 paralec- 
totype  female,  Loja,  Zamora,  Ecuador,  4°00'S, 
79°12'W,  Gaujon  (MNHN,  examined)  (Simon 
did  not  designate  a holotype  from  the  syntype 
series;  a male  lectotype  is  selected  here  to  pro- 
vide taxonomic  stability). 

Trechalea  monticola:  holotype,  juvenile  fe- 
male, Santa  Ana,  Peru,  August  1911,  Yale  Pe- 
ruvian Expedition  (MCZ,  examined). 

Other  material  examined.— ARGENTI- 
NA: Jujuy:  “S.  S.”  [?San  Salvador  de  Jujuy], 
24°11'S,  65°18'W,  February  1966,  Maury,  1 
9 (MACN).  BOLIVIA:  La  Paz:  Guanay  near 
La  Paz,  16°30'S,  68°09'W,  August  1989,  L.E. 
Pena,  1 d,  1 9,  4 juveniles  (AMNH).  BRA- 
ZIL: Acre:  Rio  Purus  NW.  of  Sena  Madureira 
Seringal  Santo  Antonio,  9°04'S,  68°40'W,  IS- 
IS September  1973,  B.  Patterson,  2 9 (MCZ). 
COLOMBIA:  Amazonas:  35  km  above  Leti- 
cia, 10°22'N,  74°28'W,  15  September  1973, 
Mary  Corn,  1 9 (MCZ).  ECUADOR:  Pasta^ 
za:  Cusuimi,  on  Cusuimi  River  150  km  SE. 
Puyo,  2°43'S,  77°40'W,  15-31  May  1971,  B. 
Malkin,  1 9 (FMNH).  PANAMA:  Canal 
Zone:  Barro  Colorado  Island,  9°09'S, 
79°50'W,  16  June-15  July  1934,  A.M.  Chick- 
ering,  1 S (MCZ).  PERU:  San  Martin:  Ekin, 

E.  of  Tarapoto,  6°30'S,  76°21'W,  9-21  March 
1947,  E Woytkowski,  2 d,  12  9 (AMNH); 
Mishqui-Yacu,  20  km  NE.  Moyobamba, 
6°03'S,  76°58'W,  16-24  August  1947, 

F. Woytkowski,  2 9,  3 juveniles  (AMNH); 
Hara,  20  miles  SE.  of  Moyabamba,  6°03'S, 
76°58'W,  1-30  June  1947,  E Woytkowski,  1 

5 (AMNH);  Huanuco:  Divisoria,  9°40'S, 
76°05'W,  23  September-3  October  1946,  E 
Woytkowski,  2 d,  10  9 (AMNH);  Loreto: 
Aquaitia,  4°00'S,  75°10'W,  1-2  September 
1946,  F.  Woytkowski,  5 d,  25  9 (AMNH); 
San  Alejandro,  4°00'S,  75°10'W,  June  1947, 
W Weyrauch,  5 d,  2 9 (AMNH);  Pasco:  Up- 
per Pachitea  River,  8°46'S,  74°3FW,  collector 

6 date  unknown,  1 9 (AMNH);  Madre  de 
Dios:  15  km  E.  of  Puerto  Moldonado  on  Rio 
Madre  de  Dios,  12°17'S,  70°52'W,  4 June 
1983,  G.C.  Hunter,  1 9 (CAS);  same  location 
& collector,  27  June  1983,  1 9 (CAS). 

Diagnosis. — This  species  is  distinguished 


CARICO— REVISION  OF  GENUS  HESYDRUS 


789 


Table  1 . — Eye  measurements  for  species  of  Hesydrus  in  mm.  Measurements  are  dimensions  within  outer 
margins  of  entities  included.  AE  row  = width  of  anterior  eye  row,  PE  row  = width  of  posterior  eye  row, 
OQA  = width  of  ocular  quadrangle  anteriorly  (width  of  anterior  median  eyes),  OQP  = width  of  ocular 
quadrangle  posteriorly  (width  of  posterior  median  eyes),  OQH  = height  of  ocular  quadrangle  (height  of 
anterior  median  eye  and  posterior  median  eye),  PLE  = diameter  of  posterior  lateral  eye,  PME  = diameter 
of  posterior  median  eye,  ALE  = diameter  of  anterior  lateral  eye,  AME  = diameter  of  anterior  median 
eye,  PLE-PME  = interdistance  between  posterior  lateral  eye  and  posterior  median  eye,  PME-PME  = 
interdistance  between  posterior  median  eyes,  ALE-AME  = interdistance  between  anterior  lateral  eye  and 
anterior  median  eye,  AME- AME  = interdistance  between  anterior  median  eyes. 


Hesy-  Hesydrus 


Hesydrus  Hesydrus  Hesydrus  Hesydrus  Hesydrus 

drus 

Hesydrus  Hesydrus 

chancha- 

palustris 

palustris 

habilis 

habilis 

canar 

canar 

caripito 

yacuiba 

mayo 

S 

9 

6 

9 

6 

9 

9 

9 

9 

AE  row 

1.12 

1.32 

1.17 

1.20 

1.29 

1.28 

1.18 

1.17 

1.47 

PE  row 

2.13 

2.55 

2.20 

2.36 

2.53 

2.50 

2.38 

2.37 

2.94 

OQA 

0.73 

0.81 

0.73 

0.73 

0.83 

0.81 

0.74 

0.72 

0.90 

OQP 

1.20 

1.35 

1.08 

1.13 

1.26 

1.21 

1.20 

1.23 

1.44 

OQH 

0.90 

0.95 

0.90 

0.96 

1.03 

1.04 

0.95 

0.85 

1.10 

PLE 

0.46 

0.49 

0.52 

0.50 

0.54 

0.52 

0.50 

0.45 

0.60 

PME 

0.44 

0.44 

0.44 

0.45 

0.47 

0.48 

0.45 

0.41 

0.54 

ALE 

0.18 

0.20 

0.17 

0.20 

0.18 

0.21 

0.20 

0.17 

0.21 

AME 

0.31 

0.33 

0.33 

0.45 

0.35 

0.38 

0.32 

0.30 

0.33 

PLE-PME 

0.40 

0.55 

0.37 

0.47 

0.50 

0.51 

0.44 

0.45 

0.55 

PME-PME 

0.46 

0.49 

0.35 

0.35 

0.41 

0.37 

0.40 

0.48 

0.48 

ALE-AME 

0.02 

0.05 

0.06 

0.06 

0.07 

0.06 

0.05 

0.06 

0.10 

AME-AME 

0.08 

0.20 

0.15 

0.15 

0.19 

0.20 

0.16 

0.19 

0.23 

by  characteristics  of  the  prominent  retrolateral 
tibial  apophysis  which  is  about  as  wide  as 
long  and  diverges  distinctly  from  the  axis  of 
the  tibia;  its  apex  is  rounded  on  one  comer 
and  acute  on  the  other.  Additionally,  the  guide 
of  the  median  apophysis  is  acute  and  directed 
distad.  The  distinctive  scape  of  the  epigynum 
emerges  dorsally  from  beneath  a distinct  rim, 
is  widest  at  about  the  middle  of  its  length,  and 
is  mgose  on  the  posterior  half.  Internally, 
about  one-third  of  the  spermathecum  is  free 
from  attachment  to  other  stmctures. 

Description. — Male  (lectotype):  Carapace 
(Fig.  1)  medium  brown  with  irregular  sub- 
marginal light  bands,  narrow  dark  marginal 
bands,  black  in  eye  region,  length  5.0,  width 


Table  2.- — Leg  measurements  of  Hesydrus  pal- 
ustris  male  in  mm. 


Leg  segment 

I 

II 

III 

IV 

Femur 

5.8 

7.3 

5.8 

6.7 

Tibia-patella 

7.7 

9.4 

6.9 

8.3 

Metatarsus 

6.2 

7.5 

5.5 

8.5 

Tarsus 

3.5 

4.0 

3.6 

4.5 

Total 

23.2 

28.2 

21.8 

28.0 

4.5.  Sternum  light,  unmarked,  length  2.30, 
width  2.15;  labium  generally  light,  lighter  at 
distal  margin,  length  0.45,  width  0.42.  Clyp- 
eus  height  0.35,  width  2.18.  Anterior  eye  row 
straight  or  slightly  recurved,  eye  measure- 
ments in  Table  1.  Cheliceral  faces  light  and 
shaped  as  for  genus,  three  retromarginal  teeth, 
subequal  in  size  and  with  a gap  between  prox- 
imal two.  Legs  II-IV-I-III,  measurements  in 
Table  2.  Color  of  legs  medium  brown,  marked 
only  with  very  faint  maculae  on  dorsum  of 
femora.  Abdomen  with  distinct,  diffuse  dorsal 
pattern  (Fig.  1),  length  4.7.  Palpus  (Figs.  2,  3) 
tibia  length  approximately  equal  to  length  of 
cymbium,  bulb  t and  st  prominent,  vd  of  ma 
acute  distally,  g of  dd  acute,  curved  distally 
towards  apex  of  c,  ecd  of  rta  prominent,  pro- 
jected somewhat  laterally,  rounded  on  outer 
edge  except  at  ventral  corner. 

Female  (paralectotype):  Carapace  with  ir- 
regular light  submarginal  bands,  length  5.6, 
width  5.5.  Sternum  unmarked,  length  3.1, 
width  2.8;  labium  length  1.0,  width  0.95. 
Clypeus  unmarked,  height  0.50,  width  2.5. 
Anterior  eye  row  slightly  recurved,  eye  mea- 
surements in  Table  1 . Chelicerae  medium 


790 


THE  JOURNAL  OF  ARACHNOLOGY 


Table  3. — Leg  measurements  of  Hesydrus  pal- 
ustris  female  in  mm. 


Leg  segment 

I 

II 

III 

IV 

Femur 

6.9 

8.1 

7.0 

8.0 

Tibia-patella 

9.0 

10.3 

8.4 

9.9 

Metatarsus 

6.6 

7.4 

6.4 

9.5 

Tarsus 

3.6 

3.3 

4.0 

4.5 

Total 

26.1 

29.1 

25.8 

31.9 

brown,  three  promarginal  teeth,  three  retro- 
marginal  teeth  with  gap  between  proximal 
two.  Legs  unmarked,  IV-II-I-III,  measure- 
ments in  Table  3.  Abdomen  with  distinct,  dif- 
fuse dorsal  pattern  similar  to  male,  venter 
light,  unmarked,  length  7.0.  Median  scape  of 
epigynum  (Figs.  4,  5)  emerges  from  under  a 
rim,  widest  in  middle  of  its  length,  rugose  at 
the  posterior  half,  spermatheca  free  from  at- 
tachment for  one-third  of  their  length. 

Variation. — Carapace  length  of  males  av- 
erage 4.74  (4. 0-5. 3,  n = ll)  and  of  females 
4.91(3.9-6.2,  n = 50).  Dorsal  pattern  similar 
in  both  sexes  with  little  variation  noted. 

Natural  history, — Average  diameter  of  22 
egg  sacs  equals  8.54  (6.1-10.5).  Occurrence 
of  egg  sacs  in  the  months  of  February,  March, 
June,  September  and  October  suggests  that  re- 
production may  occur  year  round. 

Distribution. — Known  from  the  high  ele- 
vation tributaries  of  the  Amazon  River  on  the 
Eastern  slopes  of  the  Andes  in  Peru,  Equador 
and  Bolivia.  A single  male  specimen  from  the 
Canal  Zone  seems  disjunct  from  the  of  the 
main  population.  A thorough  collecting  effort 
at  this  location  at  Barro  Colorado  Island  by 
the  author  in  1983  failed  to  find  any  speci- 
mens of  Hesydrus  although  other  trechaleids 
were  found  there  suggesting  that  the  Chick- 
ering  specimen  location  may  be  in  error.  A 
single  female  in  northern  Argentina  seems 
also  be  disjunct,  but  further  collections  are 
needed  to  determine  if  it  is  part  of  a contin- 
uous distribution  (Fig.  6). 

Hesydrus  habilis  (O.  P.-Cambridge  1896) 
Figs.  7-11 

Triclaria  habilis  O. P.-Cambridge  1896:173,  plate 

22,  fig.  9. 

Trechalea  habilis  (O. P.-Cambridge):  F.O.R-Cam- 
bridge  1902:313,  plate  30,  fig.  15. 

Hesydrus  habilis  (O. P.-Cambridge):  FO. P.-Cam- 
bridge 1903:165,  plate  15,  fig.  21;  Roewer  1954: 
137;  Bonnet  1957:2182;  Platnick  2004. 


Type  material. — Holotype  male,  Costa 
Rica,  1907,  by  Sarg  (BMNH,  examined). 

Other  material  examined. — COSTA 
RICA:  unnamed  river  near  Siquirres,  I0°06'N, 
83°31'W,  16  August  1983,  J.  Carico  & E Coy- 
le, 7 d,  9 $ (JEC);  Rio  Chirripo  de  Alantica 
near  Limon,  9°46'N,  83nO'W,  16  August 
1983,  J.  Carico  & E Coyle,  4 d,  6 ? (JEC); 
7 miles  W.  Turrialba,  9°54'N,  83°41'W,  7 Au- 
gust 1927,  W.J.  Hamilton,  Jr.,  1 d,  4 9,  4 
juveniles  (AMNH);  Rio  Corobici,  1 km  de 
Carretera  Interamen,  10°26'N,  85°10'W,  De- 
cember 1965,  C.E.  Valerio,  2 6,19  (UCR). 
HONDURAS:  Lancetilla,  14°54'N,  89°07'W, 
19  July  1929,  A.M.  Chickering,  1 $ (MCZ); 
July  1929,  A.M.  Chickering,  1 d (MCZ),  11 
July  1929,  A.M.  Chickering,  1 9 (MCZ), 
Lancetilla,  Mt.  Side  near  reservoir,  25  July 
1929,  A.M.  Chickering,  1 9 (MCZ).  PANA- 
MA: Rio  Changuinol  near  Quebrada  el  Gua- 
bo,  8°46'N,  79°56'W,  April  1980,  C.W.  Myers, 
1 9 (AMNH);  Remedios,  8°14'N,  81°51'W, 
27  February  1924,  A.  & W.  Petrunkevitch,  1 
6 (YPM),  river  10  km  W.  David,  8°26'N, 
82°26'W,  8 August  1983,  J.  Carico,  F.  Coyle, 
J.  Coddington,  W.  Eberhard,  1 d (JEC). 

Diagnosis. — The  distinctive  small  retrola- 
teral  tibial  apophysis  in  the  male  palpus  is 
wider  than  long,  truncated  distally,  and  fol- 
lows the  contour  of  the  tibia.  The  guide  of  the 
median  apophysis  is  directed  slightly  laterally. 
The  distinctive  scape  of  the  female  epigynum 
is  continuous  with  the  epigynal  plate,  not  sep- 
arated by  a ridge,  and  is  narrowed  in  its  an- 
terior half. 

Description, — Male  (Siquirres,  near  Rio 
Pacuare,  Costa  Rica):  Carapace  medium 
brown  with  irregular  submarginal  light  bands, 
narrow  dark  marginal  bands,  black  in  eye  re- 
gion, length  4.8,  width  4.8.  Sternum  light,  un- 
marked, length  2.9,  width  2.5;  labium  gener- 
ally light,  lighter  at  distal  margin,  length  0.92, 
width  0.85.  Clypeus  height  0.34,  width  1.50, 
Anterior  eye  row  slightly  recurved,  eye  mea- 
surements in  Table  1.  Cheliceral  faces  light 
and  shaped  as  for  genus,  three  retromarginal 
teeth,  subequal  in  size  and  with  a gap  between 
proximal  two.  Legs  II-IV-I-III  measurements 
in  Table  4.  Color  of  legs  medium  brown, 
marked  only  with  very  faint  maculae  on  dor- 
sum of  femora.  Abdomen  with  distinct,  dif- 
fuse dorsal  pattern  but  three  pairs  of  light 
spots  evident,  length  4.6.  Palpus  (Figs.  7,  8) 
tibia  length  approximately  equal  length  of 


CARICO— REVISION  OF  GENUS  HESYDRUS 


Figures  7-10. — Genitalia  of  Hesydrus  habilis.  7, 

8.  right  palpus;  7.  ventral  view,  8.  retrolateral  view; 

9,  10.  female  genitalia;  9.  ventral  view,  10.  dorsal 
view. 


cymbium,  bulb  t and  st  prominent,  vd  of  ma 
acute  distally,  g of  dd  acute,  directed  anterio- 
laterally,  ecd  of  rta  prominent,  cupped,  wider 
than  long,  truncated  distally  following  the 
contour  of  the  tibia,  smooth  on  outer  edge. 

Female  ( Siquirres,  near  Rio  Pacuare,  Costa 
Rica):  Carapace  with  irregular  light  submar^ 
ginal  bands,  narrow  dark  marginal  bands, 
length  5.0,  width  5.0.  Sternum  unmarked, 
length  2.9,  width  2.7;  labium  length  1.00, 
width  0.92,  lighter  distally.  Clypeus  un= 
marked,  height  0.39,  width  2.45,  Anterior  eye 
row  slightly  recurved,  eye  measurements  in 
Table  1.  Chelicerae  medium  brown,  un- 
marked, three  promarginal  teeth,  three  retro- 
marginal  teeth  equidistant,  equal  size.  Legs 
IV-II-I-III,  measurements  in  Table  5.  Abdo- 
men with  distinct,  diffuse  dorsal  pattern  sim- 
ilar to  male,  venter  light,  unmarked,  length 
5.1.  Median  scape  of  epigynum  (Figs.  9,  10) 
narrow,  continuous  with  the  epignal  plate,  not 
separated  by  a ridge,  narrower  in  the  anterior 
half,  internal  structures  as  for  genus.  The 
scape  is  continuous  with  the  epigynal  plate. 


791 


Figure  1 1 . — Distribution  of  Hesydrus  habilis  in 
Central  America. 


not  separated  by  a ridge,  and  narrowed  in  its 
anterior  half. 

Variation,- — Carapace  length  of  males  av- 
erage 4.79  (4. 2-5. 2,  n — 14)  and  of  females 
4.68  (4. 0-5. 4,  n = 23).  Dorsal  pattern  similar 
in  both  sexes  with  little  variation  noted. 

Natural  history. — Twelve  egg  sacs  col- 
lected during  the  months  of  April,  July,  Au- 
gust, and  December  have  an  average  diameter 
of  8.37  (7.1-10.2). 

Distribution. — Central  Guatemala,  Costa 
Rica  and  western  Panama  (Fig.  11). 

Hesydrus  canar  new  species 
Figs.  6,  12-15 

Type  material.— Holotype  male,  Rio  Yan- 
ayacu,  Canar,  Ecuador,  2°27'S,  79°17'W,  22 
September  1984,  F.  Man  Ging  (MECN).  Par- 
atypes:  3 males,  2 females,  same  collection 
data  as  holotype  (MECN). 

Other  material  examined. — COLOMBIA: 
Cauca:  Questrada  Huanqui,  Rio  Saija  area, 
2°56'N,  77°38'W,  18  October-3  November 
1971,  4 $ (FMNH).  ECUADOR:  Guyas:  Hac, 
San  Juaquin,  4 km  SW.  Bucay,  2°41'S, 
79°40'W,  1-4  May  1986,  S.H.  Kamey,  3 $ 
(MECN);  El  Oro:  Rio  Colorado,  0°41'N, 


Table  4. — Leg  measurements  of  Hesydrus  habilis 

male  in  mm. 


Leg  segment 

I 

II 

III 

IV 

Femur 

6.2 

7.7 

6.2 

7.0 

Tibia-patella 

8.3 

10.1 

7.4 

9.0 

Metatarsus 

6.4 

8.0 

6.0 

9.0 

Tarsus 

3.0 

3.7 

3.3 

4.4 

Total 

23.9 

29.5 

22.9 

29.4 

792 


THE  JOURNAL  OF  ARACHNOLOGY 


Figures  12-15. — Genitalia  of  Hesydrus  canar. 
12,  13.  right  palpus;  12.  ventral  view,  13.  retrola- 
teral  view;  14,  15.  female  genitalia;  14.  ventral 
view,  15.  dorsal  view. 


77°58'W,  3 November  1942,  R.  Walls,  1 $ 
(CAS);  Pichincha:  Macachi,  OHIO'S,  78°40'W, 
March  1943,  H.  Frizzell,  1 $ (CAS).  PERU: 
Piura:  Higueron  Las  Lomas,  4°39'S,  80°14'W, 
29  July  1941,  H.  & E Frizzell,  2 c?,  2 $ 
(CAS);  Quiroz  River,  4°26'S,  80°18'W,  26  De- 
cember 1940,  H.  & F Frizzell,  1 9 (CAS). 

Etymology. — The  name  is  a noun  in  ap- 
position suggested  by  the  name  of  the  prov- 
ince from  which  the  specimen  was  collected. 

Diagnosis. — The  distinctive  retrolateral 
apophysis  of  the  male  palpus  is  about  as  long 
as  wide  and  distinctly  bifurcated  distally. 
Also,  the  guide  of  the  median  apophysis  has 
a distinctive  spur  near  the  tip.  The  scape  of 
the  epigynum  is  rather  uniform  in  width  and 
is  continuous  with  the  epigynal  plate  while  not 
separated  from  it  by  a rim,  slightly  narrowed 
medially. 

Description. — Male  (holotype):  Carapace 
medium  brown  with  distinct  zig-zag  submar- 
ginal light  bands,  dark  marginal  bands  with 
undulations  into  the  submarginal  band,  black 
in  eye  region,  length  5.7,  width  5.4.  Sternum 
light,  unmarked,  length  3.1,  width  2.8;  labium 


Table  5. — Leg  measurements  of  Hesydrus  habilis 
female  in  mm. 


Leg  segment 

I 

II 

III 

IV 

Femur 

6.5 

8.0 

6.4 

7.3 

Tibia-patella 

8.4 

10.3 

7.7 

9.2 

Metatarsus 

6.3 

8.0 

6.4 

9.2 

Tarsus 

3.2 

3.8 

3.6 

4.9 

Total 

24.4 

30.1 

24.1 

30.6 

median  brown,  lighter  at  distal  margin,  length 
1.15,  width  0.93.  Clypeus  height  0.40,  width 
2.75.  Anterior  eye  row  slightly  recurved,  eye 
measurements  in  Table  1 . Cheliceral  faces 
light  and  shaped  as  for  genus,  three  retromar- 
ginal  teeth,  subequal  in  size  and  with  a gap 
between  proximal  two.  Legs  II-IV-I-III,  mea- 
surements in  Table  6.  Color  of  legs  medium 
brown,  marked  only  with  distinct  maculae  on 
dorsum  of  femora.  Abdomen  mostly  dark 
above  with  distinct,  diffuse  light  areas  in  pat- 
tern, length  5.1.  Palpus  (Figs.  12,  13)  tibia 
length  approximately  equal  length  of  cym- 
bium,  bulb  t and  st  prominent,  vd  of  ma  acute 
distally,  g of  dd  with  ante-apical  spur,  directed 
anterio-laterally,  ecd  of  rta  prominent,  bifur- 
cated with  each  division  acute  and  curved  dor- 
sally. 

Female  (paratype):  Carapace  medium 
brown  with  narrow,  distinct  zig-zag  submar- 
ginal light  bands,  dark  marginal  bands  with 
undulations  into  the  submarginal  band,  black 
in  eye  region,  length  5.4,  width  5.4.  Sternum 
light,  unmarked,  length  3.1,  width  2.8;  labium 
length  1.08,  width  1.00,  lighter  distally.  Clyp- 
eus unmarked,  height  0.41,  width  2.60.  An- 
terior eye  row  slightly  recurved,  eye  measure- 
ments in  Table  1.  Chelicerae  dark  brown, 
unmarked,  three  promarginal  teeth,  on  the  left 
side  three  retromarginal  teeth,  subequal  in  size 
and  with  a gap  between  proximal  two,  two 
submarginal  teeth  on  the  right  side.  Legs  IV- 
II-I-III,  measurements  in  Table  7.  Color  of 
legs  medium  brown,  marked  only  with  distinct 
maculae  on  dorsum  of  femora.  Abdomen  dor- 
sal pattern  similar  to  male,  venter  light,  un- 
marked, length  8.1.  Median  scape  of  epigyn- 
um (Figs.  14,  15)  rather  uniformly  narrow, 
continuous  with  the  epigynal  plate  and  not 
separated  by  a rim,  internal  structures  as  for 
genus. 

Variation. — Carapace  length  of  males  av- 
erage 5.54  (5. 0-6.0,  n = 5)  and  of  females 


CARICO— REVISION  OF  GENUS  HESYDRUS 


Table  6. — Leg  measurements  of  Hesydrus  canar 
male  in  mm. 


Leg  segment 

I 

II 

III 

IV 

Femur 

7.0 

8.6 

6.9 

8.0 

Tibia-patella 

9.5 

11.5 

8.4 

10.0 

Metatarsus 

7.5 

9.5 

7.0 

10.5 

Tarsus 

3.8 

4.5 

4.0 

5.4 

Total 

27.8 

34.1 

26.3 

33.9 

5.08  (4.2=-5.5,  n = 13).  Dorsal  pattern  similar 
in  both  sexes  with  little  variation  noted. 

Natural  history.— Average  diameter  of  4 
egg  sacs  equals  7.9  (6. 9=8. 5).  Egg  sacs  oc- 
curred in  the  months  of  May,  September  and 
October. 

Distribution. — Known  from  the  high  alti- 
tude tributaries  of  coastal  rivers  on  the  West- 
ern slopes  of  the  Andes  in  Columbia,  Ecuador 
and  Peru  (Fig.  6). 

Hesydrus  caripito  new  species 
Figs.  6,  16-17 

Type. — Holotype  female,  Caripito,  Mona- 
gas,  Venezuela,  10°07'N,  63°06'W,  17  March 
1942,  New  York  Zoological  Society  1942 
Venezuela  Expedition  (AMNH). 

Etymology. — The  name  is  a noun  in  ap- 
position suggested  by  the  name  of  the  type 
locality. 

Diagnosis.^ — Distinctive  characters  of  the 
median  scape  of  the  female  epigynum  include 
being  very  narrowed  near  the  base,  emerging 
from  beneath  the  transverse  rim,  and  its  length 
being  greater  than  half  the  length  of  the  entire 
sclerotized  epigynal  plate. 

Description. — Female  (holotype):  Cara- 
pace medium  brown  with  indistinct  submar- 
ginal light  bands,  indistinct  medium  submar- 
ginal band,  black  in  eye  region,  length  4.9, 
width  5.0.  Sternum  light,  unmarked,  length 
2.9,  width  2.6;  labium  lighter  distally,  length 
1.00,  width  0.90.  Clypeus  unmarked,  height 
0.36,  width  2.40.  Anterior  eye  row  slightly  re- 
curved, eye  measurements  in  Table  1.  Chelic- 
erae  dark  brown,  unmarked,  three  promarginal 
teeth,  three  equidistant  retromarginal  teeth, 
subequal  in  size.  Legs  IV-II-I-III,  measure- 
ments in  Table  8.  Color  of  legs  medium 
brown,  marked  only  with  distinct  maculae  on 
dorsum  of  femora.  Abdomen  dorsal  pattern 
diffuse  and  distinct,  venter  light,  unmarked, 
length  5.5.  Median  scape  of  epigynum  (Figs. 


793 


Figures  16-21. — Female  genitalia  of  Hesydrus 
species,  16,  17.  H.  caripito;  16.  ventral  view,  17. 
dorsal  view;  18,  19.  H.  yacuiba;  18.  ventral  view, 
19.  dorsal  view;  20,  21.  H.  chanchamayo;  20.  ven- 
tral view,  21.  dorsal  view. 

16,  17)  narrowed  basally,  epigynal  plate  rel- 
atively short,  internal  structures  as  for  genus. 

Natural  history. — A note  with  the  collec- 
tion states:  “Under  and  around  smooth  stones 
in  ford  across  Caripe  R.  at  water  pump  sta- 
tion.” 

Material  examined  and  distribution.— 
Known  only  from  the  type  specimen  from 
Venezuela  (Fig.  6). 

Hesydrus  yacuiba  new  species 
Figs.  6,  18,  19 

Type  material. — Holotype  female,  Yacui- 
ba, Tarija,  Bolivia,  22°02'S,  63°4rw,  18  No- 
vember 1961,  Bachmann  (MACN). 

Etymology. — The  name  is  a noun  in  ap- 
position suggested  by  the  name  of  the  type 
locality. 


794 


THE  JOURNAL  OF  ARACHNOLOGY 


Table  7. — Leg  measurements  of  Hesydrus  canar 
female  in  mm. 


Leg  segment 

I 

II 

III 

IV 

Femur 

6.8 

8.3 

6.8 

7.8 

Tibia-patella 

8.9 

10.7 

8.0 

9.5 

Metatarsus 

6.8 

8.4 

6.5 

9.3 

Tarsus 

3.6 

4.1 

3.9 

5.1 

Total 

26.1 

32.5 

25.2 

31.7 

Diagnosis. — The  scape  of  the  female  epi- 
gynum  is  continuous  with  the  epigynal  plate, 
widest  midway  along  its  length  and  expanded 
slightly  at  the  posterior  end.  The  entire  ventral 
surface  is  rugose. 

Description. — Female  (holotype):  Cara- 
pace medium  brown  with  indistinct  submar- 
ginal light  bands,  white  hairs  on  clypeus,  eye 
region  and  submarginal  band,  black  in  eye  re- 
gion, length  4.7,  width  5.1.  Sternum  light,  un- 
marked, length  2.8,  width  2.8;  labium,  lighter 
distally,  length  1.00,  width  0.90.  Clypeus  un- 
marked but  with  white  hairs,  height  0.44, 
width  2.42.  Anterior  eye  row  slightly  re- 
curved, eye  measurements  in  Table  1.  Chelic- 
erae  medium,  unmarked,  covered  in  dense 
light  and  dark  hairs,  three  promarginal  teeth, 
three  equidistant  retromarginal  teeth,  subequal 
in  size.  Legs  II-IV-I-III,  measurements  in  Ta- 
ble 9.  Color  of  legs  medium  brown,  marked 
only  with  distinct  maculae  on  dorsum  of  fem- 
ora. Abdomen  dorsal  pattern  diffuse  and  dis- 
tinct, covered  in  dense  shiny  hairs,  venter 
light,  unmarked,  length  5.1.  Median  scape  of 
epigynum  (Figs.  18,  19)  rough-surfaced,  nar- 
rowed proximally  and  distally,  internal  struc- 
tures as  for  genus. 

Natural  history. — Unknown. 

Material  examined  and  distribution. — 
Known  only  from  the  type  specimen  from  Bo- 
livia (Fig.  6). 

Hesydrus  chanchamayo  new  species 
Figs.  6,  20,  21 

Type  material. — Holotype  female,  Chan- 
chamayo, Ica,  Peru,  13°42'S,  75°48'W,  7 Feb- 
ruary 1953,  Weyrauch  (CAS). 

Etymology. — The  name  is  a noun  in  ap- 
position suggested  by  the  name  of  the  type 
locality. 

Diagnosis. — The  rather  smooth  median 
scape  of  the  female  epigynum  has  its  contin- 
uous connection  with  the  epigynal  plate 


Table  8. — Leg  measurements  of  Hesydrus  cari- 
pito  female  in  mm. 


Leg  segment 

I 

II 

III 

IV 

Femur 

5.8 

7.2 

6.0 

6.8 

Tibia-patella 

7.8 

9.3 

7.2 

8.3 

Metatarsus 

5.9 

7.5 

5.7 

8.5 

Tarsus 

2.8 

3.5 

3.3 

4.2 

Total 

22.3 

27.5 

22.2 

27.8 

broader  than  the  width  of  the  scape  and  not 
separated  by  a rim.  The  internal  structures,  in- 
cluding the  short  spermathecum,  are  heavily 
sclerotized  and  robust.  This  specimen  is  larger 
(carapace  length  6.5)  than  any  other  female  in 
the  genus  thus  far  studied. 

Description. — Female  (Holotype):  Cara- 
pace medium  brown  with  indistinct  submar- 
ginal light  bands,  indistinct  medium  band, 
black  in  eye  region,  length  6.5,  width  6.7. 
Sternum  light,  unmarked,  length  1.90,  width 
1.70;  labium  length  1.24,  width  1.70,  lighter 
distally.  Clypeus  unmarked,  height  0.60, 
width  3.0.  Anterior  eye  row  slightly  recurved, 
eye  measurements  in  Table  1 . Chelicerae  dark 
brown,  unmarked,  three  promarginal  teeth, 
three  equidistant  retromarginal  teeth,  subequal 
in  size.  Legs  II-III-I  (IV  missing),  measure- 
ments in  Table  10.  Color  of  legs  medium 
brown,  marked  only  with  indistinct  maculae 
on  dorsum  of  femora.  Abdomen  dorsal  pattern 
diffuse  and  distinct,  venter  light,  unmarked, 
length  9.2.  Median  scape  of  epigynum  (Figs. 
20,  21)  of  relatively  uniform  width  and  not 
separated  from  epigynal  plane  by  a sclerotic 
rim,  internal  structures  as  for  genus  but  heavi- 
ly sclerotized  and  robust. 

Natural  history. — Unknown. 

Material  examined  and  distribution. — 
Known  only  from  the  type  specimen  from 
Peru.  There  are  at  least  three  localities  by  the 
same  name  in  the  highlands  of  Eastern  Peru 


Table  9. — Leg  measurements  of  Hesydrus  yacui- 
ba  female  in  mm. 


Leg  segment 

I 

II 

III 

IV 

Femur 

6.0 

7.6 

6.2 

6.9 

Tibia-patella 

7.9 

9.5 

7.3 

8.5 

Metatarsus 

5.6 

7.3 

5.8 

8.2 

Tarsus 

3.3 

3.7 

3.4 

4.0 

Total 

22.8 

28.1 

22.7 

27.6 

CARICO— REVISION  OF  GENUS  HESYDRUS 


795 


Table  10. — Leg  measurements  of  Hesydrus  chan- 
chamayo  female  in  mm.  Leg  IV  missing. 


Leg  segment 

I 

II 

III 

IV 

Femur 

7.9 

9.7 

8.2 

— 

Tibia-patella 

10.5 

12.4 

9.7 

— 

Metatarsus 

7.6 

9.6 

7.7 

— 

Tarsus 

4.3 

5.3 

4.9 

— 

Total 

30.0 

37.0 

30.5 

— 

and  east  of  the  Andean  continental  divide 
(Fig.  6).  Location  on  the  map  is  arbitrarily 
central  to  these  localities  and  intended  only  to 
show  a general  geographic  reference  to  the 
other  species. 

ACKNOWLEDGMENTS 

Thanks  are  extended  to  the  following  per- 
sons and  museums  for  the  loan  of  specimens: 
A.  Kury  (MNRJ),  C.F.  Ituarte  (MLP),  N.I. 
Platnick  (AMNH),  H.W.  Levi  (MCZ,  and  via 
MECN),  the  late  M.E.  Galiano  (MACN),  C. 
Griswold  and  D.  Ubick  (CAS),  C.  Rollard 
(MNHN),  P.  Sierwald  (FMNH),  L.W.  Buss 
(YPM)  and  C.E.  Valerio  (UCR).  I thank  also 
R.  Balm  (Rutgers  Univ.)  who  provided  valu- 
able information  on  the  itinerary  of  the  Yale 
1911  Peruvian  Expedition,  and  to  the  editors, 
two  anonymous  reviewers,  N.A.  Carico  and 
E.L.  Cruz  da  Silva  for  corrections  and  sug- 
gested improvements. 

LITERATURE  CITED 

Bonnet,  P.  1957.  Bibliographia  Araneorum.  Tou- 
louse 2(3):  1927-3026. 

Bonnet,  R 1959.  Bibliographia  Araneorum.  Tou- 
louse 2(5):423 1-5058. 

Brignoli,  P.M.  1983.  A Catalogue  of  the  Araneae 
Described  Between  1940  and  1981.  (P.  Merrett, 
ed.).Manchester  University  Press,  Manchester. 
Cambridge,  F.O.R-  1902.  Arachnida — Araneida  and 
Opiliones.  Pp.  313-424.  In  Biologia  Centrali- 
Americana,  Zoology,  vol.  2 (ED.  Godman  & O. 
Salvin,  eds.).  Taylor  and  Francis,  London. 
Cambridge,  F.O.R-  1903.  On  some  new  species  of 
spiders  belonging  to  the  families  Pisauridae  and 
Senoculidae;  with  characters  of  a new  genus. 
Proceedings  of  the  Zoological  Society  of.  Lon- 
don 1903:151-168. 

Cambridge,  O.R-  1896.  Arachnida.  Araneida.  Pp. 
161-224.  In  Biologia  Centrali- Americana,  Zool- 
ogy, vol.  1 (ED.  Godman  & O.  Salvin,  eds.). 
Taylor  and  Francis,  London, 

Cambridge,  O.R-.  1897.  Arachnida.  Araneida.  Pp. 
225-232.  In  Biologia  Centrali-Americana,  Zool- 


ogy, vol.  1 (ED.  Godman  & O.  Salvin,  eds.). 
Taylor  and  Francis,  London. 

Caporiacco,  L.  di  1947,  Diagnosi  preliminari  di 
specie  nuove  de  arachnidi  della  Guiana  Britan- 
nica.  Monitore  Zoologico  Italiano  56:20-24. 

Carico,  J.E.  1986.  Trechaleidae:  A “new”  Ameri- 
can spider  family.  Pp.  305.  In  Proceedings  of  the 
Ninth  International  Congress  of  Arachnology, 
Panama  1983.  (W.G.  Eberhard,  Y.D.  Lubin  & 
B.C.  Robinson,  eds.).  Smithsonian  Institution 
Press,  Washington,  D.C. 

Carico,  J.E.  1993.  Revision  of  the  genus  Trechalea 
Thorell  (Araneae,  Trechaleidae)  with  a review  of 
the  taxonomy  of  the  Trechaleidae  and  Pisauridae 
of  the  Western  Hemisphere.  Journal  of  Arach- 
nology 21:226-257. 

Carico,  J.E.  2005.  Descriptions  of  two  new  spider 
genera  of  Trechaleidae  (Araneae,  Lycosoidea) 
from  South  America.  Journal  of  Arachnology  33: 
795-810. 

Chamberlin,  R.V.  1916.  Results  of  the  Yale  Peru- 
vian Expedition  of  1911.  The  Arachnida.  Bulle- 
tin of  the  Museum  of  Comparative  Zoology  at 
Harvard  College,  Cambridge  60(6):  177-299. 

Koch,  C.L.  1848.  Die  Arachniden.  Fiintzehnter 
Band.  Niirnberg  210  pp. 

Lehtinen,  RT.  1967.  Classification  of  the  cribellate 
spiders  and  some  allied  families,  with  notes  on 
the  evolution  of  the  suborder  Araneomorpha. 
Annales  Zoologici  Fennici  4:199-468. 

Mello-Leitao,  C.F.  1931.  Arachnidos  do  Rio  Grande 
do  Sul.  Boletin  Biologico  Rio  de  Janeiro,  Sao 
Paulo  17:10-14. 

Mello-Leitao,  C.F.  1941.  Las  aranas  de  Cordoba,  La 
Rioja,  Calamarca,  Tucuman,  Salta  y Jujuy  colec- 
tadas  por  los  Profesores  Biraben.  Revista  del 
Museo  de  La  Plata  2:99-198. 

Platnick,  N.  1.  2004.  The  World  Spider  Catalog, 
Version  4.5.  American  Museum  of  Natural  His- 
tory, online  at  http://research.amnh.org/entomol- 
ogy/spiders/catalog/index.html 

Roewer,  C.F.  1954.  Katalog  der  Araneae,  vol.  2a. 
Institut  Royal  des  Sciences  Naturelles  de  Bel- 
gique, Bruxelles. 

Pocock,  R.I.  1900,  Myriapoda  and  Arachnida.  In 
Report  on  a collection  made  by  MM.  F.V. 
McConnell  and  J.J.  Quelch  at  Mount  Roriama  in 
British  Guiana.  Transaction  of  the  Linnean  So- 
ciety of  London.  Zoology  2:64-71. 

Sierwald,  P.  1989.  Morphology  and  ontogeny  of  fe- 
male copulatory  organs  in  American  Pisauridae 
with  special  reference  to  homologous  features 
(Arachnida:  Araneae),  Smithsonian  Contribu- 
tions to  Zoology  484:1-24. 

Sierwald,  R 1990.  Morphology  and  homologous 
features  in  the  male  palpal  organ  in  Pisauridae 
and  other  spider  families  with  notes  on  the  tax- 
onomy of  Pisauridae  (Arachnida:  Araneae). 


796 


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Nemouria,  Occasional  Papers  of  the  Delaware 
Museum  of  Natural  History  35:1-59. 

Sierwald,  P.  1993.  Revision  of  the  spider  genus 
Paradossenus,  with  notes  on  the  family  Trechal- 
eidae  and  the  subfamily  Rhoicininae  (Araneae: 
Lycosoidea).  Revue  Arachnologique  10(3):53- 
74. 

Simon,  E.  1898a.  Descriptions  d’arachnides  nou- 

veaux  des  families  des  Agelenidae,  Pisauridae, 


Lycosidae  et  Oxyopidae.  Annales  de  la  Societe 
Entomologique  de  Belgique,  Bruxelles  42:1-34. 
Simon,  E.  1898b.  Histoire  Naturelle  des  Araignees. 

Vol.  2(2),  pp.  193-380,  Encyclopedic  Roret,  Paris. 
Simon,  E.  1903.  Histoire  Naturelle  des  Araignees. 
Vol.  2(4),  pp.  699-1080,  Encyclopedic  Roret, 
Paris. 

Manuscript  received  8 December  2003,  revised  26 
August  2004. 


2005.  The  Journal  of  Arachnology  33:797-812 


DESCRIPTIONS  OF  TWO  NEW  SPIDER  GENERA 
OF  TRECHALEIDAE  (ARANEAE,  LYCOSOIDEA) 
FROM  SOUTH  AMERICA 


James  E.  Carico:  School  of  Science,  Lynchburg  College,  1501  Lakeside  Drive, 
Lynchburg,  Virginia  24501  USA.  E-mail:  carico@lynchburg.edu 

ABSTRACT.  Two  new  genera  in  the  spider  family  Trechaleidae,  Trechaleoides  and  Paratrechalea,  are 
described.  The  females  of  the  two  known  species  of  Trechaleoides,  T.  keyserlingi  (F.O.R-Cambridge)  (type 
species)  and  T.  biocellata  (Mello-Leitao)  are  redescribed  and  their  respective  males  are  described  for  the 
first  time;  both  are  transferred  from  Trechalea.  Two  additional  previously  described  species,  also  both 
transferred  from  Trechalea,  are  herein  placed  in  the  genus  Paratrechalea  are  redescribed  from  their  types, 
i.e.,  the  female  of  P.  ornata  (Mello-Leitao)  (type  species)  and  male  of  P.  wygodzinskyi  (Soares  & Ca- 
margo).  The  male  of  P.  ornata  is  described  for  the  first  time.  Four  new  species  of  Paratrechalea,  P. 
longigaster,  P.  galianoae,  and  P.  azul  from  females,  and  P.  saopaulo  from  males  and  females  are  de- 
scribed. The  immature  specimen  historically  regarded  as  the  holotype  of  Trechalea  longitarsis  (C.L.  Koch) 
and  regarded  as  a mistaken  identity,  is  an  unidentified  species  of  Trechaleoides.  The  female  holotype  of 
Trechalea  limai  Mello-Leitao  is  confirmed  to  be  lost  but  is  considered  to  be  a member  of  the  genus 
Paratrechalea  based  on  a study  of  the  original  description. 

Keywords!  Trechaleidae,  Trechaleoides,  Paratrechalea,  new  genera,  new  species 


Since  the  reintroduction  of  Simon’s  (1890) 
family  Trechaleidae  (Carico  1986),  its  validity 
has  been  confirmed  through  the  work  of  others 
(Sierwald  1990  [Trechaleidae  not  recognized 
but  acknowledged  as  a distinct  "'Trechalea 
genus-group”],  1993,  1997;  Coddington  & 
Levi  1991  [cladistic  analysis];  Griswold  1993 
[cladistic  analysis]).  Beginning  with  the  re- 
definition of  the  family  along  with  a revision 
of  its  type  genus  Trechalea  Thorell  1869  (Car- 
ico 1993),  the  goal  was  to  reveal  the  taxono- 
my of  the  remaining  members  of  this  unique 
family  through  revisions  of  the  included  gen- 
era. The  current  work  represents  an  additional 
step  towards  this  goal. 

In  this  work,  two  new  genera  are  erected  to 
include  species  (specified  below)  that  were 
previously  placed  into  Trechalea  and  addi- 
tionally to  contain  species  not  previously  de- 
scribed. In  the  process  of  defining  these  gen- 
era, references  are  made  to  characters  used  in 
the  previously  mentioned  study  of  the  genus 
Trechalea  in  order  to  further  develop  and  re- 
fine a set  of  characters  that  will  ultimately  dis- 
tinguish among  all  the  closely-related  mono- 
phyletic  genera  of  the  family  {sensu  Carico 
1993). 

These  two  new  genera  share  with  TrechaT 


ea,  and  no  other  genus  identified  in  the  family, 
the  characteristic  of  having  only  the  tarsi  flex- 
ible. However,  the  characteristics  of  the  gen- 
italia clearly  distinguish  these  new  genera 
from  each  other  as  well  as  from  Trechalea.  To 
distinguish  the  males  from  those  of  Trechalea, 
the  median  apophysis  of  the  palpal  bulb  (Fig. 
1)  has  a less  complex  ventral  division  in  the 
former  species.  Additional  features  of  this 
structure,  detailed  below,  will  distinguish  be- 
tween the  new  genera.  In  females  of  these  new 
genera,  a typical  middle  field  of  the  female 
epigynum  (Figs.  6,  20),  present  in  Trechalea 
is  absent;  instead,  there  is  a pronounced  scape. 
Internally  the  notable  differences  with  Tre- 
chalea are  that  the  spermathecae  are  free  and 
that  pairs  of  diverticula  (rather  than  only  one) 
arise  from  a common  chamber.  Additional  de- 
tails of  the  external  and  internal  structures  of 
the  female  genitalia,  as  reported  below,  will 
distinguish  between  the  new  genera. 

Little  is  known  about  the  biology  of  rep- 
resentatives of  these  genera.  However,  there 
are  indications  from  fragmentary  evidence 
that  these  genera  share  a feature  with  Tre- 
chalea, i.e.,  they  apparently  occupy  a semi- 
aquatic  habitat  based  on  references  to  place 
names  of  streams  on  the  collection  labels.  The 


797 


798 


THE  JOURNAL  OF  ARACHNOLOGY 


Figures  1,  2. — Diagrammatic  genitalia  of  Tre~ 
chaleoides  and  Paratrechalea.  1.  right  palpus,  ven- 
tral view;  2.  internal  structures  of  female  genitalia. 
(Abbreviations  explained  in  text) 


unique  structure  of  the  egg  sac  and  manner  of 
carrying  the  spiderlings  on  it  while  attached 
to  the  spinnerets,  first  described  for  Trechalea 
extensa  (O.R-Cambridge)  by  Berkum  (1982), 
is  apparently  also  confirmed  as  a characteristic 
of  the  family.  This  conclusion  derives  from  an 
assumption  that  the  details  of  the  egg  sac’s 
structure,  as  described  by  Carico  (1993)  for 
Trechalea  and  presumed  to  be  a family  trait, 
is  consistent  with  the  structure  of  egg  sacs 
found  with  specimens  of  the  new  genera. 

The  distributions  of  these  two  genera  over- 
lap in  a region  of  South  America  between 
15°S  and  35°S  latitude,  an  area  which  includes 
regions  of  southern  Brazil,  northern  Argenti- 
na, and  Paraguay  and  is  locally  known  as  the 
“Cone  Sul”  (Southern  Cone).  Therefore,  it 
appears  that  their  distribution  is  primarily  re- 
lated to  streams  of  the  lower  Rio  la  Plata  river 
basin  and  the  several  smaller  coastal  streams. 
From  a preliminary  overview  of  the  distribu- 
tions of  all  trechaleid  genera  in  South  Amer- 
ica, the  two  new  genera  considered  herein 
may  be  the  predominant  representatives  of  the 
family  in  this  region.  Two  species  of  Mello- 
Leitao  from  this  region,  Trechalea  limai  Mel- 
lo-Leitao  1941  and  T.  syntrechaleoides  MqWo- 
Leitao  1941,  whose  types  were  previously 
unobtainable  from  the  Museu  Nacional,  Rio 
de  Janeiro  during  a previous  study  (Carico 
1993)  were  never  the  less  regarded  to  be  mis- 
placed in  Trechalea.  Recently,  access  to  these 
specimens  was  obtained  resulting  in  a conclu- 
sion that  T.  limai  is  lost  and  probably  de- 
stroyed (A.B.  Kury  pers.  comm.).  Careful 


Figure  3. — Distribution  of  species  of  Trechalea- 
ides. 


analysis  of  the  description  of  T.  limai  reveals 
that  it  is  a species  nomen  dubium  in  the  genus 
Paratrechalea.  Trechalea  syntrechaleoides, 
however,  is  not  congeneric  with  the  genera  in 
this  report,  and  its  status  will  be  treated  else- 
where in  a separate  generic  revision. 

The  nomenclature  of  the  genitalia  and  other 
anatomical  features  follow  Carico  (1993  [gen- 
italic  terminology  after  Sierwald  1989, 
1990]).  Because  of  its  rigidity  and  relative  re- 
sistance to  distortion,  carapace  length  is  em- 
phasized as  an  index  of  body  size,  particularly 
in  discussions  of  variation.  Measurements  and 
scales  are  in  millimeters. 

Specimens  examined  during  this  study  are 
lodged  in  the  following  museums:  Museu  de 
Zoologica  da  Universidad  de  Sao  Paulo 
(MZUSP);  Museum  of  Comparative  Zoology, 
Harvard  (MCZ);  Natural  History  Museum, 
London  (BMNH);  Museu  de  Ciencias  Natu- 
rais,  Porto  Alegre  (MCN);  Museo  Argentina 
de  Ciencias  Naturales,  Buenos  Aires 
(MACN);  Museo  Nacional  de  Historia  Natu- 
ral, Montevideo  (MNHN);  Museo  de  la  Univ- 
ersidad Nacional  de  la  Plata  (MLP);  Museu 
Nacional,  Rio  de  Janeiro  (MNRJ);  Universi- 
dade  Federal  do  Rio  Grande  do  Sul,  Porto 
Alegre  (UFRGS),  and  Peabody  Museum  of 
Natural  History,  New  Haven  (PMNH). 

Trechaleoides  new  genus 

Type  species. — Trechalea  keyserlingi 

FO.P-Cambridge  1903. 

Etymology. — The  feminine  generic  name 
indicates  its  relationship  with  the  genus  Tre- 
chalea. 

Diagnosis. — Trechaleoides  can  be  distin- 
guished from  all  other  described  genera  of 


CARICO— TWO  NEW  GENERA  OF  TRECHALEIDAE 


799 


Trechaleidae  (sensu  Carico  1993)  by  a com- 
bination of  characters.  In  the  male  palpus,  the 
ventral  division  (vd)  of  the  median  apophysis 
(ma)  is  a simple,  small,  rounded  projection 
rather  than  angular,  and  the  guide  (g)  is  con- 
spicuous, more  slender  and  tapered  than  in 
Trechalea  and  Hesydrus.  The  ventral  division 
is  also  simplified  and  rounded  in  Paratre- 
chalea  but  it  is  much  expanded  there.  The  epi- 
gynum  is  distinguished  by  a pair  of  small  pos- 
terio-lateral  projections  separated  by  sutures 
from  the  middle  anterior  field,  and  by  details 
of  the  internal  female  genitalia  including  a 
posterio-median  hood-like  chamber.  A small 
retromarginal  tooth  is  adjacent  to  the  most 
proximal  tooth  and  offset  into  the  fang  furrow. 
These  are  relatively  large  spiders  with  the  car- 
apace length  ranging  from  b.l-ll.O. 

Description. — Carapace  moderately  low, 
cephalic  area  not  distinct,  AE  row  straight  or 
slightly  recurved.  Each  basal  segment  of  male 
chelicera  not  swollen  anteriorly  and  without  a 
lateral  carina;  promarginal  teeth  three  with 
center  one  largest,  five  retromarginal  teeth 
(occasionally  four)  with  a smaller  tooth  offset 
between  the  proximal  two  into  the  fang  fur- 
row. Leg  lengths  variable  but  III  always  short- 
est while  others  often  subequal,  only  tarsi 
flexible,  all  claws  dentate,  paired  ventral  ma- 
crosetae  on  tibia. 

Male  palpal  bulb  (Fig.  1)  median  apophysis 
(ma)  with  distal,  curved  sickle-shaped  dorsal 
division  (dd)  narrow,  tapered,  with  tip  con- 
spicuous, and  directed  ventrad,  a small,  round- 
ed ventral  division  (vd)  of  variable  size  but 
shape  distinctive  for  each  species;  retrolateral 
tibial  apophysis  (rta)  arising  distally  and  lat- 
erally from  near  the  ventro-distal  rim  (vr)  with 
ectal  division  (ecd)  divided  into  two  subdivi- 
sions, dorsal  one  longer  and  curved  and  ental 
division  (end)  partly  surrounded  by  ventral 
cymbio-tibial  membrane  (vcm);  tibial  ventral 
rim  (vr)  of  ventral  protuberance  (vp)  folded 
over  to  create  a particularly  deep  depression 
in  the  ventral  cymbio-tibial  membrane  (vcm). 
The  epigynum  (Fig.  6)  is  a slightly  convex, 
nearly  circular  anterior  field  (af)  with  pair  of 
small  projections  at  posterior  margin  whose 
long  axes  tend  to  transverse,  middle  field  (mf) 
absent;  internally  (Figs.  2,  7)  the  stalked  sper- 
mathecum  head  (hs)  large  and  not  attached  to 
other  components;  a pair  of  diverticula  arising 
from  a large  common  chamber  (probably  en- 
larged portion  of  copulatory  duct),  both  cop- 


Figures  4-7. — Genitalia  of  Trechaleoides  keyser- 
lingi.  4,  5.  right  palpus;  4.  ventral  view,  5.  retrola- 
teral view;  6,  7.  female  genitalia;  6.  ventral  view, 
7.  dorsal  view,  af  = anterior  field,  cd  = copulatory 
duct,  fd  = fertilization  duct,  h = hood,  hs  = head 
of  spermathecum,  mf  = middle  field. 

ulatory  duct  (cd)  and  fertilization  duct  (fd) 
arising  from  this  common  chamber;  large, 
hood-shaped  structure  (h)  located  posterio- 
medially. 

Natural  history. — Egg  sacs  show  the  basic 
trechaleid  construction  as  described  for  Tre- 
chalea (Carico  1993,  fig,  6),  i.e.,  a flattened 
disc  with  a peripheral  “skirt”.  The  aquatic 
habitat  preference  is  suggested  by  the  refer- 
ence to  “Arroyo”  or  “Rio”  on  some  collec- 
tion labels  and  is  consistent  with  what  is 
known  of  other  genera,  i.e.;  Trechalea  (Carico 
1993),  Hesydrus  (pers.  obs.),  and  Paradossen- 
us  F.O.R -Cambridge  1903  (Brescovit  et  al. 
2000). 

Distribution. — Found  in  South  America 
southward  from  the  Brazilian  state  of  Minas 
Gerais  into  Paraguay,  northern  Argentina,  and 

Uruguay  (Fig.  3). 

Remarks. — The  specimen  mistakenly  re- 
garded by  FO.P.-Cambridge  (1903)  as  the  type 
of  Trechalea  longitarsis  is  actually  an  imma- 
ture female  of  this  new  genus  (Carico  1993) 
as  indicated  by  the  unique  characters  of  retro- 
marginal teeth  of  the  chelicerae,  particularly 
by  the  presence  of  a small  tooth  placed  into 
the  fang  furrow  between  the  proximal  two 


800 


THE  JOURNAL  OF  ARACHNOLOGY 


larger  teeth.  Although  the  typical  number  of 
retromarginal  teeth  is  five,  there  are  specimens 
which  have  four  on  one  of  the  chelicera.  The 
locality  label  with  that  specimen,  “Brazil,”  is 
also  consistent  with  the  location  of  this  genus. 
Because  of  immaturity  and  the  general  poor 
condition  of  this  specimen,  it  cannot  be  con- 
fidently attributed  to  any  of  the  species  rec- 
ognized in  this  work. 

Trechaleoides  keyserlingi 
(EO.P.-Cambridge  1903) 

Figs.  3-7 

Trechalea  keyserlingi  EO.P.-Cambridge  1903:163, 
plate  15,  figs.  1,  2;  Roewer  1954:142;  Bonnet 
1959:4679;  Petrunkevitch  1911:549;  Carico 
1993:237  (non  Trechalea)',  Platnick  2004. 

Type  material. — Holotype  female,  Rio 
Grande  do  Sul,  Brazil,  Keyserling  (BMNH, 
examined). 

Material  examined. — ARGENTINA:  Tu- 
cumdn:  San  Pedro  de  Colalao,  26°22'S, 
65°57'W,  March  1967,  A.  Barrio,  1 $ 

(MACN);  Misiones:  Puali,  27°00'S,  55°00'W, 
Sciap,  J.  Carlo?,  1 9 (MACN).  BRAZIL:  Rio 
Grande  do  Sul:  Sao  Jeronimo-Fazenda  Casa 
Branca,  29°58'S,  51°43'W,  20-21  May  1982, 
J.E.  Hennig,  1 c3  (MCN  #10373);  Sao  Leo- 
poldo,  29°46'S,  51°09'W,  25  March  1983,  C.J. 
Becker,  1 (3  (MCN  #11517);  no  locality,  28 
October  1981,  A. A.  Lise,  1 9 (MCN  #9955); 
state  unknown,  22  November  1987,  A.D. 
Brescovit,  2 9 (MCN  #17222).  PARAGUAY: 
near  Pedro  Juan  Caballero,  23°00'S,  56°00'W, 
25-27  November  1956,  C.J.D.  Brown,  1 9 
(MCZ).  URUGUAY:  Salto:  Rio  Arapey, 
30°55'S,  57°49'W,  13  December  1954,  collec- 
tor unknown,  1 9 (MNHN). 

Diagnosis. — Females  of  this  species  are 
distinguished  by  the  pair  of  posterior  protu- 
berances of  the  epigynum  which  are  smooth 
and  not  folded,  and  males  by  the  palpal  tibia 
which  is  approximately  half  the  length  of  the 
cymbium. 

Description. — Male  (Sao  Jeronimo,  Rio 
Grande  do  Sul,  Brazil):  Carapace  medium 
brown  with  wide  submarginal  light  bands, 
dark  marginal  bands  widening  posteriorly, 
black  in  eye  region,  length  7,9,  width  7.0, 
Sternum  light,  with  median  dusky  band  on  an- 
terior two-thirds,  length  4.2,  width  3.7;  labium 
reddish-brown,  lighter  at  distal  margin,  length 
1.57,  width  1.30.  Clypeus  height  0.88,  width 
3.20.  Anterior  eye  row  slightly  recurved,  a 


cluster  of  bristles  posterior  to  each  PLE,  eye 
measurements  in  Table  1 . Cheliceral  faces  me- 
dium reddish-brown,  each  with  a dark  longi- 
tudinal band  clothed  with  scattered  light  and 
dark  hairs,  five  retromarginal  teeth,  subequal 
in  size  except  smaller  fifth  one  between  first 
and  third  offset  into  the  fang  groove.  Legs  II- 
IV-I-III,  measurements  in  Table  2,  ventral  ma- 
crosetae  pairs  on  tibiae  1-4,  II-4,  III-3,  IV-3. 
Color  of  legs  medium  brown,  marked  only 
with  faint  maculae  on  dorsum  of  each  femur. 
Abdomen  hairless  above  (probably  rubbed) 
with  distinct  dorsal  pattern,  length  8.0.  Palpus 
(Figs.  4,  5)  tibia  length  approximately  half 
length  of  cymbium,  bulb  t and  st  prominent, 
vd  of  ma  flattened,  moderate-sized,  rounded 
in  outline,  and  not  covering  the  dd,  ecd  of  rta 
prominent  and  angular. 

Female  (holotype):  Carapace  light  with 
submarginal  bands,  broad  dark  median  band 
divided  longitudinally  by  a narrow  median 
band  widened  between  eyes  and  thoracic 
grooves,  length  9.0,  width  8.2.  Sternum  un- 
marked, length  5.0,  width  4.2;  labium  length 
1.65,  width  1.60.  Clypeus  dark  medially  and 
light  laterally,  height  1.11,  width  2.84.  Ante- 
rior eye  row  slightly  recurved,  eye  measure- 
ments in  Table  1 . Chelicerae  dark  and  clothed 
with  light  hair,  three  promarginal  teeth,  five 
retromarginal  teeth  on  right  side  and  five  on 
left,  the  smallest  ones  next  to  the  most  prox- 
imal teeth.  Legs  IV-II-LIII,  measurements  in 
Table  3,  femora  with  irregular  dark  maculae, 
all  other  segments  dark;  tarsi  flexible,  spines 
not  longer  than  one-third  of  respective  seg- 
ment. Abdomen  dark  median  band  with  dis- 
tinct lateral  indentations  in  the  posterior  third, 
sides  light  with  scattered  maculae,  venter  light 
length  11.0.  Pair  of  smooth  projections  at  pos- 
terior margin  of  epigynum  (Figs.  6,  7),  inter- 
nal structures  as  for  genus. 

Variation. — Carapace  length  of  males  av- 
erage 7.17  (6. 6-7. 9,  n = 3)  and  of  females 
7.13  (6. 1-8.8,  n = 10).  Dorsal  pattern  similar 
in  both  sexes  with  little  variation  noted. 

Natural  history. — An  egg  sac  from  near 
Pedro  Juan  Caballero,  Paraguay,  collected  late 
November,  measured  15.0. 

Distribution.— Northern  Argentina,  eastern 
tributaries  of  Rio  Parana  in  southern  Paraguay 
and  southern  Brazil.  Also,  in  some  coastal 
drainages  of  southern  Brazil  (Fig.  3). 

Remarks. — According  to  FO.P.-Cambridge 
(1903),  the  type  specimen  was  originally  iden- 


CARICO— TWO  NEW  GENERA  OF  TRECHALEIDAE 


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THE  JOURNAL  OF  ARACHNOLOGY 


Table  2. — Leg  measurements  of  Trechaleoides 
keyserlingi  male  in  mm. 


Leg  segment 

I 

II 

III 

IV 

Femur 

9.5 

9.75 

7.5 

9.5 

Tibia-patella 

13.0 

13.0 

9.5 

12.3 

Metatarsus 

10.3 

10.4 

7.8 

11.6 

Tarsus 

7.4 

8.1 

4.2 

7.4 

Total 

40.2 

41.25 

29.0 

40.8 

tified  by  Keyserling  (1891)  as  Trechalea  Ion- 
gitarsis  (C.L.  Koch  1848).  However,  the  for= 
mer  recognized  that  the  five  retromarginal 
teeth  of  the  chelicera  and  the  shape  of  the  epi- 
gynum  clearly  distinguish  this  species  from 
the  Koch  species.  It  is  these  same  characters, 
which,  among  others,  also  define  the  new  ge- 
nus, Trechaleoides. 

Trechaleoides  biocellata  (Mello-Leitao  1926) 
NEW  COMBINATION 
Figs.  3,  8-12 

Trechalea  biocellata  Mello-Leitao  1926:3;  Roewer 
1954:142;  Bonnet  1959:4678;  Platnick  2004. 

Type  material. — Holotype  female,  Santa 
Catharina  e Petropolis,  Rio  de  Janeiro,  Brazil, 
Fr.  Thomaz  Borgmeyer  (MNRJ,  presumed 
lost,  not  examined) 

Material  examined. — ARGENTINA:  Mi- 

siones:  Paulitz(?),  27°00'S,  55°00'W,  1954, 
Schiapelli  & De  Carlo?,  1 6 (MACN);  no  lo- 
cality, November  1954,  Scial.  Corio?,  1 6 
(MACN).  BRAZIL:  Rio  Grande  do  Sul:  Itu- 
aba-Arroio  do  Tigre,  29°20'S,  53°06'W,  11 
April  1978,  A.A.  Lise,  1 d (MCN  #7928); 
same  locality,  12  April  1978,  A.A.  Lise,  1 9 
(MCN  #7978);  same  locality,  12  April  1978, 
C.J.  Becker,  19,1  juvenile  (MCN  #7904); 
same  locality,  17  April  1978,  A.A.  Lise,  1 6, 
5 juveniles  (MCN  #7978);  Estreito  Augusto 
Cesar,  Marcelino  Ramos,  3 February,  1990,  C. 
Martinazzo,  1 d,  1 juvenile  (MCN  #19532); 


Table  3. — Leg  measurements  of  Trechaleoides 

keyserlingi  female  in  mm. 


Leg  segment 

I 

II 

III 

IV 

Femur 

11.1 

11.6 

9.5 

11.6 

Tibia-patella 

15.0 

14.8 

11.0 

14.2 

Metatarsus 

10.8 

10.1 

9.0 

13.3 

Tarsus 

8.0 

8.1 

5.0 

8.5 

Total 

44.9 

44.6 

34.5 

47.6 

Figures  8-11. — Genitalia  of  Trechaleoides  bio- 
cellata. 8,  9.  right  palpus;  8.  ventral  view,  9.  retro- 
lateral  view;  10,  11.  female  genitalia;  10.  ventral 
view,  11.  dorsal  view. 

Viamao,  near  Porto  Alegre,  30°05'S,  5r02'W, 
22  March  1975,  A.A.  Lise,  1 S (MCN 
#02537);  Garruchos  Sao  Borja,  28°irS, 
55°39'W,  10  December  1975,  A.A.  Lise,  3 6, 
3 9 (MCN  #3245);  Arroio  do  Meio,  Linha 
Alegre,  9 January  1985,  A.A.  Lise,  1 S (MCN 
#13019).  PARAGUAY:  near  Piribebuy,  Ar- 
royo Pirareta,  25°29'S,  57°03'W,  13  December 
1956,  C.J.D.  Brown,  1 9 (MCZ). 

Diagnosis. — This  species  is  distinguished 
by  characteristics  of  the  genitalia.  The  pair  of 
posterior  projections  of  the  epigynum  are 
folded  and  not  smooth,  and  the  palpal  tibia  is 
approximately  equal  to  the  length  of  the  cym- 
bium. 


Table  4. — Leg  measurements  of  Trechaleoides 
biocellata  male  in  mm. 


Leg  segment 

I 

II 

III 

IV 

Femur 

11.9 

12.6 

9.3 

12.1 

Tibia-patella 

16.5 

16.7 

11.5 

15.1 

Metatarsus 

12.7 

14.3 

9.0 

14.3 

Tarsus 

9.7 

9.0 

5.2 

9.6 

Total 

50.8 

52.6 

35.0 

51.1 

CARICO— -TWO  NEW  GENERA  OF  TRECHALEIDAE 


803 


Table  5. — Leg  measurements  of  Trechaleoides 
biocellata  female  in  mm.  Leg  I missing. 


Leg  segment 

I 

II 

III 

IV 

Femur 

— 

13.5 

10.5 

13.2 

Tibia-patella 

— 

17.0 

12.6 

15.3 

Metatarsus 

— 

13.0 

10.8 

16.7 

Tarsus 

— 

8.5 

6.2 

9.6 

Total 

— 

52.0 

40.1 

54.8 

Description, — Male  (Misiones,  Argentina): 
Carapace  medium  brown  with  wide  submar- 
ginal light  bands,  marginal  bands  widening 
posteriorly,  black  in  eye  region,  length  7.9, 
width  7.0.  Sternum  light,  unmarked,  length 
4.2,  width  3,7;  labium  reddish-brown,  lighter 
at  distal  margin,  length  1.57,  width  1.30. 
Ciypeus  height  0.88,  width  3.20.  Anterior  eye 
row  slightly  recurved,  a cluster  of  bristles  pos- 
terior to  each  PLE,  eye  measurements  in  Table 
1.  Cheliceral  faces  medium  reddish-brown, 
each  with  a dark  longitudinal  band  clothed 
with  scattered  light  and  dark  hairs,  five  retro- 
marginal  teeth,  subequal  in  size  except  smaller 
fifth  one  between  first  and  third  offset  into  the 
fang  groove.  Legs  II-IV-I~III,  measurements  in 
Table  4,  ventral  macrosetae  pairs  on  tibiae  are 

I- 4,  II-4,  III-3,  IV-3.  Color  of  legs  medium 
brown,  marked  only  with  faint  maculae  on 
dorsum  of  each  femur.  Abdomen  hairless 
above  (probably  rubbed),  with  distinct  dorsal 
pattern,  length  8.0.  Palpus  (Figs.  8,  9)  tibia 
length  approximately  equal  to  length  of  cym- 
bium,  bulb  t and  st  prominent,  vd  of  ma  small, 
flattened,  rounded  in  outline,  and  not  covering 
dd,  ecd  of  rta  prominent  and  angular. 

Female  (Paineiras,  Brazil  [substitute  for 
holotype,  see  note  below]):  Carapace  (Fig.  12) 
light  brown  with  irregular  submargieal  lighter 
bands;  irregular  light  marks  between  PE  and 
thoracic  groove,  length  8.5,  width  7.8.  Ster- 
num light  yellow,  unmarked,  length  4.5,  width 
3.6;  labium  light  brown,  unmarked,  length 
1.80,  width  1.60.  Ciypeus  with  faint  darker 
marks  beneath  PLE  and  AE,  height  0.86, 
width  3.5.  Anterior  eye  row  straight,  eye  mea- 
surements in  Table  1 . Chelicerae  reddish 
brown,  five  retromarginal  teeth,  subequal  in 
size  with  smallest  one  subproximal.  Legs:  IV- 

II- II  (I  missing),  measurem.e]nts  in  Table  5, 
yellow  with  irregular  and  indistinct  darker 
marks  on  dorsal  surfaces  of  femora,  tibiae. 
Abdomen  mid-dorsal  dark  band  distinct  with 


light  marks  at  anterior  and  lateral  edges;  sides 
with  irregular,  parallel  dark  marks,  venter  un- 
marked, length  8.6.  Pair  of  protuberances  at 
posterior  margin  of  epigynum  (Figs.  10,  11) 
with  irregular  folds  and  creases,  internal  struc- 
tures as  for  genus. 

Variation. — -Carapace  length  of  males  av- 
erage 7.72  (7. 2-8. 6,  « — 13)  and  of  females 
9.2  (7.2-11.0,  n = 6).  Average  abdominal 
lengths  equal  0.93  of  carapace  lengths  in 
males  and  0.97  in  females.  Dorsal  pattern  sim- 
ilar in  both  sexes  with  little  variation  noted. 

Natural  history. — See  generic  description. 

Distribution.- — -Eastern  tributaries  of  Rio 
Parana  in  northern  Argentina,  southern  Para- 
guay, and  southern  Brazil.  Also  some  coastal 
drainages  of  southern  Brazil  (Fig.  3). 

Remarks.-— The  female  described  above 
from  the  Museu  Nacioeal  do  Rio  de  Janeiro, 
was  identified  by  Mello-Leitao  as  Trechalea 
biocellata  and  is  assumed  to  be  the  name 
bearer  for  the  purposes  of  this  report.  I am 
reluctant  to  designate  it  as  a eeotype  in  view 
of  the  possibilities  that  the  original  holotype 
might  be  found  in  the  future. 

Paratrechalea  new  genus 

Type  species.- — Trechalea  ornata  Mello- 
Leitao  1943. 

Etymology.— The  feminine  Latin  generic 
name  indicates  the  relationship  with  the  genus 
Trechalea. 

Paratrechalea  can  be  distin- 
guished from  all  other  described  genera  of 
Trechaleidae  (sensu  Carico  1993)  by  a com- 
bination of  characters.  In  the  male  palpus  the 
ventral  division  (vd)  of  the  mediae  apophysis 
(ma)  is  flattened,  rounded  in  outline,  and 
greatly  expanded  to  mostly  obstruct  the  dorsal 
division  including  its  guide  (g).  The  epigynum 
is  distinguished  by  the  presence  of  a conspic- 
uous external  posterio-mediae  scape.  These 
are  moderate- sized  spiders  with  the  carapace 
length  ranging  3. 3-3. 8 except  for  the  male  of 
P.  wygodzinskyi  which  is  5.2. 

Description,— Carapace  moderately  low, 
cephalic  area  relatively  distinct,  AE  row 
straight.  Each  basal  segment  of  male  chelicera 
swollen  anteriorly  with  lateral  carina  on  distal 
half  (except  P.  wygodzinskyi);  three  promar- 
ginal teeth  with  center  one  largest,  three,  four 
or  five  retromarginal  teeth,  variable  in  size  and 
ieterdistaece.  Leg  lengths  variable  but  III  al- 


804 


THE  JOURNAL  OF  ARACHNOLOGY 


CARICO— TWO  NEW  GENERA  OF  TRECHALEIDAE 


805 


ways  shortest  while  others  often  subequal, 

only  tarsi  flexible,  all  claws  dentate. 

Male  palpal  bulb  (Fig.  1)  with  tip  of  distal, 
curved  sickle-shaped  dorsal  division  (dd)  of 
median  apophysis  (ma)  directed  ventrad  and 
obscured  by  broad,  rounded  ventral  division 
(vd);  retrolateral  tibial  apophysis  (rta)  arising 
distally  and  laterally  from  near  the  ventrod- 
istal  rim  (vr)  with  ectal  division  (ecd)  curved 
and  ental  division  (end)  partly  surrounded  by 
ventral  cymbio-tibial  membrane  (vcm);  tibial 
ventral  rim  (vr)  of  ventral  protuberance  (vp) 
folded  over  to  create  deep  depression  in  ven- 
tral cymbio-tibial  membrane  (vcm).  Nearly 
circular  anterior  field  (af)  of  epigynum  slight- 
ly convex,  a single  prominent  posterio-median 
scape;  dorsal  aspect,  on  each  side  of  the  fe- 
male genitalia  (Fig.  21)  with  large,  free, 
stalked,  spermathecal  head  (hs);  two  divertic- 
ula arising  from  large  common  chamber 
(probably  an  extension  of  copulatory  duct); 
large,  hood-shaped  structure  (h)  located  pos- 
terio-medially;  copulatory  duct  (cd)  and  fer- 
tilization duct  (fd)  arising  from  common 
chamber. 

Natural  history. — The  aquatic  habitat  pref- 
erence is  suggested  by  the  reference  to  “Ar- 
royo” or  “Rio”  on  some  collection  labels  and 
is  consistent  with  what  is  known  of  other  tre- 
chaleid  genera. 

Distribution. — Found  in  South  America 

southward  from  the  Brazilian  state  of  Mato 
Grosso  through  northern  Argentina  into  Uru- 
guay (Fig.  17). 

Nomen  dubium. — Unlike  many  of  Mello- 

Leitao’s  species  descriptions,  the  one  for  T. 
limai  Mello-Leitao  1941  was  relatively  com- 
plete and  was  accompanied  by  drawings  of  the 
habitus  and  epigynum.  Unfortunately  the  epi- 
gynum drawing  was  not  diagnosable  at  either 
the  generic  or  species  level.  The  habitus  was 
helpful  however  and  when  combined  with  the 
description,  it  is  possible  to  determine  the  ge- 
nus with  some  confidence.  Specifically  this 
decision  is  based  upon  body  length,  number 
of  macrosetae  pairs  on  the  tibiae,  relative 
length  of  the  legs,  and  geographic  location. 
Therefore,  I believe  that  T.  limai  is  a member 


Figure  17. — Distribution  of  species  of  Paratre- 
chalea. 


of  the  genus  Paratrechalea.  Because  of  the 
inability  to  determine  the  relationship  of  this 
species  to  others  in  the  genus,  I have  deter- 
mined that  it  should  remain  as  a nomen  du- 
bium until  and  if  the  holotype  is  ever  recov- 
ered. 

Paratrechalea  ornata  (Mello-Leitao  1943) 
NEW  COMBINATION 
Figs.  13,  14,  17-21 

Trechalea  ornata  Mello-Leitao  1943:107,  fig.  7; 

Roewer  1954:143;  Platnick  2004. 

Type  material. — -Holotype  female,  Bosque 
Alegre,  Cordoba,  Argentina,  31°35'S, 
64°34'W,  January-March  1940,  M.  Biraben 
(MLP  #15690,  examined). 

Material  examined.— ARGENTINA:  Mi- 
siones:  Isla  Maria,  27°00'S,  55°00'W,  Novem- 
ber 1954,  Schiapella?,  1 $ (MACN);  Cordo- 
ba: Santa  Rosa,  Dept,  de  Calamuchita, 


Figures  12-16.- — Dorsal  patterns  of  species  of  Trechaleoides  and  Paratrechalea.  12.  T.  biocellata  fe- 
male; 13 — 16.  Paratrechalea:  13,  14.  P.  ornata:  13.  male;  14.  female;  15.  P.  longigaster  female;  16.  P. 

galianoae  female. 


806 


THE  JOURNAL  OF  ARACHNOLOGY 


Figures  18-21. — Genitalia  of  Paratrechalea  or- 
nata.  18,  19.  right  palpus;  18.  ventral  view,  19.  re- 
trolateral  view;  20,  21.  female  genitalia;  20.  ventral 
view,  21.  dorsal  view,  af  = anterior  field,  cd  = cop- 
ulatory  duct,  fd  = fertilization  duct,  hs  = head  of 
spermathecum. 

32°04'S,  64°33'W,  February  1952,  M.J.  Viana, 
2 9 (MACN);  Buenos  Aires:  Arroyo  Pararito, 
Delta  del  Parana,  Partido  do  Tigre,  34°25'S, 
58°35'W,  29  November  1953,  A.O.  Bachman, 

1 d,  2 9,7  juveniles  (MACN);  same  locality, 
October  1954,  A.O.  Bachman,  3 9 (MACN); 
same  locality,  1 November  1953,  A.O.  Bach- 
man, 3 d,  6 9,4  juveniles  (MACN);  same 
locality,  26  December  1953,  A.O.  Bachman, 

2 9 (MACN),  8 March  1953,  A.O.  Bachman, 
1 9, (MACN);  same  locality,  18  October  1953, 
A.O.  Bachman,  2 d,  7 juveniles  (MACN);  Ar- 
royo, Carancho,  Delta  del  Parana,  36°12'S, 
58°10'W,  6 January  1952,  A.O.  Bachman,  3 
9 (MACN);  Arroyo  Correa,  near  San  Antonio 
River,  Delta  del  Parana,  Partido  de  Tigre, 
34°25'S,  58°35'W,  2 March  1951,  A.O.  Bach- 
man, 1 9 (MACN);  Arroyo  de  las  Moras,  Del- 
ta del  Parana,  Partido  de  Tigre,  34°25'S, 
58°35'W,  3 February  1955,  A.O.  Bachman,  3 
9 (MACN).  BRAZIL:  Parana:  Rio  Bronco 
do  Sul,  4°10'N,  60°47'W,  16  April  1987,  A.D. 
Brescovit,  1 9 (MCN  #17153);  Rio  Grande 
do  Sul:  Caxias  do  Sul,  Aqua  Azul,  27°23'S, 
52°25'W,  15  January  1975,  A.A.  Lise,  1 9 
(MCN).  URUGUAY:  Treinta-y-Tres:  Arroyo 
Verbal,  33°19'S,  54°42'W,  7 January  1963, 


Table  6. — Leg  measurements  of  Paratrechalea 
ornata  male  in  mm. 


Leg  segment 

I 

II 

III 

IV 

Femur 

4.0 

4.2 

3.3 

4.5 

Tibia-patella 

5.5 

5.6 

4.0 

5.7 

Metatarsus 

4.2 

4.2 

3.0 

5.2 

Tarsus 

2.2 

2.4 

1.5 

2.6 

Total 

15.9 

16.4 

11.8 

18.0 

Gambardella,  33°19'S,  54°42'W,  1 9 

(MNHN);  Paysandu:  Santa  Rita,  R.  Uruguay, 
8 November  1955,  collector  unknown,  1 9 
(MNHN);  Salto,  Rio  Arapey,  30°55'S, 
57°49'W,  13  December  1954,  collector  un- 
known, 1 9 (MNHN);  Maldonado:  Sa.  De  las 
Animas,  34°42'S,  55°19'W,  18  May  1989,  R. 
Capocasale,  F.  Costa,  1 d,  1 9 (MNHN). 

Diagnosis. — This  species  is  distinguished 
by  the  small  body  size  and  details  of  the  gen- 
italia. The  broad  median  scape  of  the  epigyn- 
um  has  a median  concavity.  The  male  palpal 
tibia  is  approximately  half  the  length  of  the 
cymbium  but  with  a large  rta.  On  the  palpal 
bulb  the  vd  of  the  ma  is  much  expanded  so 
that  the  tip  of  the  g is  out  of  view  from  the 
ventral  side. 

Description. — Male  (Argentina,  Arroyo  de 
la  Moras,  Provincia  Buenos  Aires):  Carapace 
(Fig.  13)  moderately  high,  cephalic  area  not 
elevated,  medium  brown  with  wide  submar- 
ginal light  band,  marginal  bands  widening 
posteriorly,  black  in  eye  region,  length  3.3, 
width  3.0.  Sternum  light,  unmarked,  length 
1.72,  width  1.80;  labium  reddish-brown,  ligh- 
ter at  distal  margin,  length  0.60,  width  0.60. 
Clypeus  height  0.30,  width  1.70.  Anterior  eye 
row  slightly  recurved,  eye  measurements  in 
Table  1.  Cheliceral  faces  swollen,  glabrous, 
yellowish,  lateral  longitudinal  carinae  present, 
four  retromarginal  teeth  subequal  in  size  ex- 
cept smallest  subproximal.  Legs  IV-II-I-III, 


Table  7. — Leg  measurements  of  Paratrechalea 
ornata  female  in  mm. 


Leg  segment 

I 

II 

III 

IV 

Femur 

4.3 

4.5 

3.6 

5.0 

Tibia-patella 

5.6 

5.7 

4.0 

5.9 

Metatarsus 

4.1 

4.1 

3.1 

5.3 

Tarsus 

2.3 

2.2 

1.5 

2.4 

Total 

16.3 

16.5 

12,2 

18.6 

CARICO— TWO  NEW  GENERA  OF  TRECHALEIDAE 


807 


measurements  in  Table  6,  ventral  macrosetae 
pairs  on  tibiae  are  1-5,  IE4,  III--3,  IV-3.  Color 
of  legs  light  brown,  unmarked.  Abdomen  with 
wide  median  dark  band,  narrow  light  line  on 
each  lateral  margin,  length  3.6.  Palpus  (Figs. 
18,  19)  tibia  approximately  half  length  of 
cymbium  with  end  cupped  of  very  prominent 
rta;  bulb  t and  st  prominent,  vd  of  ma  large, 
flattened,  rounded,  and  covering  most  of  dd 
including  g. 

Female  (holotype):  Carapace  (Fig.  14) 
moderately  high,  cephalic  area  not  elevated, 
color  pattern  with  a broad,  dark  median  band, 
light  submarginal  bands  with  irregular  areas 
of  white  hair,  margin  with  short  marginal  dark 
areas,  length  3.5,  width  3.2.  Sternum  light,  un- 
marked, length  not  determined,  width  1.40;  la- 
bium medium  brown,  lighter  at  distal  margin, 
length  0.65,  width  0.56.  Clypeus  height  0.27, 
width  1.38.  Anterior  eye  row  straight,  eye 
measurements  in  Table  1.  Chelicerae  each 
with  dark  longitudinal  band  on  base;  three 
promarginal  teeth  on  left  side,  two  on  the 
right,  four  retromarginal  teeth  on  both  sides. 
Legs  IV-II-LIII,  measurements  on  Table  7,  in- 
distinct grey  maculae  present  except  on  tibia 
III,  tibial  macrosetae  not  observed.  Abdomen 
median  dark  band  with  irregular  margins,  lat- 
eral areas  with  scattered  small  dark  maculae, 
venter  unmarked,  length  4.0.  Median  scape  of 
epigynum  (Figs.  20,  21),  wider  than  long, 
prominent  and  widened  posteriad  and  with  a 
single  medial  depression,  internal  structures  as 
for  genus. 

Variation. — Carapace  length  of  males  av- 
erage 3.5  (3. 3-3. 8,  n = 10)  and  of  females 
3.65  (2.8-4. 5,  n = 30).  Average  abdomen 
lengths  equal  1 .05  of  carapace  lengths  in 
males  and  1.18  in  females.  Dorsal  pattern  in 
both  sexes  ranges  from  a distinct  median  dark 
band  with  lateral  light  bands  (Fig.  13)  to  a 
much  more  diffuse  pattern  (Fig.  14).  The  di- 
ameters of  three  egg  sacs  measuring  5.5,  6.0, 
and  5.1  were  recorded. 

Natural  history. — See  generic  description. 

Distribution. — Southward  from  the  south- 
ern Brazilian  state  of  Parana  to  northern  Ar- 
gentina and  Uruguay  (Fig.  17). 

Remarks. — This  species  is  not  to  be  con- 
fused with  Hesydrus  ornatus  Mello-Leitao 
1941.  The  type  of  the  latter  species  is  a small 
spiderling  and  is  treated  as  a nomen  dubium 
in  a revision  of  the  genus  Hesydrus  (Carico 
2005). 


Figures  22-25. — Genitalia  of  Paratrechalea  spe- 
cies. 22,  23.  right  palpus  of  P.  wygodzinskyv,  22. 
ventral  view;  23.  retrolateral  view;  24,  25.  female 
genitalia  of  P.  longigaster,  24.  ventral  view,  25. 
dorsal  view. 


Paratrechalea  wygodzinskyi  (Soares  & 
Camargo  1948) 

Figs.  17,  22,  23 

Trechalea  wygodzinskyi  Soares  & Camargo  1948: 

358,  figs.  6,  7;  Roewer  1954:143;  Carico  1993: 

237  (non  Trechalea)',  Platnick  2004. 

Type  material.— Holotype  male,  Chavan- 
tina,  Mato  Grosso,  Brazil,  14°40'S,  52°2LW, 
October  1946,  H.  Sick  (MZUSP,  #E.788, 
C.1293,  examined) 

Diagnosis. — The  pedipalp  is  distinguished 
from  P.  ornata  by  the  relatively  elongated  tib- 
ia which  is  approximately  the  length  of  the 
cymbium  and  the  small  rta. 

Description. — Male  (holotype):  Carapace 
low,  cephalic  area  not  elevated,  light  with  a 
narrow  marginal  band  and  indistinct  darker 
central  area,  dark  lines  between  each  AME 
and  clypeus  margin,  length  5.2,  width  4.6. 
Sternum  light  with  a pair  of  dark  spots  in  pos- 
terior half,  length  2.52,  width  2.70;  labium 
reddish-brown,  length  0.46,  width  0.41.  Clyp- 
eus height  0.72,  width  1.93.  Anterior  eye  row 
straight,  eye  measurements  in  Table  1 . Chelic- 
erae face  reddish  brown  with  indistinct  darker 
areas  in  distal  half,  without  lateral  carina  or 


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THE  JOURNAL  OF  ARACHNOLOGY 


Table  8. — Leg  measurements  of  Paratrechalea 

wygodzinskyi  male  in  mm.  Leg  I missing. 


Leg  segment 

I 

II 

III 

IV 

Femur 

— 

8.3 

6.7 

8.5 

Tibia-patella 

— 

11.9 

7.7 

9.8 

Metatarsus 

— 

9.7 

7.1 

11.7 

Tarsus 

— 

4.6 

3.8 

5.3 

Total 

— 

34.5 

25.3 

35.3 

frontal  enlargement  on  basal  segment,  four 
subequal  retromarginal  teeth.  Legs  IV-II-III  (I 
missing),  measurements  in  Table  8,  ventral 
macrosetae  pairs  on  tibiae  are  II-5,  III-4,  IV- 
4.  Color  of  legs  light  with  dark  maculae  es- 
pecially on  ventral  side  of  femora,  less  so  on 
distal  segments.  Abdomen  light  with  striated 
patterns  of  pigment  laterally  and  above,  par- 
ticularly dorsolaterally  except  for  pair  of  light 
areas  at  two-thirds  of  length,  light  ventrally 
but  darker  laterally,  length  5.0.  Palpus  (Figs. 
22,  23)  tibia  approximately  0.8  length  of  cym- 
bium,  bulb  t and  st  prominent,  vd  of  ma  large, 
flattened,  rounded,  and  covering  most  of  the 
dd  but  leaving  g visible;  ecd  of  rta  narrow  and 
curved  ventrally,  end  very  low. 

Female:  Unknown. 

Natural  history. — Unknown. 

Material  examined  and  distribution. — 
Known  only  from  the  type  specimen  collected 
in  Mato  Grosso,  Brazil  (Fig.  17). 

Paratrechalea  longigaster  new  species 

Figs.  15,  17,  24,  25 

Type  material. — ^Holotype  female,  Santa 
Maria,  Misiones,  Argentina,  27°00'S, 
55°00'W,  1956,  M.J.  Viana  (MACN). 

Etymology. — The  name  means  “long 
stomach”  and  is  derived  from  Latin. 

Diagnosis. — This  species  is  characterized 
by  the  details  of  the  median  epigynal  scape 
which  includes  a pair  of  deep  depressions  lat- 
erally separated  by  a wedge-shaped  elevation. 
Additionally,  there  are  three  retromarginal 
teeth,  and  the  abdomen,  when  compared  with 
other  species,  is  narrow  and  elongated,  about 
twice  its  width. 

Description. — Female  (holotype):  Cara- 
pace (Fig.  15)  low,  cephalic  area  not  elevated, 
color  pattern  with  a broad,  dark  median  band, 
light  submarginal  bands  with  irregular  macu- 
lae, narrow  dark  margin,  length  3.8,  width  3.2. 
Sternum  light,  median  longitudinal  macula. 


Table  9. — Leg  measurements  of  Paratrechalea 
longigaster  female  in  mm.  Leg  I missing. 


Leg  segment 

I 

II 

III 

IV 

Femur 

— 

5.0 

3.5 

6.0 

Tibia-patella 

— 

6.5 

4.0 

6.3 

Metatarsus 

— 

4.6 

3.7 

5.8 

Tarsus 

— 

2.4 

1.5 

2.7 

Total 

— 

18.5 

12.7 

20.8 

three  small  maculae  each  side,  length  1.95, 
width  1.80;  labium  medium  brown,  lighter  at 
distal  margin,  length  0.30,  width  0.30.  Clyp- 
eus  height  0.25,  width  1.50.  Anterior  eye  row 
straight,  eye  measurements  in  Table  1 . Chelic- 
erae  each  with  dark  longitudinal  band  on  base; 
three  promarginal  teeth,  three  retromarginal 
teeth.  Legs  IV-II-III  (leg  I missing),  measure- 
ments on  Table  9,  color  light  with  small  dark 
spots  on  ventral  side  of  femora.  Abdomen  me- 
dian dark  band  bordered  laterally  with  three 
light  spots,  lateral  sides  indistinctly  marked, 
venter  with  numerous  small  dark  spots,  length 
6.50.  Median  scape  of  epigynum  (Figs.  24, 
25)  prominent,  pair  of  deep  depressions  lat- 
erally separated  by  median,  wedge-shaped  el- 
evation, internal  structures  as  for  genus. 

Natural  history, — Unknown. 

Material  examined  and  distribution. — 
Known  only  from  the  type  specimen  collected 
in  Argentina  (Fig.  17). 

Paratrechalea  galianoae  new  species 
Figs.  16,  17,  26,  27 

Type  material. — Holotype  female.  General 
M.  Belgrade,  Misiones,  Argentina,  27°00'S, 
55°00'W,  January  1966,  M.E.  Galiano 
(MACN). 

Other  material  examined. — ARGENTI- 
NA: Misiones,  General  Manuel  Belgrade,  Jan- 
uary 1966,  M.E.  Galiano,  1 $ (MACN),  To- 
buna,  February  1959,  W.  Partridge,  19 
(MACN).  BRAZIL:  Parana,  Rio  Branco  do 
Sul,  16  April  1987,  A.D.  Brescovit,  1 9 (MCN 
#17153).  (Fig.  17). 

Etymology. — The  name  is  in  honor  of  the 
collector,  the  late  M.E.  Galiano,  in  recognition 
of  her  contributions  to  arachnology  and  in  ap- 
preciation for  her  aid  to  the  author  in  this  pro- 
ject. 

Diagnosis. — This  species  is  characterized 
by  the  details  of  the  epigynum  which  include 
a unique  Y-shaped  median  ridge  on  the  round- 


CARICO-=»TWO  NEW  GENERA  OF  TRECHALEIDAE 


809 


Figures  26=29. — Female  genitalia  of  Paratre- 
chalea  species.  26,  27.  P.  galianoae;  26.  ventral 
view,  27.  dorsal  view;  28,  29.  P.  azui;  28.  ventral 
view,  29.  dorsal  view. 


ed  scape  with  a deep  cleft  found  at  the  pos- 
terio-median  margin.  Additionally,  the  cara^ 
pace  and  abdomen  have  a broad,  mediae  dark 
band  which  is  flanked  by  a light  submargieal 
band  on  the  carapace  with  white  hairs. 

I}escriptmn.— -Female  (holotype):  Cara- 
pace  (Fig.  16)  moderately  high,  cephalic  area 
not  elevated,  color  pattern  with  a broad,  dark 
median  band,  light  submarginal  bands  with 
white  hairs,  narrow  dark  margin  along  poste- 
rior half,  length  3.8,  width  3.5.  Sternum  light, 
uiumarked,  length  1.95,  width  1.80;  labium- 
medium  brown,  lighter  at  distal  margin,  length 
0.66,  width  0.70.  Clypeus  height  0.33,  width 
1.62.  Anterior  eye  row  slightly  recurved,  eye 
measurements  in  Table  1.  Chelicerae  each 
with  faint  longitudinal  band  on  base;  three 
promargieal  teeth,  four  retromarginal  teeth. 
Legs  IVTI-LIII,  measurements  in  Table  10, 
ventral  macrosetae  pairs  on  tibiae  are  L4  IL4, 
III-3,  IV-3,  color  light  and  unmarked.  Abdo- 
men with  distinct  median,  dark  band,  sides 
light  and  unmarked,  venter  medium  with  in- 
distinct mottling,  length  3.7.  Rounded  scape 
of  epigynum  (Figs.  26,  27)  prominent,  with  a 
mediae  elevation  extending  posteriad  from  the 
af  terminating  in  a Y-shaped  ridge  on  the  pos- 
terior margin  around  a deep  cleft,  internal 
structures  as  for  genus. 

Variatioe.—Carapace  length  ranges  3.0- 
3.8  among  three  females.  Dorsal  pattern  may 


Table  10, — Leg  measurements  of  Paratrechalea 
galianoae  female  in  mm. 


Leg  segment 

I 

II 

III 

IV 

Femur 

5.0 

5.3 

3.8 

5.7 

Tibia-patella 

6.7 

6.7 

4.4 

6.3 

Metatarsus 

6.5 

6.5 

3.6 

6.2 

Tarsus 

2.5 

2.5 

1.7 

3.1 

Total 

20.7 

21.0 

13.5 

21.3 

be  with  dark  median  band  (Fig.  16)  or  diffuse 
without  distinct  bands. 

Paratrechalea  azul  new  species 
Figs.  17,  28,  29 

Type  material*— Holotype  female,  Agua 
Azul,  Caixas  do  Sul,  Rio  Grande  do  Sul,  Bra- 
zil, 27°23'S,  52°25W,  15  January  1975,  A.A. 
Lise  (MCN  #02551). 

Etymology.- — ^The  name  is  a noun  in  ap- 
position suggested  by  the  name  of  the  type 
locality. 

Diagnosis.- — This  species  is  characterized 
by  the  details  of  the  epigynum  which  has  a 
pronounced  lateral  flare  to  the  posterior,  wid- 
er-than-loeg  scape  and  a mediae  indention  on 
the  posterio-median  margin.  The  body  is  dis- 
tinctly larger  than  females  of  other  species 
measured  by  the  carapace  length.  Also,  the 
legs  are  proportionally  longer  as  determined 
by  the  ratio  of  carapace  leegth/leg  IV  length, 
e.g.,  6.0  vs.  5.4  average  (53-5.6)  for  other 
species. 

Description,— Femafe  (holotype):  Cara- 
pace moderately  high,  cephalic  area  not  ele- 
vated, color  pattern  with  a diffuse  arrange- 
ment of  mottling,  length  5.1,  width  4.5. 
Sternum  light  with  faint  maculae  near  base  of 
femora,  length  2.50,  width  2.4;  labium  light, 
lighter  at  distal  margin,  length  0.88,  width 
0.85.  Clypeus  height  0.41,  width  2.04.  Ante- 
rior eye  row  slightly  recurved  to  straight,  eye 


Table  1 1 .—Leg  measurements  of  Paratrechalea 
azul  female  in  mm. 


Leg  segment 

I 

II 

III 

IV 

Femur 

7.0 

7.4 

6.0 

8.0 

Tibia-patella 

9.3 

9.7 

7.0 

9.5 

Metatarsus 

7.4 

7.1 

53 

9.0 

Tarsus 

4.0 

4.0 

2.4 

4.3 

Total 

27.7 

28.2 

20.7 

30.8 

810 


THE  JOURNAL  OF  ARACHNOLOGY 


Figures  30-33. — Genitalia  of  Paratrechalea  sao- 
paulo,  30,  31.  right  palpus;  30.  ventral  view,  31. 
retrolateral  view;  32,  33.  female  genitalia;  32.  ven- 
tral view,  33.  dorsal  view. 


measurements  in  Table  1 . Chelicerae  each 
without  distinct  marks  on  base;  three  promar- 
ginal teeth,  four  retromarginal  teeth.  Legs  IV- 
II-I-III,  measurements  in  Table  1 1 , ventral  ma- 
crosetae  pairs  on  tibiae  are  1-4  II-4,  III-3,  IV-3, 
color  light  with  indistinct  maculae.  Abdomen 
with  diffuse  arrangement  of  mottling,  sides 
light  and  unmarked,  venter  medium  without 
mottling,  length  5.6.  Scape  of  epigynum  (Figs. 
28)  prominent,  wider  than  long,  with  a flared 
posterior  scape  extending  posteriad  from  the 
af  terminating  with  an  indentation  on  posterio- 
median  margin,  median  longitudinal  ridge;  in- 
ternal structures  as  for  genus  (Fig.  29). 

Distribution. — Known  only  from  the  type 
specimens  collected  in  Brazil  (Fig.  17). 

Paratrechalea  saopaulo  new  species 
Figs.  17,  30-33 

Type  material. — Holotype  male,  Sao  Pau- 
lo, Sao  Paulo,  Brazil,  22°00'S,  49°00'W  1897, 
Moenkhouse  (PMNH).  Paratypes:  9 males,  10 
females  same  data  as  holotype  (PMNH). 

Etymology. — The  name  is  a noun  in  ap- 
position suggested  by  the  name  of  the  type 
locality. 


Table  12. — Leg  measurements  of  Paratrechalea 
saopaulo  male  in  mm. 


Leg  segment 

I 

II 

III 

IV 

Femur 

4.3 

4.2 

3.4 

4.8 

Tibia-patella 

6.2 

5.9 

4.0 

5.5 

Metatarsus 

4.6 

4.5 

3.3 

5.5 

Tarsus 

2.5 

2.3 

1.5 

2.5 

Total 

17.6 

16.9 

12.2 

18.3 

Diagnosis. — This  species  is  distinguished 
by  the  small  body  size  and  details  of  the  gen- 
italia. Externally,  the  median  division  of  the 
epigynum  separates  two  posterio-lateral  divi- 
sions and  has  a furrow  along  the  posterior 
edge.  The  male  palpal  tibia  is  approximately 
equal  the  length  of  the  cymbium.  The  rta  ental 
division  is  a small,  dark,  sclerotized  projection 
while  the  ectal  division  is  larger,  acute,  white 
and  lightly  sclerotized.  On  the  palpal  bulb  the 
vd  of  the  ma  is  much  expanded  and  rounded 
while  the  tip  of  the  g is  visible  from  the  ven- 
tral side. 

Description. — Male  (holotype):  Carapace 
moderate  high,  cephalic  area  not  elevated,  col- 
or pattern  faded  due  to  age  but  faintly  resem- 
bles Fig.  15,  length  3.8,  width  3.2.  Sternum 
light,  central  dark  macula,  length  2.1,  width 
1.6;  labium  light  reddish-brown,  lighter  at  dis- 
tal margin,  length  0.63,  width  0.54.  Clypeus 
height  0.28,  width  1.60.  Anterior  eye  slightly 
recurved,  eye  measurements  in  Table  1.  Che- 
licerae faces  swollen,  glabrous,  yellowish,  lat- 
eral longitudinal  carinae  present,  three  retro- 
marginal  teeth  subequal.  Legs  IV-I-II-III, 
measurements  in  Table  12,  ventral  macrosetae 
pairs  on  tibiae  are  1-5,  II-5,  III-3,  IV-3.  Color 
of  legs  light  with  small  maculae  at  the  bases 
of  most  macrosetae.  Abdomen  color  faded 
from  age  but  similar  to  Fig.  15,  length  4.7. 
Palpus  (Figs.  30,  31)  tibia  approximately 
equal  to  length  of  cymbium,  cupped  end  of 


Table  13. — Leg  measurements  of  Paratrechalea 
saopaulo  female  in  mm. 


Leg  segment 

I 

II 

III 

IV 

Femur 

4.1 

4.2 

2.5 

5.2 

Tibia-patella 

5.6 

5.5 

3.7 

5.3 

Metatarsus 

4.0 

3.8 

3.0 

5.0 

Tarsus 

2.0 

1.9 

1.4 

2.1 

Total 

15.7 

15.4 

10.6 

17.6 

CARICO-^TWO  NEW  GENERA  OF  TRECHALEIDAE 


811 


prominent  rta  white,  acute  and  ect  a small 
dark  projection;  bulb  t and  st  prominent;  vd 
of  ma  large,  flattened,  rounded,  and  covering 
most  of  dd  but  g is  prominent. 

Female  (Paratype):  Carapace  moderately 
high,  cephalic  area  not  elevated,  color  pattern 
as  with  male,  length  3.8,  width  3.3.  Sternum 
light,  small  central  macula,  length  1.7,  width 
1,8;  labium  medium  brown,  lighter  at  distal 
margin,  length  0.61,  width  0.60.  Clypeus 
height  0.42,  width  1.60,  Anterior  eye  row 
slightly  recurved,  eye  measurements  in  Table 
1.  Chelicerae  medium;  three  promargieal 
teeth,  three  retromarginal  teeth  equidistant  and 
equal  in  size.  Legs  IV-I-II-III,  measurements 
in  Table  13,  color  as  in  male.  Abdomen  color 
as  in  male,  length  5.3.  Pair  of  protuberances 
at  posterio-laterally  on  margin  of  epigynum 
continuous  with  mediae  elevation  (Fig.  32), 
mediae  elevation  widened  anteriorly  and  with 
a medial  furrow  at  posterior  margin;  internal 
parts  (Fig.  33)  as  for  genus. 

¥ariatioe.— Carapace  length  of  males  av- 
erage 3.6  (3. 3-3. 9,  n =10)  and  of  females  3.5 
(3. 3-3. 9,  n = 10).  The  diameters  of  two  egg 
sacs  measuring  4.8  and  5.3  were  recorded. 
Egg  sac  structure  is  typical  for  the  family  but 
with  upper  valve  arched  higher. 

Natural  history «=^Uekeowe. 
Distribution*— Known  only  from  the  type 
series  collected  in  Brazil  composed  of  10 
males  and  10  females  (Fig.  17). 

ACKNOWLEDGMENTS 

Thanks  are  extended  to  the  following  per- 
sons and  museums  for  the  loan  of  specimens: 
R.  Pinto  da  Rocha  and  J.L.M.  Leme 
(MZUSP);  H.W.  Levi  (MCZ);  P.D.  Hillyard 
and  J.  Beccaloei  (BMNH);  E.H.  Buckup  and 
A. A.  Lise  (MCN);  the  late  M.E,  Galiano 
(MACN);  R.M.  Capocasale  (MNHN);  C.E 
Ituarte  (MLP);  A.B.  Kury  and  R.  Baptista 
(MNRJ);  Estevam  Luis  Cruz  da  Silva 
(IJFRGS);  and  C.L.  Remington  (PMNH). 
W.A.  Sherwood  helped  with  translation  from 
Portuguese.  Thanks  also  to  N.A.  Carico,  E.L. 
Cruz  da  Silva,  editors  and  reviewers  who 
helped  make  important  improvements. 

LITERATURE  CITED 

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Carico,  J.E.  1986.  Trechaleidae:  A “new”  Ameri- 
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1903:151-168. 

Coddington,  J.A.  & H.W.  Levi.  1991.  Systematics 
and  evolution  of  spiders  (Araneae).  Annual  Re- 
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Griswold,  C.E.  1993.  Investigations  into  the  phy- 
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Keyserling,  E.  1891.  Die  Spinnen  Americas.  Bras- 
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Melio-Leitio,  C.F.  1926.  Algumas  aranhas  do  Brasil 
Meridional.  Boletim  Museu  Nacional  do  Rio  de 
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Mello-Leitao,  C.F.  1941a.  Aranhas  do  Parana.  Ar- 
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Mello-Leitao,  C.F.  1941b.  Las  aranas  de  Cordoba, 
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Mello-Leitao,  C.F.  1943.  Aranas  nuevas  de  Men- 
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Petrunkevitch,  A.  1911.  A synonymic  index-cata- 
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America  with  all  adjacent  islands,  Greenland, 
Bermuda,  West  Indies,  Terra  del  Fuego,  Gala- 
pagos, etc.  Bulletin  of  the  American  Museum  of 
Natural  History  29:1-791. 

Platnick,  N.L  2004.  The  World  Spider  Catalog,  Ver- 
sion 4,5.  American  Museum  of  Natural  History, 
online  at  http://research.amnh.org/entomology/ 
spiders/catalog/iedex . html 

Roewer,  C.E  1954,  Katalog  der  Araneae,  voL  2a. 
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gique, Bruxelles. 


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ii 


Sierwald,  P.  1989.  Morphology  and  ontogeny  of  fe- 
male copulatory  organs  in  American  Pisauridae, 
with  special  reference  to  homologous  features 
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Sierwald,  P.  1990.  Morphology  and  homologous 
features  in  the  male  palpal  organ  in  Pisauridae 
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Sierwald,  P.  1993.  Revision  of  the  spider  genus 
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Manuscript  received  8 December  2003,  revised  26 
August  2004. 


2005.  The  Journal  of  Arachnology  33:813-819 


LIVING  WITH  THE  ENEMY:  JUMPING  SPIDERS  THAT  MIMIC 

WEAVER  ANTS 


Ximena  J.  Nelson^  Robert  R.  Jackson* , G.B.  Edwards^  and  Alberto  T,  Barrioe^: 
^Department  of  Biological  Sciences,  University  of  Canterbury,  Private  Bag  4800, 
Christchurch,  New  Zealand  E-mail:  robertjackson@canterbury.ac.nz;  ^Florida  State 
Collection  of  Arthropods,  Division  of  Plant  Industry,  Gainesville,  Florida  32614- 
7100,  U.S.A.;  ^Entomology  Division,  International  Rice  Research  Institute,  PO  Box 
3127,  Makati  Central  Post  Office,  1271  Makati  City,  Philippines 

ABSTRACT.  Ants  prey  on  salticids,  and  encounters  with  weaver  ants  (Oecophylla  smaragdina  (Fabri- 

cius  1775))  appear  to  be  especially  dangerous  for  many  salticids.  In  the  Philippines,  Myrmarachne  assimilis 
Banks  1930  is  a salticid  that  mimics  Oecophylla  smaragdina.  We  tested  for  the  abilities  of  four  categories 
of  salticids,  plus  M.  assimilis,  to  survive  in  the  proximity  of  weaver  ants.  The  four  categories  were:  (1) 
myrmecomorphic  (ant-like  species  other  than  M.  assimilis);  (2)  myrmecophagic  (ant-eating  species);  (3) 
myrmecophilic  (a  species  that  is  either  myrmecophagic  nor  myrmecophagic,  but  is  known  to  associate 
with  ants)  and  (4)  ordinary  (species  that  are  neither  ant-like  nor  ant-eating,  and  are  not  known  to  associate 
with  ants).  The  hypothesis  investigated  here  is  that  M.  assimilis  has,  compared  with  other  salticids,  es- 
pecially pronounced  ability  to  survive  in  close  proximity  with  this  particular  ant  species.  The  individual 
salticids  used  in  our  experiments  had  not  had  previous  contact  with  weaver  ants  or  any  other  ants.  When 
confined  with  groups  of  10  weaver  ants,  the  myrmecomorphic,  myrmecophagic  and  myrmecophilic  species 
survived  significantly  more  often  than  ordinary  salticids,  but  Myrmarachne  assimilis  survived  significantly 
more  often  than  all  other  categories.  When  kept  with  groups  of  20  ants,  there  was  a proportional  decrease 
in  the  number  of  salticids  that  survived  within  each  salticid  category.  However,  few  salticids  survived 
when  confined  with  groups  of  40  ants,  regardless  of  category. 

Keywords:  Salticidae,  mimicry,  predation,  myrmecomorphy,  myrmecophily 


In  the  Philippines,  Diacamma  rugosum  (Le 
Guillou  1842)  (previously  known  as  D.  va- 
gans),  Dolichoderus  thoracicus  Stitz  1925 
(previously  known  as  D.  bitub erculatus),  Oec- 
ophylla smaragdina  (Fabricius  1775),  Odon- 
tomachus  sp.,  Polyrachis  spp.  and  Solenopsis 
geminata  (Fabricius  1804)  are  ants  that  prey 
on  jumping  spiders  (Salticidae)  (Nelson  et  al. 
2004).  In  an  earlier  laboratory  study  (Nelson 
et  al.  2004),  four  categories  of  salticids  were 
tested  with  these  same  ant  species  to  measure 
their  ability  to  survive  in  the  presence  of  ants: 
(1)  myrmecophagic  species  (i.e.,  species  that 
select  ants  as  preferred  prey;  see  Li  & Jackson 
1996),  (2)  myrmecomorphic  species  (i.e.,  spe- 
cies that  resemble  ants;  see  Jackson  & Willey 
1994;  Cushing  1997),  (3)  myrmecophilic  spe- 
cies (i.e.,  a salticid  species  that  is  neither  myr- 
mecophagic nor  myrmecomorphic,  but  known 
to  associate  with  ants;  see  Nelson  et  al.  2004) 
and  (4)  ordinary  species  (i.e.,  species  that  are 
not  known  to  associate  with  ants  and  are  nei- 


ther ant  eaters  nor  ant  mimics;  see  Jackson  & 
Pollard  1996).  These  tests  were  carried  out  in 
small  cages  (diameter  90  mm)  by  putting  one 
salticid  together  with  one  or  with  five  ants  per 
cage  and  then  measuring  how  many  spiders 
survived  after  10  h with  the  ants.  The  ordinary 
salticids  had  the  least  success  at  surviving 
these  tests,  suggesting  that  ant  eaters,  ant 
mimics  and  ant  associates  have  generalized 
adaptations  that  enhance  their  abilities  to  sur- 
vive in  the  presence  of  a variety  of  ants,  at 
least  when  the  number  of  ants  is  small. 

Here  we  investigate  the  ability  of  a variety 
of  salticids  to  survive  in  the  presence  of  nu- 
merous ants  in  large  cages  and  we  focus  on  a 
particular  ant  species,  Oecophylla  smaragdi- 
na. There  are  two  species  in  the  genus  Oec- 
ophylla, O.  smaragdina  in  tropical  Asia  and 
Australasia  and  O.  longinoda  (Latreille  1802) 
in  tropical  Africa.  Known  as  ‘weaver  ants’, 
these  two  species  often  dominate  local  arbo- 
real habitats  (Vanderplank  1960;  Lokkers 


813 


814 


THE  JOURNAL  OF  ARACHNOLOGY 


1986)  where  they  make  nests  by  spinning 
leaves  together  with  silk.  The  larvae  of  Oec~ 
ophylla  secrete  the  silk  (Doflein  1905),  but  the 
workers  determine  where  the  silk  goes.  By 
carrying  the  larvae  about  and  moving  them 
across  locations  in  need  of  silk,  the  major 
workers  of  Oecophylla  use  the  larvae  as  nest- 
building tools  (Holldobler  & Wilson  1977a). 
Minor  workers  generally  remain  inside  the 
nests,  whereas  the  more  numerous  major 
workers  leave  the  nests  and  function  as  ag- 
gressive predators  and  soldiers  for  the  colony 
(Holldobler  & Wilson  1977b,  1978;  Holldob- 
ler 1983).  A single  Oecophylla  colony,  with 
one  queen,  is  typically  spread  across  numer- 
ous nests  and  sometimes  more  than  one  tree 
(Holldobler  & Wilson  1977c).  As  many  as 
half  a million  workers  may  live  in  a single 
colony  (Holldobler  1983). 

Different  species  of  Myrmarachne  resemble 
different  ant  species  (Wanless  1978;  Edmunds 
2000),  but  Myrmarachne  assimilis  is  unique 
among  the  Philippine  species  studied  because 
it  alone  resembles  O.  smaragdina.  For  Myr- 
marachne, myrmecomorphy  appears  to  func- 
tion primarily  as  Batesian  mimicry,  where 
predators  that  avoid  the  model  (the  ant)  also 
avoid  the  mimic  (the  salticid).  However, 
Batesian  mimics  of  ants  may  be  forced  to 
‘walk  a tightrope’,  needing  to  ‘live  with  the 
enemy’.  They  need  to  be  close  to  the  model 
for  safety  from  other  predators  but  at  the  same 
time  they  need  to  avoid  becoming  the  model’s 
prey  (see  Reiskind  1970;  Edmunds  1974;  El- 
gar 1993;  Oliveira  1988).  Weaver  ants  appear 
to  be  exceptionally  aggressive,  yet  M.  assi- 
milis routinely  keeps  close  company  with 
weaver-ant  colonies  in  nature. 

Cuticular  hydrocarbons  are  used  by  many 
ants  for  distinguishing  between  nestmates  and 
non-nestmates  (Holldobler  & Wilson  1990; 
Thomas  et  al.  1999;  Wagner  et  al.  2000). 
Chemical  mimicry  of  ants  has  been  reported 
for  the  salticid  Cosmophasis  bitaeniata  (Key- 
serling  1882)  (Allan  & Elgar  2001;  Allan  et 
al.  2002;  Elgar  & Allan  2004).  Perhaps  in  the 
field  M.  assimilis  uses  some  form  of  chemical 
communication  to  avoid  predation  by  O. 
smaragdina.  However,  the  objective  of  the 
present  study  was  not  to  investigate  a hypoth- 
esis about  mimics  exploiting  the  nest-mate 
recognition  system  of  O.  smaragdina.  Instead, 
our  objective  was  to  investigate  whether  M. 
assimilis  might  have  evolved  adaptations  that 


make  it  especially  proficient  at  surviving  in 
the  presence  of  its  model  even  in  the  absence 
of  opportunity  to  acquire  nest-mate  cues.  The 
salticids  we  used  were  from  laboratory  cul- 
tures and  could  not  have  acquired  any  host- 
specific  cuticular  hydrocarbons  by  feeding  on 
ants  or  through  direct  contact  with  ants  (see 
Elgar  & Allan  2004)  because  the  individuals 
we  used  had  never  encountered  ants  before 
being  tested.  We  tested  different  types  of  sal- 
ticids in  the  laboratory  by  confining  them  in 
cages  with  groups  of  weaver-ants,  our  predic- 
tion being  that  M.  assimilis  would  survive  of- 
ten more  than  other  salticids,  including  other 
myrmecomorphs  that  do  not  specifically  mim- 
ic weaver  ants. 

METHODS 

In  the  Philippines,  our  study  site  was  the 
vicinity  of  Los  Banos  (Laguna  Province,  Lu- 
zon, 14°  10'  N 121°  14'  E),  including  a rain  for- 
est habitat  at  Mt.  Makiling.  Laboratory  tests 
were  performed  at  the  International  Rice  Re- 
search Institute  (IRRI)  in  Los  Banos.  When 
needed,  we  collected  weaver  ants  from  the 
field,  but  all  salticids  used  in  experiments 
came  from  laboratory  cultures  and  none  had 
prior  experience  with  ants  of  any  species.  No 
individual  salticid  nor  any  individual  ant 
group  was  tested  more  than  once.  Tests  were 
aborted  whenever  two  or  more  ants  died  dur- 
ing testing,  but  this  rarely  happened.  For  each 
salticid  species,  a series  of  tests  was  carried 
out  using  both  mature  females  and  juveniles. 
Body  length  of  the  adult  salticids  varied  (see 
Nelson  et  al.  2004)  and  juveniles  were  used 
when  they  were  3mm  long.  Salticid  mainte- 
nance procedures  were  the  same  as  in  earlier 
spider  studies  (Jackson  & Hallas  1986). 

All  tests  began  at  c.  0800  hours  and  lasted 
10  h (laboratory  photoperiod  12L:12D,  lights 
on  at  0700  hours)  and  consisted  of  placing  a 
single  salticid  in  a cage  with  either  10,  20  or 
40  ants.  At  the  end  of  each  test,  we  counted 
how  many  salticids  were  still  alive.  Our  ob- 
jective in  this  study  was  only  to  compare  the 
percent  survival  for  the  different  groups  of 
salticids.  Latency  to  attack  and  the  behavior 
of  ants  and  spiders  during  the  tests  were  not 
recorded.  Survival  data  were  analyzed  using 
tests  of  independence  (Sokal  & Rohlf  1995), 
with  Bonferroni  adjustments  being  applied 
whenever  multiple  comparisons  were  made 
using  the  same  data  sets  (see  Rice  1989). 


NELSON  ET  AL.— JUMPING  SPIDERS  AND  WEAVER  ANTS 


815 


Table  1. — Salticids  used  in  tests  with  ant  workers  in  laboratory.  Ordinary  salticid:  species  that  are  not 
known  to  associate  with  ants  and  are  neither  ant  eaters  nor  ant  mimics,  Myrmecophagic  salticid:  species 
that  select  ants  as  preferred  prey.  Myrmecomorphic  salticid:  species  that  resemble  ants.  Myrmecophilic 
salticid:  a salticid  species  that  is  neither  myrmecophagic  nor  myrmecomorphic,  but  known  to  associate 
with  ants. 


Species  of  Salticidae 

Category 

Bavia  sexpunctata  (Doleschall  1959) 

Ordinary  salticid 

Chalcotropis  gulosa  (Simon  1902) 

Myrmecophagic 

Chalcotropis  luceroi  Barrion  & Litsinger  1995 

Myrmecophagic 

Cosmophasis  estrellaensis  Barrion  & Litsinger  1995 

Ordinary  salticid 

Epeus  hawigalboguttatus  Barrion  & Litsinger  1995 

Ordinary  salticid 

Harmochirus  brachiatus  (Thorell  1877) 

Ordinary  salticid 

Heratemita  alboplagiata  (Simon  1899) 

Ordinary  salticid 

Lagnus  sp. 

Ordinary  salticid 

Mantisatta  longicauda  Cutler  & Wanless  1973 

Ordinary  salticid 

Menemerus  bivittatus  (Dufour  1831) 

Ordinary  salticid 

Myrmarachne  assimilis  Banks  1930 

Myrmecomorphic 

Myrmarachne  bakeri  Banks  1930 

Myrmecomorphic 

Myrmarachne  bellicosa  (G.  & E.  Peckham  1892) 

Myrmecomorphic 

Myrmarachne  bidentata  Banks  1930 

Myrmecomorphic 

Myrmarachne  maxillosa  (C.  L.  Koch  1846) 

Myrmecomorphic 

Myrmarachne  nigella  Simon  1901 

Myrmecomorphic 

Orthrus  bicolor  Simon  1900 

Ordinary  salticid 

Phintella  piatensis  Barrion  & Litsinger  1995 

Myrmecophilic 

Portia  labiata  (Thorell  1887) 

Ordinary  salticid 

Plexippus  petersi  (Karsch  1878) 

Ordinary  salticid 

Siler  semiglaucus  Simon  (1901) 

Myrmecophagic 

Telamonia  masinloc  Barrion  & Litsinge  1995r 

Ordinary  salticid 

Thiania  sp. 

Ordinary  salticid 

Xenocytaea  sp. 

Myrmecophagic 

We  tested  24  salticid  species  (Table  1),  all 
of  which  were  also  used  in  the  earlier  study 
(Nelson  et  al.  2004).  Statistical  analysis  was 
based  on  the  a priori  categories  from  the  ear- 
lier study,  plus  one  additional  a priori  cate- 
gory (mimic  of  the  weaver  ant,  M.  assimilis). 
Other  than  M.  assimilis,  these  categories  were: 
myrmecomorphic  salticids  (Myrmarachne 
species  other  than  M.  assimilis)’,  myrmeco- 
phagic salticids,  ordinary  salticids  and  a myr- 
mecophilic salticid  (Table  1).  Voucher  speci- 
mens of  all  species  have  been  deposited  in  the 
IRRI  Taxonomy  Laboratory  in  Los  Banos  and 
in  the  Florida  State  Collection  of  Arthropods 
in  Gainesville. 

The  testing  apparatus  was  a cylindrical 
plastic  cage  (diameter  & height  c.  200  mm) 
with  a ventilation  hole  (diameter  10  mm;  cov- 
ered by  fine-mesh  metal  screening)  centered 
at  the  top,  and  with  four  cork  holes  (diameter 
of  each,  10  mm)  spaced  evenly  around  the  top 
of  each  cage,  each  hole  was  10  mm  from  the 
edge  of  the  cage  top.  The  cages  rested  on  plas- 


tic pots  filled  with  water.  A cotton  roll  (di- 
ameter 5 mm,  length  40  mm)  was  inserted 
through  a hole  centered  in  the  bottom  of  each 
cage.  By  protruding  from  the  bottom  of  the 
cage  into  the  pot  of  water,  the  cotton  roll  re- 
mained water  logged  for  the  duration  of  each 
test  and  provided  humidity  and  drinking  water 
for  the  spiders  and  the  ants  inside  the  cage. 
Four  green  mango  leaves  (each  c.  150  mm 
long),  each  still  attached  to  a stem  (one  leaf 
per  stem,  stem  c.  200  mm  long),  were  wedged 
into  each  cage.  Numerous  trials  were  run  si- 
multaneously. 

A large  number  of  major  workers  were  col- 
lected from  a single  representative  colony  of 
O.  smaragdina  in  a mango  tree.  These  ants 
were  then  maintained  as  a ‘laboratory  colony’ 
in  a large  terrarium.  From  this  large  laboratory 
colony,  we  established  smaller  groups  in  the 
cages  by  placing  a specified  number  (10,  20, 
40)  of  workers  in  each  cage  16  h before  test- 
ing began.  Whenever  the  laboratory  colony 
was  depleted,  we  replenished  it  by  collecting 


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THE  JOURNAL  OF  ARACHNOLOGY 


more  major  workers  from  the  same  field  col- 
ony as  before. 

Testing  began  by  introducing  a single  sal- 
ticid  through  one  of  the  cork  holes  at  the  top 
of  the  cage,  with  a rule  that  no  ants  could  be 
within  50  mm  of  the  hole  when  the  salticid 
was  introduced.  With  four  cork  holes  to 
choose  from,  this  criterion  was  always  achiev- 
able. Each  test  spider  was  first  taken  into  a 40 
mm  long  (diameter  5 mm)  clear  glass  tube 
(plugged  by  a cork  at  both  ends).  After  10  min 
the  corks  from  the  tube  and  a hole  in  the  top 
of  the  cage  were  removed  and  the  open  end 
of  the  tube  was  placed  against  the  open  hole 
of  the  cage.  If  the  spider  did  not  enter  the  cage 
immediately,  the  cork  at  the  other  end  of  the 
tube  was  removed  and  a brush  was  used  gent- 
ly to  push  the  spider  out  of  the  tube  and  into 
the  cage.  For  each  combination  of  salticid  spe- 
cies and  each  ant-group  size,  equal  numbers 
of  tests  (ji  = 100)  were  carried  out.  Between 
tests,  cages  were  wiped  clean  with  80%  eth- 
anol, followed  by  distilled  water.  Transfer 
tubes  and  corks  were  also  cleaned  with  80% 
ethanol,  followed  by  distilled  water.  The 
cleaning  routine  was  a precaution  against  the 
possibility  that  chemical  traces  from  previous 
ants  and  salticids  might  influence  test  out- 
comes. 

RESULTS 

Data  from  testing  with  each  ant-group  size 
are  considered  separately.  However,  within 
each  group  size,  we  pooled  many  of  the  data 
sets  that  were  not  significantly  different  from 
each  other  (in  each  instance,  P > 0.1).  For 
each  species  of  salticid  data  for  adults  were 
pooled  with  data  for  juveniles.  Data  for  the 
various  species  within  each  category  were 
also  pooled,  resulting  in  three  sets  of  pooled 
data  (myrmecophagic,  myrmecomorphic  and 
ordinary).  Data  for  myrmecophagic,  myrme- 
comorphic and  myrmecophilic  salticids  were 
then  pooled  and  compared  with  Myrmarachne 
assimilis  and  with  ordinary  salticids,  greatly 
simplifying  data  presentation.  However,  the 
trends  from  using  myrmecophagic,  myrme- 
comorphic and  myrmecophilic  salticids  also 
held,  and  were  statistically  significant,  when 
myrmecophagic  and  myrmecomorphic  salti- 
cids were  each  compared  alone  with  M.  assi- 
milis and  with  ordinary  salticids. 

With  each  of  the  three  ant-group  sizes,  the 
% survival  of  ordinary  salticids  was  signifi- 


cantly less  than  that  of  myrmecophagic,  myr- 
mecomorphic and  myrmecophilic  salticids 
(pooled)  (A2  = 974.57,  P < 0.001,  10  ant 
tests)  {X^  = 855.89,  P < 0.001,  20  ant  tests) 
{X  " 80.95,  P < 0.001,  40  ant  tests)  (Fig.  1). 
With  groups  of  40  ants,  the  % survival  of  M. 
assimilis  was  not  significantly  different  from 
that  of  myrmecophagic,  myrmecomorphic  and 
myrmecophilic  salticids  (pooled)  {X  = 3.17, 
P — 0.075).  However,  with  smaller  ant  groups 
(20  or  10),  the  survival  rate  of  M.  assimilis 
was  significantly  higher  than  that  of  myrme- 
cophagic, myrmecomorphic  and  myrmeco- 
philic salticids  (pooled)  {X  “ 19.49,  P < 
0.001,  10  ant  tests)  {X  = 23.84,  P < 0.001, 
20  ant  tests). 

DISCUSSION 

The  vicinity  of  weaver-ant  colonies  appears 
to  be  particularly  dangerous  for  salticids,  in- 
cluding salticids  that  mimic  ants  (i.e.,  ants  are 
‘enemies’).  In  groups  of  40  ants,  few  salticids 
survived,  regardless  of  category.  In  groups  of 
10  and  20  ants,  salticid  survival  fell  into  three 
clusters.  Ordinary  salticids  had  the  lowest  pro- 
portion of  survivors  and  M.  assimilis  had  the 
highest.  Myrmecomorphic  salticids  (other 
than  M.  assimilis),  myrmecophagic  salticids 
and  the  myrmecophilic  species  (Phintella  pia- 
tensis)  had  intermediate  survival  values. 

That  ordinary  salticids  had  the  lowest  per- 
centage of  survivors  was  consistent  with  the 
earlier  study  (Nelson  et  al.  2004),  but  there 
were  also  some  differences  between  the  find- 
ings in  this  study  and  the  earlier  study.  In  the 
earlier  study,  ant  mimics,  ant  eaters  and  P. 
piatensis  (the  myrmecophile)  had  distinguish- 
ably  different  survival  values,  but  these  cate- 
gories were  not  discernible  in  the  present 
study  where  we  used  groups  of  10-40  ants. 
Another  difference  was  that,  in  the  earlier 
study,  the  proportion  of  surviving  M.  assimilis 
did  not  differ  significantly  from  that  of  other 
ant  mimics  with  a variety  of  ant  species, 
whereas  M.  assimilis  was  clearly  distinguish- 
able from  other  ant  mimics  in  the  present 
study  using  only  O.  smaragdina. 

For  any  salticid,  avoidance  might  be  the 
most  straightforward  protection  from  attacks 
by  ants.  Although  spider  eyes  generally  lack 
the  structural  complexity  required  for  acute 
vision  (Land  1985),  salticids  have  unique, 
complex  eyes  (Land  1969a,b;  Blest  et  al. 
1990)  that  support  resolution  abilities  with  no 


NELSON  ET  AL.— JUMPING  SPIDERS  AND  WEAVER  ANTS 


817 


1 0 Ants  20  Ants  40  Ants 

Ant  colony  size 


Figure  1 . — Percent  survival  of  different  categories  of  salticids  in  tests  with  groups  of  Oecophylla  smar- 
agdina  (Table  1).  For  each  salticid  species,  with  each  ant-group  size,  n = 200  (100  adults  and  100 

juveniles).  Data  pooled  in  histograms,  n for  pooled  data  is  indicated  above  each  bar. 


known  parallels  in  other  animals  of  compa- 
rable size  (Land  & Fernald  1992;  Land  & 
Nilsson  2002).  Exceptional  eyesight  may  en- 
able salticids  to  be  especially  effective  at  de- 
tecting ants  from  a distance  and  avoiding  dan- 
gerous proximity,  but  the  strategies  of 
myrmecophilic,  myrmecomorphic  and  myr- 
mecophagic  salticids  cannot  be  simply  to 
avoid  ants.  For  example,  myrmecophagic  sal- 
ticids must  at  least  intermittently  come  close 
enough  to  attack  individual  ants. 

For  Myrmarachne,  the  resemblance  to  the 
ant  model  appears  to  function  primarily  as 
Batesian  mimicry.  My rmarac hue's  mimicry  of 
an  aggressive  model  puts  these  salticids  in  a 
difficult  situation.  Successfully  using  mimicry 
to  achieve  safety  from  other  predators  would 
seem  to  require  that  individuals  of  Myrmar- 
achne  come  close  to  the  ants  that  serve  as 
their  models,  but  they  must,  at  the  same  time, 
avoid  becoming  the  modePs  prey  (see  Re- 
iskind  1970;  Edmunds  1974;  Elgar  1993; 
Oliveira  1988).  For  M.  assimilis,  the  problem 
is  specifically  how  to  stay  close  enough  to  be 
an  effective  Batesian  mimic  of  one  of  its  own 
especially  dangerous  predators,  O.  smaragdi- 
na  (Nelson  et  al.  2004). 

Our  hypothesis  was  that  M.  assimilis  has 


evolved  adaptations  that  make  it  especially 
proficient  at  surviving  in  the  presence  of  its 
model  and  our  findings  support  this  hypothe- 
sis. However,  further  research  is  needed  for 
clarifying  precisely  what  these  adaptations 
might  be.  Ants  rely  primarily  on  chemical,  not 
visual,  information  for  detecting  other  ants 
(Holldobler  & Wilson  1990).  Many  ants  use 
cuticular  hydrocarbons  to  distinguish  between 
nestmates  and  non-nestmates  (Holldobler  & 
Wilson  1990;  Thomas  et  al.  1999;  Wagner  et 
al.  2000).  The  salticid  spider  Cosmophasis  bi- 
taeniata  (Keyserling  1882)  associates  with  O. 
smaragdina  and  is  an  exploitative  chemical 
mimic  of  its  host  (Allan  & Elgar  2001;  Allan 
et  al.  2002).  Whether  M.  assimilis  uses  a sim- 
ilar strategy  to  avoid  predation  by  O.  smar- 
agdina while  in  the  vicinity  of  its  model  has 
not  been  investigated.  However,  in  this  study, 
the  salticids  were  from  laboratory  cultures 
and,  unless  it  was  during  the  duration  of  the 
tests  itself,  they  could  not  have  acquired  any 
host-specific  cuticular  hydrocarbons  from  ants 
by  direct  contact  with,  or  close  proximity  to, 
the  ants. 

ACKNOWLEDGMENTS 
Work  in  the  Philippines  was  generously  as- 
sisted by  the  International  Rice  Research  In- 


818 


THE  JOURNAL  OF  ARACHNOLOGY 


stitute  (IRRI).  We  are  especially  grateful  to 
Kong  Luen  Heong  and  Tom  W.  Mew  for  the 
numerous  ways  in  which  they  supported  the 
research  and  to  the  following  IRRI  staff  for 
technical  assistance:  Elpie  Hernandez,  Errol 
Rico,  Glicerio  Javier,  Josie  Lynn  Catindig  and 
Clod  Lapis.  This  research  was  funded  in  part 
by  a grant  to  R.R.J.  from  the  Marsden  Fund 
of  the  New  Zealand  Royal  Society  (UOC512). 

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819 


Rice,  W.R.  1989.  Analysing  tables  of  statistical 
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Wagner,  D.,  M.  Tissot,  W.  Cuevas  & D.M.  Gordon. 
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Manuscript  received  11  February  2004,  revised  27 
September  2004. 


2005.  The  Journal  of  Arachnology  33:820-825 


A NEW  TECHNIQUE  EOR  EXAMINING  SUREACE 
MORPHOSCULPTURE  OF  SCORPIONS 


Erich  S.  Volschenk':  Curtin  University  of  Technology,  School  of  Environmental 
Biology,  GPO  Box  U 1987,  Perth,  Western  Australia  6845,  Australia;  Western 
Australian  Museum,  Francis  Street,  Perth  6000,  Western  Australia,  Australia;  and 
Queensland  Museum,  Box  3300,  South  Brisbane,  Queensland,  4101,  Australia. 

ABSTRACT.  A new  technique  for  examining  the  exomorphology  of  the  scorpion  epicuticle  is  described 
that  utilizes  the  fluorescent  property  of  scorpion  cuticle.  Fluorescence  of  the  scorpion  exoskeleton  under 
longwave  ultraviolet  light  is  a well  known  property  previously  only  utilized  for  the  capture  or  observation 
of  scorpions  at  night.  Fluorescence  is  an  energy  emission  that  is  analogous  to  the  secondary  electron 
emissions  utilized  in  electron  microscopy  to  provide  information  about  surface  detail.  This  new  technique 
is  fast,  inexpensive  and  non-destructive,  and  provides  an  alternative  means  of  documenting  of  surface 
macrosculpture  for  the  description  and  identification  of  scorpion  species. 

Keywords:  Fluorescence,  scorpion,  epicuticle,  exomorphology,  images 


Among  the  many  unique  and  unusual  fea- 
tures that  scorpions  exhibit,  arguably  the  most 
curious  is  their  fluorescence  on  exposure  to 
long  wavelength  UV  (ultraviolet  light).  Fluo- 
rescence is  an  energy  (light)  emission  that  re- 
sults from  the  excitation  of  electrons  in  certain 
compounds  by  light  of  specific  wavelengths. 
Once  excited  by  a photon,  the  electrons  of 
these  compounds  almost  immediately  return 
to  their  previous  energy  state,  and  simulta- 
neously a lower  level  energy  emission  (visible 
light)  results. 

Pavan  (1954a)  first  demonstrated  that  UV 
light  of  wavelength  366.3  nm  causes  maxi- 
mum fluorescence  of  scorpion  epicuticle. 
Scorpion  fluorescence  has  captivated  the  in- 
terest of  researchers  (Honetschlacher  1965; 
Lawrence  1954;  Williams  1980)  since  it  was 
revealed  that  they  exhibit  this  curious  phe- 
nomenon. Pavan  (1954a,  1954b)  found  that 
the  fluorescence  emanates  from  the  outermost 
layer  of  the  cuticle,  the  epicuticle,  but  was  un- 
able to  discover  the  fluorescent  compound  or 
compounds.  More  recently,  Stachel  and 
Stockwell  (1999)  isolated  the  fluorescent  com- 
pound, (3-carboline,  from  scorpion  epicuticle. 

' Corresponding  address:  Department  of  Inverte- 
brate Zoology,  American  Museum  of  Natural  His- 
tory, 79th  street  @ Central  Park  West,  New  York, 
NY.  10024,  United  States  of  America.  E-mail: 
e volsche  @ amnh.org 


The  intensity  of  scorpion  fluorescence  varies 
among  species  and  the  time  elapsed  since  the 
last  molt,  and  non-fluorescent  scorpions  are 
unknown  (Stahnke  1972).  Despite  a reason- 
able understanding  of  the  origins  of  the  fluo- 
rescence in  scoipions,  there  is  still  no  consen- 
sus as  to  why  this  phenomenon  exists.  The 
fluorescent  property  has  to  date  been  exploited 
most  successfully  as  a tool  in  their  observa- 
tion, detection  or  capture  (Stahnke  1972). 
Scorpions  are  predominantly  nocturnal  and, 
equipped  with  a blacklight,  a researcher  can 
find  many  more  specimens,  as  well  as  species, 
at  night  than  is  possible  during  the  day  with 
an  equivalent  searching  effort  (Honetschlach- 
er 1965;  Lamoral  1979;  Sissom  et  al.  1990; 
Williams  1980). 

Images  of  biological  specimens  made  from 
SEM  (scanning  electron  microscopes)  pre- 
dominantly utilize  the  detection  of  emission 
of  SEs  (secondary  electrons)  to  form  digital 
images.  Secondary  electrons  result  when  a fo- 
cused beam  of  electrons  of  sufficient  accel- 
eration voltage  passes  over  a suitable  (con- 
ductive) subject,  typically  of  high  molecular 
mass.  High  energy  electrons  from  the  primary 
beam  displace  loosely  bound  outer-orbital 
electrons  in  the  subject,  and  SEs  are  emitted 
from  the  surface  of  the  specimen.  These  SEs 
have  a different  voltage  (energy)  to  that  of  the 
electron  beam  that  scans  the  surface  of  the 


820 


VOLSCHENK— IMAGING  SCORPION  FLUORESCENCE 


821 


Figure  1. — Carapace  of  Lychas  sp.I.  from  Aus-  Figure  2. — Carapace  of  Lychas  sp.l.  from  Aus- 
tralia (WAM;  conventional  image  (scale  bar  = tralia,  fluorescence  image  (scale  bar  = 1mm). 
1mm). 


specimen  and  are  principally  utilized  in  the 
production  of  images  of  surface  detail  from 
electron  microscopes.  The  production  of  the 
SE  emission  in  an  electron  microscope  is  anal- 
ogous to  the  light  emission  called  fluores- 
cence, and  prompted  the  author  to  considered 
experimentation  with  imaging  of  cuticular  sur- 
face detail  from  the  fluorescence  of  scorpions. 
The  surface  sculpturing  (granulations  and  ca- 
rinae)  of  scorpions  is  frequently  utilized  in  the 
identification  of  species  (Lamoral  1979;  Sis- 
som  1990),  however,  this  useful  character  can 
be  difficult  to  examine  as  it  is  often  obscured 
by  complex  color  patterns  lying  beneath  the 
cuticle.  Images  made  using  this  fluorescence 
technique  were  recently  published  by  Prendini 
(2003a,  2003b,  2003c)  and  further  exemplify 
its  usefulness. 

METHODS 

The  specimens  used  to  exemplify  this  tech- 
nique are  lodged  in  the  Western  Australian 
Museum:  Lychas  sp.  1 (ESV2255),  Lychas 
sp.2  (T56392)  and  Lychas  variatus  (Thorell 
1876)  (WAM  97/1226);  and  the  Queensland 
Museum:  Hemilychas  alexandrinus  (Hirst 


1911)  (S58519).  Images  were  taken  with  a 
Leica  DC  100  digital  camera  attached  to  a Lei- 
ca  MZ6  stereo  dissection  microscope,  fitted 
with  an  iris  diaphragm.  Standard  illumination 
was  provided  from  a Leica  light  source.  Ul- 
traviolet illumination  was  provided  from  mod- 
ified portable  blacklight  units  normally  uti- 
lized in  the  field  detection  and  collection  of 
scorpions.  Each  unit  consisted  of  a portable 
12V  fluorescent  light  fixture,  fitted  with  two 
black  light  tubes  (National,  FL8  BL-B),  and 
powered  by  a 12V  rechargeable  lead-acid  bat- 
tery (Panasonic,  LC-R127R2P).  When  fluo- 
rescence images  were  being  taken,  the  two 
blacklights  were  placed  on  either  side  of  the 
specimen.  Specimens  were  imaged  at  night  to 
minimize  extraneous  light.  Conventional  illu- 
mination was  used,  with  the  iris  diaphragm 
fully  constricted  to  provide  maximum  depth 
of  field,  to  position  and  focus  the  image,  after 
which  the  blacklights  were  switched  on  and 
all  other  sources  of  illumination  (except  com- 
puter monitor  which  was  turned  away  from 
the  microscope)  were  switched  off.  All  images 
were  taken  with  the  slow  imaging  option  of 
the  DC  100  software,  owing  to  the  lower  in- 
tensity of  the  fluorescence,  longer  periods  (up 


822 


THE  JOURNAL  OF  ARACHNOLOGY 


Figure  3. — Mesosomal  tergites  of  Lychas  sp.2. 
from  Australia,  conventional  image  (scale  bar  = 
1mm). 


to  10  seconds)  were  required  per  image  cap- 
ture. 

For  imaging,  each  specimen  was  placed 
into  a small  glass  petri  dish  with  enough  90- 
100%  ethanol  to  just  cover  it.  The  clarity  of 
the  image  deteriorated  considerably  as  the 
depth  of  ethanol  above  the  specimen  in- 
creased. More  dilute  concentrations  of  ethanol 
were  also  trialed,  however  70-80%  mixtures 
developed  a faint  scum  over  the  surface  that 
decreased  the  clarity  of  the  images. 

Images  of  epicuticle  fluorescence  were  in 
shades  of  blue,  and  these  were  converted  to 
greyscale  in  the  graphics  editing  package  Cor- 
el® Photo-Paint  (version  7).  Some  images 
were  also  enhanced  for  publication  by  making 
minor  improvements  to  levels  of  brightness 
and  contrast,  the  same  adjustments  typically 
being  conducted  on  images  made  using  a 
SEM.  The  technique  described  in  this  contri- 
bution is  exemplified  using  four  different  spe- 
cies of  Australian  buthids. 

RESULTS 

Fluorescence  images  (Figs.  2,  4,  6 & 8)  re- 
veal grey  scale  surface  detail  and  structure  of 
the  external  sculpturing  of  scorpion  exoskel- 


Figure 4. — Mesosomal  tergites  of  Lychas  sp.2. 
from  Australian,  fluorescence  image  (scale  bar  = 
1 mm). 


eton.  Conventional  imaging  under  ethanol  al- 
most completely  obscures  the  surface  sculp- 
turing in  images,  (Figs.  1,  3,  5 & 7)  but 
provides  accurate  documentation  of  color  pat- 
terning. Surface  detail  revealed  in  the  fluores- 
cent images  mimics  those  obtained  from  scan- 
ning electron  microscopes  except  that  setae 
and  macrosetae  are  not  revealed,  and  the 
depth  of  field  is  relatively  shallow. 

Figures  1 and  2 depict  the  carapace  of  Ly- 
chas sp.  1,  an  undescribed  species  from  Aus- 
tralia. The  specimen  had  become  badly  dis- 
torted during  or  following  preservation  (tissue 
displacement  was  evident  beneath  the  cuticle). 
Consequently,  under  conventional  illumina- 
tion the  carapace  had  a glassy  semitransparent 
appearance,  resulting  from  light  reflecting 
from  beneath  the  carapace.  The  fluorescent 
image  reveals  only  the  surface  detail  and  this 
detail  could  accurately  be  compared  with 
more  intact  specimens  or  similarly  damaged 
specimens  to  facilitate  the  identification  of 
more  intact  specimens  of  this  species.  Figures 
3 and  4 depict  the  mesosomal  tergites  of  Ly- 
chas sp.  2,  another  undescribed  Lychas  spe- 
cies from  Australia.  Figure  5 depicts  the  or- 
nately patterned  carapace  of  Lychas  variatus 


VOLSCHENK— IMAGING  SCORPION  FLUORESCENCE 


823 


Figure  5. — Carapace  of  Lychas  variatus  (Thorell 
1876),  conventional  image  (scale  bar  = 1mm). 


while  the  fluorescent  image  (Fig.  6)  reveals 
the  poorly  sculptured  surface.  Figures  7 and  8 
depict  the  lateral  aspects  of  metasomal  seg- 
ment V of  Hemilychas  alexandrine,  another 
Australian  buthid.  The  finely  reticulate  pattern 
is  seen  in  Fig.  7 using  standard  illumination, 
whereas  punctated  nature  of  this  metasomal 
segment  is  revealed  in  the  fluorescent  image, 
Fig  8.  In  this  case  the  fluorescent  image  re- 
vealed surface  detail  not  associated  with  gran- 
ulations, but  with  punctations. 

DISCUSSION 

The  technique  described  here,  for  imaging 
scorpions  under  UV  light  provides  images 
with  detail  similar  to  those  taken  with  a scan- 
ning electron  microscope.  Unlike  specimens 
examined  in  a conventional  SEM,  those  from 
which  the  fluorescence  images  were  made 
were  not  coated  in  conductive  material  and 
were  taken  under  normal  atmospheric  condi- 
tions. Fluorescence  imaging  is  a non-destruc- 
tive technique  that  can  be  applied  to  type 
specimens.  These  images  reveal  information 
about  the  surface  sculpturing  of  the  cuticle 
that  may  otherwise  be  obscured  or  over-en- 
hanced by  subcuticular  pigmentation.  Images 


Figure  6. — Carapace  of  L.  variatus,  fluorescence 
image  (scale  bar  = 1mm). 


of  scorpion  fluorescence  are  proposed  to  aug- 
ment line  drawings  for  the  documentation  of 
surface  sculpture  in  scorpions.  This  imaging 
protocol  provides  a much  cheaper  substitute 
for  SEM.  Using  a digital  camera,  mounted  to 
a dissection  microscope,  images  can  be  taken 
as  quickly  or  slowly  as  possible  and  adjust- 
ment of  the  specimen  can  be  made  directly 
and  immediately.  A particular  advantage  of 
this  technique  over  SEM  is  the  ability  to  man- 
age very  large  specimens.  Many  scorpions  are 
too  large  to  be  examined  examined  using 
SEM  without  dissecting  the  specimen  before 
mounting  the  area  of  interest  onto  a stub.  The 
fluorescent  technique  described  here  can  be 
applied  to  large  scorpions  without  dissecting 
the  specimen. 

Some  drawbacks  of  this  technique  relate  to 
the  low  depth  of  field  experienced  at  high 
magnifications,  and  a slightly  grainy  appear- 
ance to  the  images.  The  relatively  large  size 
of  scorpions,  compared  with  most  other  chel- 
icerates,  implies  that  low  depth  of  field  issues 
are  not  likely  to  be  experienced  unless  im- 
aging the  smallest  of  scorpions,  or  very  small 
structures  such  as  chelicerae  and  tarsi.  An  ad- 


824 


THE  JOURNAL  OF  ARACHNOLOGY 


Figure  7. — Lateral  aspect  of  metasoma  V of 
Hemilychas  alexandrinus  (Hirst  1911),  convention- 
al image  showing  color  patterning  and  some  seta- 
tion  (scale  bar  = 1mm). 


Figure  8. — Lateral  aspect  of  metasoma  V of  H. 
alexandrinus:  fluorescence  image,  showing  surface 
punctations  (scale  bar  = 1mm). 


ditional  drawback  is  the  non-fluorescent  na- 
ture of  setae  and  macrosetae,  making  this 
technique  unsuitable  for  investigation  into 
chaetotaxy.  Interestingly,  the  base  of  some 
setae  and  the  areoles  of  trichobothria  typi- 
cally fluoresce  more  brightly  than  the  sur- 
rounding surfaces  and  this  property  can  assist 
in  the  location  of  trichobothria.  The  quality 
of  digital  images  has  improved  considerably 
since  this  study  was  conducted,  and  smoother 
images  are  already  characteristic  of  high  res- 
olution digital  cameras.  With  the  application 
of  fluorescent  stains  and  histological  prepa- 
rations, this  technique  may  be  applicable  to 
other  organisms  that  do  not  naturally  fluo- 
resce. 

ACKNOWLEDGMENTS 

This  paper  formed  part  of  the  author’s  doc- 
toral thesis,  which  was  supported  by  a Curtin 
University  Postgraduate  Scholarship,  and  re- 
search grant  from  ABRS  (Australian  Biolog- 
ical Resources  Study).  I thank  Prof.  Jonathan 
Majer  (Curtin  University  of  Technology)  for 
the  use  of  his  digital  camera  and  microscope 
set-up.  Thanks  are  also  given  to  Dr.  Mark  Har- 
vey and  Dr.  Bill  Humphreys  (Western  Austra- 
lian Museum),  Dr.  Robert  Raven  (Queensland 
Museum),  Dr.  Lorenzo  Prendini  (American 
Museum  of  Natural  History)  and  Dr.  David 
Sissom  (West  Texas  A&M  University)  and  the 
two  anonymous  referees  who  provided  con- 
structive reviews  of  earlier  versions  of  this  pa- 
per. 


LITERATURE  CITED 

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nals and  Magazine  of  Natural  History  (8)  8:462- 
473. 

Honetschlacher,  L.D.  1965.  A new  method  for  hunt- 
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Lamoral,  B.H.  1979.  The  Scorpions  of  Namibia 
(Arachnida:  Scorpionida).  Annals  of  the  Natal 
Museum  23:497-784. 

Lawrence,  R.E  1954.  Fluorescence  in  Arthropoda. 
Journal  of  the  Entomological  Society  of  South- 
ern Africa  17:167-170. 

Pavan,  M.  1954a.  Primi  dati  per  la  caraterizzazione 
della  sostanza  fluorescente  nel  tegumento  degli 
scorpion!.  Bolletino  Societa  Italiana  Biologia 
Sperimentale  30:803-805. 

Pavan,  M.  1954b.  Studi  sugli  scorpion!  I,  una  nuova 
caratteristica  tipica  del  tegumentodegli  scorpion!. 
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abuthiis  muelleri,  and  implications  for  the  phy- 
logeny  of  Parabuthus  (Scorpiones:  Buthidae). 
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Prendini,  L.  2003b.  A new  genus  and  species  of 
bothriurid  scorpion  from  the  Brandberg  Massif, 
Namibia,  with  a reanalysis  of  bothriurid  phylog- 
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of  Lisposoma  Lawrence.  Systematic  Entomology 
28:149-172. 

Prendini,  L.  2003c.  Systematics  and  biogeogra- 
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Scorpiones),  with  a discussion  on  phylogenetic 
methods.  Invertebrate  Systematics  17:185- 
259. 

Sissom,  W.D.  1990.  Systematics,  biogeography,  and 
paleontology.  In  G.  A.  Polls  (ed)  Systematics, 
biogeography,  and  paleontology.  Stanford  Uni- 
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Sissom,  W.D.,  G.A.  Polls  and  D.D.  Watt.  1990. 
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Stachel,  S.L.,  S.A.  Stockwell  and  D.L.V.  Vranken. 
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Manuscript  received  9 July  2003,  revised  30  June 
2004. 


2005.  The  Journal  of  Arachnology  33:826-849 


THE  EMERGENCE  OF  MANIPULATIVE  EXPERIMENTS 
IN  ECOLOGICAL  SPIDER  RESEARCH  (1684-1973) 

James  R.  Bell:  Warwick  HRI,  Wellesbourne,  Warwickshire.  CV35  9EE  UK.  E-mail: 
j.r.bell@warwick.ac.uk 

ABSTRACT.  The  history  of  spider  ecology  is  discussed  from  its  early  beginnings  in  1684  when  the 
natural  historian  Martin  Lister  published  his  observations,  to  the  post-war  period  up  until  1973  when 
ecological  spider  research  gathered  momentum.  While  there  have  been  many  important  observations  since 
Lister,  spider  ecology  appeared  explicitly  in  the  titles  of  papers  only  after  the  turn  of  the  20^*^  century. 
However,  much  of  what  was  published  up  until  the  1950s  is  of  little  scientific  value  because  these  works 
contained  natural  history  notes  and  conjecture,  not  manipulative  experimentation.  The  exception  was  a 
paper  written  in  1939  by  Pontus  Palmgren  who  was  not  an  ecologist  but  paradoxically  a functional 
anatomist  with  a particular  interest  in  ornithology.  His  paper  was  in  the  spirit  of  Ernst  Haeckel’s  original 
definition  of  ecology  that  was  seen  as  synonymous  with  physiology,  a legacy  that  was  detected  in  many 
of  the  papers  decades  after  Palmgren.  However,  there  was  little  evidence  that  ecological  theory  was  being 
tested.  Instead,  theoretical  inputs  were  largely  ignored  with  most  spider  ecologists  preferring  to  pursue  the 
somewhat  circular  interest  of  basic  observational  studies.  Eventually  after  some  considerable  delay,  Charles 
Elton’s  theories  of  the  niche  and  succession  fed  into  spider  ecology  but  the  papers  were  often  weak  and 
invariably  flawed  due  to  the  absence  of  experimental  manipulations.  Notably,  it  was  not  until  the  1950s, 
when  the  elegant  experiments  of  Edwin  Nprgaard  who  manipulated  the  system  in  order  to  understand  the 
interactions  between  spiders  and  their  environment,  that  scientific  spider  ecology  began.  Edwin  Nprgaard 
should  be  credited  as  the  father  of  ‘spider  ecology’,  although  Matthias  Schaefer  and  Sven  Almquist  also 
made  important  contributions  to  the  field  and  should  not  be  overlooked.  These  researchers  employed 
manipulative  techniques  during  a period  in  which  this  experimental  approach  was  not  widely  used  in 
spider  ecology.  I conclude  this  review  with  a look  to  the  future  and  predict  that  model  selection  will 
become  much  more  prevalent,  although  it  will  never  replace  manipulative  experimentation.  One  outstand- 
ing issue  that  has  remained  since  1684  has  been  the  gift  of  ecological  theory  to  the  wider  scientific 
community.  Although  spider  ecologists  have  received  theoretical  frameworks  from  other  disciplines  such 
as  botany  and  entomology,  they  have  never  reciprocated  although  they  are  now  well  placed  to  do  so. 

Keywords:  Ecology,  Nprgaard,  inductive  method,  history  of  science 


In  this  review,  the  aim  is  to  trace  the  early 
advances  in  spider  ecology  to  individual  au- 
thors who  were  instrumental  in  shaping  our 
current  understanding  of  ecology  as  a modern 
science.  The  motivation  for  this  paper  is  to 
reveal  to  the  ecological  community  some  of 
the  best  early  research  in  the  first  half  of  the 
20th  century  when  it  is  believed  that  ecolog- 
ical spider  experiments  really  began.  This  pe- 
riod has  remained  elusive  to  most  researchers, 
because  the  majority  of  ecological  literature 
pre-1970  is  not  available  electronically  and 
ecological  research  tends  to  have  a short  ci- 
tation life-time  which  rarely  extends  beyond  a 
decade.  For  example,  there  are  two  excellent, 
but  very  similar  experiments  on  orientation  in 
Frontinella  communis  (Hentz  1850)  (Linyphi- 
idae).  The  first  by  Pointing  (1965)  was  not 
picked  up  by  Suter  (1981)  or  those  who  did 


the  peer  review  and  editing,  simply  because 
the  reference  was  not  in  general  electronic  cir- 
culation (Robert  Suter  pers.  comm.).  This  is 
not  especially  embarrassing  because  for  most 
authors  there  has  rarely  been  a need  to  look 
deep  into  the  scientific  literature — in  fact,  eco- 
logical journals  positively  discourage  it. 

Contrast  this  experience  in  ecology  with 
that  of  spider  taxonomy  in  which  investigators 
can  turn  to  a series  of  catalogues  that  list  near- 
ly all  the  publications  since  Clerck  in  1757 
(e.g.,  Platnick  2005).  Taxonomists  have  the 
expectation  that  all  important  texts  will  be  cit- 
ed independent  of  date  of  original  publication, 
even  if  a paper  is  drawn  from  the  eighteenth 
century.  Ecology  would  sometimes  do  well  to 
embrace  the  citation  ethos  that  taxonomy  is 
unique  in  upholding.  There  is  a strong  argu- 
ment to  suggest  that  ecology  may  have  come 


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827 


out  of  the  doldrums  much  more  quickly  if 
studies  were  read,  cited  and  then  developed 
further.  Instead,  it  seems  that  many  of  the  in- 
dividuals working  during  the  embryonic  phase 
in  spider  ecology,  studied  in  isolation  with 
few,  if  any,  academic  exchanges. 

Ecology  could  be  described  as  a new  sci- 
ence because  it  is  less  than  150  years  old  and, 
for  example,  only  one  tenth  the  age  of  “Ar- 
istotelian” taxonomy.  Its  formal  beginnings 
were  in  1866  when  this  new  branch  of  science 
was  erected  by  Ernst  Haeckel,  a German  in- 
vertebrate zoologist.  Haeckel  coined  the  word 
“ecology”  in  his  book  “Generelle  Morphol- 
ogic der  Organismen”  from  the  Greek,  “oi- 
kos”  meaning  the  study  of  the  home.  Ecology 
has  always  been  defined  quite  loosely,  but  in 
this  review  it  is  defined  as  the  scientific  study 
of  the  abiotic  (e.g.,  temperature)  and  biotic 
(e.g.,  competition)  interactions  between  or- 
ganisms and  their  natural  environment.  Im- 
plicitly, ecology  contains  a field  component 
and  is  not  purely  laboratory  based. 

Defining  ecological  spider  research  as  sci- 
entific.— There  is  a need  to  make  objective 
judgments  about  which  papers  have  scientific 
merit,  versus  those  that  have  no  scientific  mer- 
it. To  assess  papers  for  scientific  merit,  there 
is  a need  to  be  clear  about  what  parameters 
underpin  science.  Although  there  is  general 
agreement  that  the  first  scientist  was  the  6^*^ 
century  B.C.  Greek  Thales  of  Miletus,  the  sci- 
entific method  with  which  we  are  familiar  to- 
day evolved  during  a revolution  of  thinking 
during  the  16^*^  century  onwards.  Ecologists 
generally  follow  the  scientific  protocol  known 
as  the  inductive  method,  rather  than  the  clas- 
sical deductive  method  practiced  by  a handful 
of  Bayesian  ecologists  and  the  great  majority 
of  physicists  (Popper  1977;  Murray  2001; 
Oksanen  2001).  This  distinction  is  important 
because  ecologists  are  often  not  aware  of  the 
dichotomy  between  these  approaches  or  the 
implications  of  applying  either  approach  to 
their  research.  The  replicated,  randomized  de- 
signs typical  of  the  inductive  methods  are  a 
vital  tool  to  ecologists  who  will  find  the  per- 
vasive use  of  universal  laws  an  anathema — 
the  reverse  is  true  for  a deductivist.  Oksanen 
(2001)  criticizes  such  a clear  distinction  ar- 
guing for  the  hybrid  approach  in  which  ecol- 
ogists switch  scientific  philosophies  depend- 
ing on  the  scale  of  the  system  and  the 
constraints  on  replication  and  randomization. 


In  the  current  climate,  he  has  mild  (Cottenie 
& De  Meester  2003)  or  no  support  (Hurlbert 
1984,  2004),  but  it  will  be  interesting  to  see 
how,  or  indeed  if,  this  debate  will  change  the 
way  ecological  experiments  are  done  in  the 
future.  Unlike  physics,  nearly  all  ecologists 
will  argue  that  “laws”  are  absent  from  ecol- 
ogy because  organisms  cannot  so  easily  be  pi- 
geon-holed. Consider  the  statement  that  “all 
spiders  are  entirely  carnivorous  in  the  pres- 
ence of  a diversity  of  prey.”  This  was  the  per- 
ceived view  until  very  recently  when  it  was 
found  that  a small  minority  of  spiders  inten- 
tionally supplement  their  diet  with  nectar  and 
pollen  (Jackson  et  al.  2001;  Ludy  2004).  That 
is  not  to  say  that  all  of  ecology  is  without 
basic  rules,  since  theorems  are  often  used  and 
are  sometimes  law-like  in  nature  (Turchin 
2001). 

Not  all  ecologists  are  theory  driven,  but  all 
recognize  that  ecology  is  empirical  and  there- 
fore implicitly  include  at  least  one  experiment. 
It  is  strongly  argued  by  many  that  experimen- 
tal ecology  should  include  a hypothesis  to  for- 
malize the  procedure  (Wise  1993  and  see 
Ricklefs  & Miller  1999  for  approach).  The  ap- 
proach to  formalizing  a hypothesis  is  poorly 
defined,  not  least  because  there  are  multiple 
opinions  of  what  constitutes  a hypothesis 
(Platt  1964;  Connor  & Simberloff  1986).  In 
the  context  of  this  paper,  I simply  refer  to  hy- 
potheses as  questions  or  statements  that  are  to 
be  tested,  accepting  that  this  definition  is  not 
all-encompassing.  Classically,  hypotheses 
were  of  the  null  form  (i.e.,  statement  of  no 
relationship;  a negative  statement),  which 
have  been  heavily  criticized  in  ecology  and 
are  now  not  widely  used  (Quinn  & Dunham 
1983;  Turchin  1999;  Anderson  et  al.  2000; 
Murray  2001).  Instead,  science  now  encom- 
passes many  variants  including  statistical  (i.e., 
the  use  of  predictors  and  probabilities  to  eval- 
uate relationships)  and  alternative  hypotheses 
(i.e.,  statement  of  a relationship;  a positive 
statement),  all  of  which  I consider  valid  for 
the  purpose  of  this  review  (Platt  1964;  John- 
son 1999;  Anderson  et  al.  2000). 

Ecological  research  that  has  gained  the 
most  credibility  has  been  that  which  includes 
manipulative  experiments  to  control  more 
clearly  the  effects  of  a variable  on  a subject 
(Hairston  1989;  Wise  1993;  Ricklefs  & Miller 
1999;  Hurlbert  2004).  Without  manipulation, 
ecology  becomes  very  generalized  and  has 


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THE  JOURNAL  OF  ARACHNOLOGY 


very  little  explanatory  power  because  it  lacks 
the  appropriate  conditions  and  controls.  Such 
studies  that  are  without  manipulation  can  only 
be  suggestive,  rather  than  explicit  tests  of  hy- 
potheses and  tend  to  be  observational.  Obser- 
vational studies  occupy  a “half-way  house” 
between  natural  history  and  formal  science 
(Lubchenco  & Real  1991;  Wise  1993).  Ob- 
servational studies  have  an  empirical  basis, 
but  no  treatment  structure  and  represent  much 
of  what  spider  ecologists  practice.  While  this 
method  is  not  a test  of  a hypothesis,  it  forms 
the  essential  groundwork  for  later  explicit 
testing  and  is  a valuable  scientific  tool  as  long 
as  the  results  are  not  overstated. 

There  is  a need  to  make  a distinction  be- 
tween ecology  and  other  related  disciplines. 
Natural  history  and  faunistics  often  purport  to 
be  a branch  of  ecology  and  are  sometimes  re- 
ferred to  as  “scientific.”  Without  exception 
these  neither  present  any  kind  of  hypothesis  or 
manipulation  and  are  without  any  rigid  exper- 
imental framework.  Further  evolved  is  theoret- 
ical ecology  which  replaces  the  field  compo- 
nent with  mathematical  simulation.  Common 
to  these  three  disciplines  are  that  they  can  only 
generate  new  hypotheses  and  concepts,  but 
they  can  never  be  a real  test  of  them.  Conse- 
quently, theoretical  ecology,  natural  history 
and  faunistics  will  not  be  at  the  center  of  this 
review,  but  are  implicit  in  the  evolution  of 
ecology  as  a discipline  and  will  be  referred  to 
throughout. 

METHODS 

Literature  search. — In  the  trawl  of  ecolog- 
ical publications  for  this  review,  all  empirical 
experiments  up  to  1973  have  been  considered. 
The  process  of  deciphering  whether  hypothe- 
ses were  apparent  in  a paper  has  been  at  times, 
extremely  difficult  and  on  other  occasions 
quite  straight  forward.  This  is  because  some 
authors  were  quite  explicit  about  their  inten- 
tions expressing  them  in  bullet  form  (e.g.,  Hy- 
pothesis 1,  2 and  3 etc.),  while  others  were 
much  more  discrete.  I have  tried  to  highlight 
both  cases,  but  will  have  inevitably  failed  to 
classify  all  types  correctly.  Thus,  I offer  my 
interpretations  of  what  hypotheses  are  being 
tested  as  suggestive,  but  not  conclusive.  What 
was  easier  to  assess  was  the  quality  of  the 
empirical  data  as  well  as  the  subject  or  its  en- 
vironment being  tested.  In  the  review,  I have 
drawn  attention  to  some  of  the  best  manipu- 


lations and  highlighted  others  that  I have  felt 
to  be  fundamentally  erroneous.  Until  the 
1 950s,  results  were  rarely  rationalized  through 
the  use  of  any  statistics,  therefore  I have  not 
imposed  the  need  for  statistical  tests  so  long 
as  data  have  been  given  appropriate  interpre- 
tation. Thus,  the  best  examples  I highlight  fol- 
low a logical  sequence  of  hypothesis  state- 
ments, experimental  manipulation,  data 
acquisition  and  rationalization,  which  I iden- 
tify as  the  benchmark  for  the  purposes  of  this 
review. 

For  the  review  of  the  spider  literature, 
Pierre  Bonnet’s  “Bibliographia  Araneorum” 
(Bonnet  1945)  which  lists  8000+  papers  from 
Aristotle  to  1939  was  used — all  titles  were 
read  in  combination  with  the  online  database 
JSTOR  which  covered  the  period  1684-1973. 
Post  1939,  the  Zoological  Record  replaced 
Bibliographia  Araneorum.  For  both  Bonnet 
and  the  Zoological  Record,  the  search  term 
“ecolog*”  and  its  linguistic  derivatives  “oko- 
log*/ecologisch*/ekologitsch*”  were  selected 
as  keywords  that  might  appear  in  the  title  of 
an  ecological  paper.  For  the  JSTOR  search 
(1684-1973),  all  papers  that  included  one  or 
more  of  the  following  keywords  “spider,  spi- 
ders, ecology,  ecological,  aranea,  araneae” 
were  read.  Additionally,  the  “Web  of  Sci- 
ence” online  database  was  searched  using  the 
terms  “aranea*  OR  spider*  NOT  mite*  NOT 
monkey*”  from  1970,  the  date  of  its  incep- 
tion, to  1973.  While  these  keyword  searches 
are  not  a “catch-all”  of  the  entire  ecological 
literature,  it  does  strike  at  the  center  of  the 
subject.  Once  papers  were  identified,  they 
were  critically  examined  for  evidence  of  a hy- 
pothesis, experimental  framework,  manipula- 
tion etc,  as  described  above.  The  limitation  of 
this  study  is  that  papers  published  in  non-Eu- 
ropean languages  have  not  been  analyzed. 

THE  HISTORY  OF  ECOLOGICAL 
SPIDER  RESEARCH 

The  ecological  spider  literature  between 
1684  and  1956:  a period  of  slow  develop- 
ment.— The  illusion  that  readers  may  have  is 
that  ecology  started  early  in  the  19*'^  century, 
as  a literature  scan  reveals  a plentiful  supply 
of  “ecological”  publications.  For  example,  a 
paper  by  Boys  (1880)  on  the  influence  of  the 
tuning  fork  on  the  orb  web  of  the  garden  spi- 
der appears  to  be  a promising  ecological  in- 
vestigation, detailing  how  he  simulated  the  vi- 


BELL— A HISTORY  OF  ECOLOGICAL  SPIDER  RESEARCH 


829 


Figure  1. — John  Blackwall  (1790-1881)  is  cred- 
ited as  the  first  to  recognize  the  taxonomic  impor- 
tance of  the  male  palpus.  Other  than  his  taxonomic 
work,  he  also  conducted  behavioral  experiments  on 
spiders,  including  those  on  ballooning  motivation, 
in  which  he  referred  to  hypotheses.  Additionally,  he 
also  wrote  15  papers  on  ornithology  and  is  recog- 
nized as  having  made  an  important  contribution  to 
the  study  of  bird  migration.  Source:  Photo  Bonnet 
(1945)  plate  IV.  Note:  The  Natural  History  Muse- 
um, London  holds  many  portraits  of  scientists,  but 
the  original  of  John  Blackwall  appears  to  have  been 
lost.  Bonnet  (1945)  now  appears  to  be  the  only 
source  (Peter  Merrett  pers.  comm.). 

brations  of  a trapped  fly;  a basic  example  of 
a manipulation.  However,  Boys  (1880)  was 
unable  to  interpret  the  effect  of  the  tuning 
fork,  nor  did  he  collect  any  worthwhile  data 
to  present.  Boys  (1880)  is  not  unusual  for  his 
time,  as  many  articles  are  of  a similar  type. 
For  example,  John  Blackwall  (Fig.  1),  the  re- 
nowned English  arachnologist  who  first  dis- 
covered the  taxonomic  importance  of  palps 
and  epigyna,  could  also  have  been  the  founder 
of  spider  ecology.  Writing  between  1827- 
1877,  Blackwall  was  an  independent  thinker 
and  not  one  to  conjecture.  To  the  ecologist,  he 
will  be  best  known  for  attempting  to  unravel 
the  mechanics  of  ballooning  spiders  which 


Figure  2. — Martin  Lister  (birth  not  recorded,  but 
baptized  1639,  died  1712),  a medic,  is  widely  rec- 
ognized as  the  “father  of  arachnology.”  In  1685, 
Lister  was  elected  as  vice  president  of  the  Royal 
Society  under  the  president  Samuel  Pepys,  in  rec- 
ognition of  his  achievements  in  natural  history.  His 
interests  did  not  stop  at  spiders,  and  perhaps  his 
greatest  accolade  was  for  his  research  in  conchol- 
ogy.  He  recognized  the  value  of  fossils  and  was  the 
first  to  attempt  a comparative  anatomy  of  the  Mol- 
lusca  in  his  “Exercitatio  anatomica,”  “Historia  sive 
synopsis  methodica  conchyliorum”  and  “Historia 
conchyliorum,”  which  have  received  lasting  rec- 
ognition. However,  although  he  made  plenty  of  ob- 
servations of  spiders  and  other  organisms,  he  did 
not  complete  any  formal  experiments  and  he  is  best 
described  as  a taxonomist,  natural  historian  and  in- 
tellectual. Source:  Photo  supplied  by  kind  permis- 
sion of  Basil  Harley  and  John  Parker,  the  authors 
of  “Martin  Lister’s  English  Spiders,  1678”  pub- 
lished by  Harley  Books. 

had  captured  the  attention  of  a number  of  em- 
inent scientists  since  the  17‘^  century,  most  no- 
tably Martin  Lister  (1684)  who  recognized 
that  it  was  silk  that  dragged  spiders  into  the 
atmosphere  (Fig.  2). 

It  was  not  until  later  that  Bon  de  Saint-Hi- 
laire  (1710)  described  the  forces  that  cause 
lift.  However,  there  was  also  some  fanciful 


830 


THE  JOURNAL  OF  ARACHNOLOGY 


thinking  that,  for  example,  gossamer  was  the 
biproduct  of  evapotranspiration  at  harvest 
time  or  related  to  the  vapors  of  the  earth 
(Bechstein  1799).  Blackwall  was  able  to  dis- 
miss these  and  other  nonsenses  by  experimen- 
tation (Blackwall  1827).  He  first  described  the 
tip-toe  behavior  and  the  “force”  (i.e.,  drag) 
on  the  dragline  which,  through  convection  in 
the  planetary  boundary  layer  (which  he 
termed  “rarefraction  of  the  air  contiguous  to 
the  heated  ground”),  allowed  spiders  to  be- 
come airborne.  Rather  ground  breaking  was 
the  recognition  that  spiders  have  some  limited 
control  over  their  excursion,  either  drawing  in 
the  line  or  allowing  more  silk  out,  though  pre- 
viously Lister  (1684)  intimated  that  this  might 
be  a possibility.  Despite  these  leaps  of  knowl- 
edge, Blackwall  never  presented  any  data  or 
described  even  his  experiments  in  sufficient 
detail  that  they  could  be  replicated.  He  did 
refer  to  hypotheses,  but  there  was  certainly  no 
evidence  that  these  were  formally  tested  and 
thus  it  is  difficult  to  judge  the  validity  of  his 
claims.  It  is  arguable  that  whilst  Blackwall 
was  clearly  a man  before  his  time,  he  did  not 
practice  science,  but  instead  published  obser- 
vation with  limited  interpretation  and  may 
best  be  described  as  a natural  philosopher  and 
taxonomist. 

It  may  seem  harsh  to  judge  Blackwall  ac- 
cording to  procedures  of  contemporary  mod- 
ern science,  but  in  fact  “modern  deductive 
science”  was  practiced  150  years  before 
Blackwall — see  exhaustive  treatment  of  the 
history  of  science  in  Gribbin  (2002).  Argu- 
ably, the  first  practitioner  of  modern  deductive 
science  was  Isaac  Newton.  Newton  experi- 
mented at  the  same  time  that  Martin  Lister 
was  active  in  arachnology  and  both  were  fel- 
lows of  the  Royal  Society  at  its  inception  in 
1662.  One  can  only  speculate  whether  Newton 
and  Lister  actually  ever  met  as  fellows  in  the 
rooms  of  the  Royal  Society,  it  being  a breed- 
ing ground  for  new  ideas.  Lister's  big  idea 
was  that  silk  gave  spiders  lift,  the  number  and 
length  of  the  threads  and  the  spider’s  posture 
determined  whether  they  were  to  be  “carried 
into  the  air  by  an  external  force”  (Lister  1684 
p.  593).  To  understand  principles  of  “drag,” 
which  underpin  ballooning,  is  complex  and 
does  require  a rigorous  understanding  of  New- 
tonian physics  and  a good  manipulative  ex- 
periment— Lister  had  neither.  However,  in 
terms  of  his  thinking.  Lister  was  a man  before 


his  time  because,  even  in  today’s  research 
world  with  the  most  sophisticated  technology 
at  our  disposal  and  with  over  300  years  of 
Newtonian  physics  behind  us,  quantifying 
Lister’s  “external  force”  is  at  the  cutting  edge 
of  current  scientific  discovery.  We  should  re- 
flect on  the  merits  of  Lister’s  work  in  terms 
of  his  ground-breaking  work  on  the  taxonomy 
and  classification  of  spiders  and  shells  (Fig. 
2),  accepting  that  he  also  made  a philosophi- 
cal, but  not  an  experimental  contribution  to 
dispersal  ecology. 

That  there  was  an  absence  of  scientific  eco- 
logical experimentation  until  the  mid  part  of 
the  20^*^  century  is  not  to  dismiss  the  fact  that 
there  were  many  good  practitioners  of  natural 
history  during  and  after  BlackwalTs  period. 
Some  of  these  individuals  took  the  opportu- 
nity to  publish  beautifully  illustrated  taxo- 
nomic notes  supplemented  with  limited  as- 
pects of  spider  behavior,  many  of  which  are 
now  seen  as  “classics.”  These  included  the 
Reverend  Octavius  Pickard  Cambridge  (“Spi- 
ders of  Dorset”  published  between  1879- 
1881),  James  Emerton  (“The  Common  Spi- 
ders of  the  United  States”  published  1902), 
and  latterly  B.J.  Kaston  (“The  Spiders  of 
Connecticut”  published  1948),  W.  Gertsch 
(“American  Spiders”  published  1949)  and 
George  Locket  & Arthur  Millidge  (“British 
Spiders”  published  between  1951-1953). 
Others  were  more  explicit  about  the  natural 
history  content,  devoting  most,  if  not  all  of 
their  book  to  observation.  These  began  in  the 
latter  half  of  the  19‘^  century  with  Henry 
McCook  (“American  Spiders  and  their  Spin- 
ning Work”  published  between  1889-1894), 
Eugene  Simon  (“Histoire  Naturelle  des  Araig- 
nees”  published  between  1892-1903),  Pele- 
grin  Franganillo-Balboa  (“Las  Aranas”  pub- 
lished 1917),  E.  Nielsen  (“De  Danske 
Edderkoppers  Biologi”  published  1928),  Lu- 
cien  Berland  {Les  Araignees  published  1938) 
and  William  Bristowe  (“The  Comity  of  Spi- 
ders” published  1939-1941).  Some  authors 
were  able  to  reach  a wider  market  by  popu- 
larizing their  work  to  a mass  audience.  Ar- 
guably, this  began  with  John  Comstock  and 
his  “The  Spider  Book”  (published  1913)  and 
followed  much  later  by  K.  McKeown  (“Spi- 
der Wonders  of  Australia”  published  1936) 
and  John  Crompton  (“The  Spider”  published 
1950).  Good  though  their  observations  may 
seem,  prudence  suggests  that  intimate  ecolog- 


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831 


ical  relationships  are  best  described  through  a 
process  of  experimentation  not  just  observa- 
tion; the  domain  of  journals  not  books. 

Of  all  of  the  8000+  papers  in  Bonnet’s  Bib- 
liographia  Araneorum,  less  than  0.1%  of  the 
journal  papers  mention  the  word  “ecology” 
or  its  linguistic  derivatives  “okologie/ecolo- 
gie/ecologische/ekologitschni”  in  the  title.  Of 
those  that  do,  it  is  evident  that  ecology  as  a 
discrete  subject  appeared  in  the  first  half  of 
the  20^*^  century  (i.e.,  Shelford  1912;  Adams 
1915;  Rau  1922,  1926;  Weese  1924a,  1924b; 
Holmquist  1926;  Peus  1928;  Elliot  1930;  Ko- 
losvary  1930,  1933a,  1933b,  1937,  1938, 
1939a,  1939b;  Gebhardt  1932;  Krogerus 
1932;  Ives  1934;  Geijskes  1935;  Kidd  et  al. 
1935;  Drensky  1936;  Ksiazkowna  1936;  Le- 
ver 1937;  Petrusewicz  1938).  One  of  the  bet- 
ter papers  of  the  above  cohort  is  by  Frank  El- 
liott on  spiders  of  a beech-maple  forest 
published  in  1930.  Yet,  this  paper  and  all  the 
aforementioned  are  nothing  more  than  ex- 
panded field  notebooks  that  include  list  upon 
list  of  spiders  found  in  different  strata  or  sea- 
sons. It  is  recognized  that  the  early  naturalists 
needed  to  lay  foundations  and  simple  princi- 
pals to  investigate  the  possibility  of  further 
testing.  Yet,  at  the  same  time  they  had  no  fo- 
cus, or  apparent  aim  to  their  obsessional  col- 
lecting sprees.  While  one  can  find  merit  in 
their  observation,  the  lack  of  scientific  rigor 
in  the  pre-1939  literature  rarely  invites  close 
inspection  for  today’s  ecologists  except  to 
glean  distribution  and  habitat  data. 

The  lack  of  a scientific  approach  might  be 
explained  by  the  fact  that  only  a few  journals 
were  dedicated  to  solely  publishing  ecological 
experiments,  including  “Ecology”  (started 
1920),  “Zeitschrift  fiir  Morphologie  und  Oko- 
logie  der  Tiere”  (started  1924  but  now  known 
as  Oecologia  since  1968),  “Ecological  Mono- 
graphs” (started  1931),  “Journal  of  Animal 
Ecology”  (started  1932)  and  later  still,  “Oi- 
kos”  (started  1949).  However,  as  has  been  ev- 
ident throughout  the  screening  process,  find- 
ing a pre- 1950s  arachnological  “experiment” 
worthy  of  publication  in  these  international 
journals  has  been  challenging. 

One  fundamental  problem  was  that  ecolog- 
ical concepts  were  rarely  formalized  until 
Charles  Elton  (Fig.  3),  the  so  called  “father 
of  ecology,”  who  laid  the  foundations  for  fur- 
ther testing.  In  his  seminal  1927  book  titled 
“Animal  Ecology,”  Elton  outlined  several 


Figure  3. — Charles  Elton  (1900-1991)  was  edu- 
cated at  New  College  Oxford  where  he  immersed 
himself  in  zoology.  The  catalyst  for  his  radical 
thinking  was  a product  of  an  expedition  to  Spits- 
bergen in  1921,  where  he  was  struck  by  the  con- 
trasting life  histories  of  many  animals  living  there. 
Elton  produced  his  seminal  work  titled  “Animal 
Ecology”  in  1927  in  which  he  described  his  theory 
of  the  niche  and  his  pyramid  of  numbers.  Elton  had 
much  greater  impact  in  arachnology  than  his  pre- 
decessors. This  is  particularly  true  of  the  American 
Victor  Shelford  (1877-1968),  who  despite  formal- 
izing ecology  as  a discrete  science,  was  rarely  cited 
by  arachnologists.  Source:  Photo  supplied  by  Cath- 
erine Dockerty,  Reader  Services  Librarian,  Charles 
Elton  Library,  Department  of  Zoology,  Oxford  Uni- 
versity, UK. 

ecological  ideas  including  food  chains,  nutri- 
ent cycles,  ecological  niches  and  the  pyramid 
of  numbers.  If  arachnologists  had  embraced 
these  concepts  and  tested  Elton’s  theories, 
then  there  would  have  been  a plentiful  supply 
of  arachnological  experiments  worthy  of  in- 
ternational recognition.  Instead,  arachnolo- 
gists set  about  producing  a profusion  of  spe- 
cies lists,  often  without  interpretation  and 
making  no  attempt  to  relate  their  studies  with 
current  theory. 

Interpretation  of  data  is  greatly  aided  by 
statistical  inference,  but  statistics  were  absent 
from  ecology  until  the  turn  of  the  20^*’  century. 
The  lack  of  statistical  methodology  was  per- 
haps the  biggest  frustration  to  the  early  ecol- 
ogists who  were  unable  to  rationalize  their 
findings.  Arguably,  the  most  significant  ad- 
vance in  statistical  ecology  was  the  appoint- 
ment of  Ronald  A.  Fisher  (Fig.  4)  in  1922  to 
Rothamsted  Experimental  Station.  Fisher,  the 
architect  of  modern  statistical  field  ecology. 


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THE  JOURNAL  OF  ARACHNOLOGY 


Figure  4. — Sir  Ronald  Aylmer  Fisher  (1890- 
1962),  was  a eugenicist  and  friend  of  Leonard  Dar- 
win, son  of  Charles,  who  himself  was  the  president 
of  the  Eugenics  Education  Society  for  which  Fisher 
wrote  many  articles.  However,  he  is  best  known  for 
shaping  our  understanding  of  statistical  research 
methods  in  ecology.  Fisher  enforced  the  view  that 
experiments  need  to  have  both  treatments  and  a 
control.  Furthermore,  he  stated  that  these  must  be 
properly  replicated  and  randomized,  outlining  his 
ideas  in  books  aimed  at  field  ecologists.  He  will  be 
perhaps  best  remembered  in  statistics  for  the  AN- 
OVA,  which  was  developed  as  a result  of  his  work 
in  genetics.  The  ANOVA  was  first  used  to  show 
that  the  inheritance  of  continuous  traits  could  be 
fully  explained  by  a Mendelian  model.  This  valu- 
able tool  was  used  by  arachnologists  in  the  1950s 
and  thereafter  continuously  until  the  present  day. 
Source:  Photo  supplied  by  Gavin  Ross,  Rothamsted 
Research,  UK. 


developed  statistical  solutions  to  complex 
field  experiments,  such  as  the  ANOVA,  and 
laid  down  concepts  such  as  maximum  likeli- 
hood. Uniquely,  he  was  able  to  formalize  his 
approach  in  readable  texts  for  biologists.  His 
seminal  works  were  “Statistical  Methods  For 
Research  Workers”  and  “The  Design  of  Ex- 
periments” first  published  in  1925  and  1935 
respectively.  While  it  is  true  that  these  two 
texts  made  an  impact  in  some  areas  of  ecology 
soon  after  they  were  published  (e.g.,  botany 


and  entomology),  these  texts  did  not  feed  into 
spider  research  until  the  1950s  (e.g.,  Barnes 
& Barnes  1955;  Kuenzler  1958). 

For  some  unknown  reason,  theoretical  and 
statistical  hindrances  did  not  deter  entomolo- 
gists who  were  beginning  to  make  significant 
inroads  in  insect  science.  Of  particular  fasci- 
nation to  entomologists  at  that  time  were  com- 
petitive interactions  and  fluctuations  in  insect 
populations.  Mathematical  descriptions  of  the 
rhythmic  fluctuations  in  animal  populations 
had  been  available  since  the  1920s  (Lotka 
1925;  Volterra  1926;  Nicholson  & Bailey 
1935).  Later,  Crombie  (1945,  1946)  was  one 
of  the  hrst  to  test  the  model  on  insects.  Work- 
ing with  two  species  of  grain  beetle  from  the 
genera  Tribolium  (Coleoptera,  Tenebrionidae) 
and  Oryzaephilus  (Coleoptera,  Silvanidae), 
Crombie  was  able  to  measure  the  equilibrium 
population  densities  and  competition  coeffi- 
cients to  show  that  coexistence  did  occur  at 
the  predicted  levels,  thus  validating  his  model. 
Similarly,  Varley  (1947)  should  also  be  men- 
tioned for  his  scientific  approach  to  the  study 
of  the  knapweed  gall-fly,  Urophora  jaceana 
(Hering  1935)  (Diptera,  Tephritidae),  in  which 
he  was  able  to  determine  the  density  depen- 
dent factors  which  affected  mortality.  Ecology 
appeared  to  be  alive  and  well  in  entomology 
(see  Varley  et  al.  1973)  but  was  suffering  from 
poor  health  in  arachnology.  Spider  ecology’s 
deep  malaise  was  only  lifted  by  the  interven- 
tion of  a physiologist  in  1939,  although  there 
were  some  encouraging  philosophical  begin- 
nings after  the  turn  of  the  20^^  century. 

The  earliest  ecological  reference  cited  by 
David  Wise  (1993),  the  author  of  the  only 
dedicated  book  on  spider  ecology,  was  Dahl 
(1906).  Friedrich  Dahl  published  over  60  pa- 
pers on  spiders  between  1883-1927,  but  it 
was  Dahl’s  (1906)  paper  on  mating  success 
that  showed  he  could  think  along  ecological 
lines,  stating  “there  are  no  two  species  of  in- 
digenous spiders  that  occupy  precisely  the 
same  position  in  nature’s  household”  (quoted 
from  Wise  1993).  However,  Dahl  was  a nat- 
ural philosopher,  a hypothesis  generator,  not  a 
tester  of  his  own  ecological  theories.  Like- 
wise, much  the  same  could  be  said  for  Her- 
mann Wiehle  who  studied  the  structure  and 
function  of  the  orb  web  for  his  PhD  thesis  at 
the  University  of  Halle.  He  published  contin- 
uously for  nearly  50  years  but  5 papers  be- 
tween 1927  and  1937,  mostly  for  the  journal 


BELL— A HISTORY  OF  ECOLOGICAL  SPIDER  RESEARCH 


833 


‘'Zeitschrift  fur  Morphologic  und  Okologie 
der  Tiere,”  are  notable  (cited  in  Bonnet  1945). 
However,  despite  this  prolific  academic  activ- 
ity,  Wiehle  was  only  concerned  with  the  con- 
struction of  the  web  and  its  measurement,  sad- 
ly ecology  was  never  at  the  center  of  his 
observations  (Samuel  Zschokke  pers.  comm.). 
This  is  perhaps  because  Wiehle  worked  as  a 
teacher  and  industrial  worker  after  his  PhD 
and  had  no  resources  to  answer  the  ecological 
questions  that  must  have  arisen  during  his  re- 
search. Questions  regarding,  for  example,  ori- 
entation and  behavioral  thermoregulation, 
would  probably  have  been  observed  by  Wieh- 
le, although  to  answer  these  would  have  re- 
quired a mathematical  understanding,  a good 
experiment  and  plenty  of  time.  Two  well  ex- 
ecuted examples  came  very  much  later.  Both 
Pointing  (1965)  and  Krakauer  (1972)  did  have 
good  experiments,  but  they  were  also  reliant 
on  the  latest  technology  to  make  accurate  tem- 
perature measurements.  The  level  of  accuracy 
allowed  them  to  draw  the  same  conclusion 
that  web- spinning  spiders  use  behavioral  and 
physiological  thermoregulation — -something 
which  Wiehle  could  not  have  concluded  be- 
cause of  the  lack  of  suitable  apparatus  and  in- 
stitutional support.  However,  Wiehle  and  his 
peers  could  have  looked  at  simple  habitat  se- 
lection by  web- spinning  spiders  and  qualita- 
tively noted  the  effect  of  independent  vari- 
ables (e.g.,  wind)  in  the  same  vein  as  Eberhard 
(1971)  and  Enders  (1973).  These  were  good 
but  basic  studies  and  ones  that  Wiehle  and 
others  could  have  executed;  however,  despite 
their  obvious  suitability,  they  did  not  appear 
until  the  1960s. 

Foetus  Palmgren  (Fig.  5),  a distinguished 
Professor  of  Zoology  at  the  University  of  Hel- 
sinki between  1940-1971,  was  best  known  for 
his  anatomical  research  in  ornithology  (Ko- 
ponen  1994).  He  was  often  heard  repeating 
Galileo’s  motto  “to  measure  everything  and 
make  the  immeasurable  measurable”  (von 
Haartman  1994);  this  he  applied  rigorously  to 
his  work  on  the  functional  anatomy  of  bird’s 
legs,  spider  muscles  and  trichobothria.  Palm- 
gree  clearly  enjoyed  a diversity  of  disciplines, 
including  ecology,  publishing  one  scientific 
paper  of  note.  Between  finishing  his  PhD  and 
his  appointment  to  professorship,  Palmgren 
turned  his  attention  away  from  birds  for  a 
short  while  to  investigate  the  ecology  of  a 
fishing  spider  in  1939. 


Figure  5. — Professor  Pontus  Palmgren  (1907- 
1993),  a physiologist  who  thought  along  ecological 
lines  when  trying  to  unravel  the  effect  of  environ- 
mental stimuli  on  Dolomedes  fimbriatus.  However, 
he  will  be  best  remembered  for  his  groundbreaking 
work  in  ornithology,  particularly  that  which  relates 
to  functional  anatomy.  Source:  Photo  supplied  by 
kind  permission  of  his  son,  Kaj  Palmgren  and  with 
thanks  to  the  Tvarminne  Zoological  Station,  Uni- 
versity of  Helsinki,  Finland. 

Translated  from  its  original  German,  Palm- 
gren’s  (1939)  paper  was  titled  “Ecological 
and  physiological  studies  concerning  the  spi- 
der Dolomedes  fimbriatus  (Clerck  1757)  (Pi- 
sauridae).”  It  is  immediately  apparent  that  this 
paper  is  clearly  a significant  contribution  to 
ecology.  Furthermore,  it  is  in  the  spirit  of 
Ernst  HaeckeFs  original  definition  of  ecology 
that  was  seen  as  synonymous  with  physiology, 
a view  espoused  by  the  entomologist  Victor 
Shelford  and  by  others  after  the  turn  of  the 
20*  century  (McIntosh  1987).  The  paper  in- 
cludes a number  of  alternative  hypotheses  and 
manipulations  both  in  the  laboratory  and  the 
field.  Palmgren  (1939)  demonstrated  experi- 
mentally that  D.  fimbriatus  was  both  positive- 
ly phototaxic  and  negatively  geotactic  and 


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THE  JOURNAL  OF  ARACHNOLOGY 


was  aware  that  Dolomedes  preferred  damp 
habitats.  However,  while  he  could  demon- 
strate physiologically  that  individuals  dehy- 
drate quickly  through  the  skin,  he  was  unable 
to  explain  why  individuals  did  not  orientate 
themselves  towards  saturated  air  in  his  behav- 
ioral experiments  in  the  lab.  Palmgren  then 
studied  individuals  into  the  field  where  he  in- 
vestigated the  consequences  of  habitat  condi- 
tions on  spider  mortality.  Placing  individuals 
in  cages  (4  cm  X 2 cm)  in  four  different  hab- 
itats (10  individuals  per  habitat)  of  increasing 
dampness  (i.e.,  1.  open  pine  forest  with  dry 
heath  (Calluna  vulgaris  (L.));  2.  hazel  {Cor- 
ylus  avellana  L.)  copse;  3.  moist  mixed  Alnus 
glutinosa  (L.)-Betula  verrucosa  Ehrh.  wood 
and;  4.  a Sphagnum  moss  carpet  with  other 
marsh  plants),  he  then  measured  the  climatic 
conditions  and  lifespans  of  the  spiders  in  each 
treatment.  Palmgren  (1939)  was  fascinated  to 
observe  that  individuals  placed  in  the  bog  had 
the  longest  lifespans,  despite  the  climatic  con- 
ditions remaining  roughly  the  same  between 
the  four  habitats.  This  he  attributed  to  the  fact 
that  in  the  bog  there  was  always  a constant 
availability  of  water,  although  one  wonders 
why,  if  this  were  true,  he  never  recorded  com- 
pletely saturated  air  most  of  the  time.  It  is  sus- 
pected that  if  these  measurements  were  re- 
peated with  modern  data  loggers,  that  the 
variance  in  humidity  would  be  different  be- 
tween the  bog  and  the  dry  heath  and  may  have 
changed  the  course  of  his  discussion  slightly. 

It  is  perhaps  not  surprising,  given  that  this 
paper  is  written  in  German  and  not  electron- 
ically indexed,  that  it  is  rarely  cited  by  modern 
scientists.  In  one  sense,  this  is  a mistake  be- 
cause Palmgren  (1939)  was  way  ahead  of  his 
peers.  However,  Palmgren’s  (1939)  experi- 
ments do  not  always  stand  up  to  modern-day 
scrutiny.  The  physiological  measurements  are 
satisfactory,  and  the  only  thing  that  would 
change  if  repeated  today  would  be  the  tech- 
nology and  the  numbers  of  replicates.  How- 
ever, it  is  the  fieldwork  where  the  reader  is 
left  wanting.  As  would  be  commonplace  in 
any  study  of  its  kind,  the  first  step  would  have 
been  to  present  the  numerical  case  for  spiders 
appearing  to  have  some  kind  of  habitat  asso- 
ciation. This  could  have  been  done  with  sim- 
ple density  estimates  from  selected  habitats. 
The  second  step  would  have  been  to  design 
an  experiment  that  allowed  spiders  to  exploit 
their  environment  naturally,  observing  their 


behavior  and  the  frequency  of  mortality.  The 
idea  that  caged  spiders  are  a field  test  of  what 
was  observed  in  the  laboratory  is  idiosyncrat- 
ic. Modern  ecologists  do  confine  wandering 
spiders,  but  the  tendency  is  for  them  to  use 
large  semi-natural  enclosures  (i.e.,  >lm2),  not 
small  cages  (i.e.,  Scm^). 

It  is  clear  to  modern  ecologists  that  Palm- 
gren (1939)  needed  to  make  more  connections 
between  environment  and  spider  mortality, 
which  is  suggestive  of  a correlation  coeffi- 
cient. The  lack  of  statistical  inference  frus- 
trated many  ecologists  including  Shelford 
(1930,  p.  236)  who  stated  “often  one  sees  pa- 
pers containing  weather  data  with  no  interpre- 
tation or  correlation  of  the  biological  facts.” 
However,  even  though  correlations  were  used 
in  ecological  studies  of  the  period  (e.g.,  Nash 
1933),  they  were  by  no  means  commonplace. 
For  example,  even  under  the  supervision  of 
Ronald  Fisher,  Barnes  (1932)  overlooked  the 
importance  of  using  any  statistics  at  all  to  sup- 
port his  study  on  fluctuating  insect  popula- 
tions, which  is  remiss.  It  is  true  that  Palm- 
gren’s  (1939)  study  would  have  been  greatly 
improved  by  the  use  of  correlations,  but  sta- 
tistics were  not  part  of  the  culture  of  the  ma- 
jority of  ecologists  of  the  period,  and  Palm- 
gren cannot  be  chastised  for  this  omission. 

Ecological  theory  seemed  more  palatable 
than  statistics  to  arachnologists  and  finally 
showed  signs  of  making  an  impact,  particu- 
larly Elton’s  (1927)  theories  of  the  niche  and 
succession.  Elton’s  theories  became  the  pre- 
occupations for  post-war  arachnologists  (e.g., 
Gibson  1947;  Lowrie  1948;  Muma  & Muma 
1949;  Dowdy  1951  and  many  others  not  in- 
cluded here).  One  notable  Eltonite  was  an 
American  named  Robert  Barnes  who  exam- 
ined the  ecology  of  spiders  in  non-forested 
maritime  communities  for  his  PhD  at  Duke 
University,  North  Carolina.  Barnes  produced 
three  notable  papers  loosely  centered  around 
niche  theory  and  distribution  (Barnes  1953; 
Barnes  & Barnes  1954,  1955).  Arguably, 
Barnes’  most  cited  paper  is  his  1955  work  ti- 
tled “The  Spider  population  of  the  abstract 
broomsedge  community  of  the  southeastern 
Piedmont.”  This  paper  examined  the  spider 
community  in  terms  of  its  homogeneity,  den- 
sity, population  stability  and  range.  Barnes 
used  an  ANOVA  to  form  the  view  that  of  the 
29  fields  studied,  the  population  structure  was 
essentially  the  same — yet  for  all  the  paper’s 


BELL— A HISTORY  OF  ECOLOGICAL  SPIDER  RESEARCH 


835 


merits,  a hypothesis  was  lacking.  Despite  this 
and  other  papers  of  that  time  being  good  ex- 
amples of  basic  ecology,  they  fail  to  make  the 
relationship  between  environment  and  the  spi- 
der community,  because  they  did  not  try  to 
control  or  manipulate  the  system,  severely 
weakening  their  conclusions.  Barnes  could 
have  tried  to  deconstruct  the  abstract  com- 
munity by  manipulating  the  stand-type  to  see 
which  species  were  specifically  related  to  the 
structure  or  physiognomy  of  the  broomsedge. 
By  doing  so,  the  ecology  of  the  community 
would  have  been  more  clearly  understood. 
The  work  of  Barnes  and  others  of  the  time 
illustrate  that  many  “observational  studies” 
were  apparent  and  that  the  value  of  manipu- 
lation was  not  generally  recognized  until  later. 

Duffey  (1956)  was  one  of  the  first  to  in- 
clude a basic  manipulation  in  his  paper  on 
“The  aerial  dispersal  of  a known  spider  pop- 
ulation,” the  subject  of  his  PhD.  For  centuries, 
spiders  had  been  observed  ballooning,  al- 
though it  was  not  known  what  caused  them  to 
leave.  Duffey  set  about  attempting  to  under- 
stand the  influence  of  population  density  and 
microclimate  on  ballooning  success  by  using 
greased  canes  protruding  from  the  sward  of 
limestone  grassland.  While  one  can  detect  that 
Duffey  excelled  in  the  powers  of  observation, 
not  all  his  conclusions  are  supported  by  his 
data.  Fundamentally,  Duffey  should  have  ma- 
nipulated the  spider  and  microclimate  and 
then,  statements  such  as  “temperature  has  a 
more  important  influence  on  aerial  dispersal 
than  have  other  microclimatic  factors”  (p. 
Ill),  could  have  be  demonstrated  probabilis- 
tically, not  subjectively.  Thus  Duffey ’s  (1956) 
paper  pertains  to  be  a basic  manipulative  ex- 
periment which  does  not  explain  how  or  why 
they  balloon  or  shed  light  on  their  relationship 
with  the  habitat  and  its  role  in  dispersal.  Duf- 
fey published  several  other  ecological  papers 
which  tended  to  be  observational  studies  of 
conservation  management  appeal,  rather  than 
of  academic  scientific  interest. 

Edwin  N0rgaard  (Fig.  6),  a Danish  primary 
school  teacher,  published  two  ground-break- 
ing papers  in  the  journal  Oikos  which  are  still 
cited  fifty  years  after  their  publication 
(Nprgaard  1951,  1956).  It  was  these  and  other 
contributions  which  were  of  particular  inspi- 
ration to  Toft  (2002)  who  elucidated  upon 
N0rgaard’s  contribution  to  ecology  in  his 
opening  address  to  the  European  Colloquium 


Figure  6. — Edwin  Nprgaard  (1910-present)  the 
modern  day  father  of  spider  ecology  who  under- 
stood the  value  of  experimental  design.  His  two  pa- 
pers published  in  Oikos  are  seminal  works  and  con- 
tinue to  be  cited  50  years  after  their  publication. 
Educated  as  a school  teacher,  Nprgaard  did  his 
fieldwork  during  school  holidays,  managing  to 
maintain  parallel  interests  in  teaching  and  natural 
history.  He  wrote  39  papers,  articles,  books  and 
book  chapters  over  a period  of  1936-1998  and  was 
editor  of  the  Danish  journal  “Flora  og  Fauna”  for 
30  years.  Although  he  has  retired,  he  still  continues 
to  write  popular  articles  for  the  Natural  History 
Mueum,  Aarhus.  Source:  Spren  Toft,  University  of 
Aarhus,  Denmark.  Photo  supplied  by  E.  Nprgaard. 

of  Arachnology,  Denmark  2000.  Toft  (2002) 
cited  N0rgaard’s  first  ecology  paper  in  1951 
paper  as  “unprecedented  in  the  scientific  ap- 
proach” and  that  Nprgaard  “combined  field 
observations  with  detailed  laboratory  experi- 
mentation, turn[ing]  natural  history  into  the 
experimental  science  of  ecology.”  It  is  un- 
equivocal that  Toft  (2002)  believed  that 
N0rgaard  was  the  first  arachnological  ecolo- 
gist, but  he  was  not  alone.  The  best  textbook 
on  animal  ecology  during  the  post  war  period, 
referred  to  N0rgaard’s  work  as  “outstanding” 
(Macfadyen  1966,  p.  63). 


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THE  JOURNAL  OF  ARACHNOLOGY 


In  his  first  paper  N0rgaard  (1951)  presented 
a suite  of  experiments  which  sought  to  ex- 
amine the  distributional  ecology  of  two  co- 
occurring  lycosids  in  a sphagnum  bog.  His 
scientific  rigor  was  evident  by  his  thorough 
experimental  examination  and  manipulation 
of  the  microclimate.  Having  made  microcli^ 
matic  field  measurements  in  the  different 
zones  of  the  sphagnum,  he  did  not  conjecture 
that  microclimate  was  determining  the  differ- 
ences between  the  distribution  of  Pardosa 
pullata  (Clerck  1757)  and  Pirata  piraticus 
(Clerck  1757)  (Lycosidae).  Instead,  he  went 
into  the  laboratory  to  manipulate  these  vari- 
ables and  examine  more  closely  their  effect 
on  the  spiders.  By  doing  so,  he  linked  the  lab 
to  the  field  to  erect  a probable  “cause  and 
effect”  scenario.  He  elucidated  upon  these 
findings  at  length  to  conclude  that  “there  ex- 
ists a clear  correlation  between  the  microcli- 
mate conditions  of  the  habitats  and  the  spi- 
der's requirements.”  Ideally,  this  statement 
needed  underpinning  with  correlations  be- 
tween density  estimates  and  average  temper- 
atures in  the  two  layers  of  Sphagnum.  Argu- 
ably, because  there  was  an  absolute  zonation 
between  the  two  species,  density  measure- 
ments could  be  viewed  as  redundant. 

N0rgaard  clearly  demonstrated  a scientific 
approach,  but  lacking  in  his  first  Oikos  paper 
was  an  explicit  hypothesis  and  a direct  quan- 
titative link  to  the  environment.  Implicit  with- 
in his  design  was  a statistical  hypothesis  state- 
ment that  microclimate  was  predicted  to  be 
the  cause  of  the  distributions,  written  in  the 
introduction  as  “differences  in  their  distribu- 
tion will  be  viewed  in  relation  to  the  structure 
and  microclimate  of  the  sphagnum  carpet.” 
N0rgaard's  (1956)  second  paper  in  Oikos  on 
the  environment  and  behavior  of  Theridion 
saxatile  (now  Achaearanea  riparia  (Black- 
wall,  1834))  (Theridiidae)  is  quite  outstanding 
but  in  addition,  an  explicit  hypothesis  was 
clearly  stated.  Furthermore,  N0rgaard's  1956 
paper  is  an  improvement  on  his  1951  publi- 
cation because  he  also  provided  quantitative 
data  on  the  distribution  of  the  spider.  He  set 
out  to  investigate  whether  Nielsen’s  (1932) 
claim  that  T.  saxatile  A “egg  cocoons  are 
sometimes  suspended  somewhat  below  the 
nest  to  be  sunned,”  was  the  real  explanation 
of  this  behavior”  (as  quoted  in  N0rgaard 
(1956,  p.l60),  itself  a translation  from  Niel- 
sen’s Danish  as  found  in  his  volume  1 on  p. 


189).  N0rgaard  (1956)  took  Nielsen’s  state- 
ment and  made  it  his  hypothesis  and  used  it 
to  design  a suite  of  microclimatic  experiments 
to  test  the  role  of  temperature  in  the  devel- 
opment and  behavior  of  immature  and  adult 
spiders  and  their  egg  sacs.  This  eloquent  set 
of  experiments  resulted  in  N0rgaard  rejecting 
Nielsen’s  claim,  instead  accepting  what  was 
an  alternative  hypothesis  that  egg  sac  migra- 
tion between  30-35  °C  is  an  avoidance  be- 
havior to  prevent  thermally  induced  sub-lethal 
and  lethal  effects. 

N0rgaard’s  achievements  are  best  illustrated 
when  they  are  compared  with  similar  studies 
of  that  time,  such  as  Shulov  (1940)  and  Jones 
(1941).  Shulov  (1940)  looked  more  generally 
at  the  effects  of  microclimate  on  the  devel- 
opment in  Latrodectus  tredecim-guttatus  (now 
L,  tredecimguttatus  (Rossi  1790))  and  L.  pal- 
lidus  O.  R-Cambridge  1872  (Theridiidae)  and 
Jones  (1941)  attempted  to  determine  the  effect 
of  temperature  and  humidity  on  Agelena  na- 
evia  (now  Agelenopsis  naevia  (Walckenaer, 
1842))  (Agelenidae).  Both  these  papers  are  of 
an  excellent  high  standard  and  they  both  ma- 
nipulate the  natural  system.  Where  they  both 
fail  ecologically  is  that  their  experiments  are 
purely  laboratory  based,  and  no  data  are  taken 
from  the  field  to  support  their  laboratory  mea- 
surements, although  it  should  be  noted  that 
Shulov  (1940)  fills  his  paper  with  additional 
natural  history  notes.  These  papers  illustrate 
the  difference  between  biology  which  is 
“pure”  and  ecology  which  is  “applied.”  In 
this  respect,  ecology  has  always  strongly  sup- 
ported applied  fieldwork  over  laboratory  mea- 
surements made  in  isolation  and  without  ref- 
erence to  nature  (Shelford  1930).  Pure  biology 
does  not  impose  this  constraint  necessarily,  in- 
sofar as  abstract  physiological  measurements 
are  valid  and  need  not  be  couched  in  terms  of 
what  actually  happens  in  the  field. 

It  has  been  observed  that  in  reading  many 
papers  from  the  period  up  until  1956  that  most 
were  concerned  with  physiological  effects  on 
spiders,  not  population  ecology  which  ap- 
peared to  be  leading  the  charge  in  entomolo- 
gy- 

The  literature  between  1956  and  1973: 
did  spider  ecologists  engage  in  science?.- — 
The  volume  of  papers  and  the  number  of  jour- 
nals accepting  them  accelerated  after  the  Sec- 
ond World  War.  This  post-war  period  has 
already  been  reviewed  by  Turnbull  (1973)  and 


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837 


therefore  it  would  be  fruitless  to  re-review  this 
period.  Instead  the  purpose  of  this  section  is 
to  examine  whether  the  elegant  experimenta- 
tion that  N0rgaard  pursued  was  evident  in  oth- 
ers soon  after  1956.  To  extend  this  trawl  of 
the  ecological  literature  up  until  the  present 
day  is  beyond  the  scope  of  this  review.  In- 
stead, although  somewhat  arbitrarily,  I have 
chosen  to  confine  my  analysis  of  the  literature 
to  the  actual  publication  date  of  Turnbull’s 
1973  review.  However,  in  the  case  of  Susan 
Riechert,  where  the  author  has  had  a single 
international  publication  footprint  in  the  pre- 
1973  literature,  I extend  my  search  a little  be- 
yond the  1973  cut-off  date  because  it  is  evi- 
dent that  she  continues  to  have  a lasting 
impact  on  spider  ecology. 

Of  the  300+  papers  treated  by  Turnbull,  a 
minority  relate  to  more  general  biological 
phenomena  (e.g.,  the  various  headings  detail- 
ing processes  such  as  “spider  silk  and  spin- 
ning organs;”  “development,”  etc.),  which 
are  not  strictly  ecological  and  hence  are  not 
considered  further.  Of  the  papers  reviewed 
that  do  pertain  to  ecology,  the  heading  “pop- 
ulation and  community  ecology  of  spiders”  is 
by  far  the  largest  section,  followed  by  those 
related  to  “spider  feeding”  and  “webs.”  Very 
small  sections  refer  to  “survival  and  mortali- 
ty,” “reproduction,”  “energy  flow”  and  “dis- 
persal.” Surprisingly,  a section  devoted  to 
competition  is  absent. 

An  analysis  of  the  literature  cited  in  Turn- 
bull  (1973)  reveals  a number  of  authors  who 
will  still  be  familiar  to  students  today.  John 
Cloudsley-Thompson  (1957),  for  example, 
wrote  an  excellent  paper  on  the  then  valid  ge- 
nus Ciniflo  (now  Amaurobius  C.  L.  Koch 
1837)  (Amaurobiidae).  He  worked  to  an  ex- 
plicit alternative  hypothesis  that  nocturnal  be- 
havior in  primitive  spiders  was  the  result  of 
competition  with  more  modern,  successful  di- 
urnal species,  Cloudsley-Thompson  (1957) 
went  further  than  Shulov  (1940)  and  Jones 
(1941)  before  him,  demonstrating  elegantly 
the  relations  between  microclimate  and  amau- 
robiids.  However,  Cloudsley-Thompson  was  a 
physiologist  by  his  own  admission  and  al- 
though he  discussed  his  results  in  an  ecological 
context  (e.g.,  “the  present  work  again  stresses 
the  importance  of  moisture  on  the  distribution 
of  spiders,”  pp.  150),  he  did  not  collect  field 
data  to  support  his  analysis.  Excellent  though 
his  work  is,  Cloudsley-Thompsoe’s  research  is 


strictly  physiological,  of  which  there  are  many 
examples  from  the  time  (e.g.,  Lagerspetz  & 
Jaynas  1959;  Miyashita  1968). 

A number  of  authors  continued  to  pursue 
“observational  studies”  in  the  post- 1960s  era, 
after  the  first  wave  of  natural  historians  in  the 
1940s.  This  includes  Turnbull’s  (1960)  work 
on  the  stratification  of  spiders  found  in  oak 
woods.  This  type  of  research,  of  which  there 
are  many,  (e.g,,  Cherrett  1964;  Duffey  1962, 
1963,  1968;  Huhta  1971;  Sudd  1972)  remains 
true  to  Elton’s  (1927)  theory  of  the  niche,  but 
they  are  not  an  explicit  test  of  it.  Of  consid- 
erable merit  is  the  work  of  Sven  Almquist 
(Fig.  7)  who  came  much  closer  to  understand- 
ing habitat  selection  than  any  of  his  peers,  but 
who  was  completely  overlooked  by  both 
Turnbull  (1973)  and  by  Wise  (1993).  Almqu- 
ist, a Swede,  studied  at  the  University  of  Lund 
for  his  thesis  titled  “Habitat  selection  and  spa- 
tial distribution  of  spiders  in  coastal  sand 
dunes,”  which  was  submitted  in  1973. 
Almquist  married  laboratory  tests  of  micro- 
climate (Almquist  1970,  1971)  with  field  ex- 
periments of  habitat  selection  and  association 
(Almquist  1973a,  b).  In  his  1973b  paper, 
which  includes  a field  test  of  his  earlier  lab- 
oratory measurements  of  temperature  and  hu- 
midity, he  writes:  “This  paper  deals  with  the 
correlations  between  the  distribution  of  fifteen 
spider  species  of  coastal  sand  dunes  and  the 
thermal  tolerance  and  preference,  and  resis- 
tance to  desiccation  of  each  of  those  species 
under  laboratory  conditions”  (p.  134) — an  un- 
derstated alternative  hypothesis.  Almquist 
worked  in  the  spirit  of  Nbrgaard’s  research  on 
microclimate  two  decades  earlier.  Understand- 
ably due  to  technological  advances,  Alm- 
quist’s  measurements  are  much  more  accurate 
than  N0rgaard’s,  but  most  striking  is  the  level 
of  detail  that  is  given  throughout  his  work 
which  is  not  technologically  driven.  General- 
ly, Almquist  concludes  his  1973b  paper,  hav- 
ing compared  actual  densities  with  climatic 
differences  in  the  field  and  underpinned  by  his 
early  manipulative  microclimatic  research  in 
the  lab,  by  stating  “.  . . habitat  selection  is 
fundamentally  controlled  by  those  require- 
ments of  the  microclimate  and  the  vegetation 
conditions,  . . ” In  the  same  year,  on  a differ- 
ent dune  system,  the  Dutch  scientist  van  der 
Aart  (1973)  independently  substantiated  the 
conclusions  of  Almquist  using  what  is  be- 
lieved to  be  the  first  example  of  ordination  in 


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THE  JOURNAL  OF  ARACHNOLOGY 


Figure  7. — Dr  Sven  Almquist  (1918-present) 
wrote  an  exceptional  set  of  ecological  papers  of  spi- 
ders from  Swedish  sand  dunes,  which  was  the  prod- 
uct of  his  1973  PhD  thesis  from  the  University  of 
Lund.  Like  Edwin  Nprgaard,  Dr.  Almquist  took  up 
teaching.  He  retired  from  his  post  as  senior  master 
in  biology  at  Mahno  grammar  School  in  1983  after 
37  years  of  service.  Dr.  Almquist  started  publishing 
in  1970  and  has  written  9 papers  and  published  one 
popular  Swedish  language  spider  book.  Although 
he  continues  to  publish,  his  interests  are  confined 
to  the  systematics  of  Swedish  spiders.  His  study  of 
the  systematics  of  Swedish  spiders  is  the  subject  of 
his  three  volume  magnum  opus,  the  first  volume  of 
which  will  be  published  soon.  Source;  S.  Almquist 
(with  the  help  of  University  of  Lund). 

spider  ecology,  although  this  was  16  years  af- 
ter its  first  use  in  botany  (Bray  & Curtis 
1957).  Van  der  Aart  (1973)  used  principal 
components  analysis  (PCA)  to  investigate 
whether  the  hypothesis  of  the  multidimension- 
al niche  space  was  valid  for  a community  of 
dune-living  wolf  spiders.  PCA  is  now  known 
to  fail  to  meet  the  requirements  of  most  eco- 
logical datasets,  and  van  der  Aart  (1973)  is 
guilty  of  over-interpretation  of  his  results. 
However,  many  studies  agree  with  van  der 
Aart’s  (1973)  main  findings  that  differences 
exist  between  seaward  and  landward  spider 


communities,  and  that  the  spatial  distribution 
of  spider  species  is  linked  to  vegetation  struc- 
ture. 

The  re-appearing  figure  of  Charles  Elton 
suggests  that  he  was  an  extremely  influential 
thinker,  not  least  for  his  contribution  on  the 
role  of  habitats  in  animal  ecology.  Elton’s 
(1946)  work  is  evident  in  Tretzel’s  (1952, 
1954,  1955)  theory-driven  spider  research 
concerning  competition,  maturity,  reproduc- 
tion and  phenology.  Tretzel  is  perhaps  best 
known  for  his  writings  on  interspecific  com- 
petition, although  this  theory  is  not  his  own 
but  appeared  explicitly  in  Nicholson  & Bai- 
ley’s paper  on  the  '‘Balance  of  animal  popu- 
lations” in  1935  and  implicitly  in  Volterra’s 
paper  in  1926.  Within  spider  ecology,  Tretzel 
has  some  influence  and  spawned  a number  of 
studies  over  several  decades  (e.g.,  Vlijm  et  al. 
1963;  Luczak  1966;  Vlijm  & Kessler-Geschi- 
ere  1967;  Merrett  1967,  1968,  1969;  Den  Hol- 
lander 1971  among  many  others  not  cited 
here).  Tretzel’s  view  was  that  interspecific 
competition  explained  many  of  the  differences 
observed  between  closely  related  species,  in- 
cluding their  temporal  (e.g.,  phenology)  and 
spatial  distributions  (e.g.,  habitat).  An  early 
exponent  of  Tretzel’s  work  was  Edward  Kuen- 
zler  (1958)  who  published  a paper  on  niche 
relations  of  three  species  of  Lycosa  (Lycosi- 
dae)  in  South  Carolina.  Using  mark- recapture, 
Kuenzler  (1958)  presented  habitat  selection, 
density  and  home-range  data  as  well  as  some 
limited  meteorological  comparisons  to  asso- 
ciate with  spider  activity.  He  showed  that 
whilst  the  niche  relations  of  L.  carolinensis 
(now  Hogna  carolinensis  (Walckenaer  1805)) 
and  L.  timuqua  (now  Hogna  timuqua  (Wallace 
1942))  could  not  be  separated,  L.  rabida  (now 
Rabidosa  rabida  (Walckenaer  1837))  did  not 
overlap  with  the  other  two  species  because  it 
accessed  the  vertical  component  of  the  habitat, 
rather  than  just  remaining  on  the  ground  or  in 
its  burrow.  It  is  of  note  that  Kuenzler’s  (1958) 
research  does  not  include  manipulation  and 
his  meteorological  correlations  are  highly 
speculative,  even  though  he  was  aware  of 
Nprgaard’s  more  clinical  approach. 

Kuenzler  and  other  studies  that  are  a test  of 
Tretzel’s  work  are  a paradox:  they  show  con- 
siderable merit  because  they  are  a test  of  eco- 
logical theory  yet  present  no  explicit  hypoth- 
eses. One  is  left  wondering  why?  It  seems  as 
if  many  of  the  population  studies  at  the  time 


BELL— A HISTORY  OF  ECOLOGICAL  SPIDER  RESEARCH 


839 


were  hypothesis  generating,  as  experiments 
were  not  a test  of  anything  specific  or  at  least 
anything  that  would  suggest  a hypothesis. 
This  is  not  unusual,  as  McIntosh  (1987)  de- 
clares that  “ecology,  like  biology,  has  com- 
monly been  criticized  for  its  lack  of  an  ex- 
plicit and  testable  theoretical  framework”  (p. 
257).  For  some  reason,  many  of  the  popula- 
tion studies,  which  were  in  a similar  vein  to 
Kuenzler  (1958),  also  chose  lycosid  spiders  as 
their  model  organisms  (e.g.,  Hackman  1957; 
Kajak  & Luczak  1961;  Dondale  et  al.  1970; 
Kessler  1973).  It  is  evident  that  there  was  a 
community  of  researchers  working  on  lycos- 
ids  who  were  interacting  despite  their  dispa- 
rate distribution  across  Northern  Europe  and 
America.  Possibly  because  of  the  interaction 
and  because  lycosid  spiders  were  a tractable 
model  organism,  a number  of  important  ad- 
vances in  spider  ecology  materialized  as  a re- 
sult of  this  research  activity.  It  was  relatively 
easy  to  demonstrate  lycosid  habitat  choice  in 
a simply  designed  natural  experiment  in  grass- 
land (e.g..  Den  Hollander  & Lof  1972),  but 
the  many  facets  of  habitat  choice  needed  cal- 
ibration and  manipulation.  Experiments  of 
varying  complexity  showed  that  habitat 
choice  provided  a useful  tool  in  explaining  ly- 
cosid cannibalism  (Hallander  1970),  balloon- 
ing success  (Richter  1967,  1970a,  1970b, 
1971)  frequency  of  feeding  (Edgar  1970),  re- 
productive rate  (Richter  et  al.  1971)  and  court- 
ship display  (Hallander  1967),  among  others. 
While  these  studies  should  be  noted,  perhaps 
one  lycosid  study  stands  out  above  all  other 
work  for  the  period:  Matthias  Schaefer  (Eig. 
8)  has  been  widely  recognized  as  making  a 
significant  contribution  to  the  study  of  spider 
competition  and  his  work  is  exemplary. 
Schaefer’s  (1972)  research  involved  six  years 
studying  eleven  dominant  lycosid  species  that 
occurred  in  17  different  coastal  habitats.  His 
major  conclusion  was  that  species  were  ‘iso- 
lated’ either  in  space  or  time.  Schaefer  hy- 
pothesized that  abiotic  influences  were  having 
a much  greater  effect  than  competitive  dis- 
placement, despite  evidence  from  his  labora- 
tory experiments  which  suggested  that  there 
were  strong  biotic  interactions  between  spe- 
cies. In  a re-analysis  of  Schaefer’s  work  as 
summarized  by  Marshall  & Rypstra  (1999), 
Wise  (1993)  suggested  that  Schaefer  was  too 
conservative,  in  that  he  actually  had  compel- 
ling evidence  of  interspecific  competition. 


Figure  8. — Matthias  Schaefer  (1942-present) 
whose  manipulative  experiments  concerning  lycos- 
id competition  during  the  1970s  have  been  widely 
recognized  as  a significant  contribution  to  the  field. 
Matthias  Schaefer  has  held  a professorship  at  the 
Institute  for  Anthropology  and  Zoology,  University 
of  Gottingen  since  1977.  For  the  last  35  years,  he 
has  been  an  author  of  1 3 1 scientific  works  spread 
across  a broad  research  base.  Notably,  he  has  main- 
tained a consistent  and  long  standing  interest  in  soil 
processes  in  beech  forests,  particularly  that  which 
relates  to  the  involvement  of  invertebrates  in  the 
decomposition  process.  Source:  Photo  supplied  by 
M.  Schaefer. 


Wise  (1993)  also  revealed  that,  however 
good  Schaefer’s  findings  may  be,  it  was  un- 
fortunate that  there  was  an  oversight  in  the 
experimental  design:  Schaefer  lacked  a prop- 
erly replicated  control.  It  is,  perhaps,  impor- 
tant to  state  that  statistical  probabilities  can  be 
undermined  if  the  experimental  design  is  not 
robust,  as  highlighted  by  Ronald  Fisher.  Fisher 
identified  the  problems  of  a lack  of  replication 
and  the  absence  of  a control  in  the  1920s 
when  he  was  confronted  with  analyzing  the 
Broadbalk  experiment  at  Rothamsted  Experi- 
mental Station  (Gavin  Ross  pers.  comm).  The 
importance  of  experimental  design  was  high- 
lighted in  Fisher’s  books  designed  for  field- 


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THE  JOURNAL  OF  ARACHNOLOGY 


workers,  but  it  is  frustrating  to  see  that  these 
problems  still  plagued  notable  and  widely  cit- 
ed works  during  the  1960s  and  1970s.  Prob- 
lems of  replication  can  be  found  in  Clarke  & 
Grant’s  (1968)  manipulative  experiment 
which  attempted  to  investigate  role  of  spiders 
as  predators  in  a beech-maple  forest.  Identi- 
fied by  Wise  (1993)  as  a classic,  the  study 
used  enclosures  in  which  they  removed  spi- 
ders to  observe  the  effect  on  Collembola,  their 
likely  prey.  However,  at  the  admission  of  the 
authors  (p.  1 1 54),  the  experiment  was  not 
properly  replicated  (3  controls,  1 treatment), 
and  suffered  from  pseudoreplication  (Wise 
1993),  still  a hotly  debated  issue  in  ecology 
(Oksanen  2001,  2004;  Hurlbert  2004). 

Conversely,  Eliza  D^ibroska-Prot’s  experi- 
ments did  not  suffer  from  a lack  of  replication 
or  control  and  were  large  in  number.  In  300 
separate  experiments,  she,  along  with  her  col- 
leagues Jadwiga  Luczak  and  Kazimierz  Tar- 
wid  at  the  Institute  of  Ecology,  Warsaw,  in- 
vestigated spider-mosquito  predator-prey 
ratios  in  a series  of  five  papers  (D^broska-Prot 
1966;  Luczak  & D^ibroska-Prot  1966;  D^- 
broska-Prot  et  al.  1966,  1968).  The  group  was 
aware  of  the  theoretical  background  to  their 
work  making  reference  to  Hollings  disc  equa- 
tion (D^broska-Prot  et  al.  1968),  a widely 
used  theoretical  approach  to  predator-prey  in- 
teractions. However,  for  all  its  merits,  their  ex- 
perimental methods  are  difficult  to  follow  and 
I remain  uncertain  as  to  how  the  experiments 
proceeded  and  their  justification  for  certain  id- 
iosyncrasies. For  example,  the  team  used  iso- 
lators (enclosures)  that  followed  a split-plot 
design  in  which  both  a control  and  a treatment 
were  nested  within  a single  enclosure,  sepa- 
rated by  a screen.  There  were  ten  such  enclo- 
sures into  which  spiders  and  mosquitoes  were 
added  and  observed  three  times  a day  over  a 
period  of  six  months.  For  some  treatments 
with  particular  species  they  used  40  mosqui- 
toes per  plot  and  for  others  50,  whilst  in  the 
control  there  were  always  50  mosquitoes. 
Concurrently,  the  team  varied  the  numbers  of 
spiders  introduced  inconsistently  between  spe- 
cies and  not  all  spider  introductions  happened 
at  the  same  time,  with  one  species  being  add- 
ed on  the  8“^  day  of  the  experiment  and  the 
rest  at  the  beginning.  I also  cannot  find  evi- 
dence of  the  300  experiments  to  which  they 
refer,  and  am  of  the  belief  that  the  word  ex- 
periment may  be  misused  and  intended  to  re- 


fer to  a replicate*treatment*species  combina- 
tion. However,  despite  these  flaws,  I don’t 
believe  their  major  finding  that  wandering  spi- 
ders exert  more  pressure  on  mosquitoes  than 
sedentary  web-spinning  spiders  is  contentious. 

D^broska-Prot  manipulated  the  system  to 
allow  direct  observation  of  prey  consumption, 
but  this  has  not  always  been  possible.  Spider 
researchers  have  for  a long  time  been  much 
more  likely  to  use  indirect  methods  to  detect 
prey  proteins  in  the  gut,  such  as  precipitin  test. 
Its  first  use  was  in  mosquito  research  in  1947; 
later  this  knowledge  was  applied  to  spiders  in 
the  study  of  the  spruce  budworm  in  1963.  As 
the  1980s  approached,  the  precipitin  test  was 
being  replaced  by  the  enzyme  linked  immu- 
nosorbent assay  (ELISA),  but  in  this  interven- 
ing period,  researchers  were  also  experiment- 
ing with  radioactive  isotopes.  Moulder  & 
Reichle  (1972)  used  Cesium^^^  at  the  land- 
scape scale,  introducing  the  isotope  to  the  for- 
ests of  the  Oak  Ridge  reservation  in  Tennes- 
see, USA.  The  method  of  application  is  poorly 
described  in  the  paper,  but  Auerbach  et  al. 
(1964)  describe  how  this  radioactive  tracer 
was  applied  to  a 20m  X 25m  stand  of  trees. 
Uptake  occurred  through  the  bark,  using  water 
as  a diluent.  The  build-up  of  radiocesium  was 
traceable  in  the  leaves  of  the  canopy  of  33 
trees.  When  the  leaves  fell  onto  the  forest 
floor,  decomposers  then  bioaccumulated  the 
radioactive  cesium  and  it  was  then  passed  on 
to  any  predator  that  consumed  them.  On  the 
assumption  that  these  were  ground  active 
predators,  pitfall  traps  were  used  to  catch  spi- 
ders. As  indicated  by  the  researchers,  has 
a half-life  of  30  years,  which  formed  the  jus- 
tification for  choosing  this  over  the  much  less 
radioactive  Cynics  would  suggest  that 

spiders  were  a viable  measure  of  how  to  mon- 
itor bioaccumulation  of  radioactive  isotopes 
for  the  United  States  Atomic  Energy  Com- 
mission (USAEC)  and  that  the  paper’s  ecolog- 
ical significance  was  merely  a byproduct  of 
their  findings.  That  said,  this  byproduct 
showed  that  trophic-level  food-chain  interac- 
tions could  be  measured  and  that  spiders  were 
important  predators  in  forest  ecosystems. 
However,  Moulder  & Reichle  (1972)  failed  to 
demonstrate  that  the  bioaccumulation  of  Ce- 
sium*^^  had  little  or  no  effect  on  spider  behav- 
ior. This  failing  had  implications  on  the  esti- 
mates of  rates  of  consumption  of  the  prey  and 
the  subsequent  catchability  of  the  spiders  in 


BELL— A HISTORY  OF  ECOLOGICAL  SPIDER  RESEARCH 


841 


the  pitfall  traps.  If  consumption  rate  and 
catchability  were  artifacts  of  the  change  in 
spider  behavior  following  application  of  the 
tracer,  the  published  data  are  likely  to  be  a 
conservative  estimate.  The  same  criticism 
should  be  lodged  at  Van  Hook  (1971),  in  a 
related  paper,  who  was  also  supported  by  the 
USAEC.  Van  Hook  (1971)  studied  the  uptake 
of  the  isotopes  of  calcium,  potassium  and  so- 
dium on  a caged  (0.25  m^)  grassland  lycosid 
population.  His  energy  flow  diagrams  are  il- 
luminating (e.g.,  fig.  7 in  Van  Hook  (1971)), 
showing  Lycosa  at  the  top  of  the  food  chain 
and  the  interactions  between  it  and  its  envi- 
ronment. However,  the  fundamental  question 
remains,  did  the  consumption  of  istope-tagged 
prey  affect  spider  behavior?  If  so,  thee  the 
study  is  drastically  undermined. 

David  Quammee,  widely  recognized  for 
popularizing  ecology  and  biogeography,  is  in 
no  doubt  of  the  impact  of  one  award  winning 
experiment  that  is  now  “famous  for  its  logical 
elegance,  for  its  results  and  for  its  gonzo 
methods”  (p.  428  Quammen  1996).  There  is 
further  added  praise  from  Lubchenco  & Real 
(1991)  in  their  review  of  classic  papers  in 
ecology,  who  suggested  that  it  was  “one  of 
the  most  ambitious  and  successful  large  scale 
experiments  attempted  in  ecological  research” 
(p.  726).  I am,  of  course,  referring  to  the  work 
of  Dan  Simberloff  and  Edward  Wilson,  who 
cast  a shadow  over  all  but  a tiny  portion  of 
ecological  research  produced  in  the  1970s.  Al- 
though spiders  were  not  the  specific  focus  of 
the  work  they,  along  with  the  rest  of  the  ar- 
thropods collected,  were  a test  of  the  equilib- 
rium theory  which  was  in  need  of  empirical 
validation.  Based  in  the  Florida  Bay,  Simber- 
loff and  Wilson  identified  suites  of  mangrove 
islands  which  were  each  covered  with  a tent 
and  ‘defaunated’  using  methyl  bromide  fu- 
migation (Simberloff  & Wilson  1969;  Wilson 
& Simberloff  1969).  The  fauna  of  six  of  these 
islands  were  ceesused  before  and  after  treat- 
ment, leading  Simberloff  & Wilson  (1969)  to 
conclude  that  recolonizatioe  curves  ap- 
proached a stable  equilibrium  with  the  exact 
number  determined  by  the  distance  from  the 
source  habitats  and  the  size  of  the  island. 
Throughout,  Simberloff  & Wilson  (1969)  ob- 
served rapid  species  turnover  and  alluded  to 
the  fact  that  the  majority  of  the  fauna  were 
“obligate  transients,”  which  were  at  the  mer- 
cy of  the  wind.  This  includes  a discussion  of 


ballooning  spiders  in  which  it  is  highlighted 
that  the  distances  could  not  be  calculated  or 
correlated  with  wind  measurements  because 
of  a number  of  technical  issues. 

It  would  be  remiss  not  to  mention  the  work 
of  Susan  Riechert  who  published  her  first  pa- 
per in  1972  and  her  first  international  paper  in 
the  following  year.  Riechert  has  been  prolific 
in  her  publishing  and  her  contribution  to  ecol- 
ogy cannot  be  underestimated.  For  example, 
her  paper  regarding  thermal  balance  and  prey 
availability  in  Agelenopsis  aperta  (Gertsch 
1934)  (Agelenidae)  remains  one  of  the  few 
papers  to  attempt  to  unravel  the  complexities 
of  spider-habitat  associations  (Riechert  & Tra- 
cey 1975).  Riechert  has  maintained  a focus  on 
A.  aperta  for  the  past  30  years,  starting  with 
her  PhD  work  published  in  1973.  Riechert  et 
al7s  (1973)  paper  was  not  a manipulative  ex- 
periment in  itself,  but  it  was  well  designed  and 
presented  a strong  case  to  suggest  that  spiders 
and  their  habitat  were  correlated.  What  is  ap- 
parent in  retrospect  was  that  her  PhD  research 
laid  the  groundwork  for  a multitude  of  studies 
which  had  a strong  manipulative  component 
and  solid  theoretical  background.  A mono- 
graph on  the  contribution  of  Susan  Riechert  is 
long  overdue  and  would  be  extremely  reward- 
ing (but  see  Wise  1993  for  a detailed  over- 
view of  her  research  up  until  the  early  1990s). 
Two  other  “appearing  lights”  beginning  their 
research  at  the  same  time  as  Riechert  were 
Frank  Enders  and  William  Eberhard  whose 
work  on  web-site  selection  is  still  widely  read 
today,  and  who  began  publishing  their  main- 
stream work  in  the  early  1970s.  I refer  readers 
to  Wise  (1993)  and  to  specific  reviews  on 
web-site  selection  for  a proper  treatment  of 
their  work,  most  of  which  extends  beyond  the 
cut-off  date  for  this  review. 

To  summarize  the  period  of  1956-1973, 
there  was  a profusion  of  literature  that  did  not 
engage  science,  but  pursued  an  often  circular 
interest  of  basic  observational  studies.  Fun- 
damentally, these  often  fell  short  of  the  sci- 
entific approach  because  they  did  not  manip- 
ulate the  system,  or  if  they  did,  they 
manipulated  to  the  wrong  component.  These 
studies  are  still  informative  but  they  must  be 
treated  with  caution  as  some  findings  sway  in 
the  favor  of  conjecture,  not  substantive  prob- 
ability. For  example,  Chew’s  (1961)  natural 
experiment  is  a small  study  of  spiders  {n  = 
817  individuals)  of  a desert  community.  Sur- 


842 


THE  JOURNAL  OF  ARACHNOLOGY 


prisingly,  it  is  still  widely  cited  but  is,  in  my 
view,  eiToneoiis.  There  are  errors  in  the  stan- 
dardization of  the  sampling  regime  and  wild 
conjectural  statements  made  in  the  discussion 
which  are  unsupported  by  a formal  analysis 
and  an  evidence-based  manipulation  (e.g.,  the 
role  of  temperature).  When  done  well,  obser- 
vational studies  are  an  extremely  valuable  re- 
source to  ecologists.  Robinson  & Robinson’s 
(1973)  study  of  the  giant  wood  spidQY  Nephila 
maculata  (now  Nephila  pilipes  (Fabricius 
1793))  (Tetragnathidae),  illustrates  this  point 
precisely.  It  is  complete  in  its  approach  and 
does  not  suffer  the  illusion  that  it  is  anything 
other  than  a hypothesis  generating  autecolog- 
ical  paper. 

An  overview  of  the  literature  sampled. — 

If  I were  to  summarize  what  impact  most  of 
the  papers  included  in  this  review  have  had 
on  ecology,  then  I could  do  no  better  than  to 
quote  Turnbull’s  (1973,  p.  333)  synopsis  of 
over  300  “ecological”  studies:  “I  wish  I 
could  also  say  that  I had  found  no  shortage  of 
good  papers,  or  good,  well  supported  infor- 
mation on  spider  ecology.  There  are  some  ex- 
cellent papers,  but  there  are  also  large  quan- 
tities of  repetitious  mediocrity.  I am  dismayed 
at  the  number  of  papers  that,  if  they  do  not 
belong  in  ecology  do  not  belong  anywhere. 
[These  papers]  . . . leave  me  wondering  why 
they  were  written,  or  if  written,  why  any  jour- 
nal would  publish  them.  They  are  often  the 
product  of  the  crudest  methodology;  they  pre- 
sent data  sets  that  cannot  be  analyzed;  they 
come  to  no  conclusions;  and  they  are  not  put 
into  any  sort  of  relationship  with  general  prin- 
ciples, ecological  or  otherwise.”  While  I ap- 
preciate that  spider  ecology  needed  to  go 
through  a period  of  evolution,  it  is  surprising 
that  the  mediocrity  prevailed  for  so  long  and 
that  the  revolution  appeared  as  late  as  the  mid- 
twentieth century.  Arguably,  Turnbull  did  not 
expedite  the  rise  of  spider  ecology  by  pub- 
lishing cutting-edge  research  himself.  Instead, 
he  could  be  accused  of  being  no  different 
from  his  peers,  in  that  his  work  was  neither 
remarkable  nor  original;  for  those  qualities, 
spider  ecologists  need  to  look  to  elsewhere. 

Rainer  Foelix,  author  of  the  “Biology  of 
Spiders”,  wrote  in  the  opening  lines  of  his 
ecological  chapter  “the  interactions  between 
spiders  and  their  environment  have  been  in- 
vestigated systematically  only  within  the  past 
few  decades”  (Foelix  1982,  p.  232).  If  there 


was  a need  to  be  more  exact,  it  is  argued  that 
arachnological  ecology  began  with  Pontus 
Palmgren  in  the  late  1930s  and  was  refined  in 
the  mid  1950s  by  Edwin  Nprgaard  with  his 
experiments  of  microclimate.  Both  men  un- 
derstood that  to  manipulate  the  system  is  to 
understand  the  relationships  between  spiders 
and  their  environment  more  clearly.  Edwin 
Nprgaard  built  on  the  experiences  of  Pontus 
Palmgren  who  worked  in  the  spirit  of  Haeck- 
el’s physiological  definition  of  ecology.  How- 
ever, Nprgaard’s  work  was  exemplary  because 
he  recognized  the  need  to  make  both  field  and 
controlled  laboratory  observations.  Sven 
Almquist  and  Matthias  Schaefer  also  recog- 
nized the  elegance  of  manipulation  and  their 
work  is  exceptional  for  the  period. 

CONCLUDING  REMARKS 

Spider  research  and  experimental  de- 
sign.— I hope  that  through  the  course  of  this 
review,  I have  managed  to  convey  at  least  two 
things:  the  power  of  hypothesis  testing  and  the 
need  for  a manipulation  of  either  the  habitat 
or  the  spider,  and  sometimes  both.  I would 
like  to  encourage  students  in  all  branches  of 
arachnology  to  consider  the  value  of  manip- 
ulative experiments  that  are  part  of  a well 
planned  design,  and  to  move  away  from  pure 
faunistics,  which  is  provincial  and  therefore  of 
little  value.  Furthermore,  while  I recognize 
that  hypotheses  are  not  always  appropriate 
(e.g.,  when  there  are  provisional  data)  and  that 
when  used  imprecisely  they  seem  rather  drab, 
detectable  hypothesis  statements  add  a great 
deal  of  depth  to  most  experimental  designs. 
These  statements  need  not  be  of  the  null  form, 
but  can  include  multiple  dynamic  alternatives. 

Spider  research  and  ecological  theory. — 
It  is  evident  that  most  studies  included  in  this 
review  had  only  a peripheral  interest  in  testing 
ecological  theory.  This  explains  why  spider 
ecology  was  in  the  doldrums  and  remained  in- 
ward-looking during  a period  when  other  dis- 
ciplines embraced  the  interaction  between  the- 
ory, experiments  and  empirical  tests.  For 
example,  it  has  been  argued  by  Statzner  et  al. 
(2001)  that  entomology  has  generated  a num- 
ber of  general  theories  in  ecology,  but  that 
botany  has  made  the  most  significant  contri- 
butions. Perhaps  one  of  the  most  notable  the- 
ories that  has  come  directly  from  entomology 
and  which  had  general  appeal  to  ecologists  is 
the  Habitat  Templet  by  the  entomologist  T.R.E 


BELL— A HISTORY  OL  ECOLOGICAL  SPIDER  RESEARCH 


843 


Southwood  (1977).  More  recently.  Ilka  Han- 
ski  has  had  a similar  impact  with  his  Theory 
of  Metapopulations  derived  from  extensive 
butterfly  studies  (Hanski  1999).  While  it  is 
easy  to  demonstrate  the  positive  impact  spider 
research  has  had  on  other  science  disciplines 
such  as  biochemistry  (e.g.,  spider  silks  feed- 
ing  into  our  understanding  of  arthropod  silks 
and  their  evolution),  it  is  difficult  to  find  a 
single  example  where  this  has  happened  in 
ecology  pre-1973. 

I have  consulted  fellow  scientists  in  nu- 
merous countries  on  the  thorny  issue  of  the 
impact  of  spider  research  on  other  science  dis- 
ciplines. International  scientists  were  even 
asked  if  they  could  give  an  example  of  a the- 
ory that  was  not  restricted  by  the  1973  cut- 
off date — none  were  forthcoming.  Why 
should  this  be  so?  During  the  embryonic 
phase  of  spider  ecology,  it  could  be  argued 
that  spiders  were  dealt  with  as  a second  taxon 
to  the  insects.  Indeed,  whereas  entomologists 
were  likely  to  be  snapped  up  by  institutions 
wishing  to  employ  them,  arachnologists  were 
not.  It  is  also  evident  that  communication  be- 
tween research  groups  and  individuals  was 
poor.  For  example,  it  has  been  observed  by 
scientists  both  sides  of  the  English  Channel 
that,  due  to  language  barriers,  papers  written 
in  anything  other  than  the  mother  tongue  of 
the  author  were  largely  ignored.  All  these  fac- 
tors would  have  meant  that  an  exchange  of 
hypotheses  were  all  the  more  difficult.  We 
know  that  hypotheses  drive  theory  and  thus 
theoretical  spider  ecology  must  have  suffered 
as  a result. 

But  what  is  our  excuse  now  that  we  are  in 
the  2P'-  century?  We  meet  regularly  at  confer- 
ences, congresses  and  seminars  and  for  some 
of  the  ecology  journals  we  even  have  pre-pub- 
lication access  to  papers  as  well  as  a wealth 
of  electronic  media  and  back  issues.  Further- 
more, spiders  are  well  distributed,  often  in 
abundance  and  available  for  study  throughout 
much,  sometimes  all  of  the  year.  It  is  not  as 
if  we  do  not  have  our  hand  on  the  pulse  or 
have  an  obliging  model  organism.  It  seems  to 
me  as  if  there  are  no  big  questions  in  ecology 
which  pre-dispose  spiders  to  scientists  in  the 
search  for  their  big  ideas.  Perhaps  this  is  be- 
cause we  still  do  not  know  enough  about  our 
commonest  spiders  that  would  encourage 
sceptics  to  take  a closer  look.  That  was  cer- 
tainly true  in  agriculture  as  it  has  only  been 


in  the  last  three  decades  that  spiders  have 
stopped  hiding  behind  the  large,  looming 
shadow  of  insect  economic  entomology  and 
branched  out  in  to  the  collective  that  is  now 
known  as  “beneficial  predators.”  Howell  & 
Pienkowski  (1971),  for  example,  give  a short 
breakdown  of  experimental  studies  of  spiders 
in  American  agriculture  and  show  that,  apart 
from  a limited  number  of  studies  in  sweet 
corn,  sugarcane,  sorghum  and  cotton,  spider 
studies  are  otherwise  absent.  Post-second  mil- 
lennium, much  has  changed  and  there  are  now 
numerous  groups  around  the  world  solely  re- 
searching the  role  of  spiders  in  agriculture. 

I do  believe  that  the  lack  of  a new  general 
theory  applicable  to  ecology  will  not  last  for 
much  longer.  The  reason  for  this  confidence  is 
because  Susan  Riechert  (pers.  comm.)  has  ar- 
gued that,  although  spiders  have  not  initiated 
new  theory,  they  have  proved  important  ex- 
perimental subjects  that  have  given  support  to 
our  understanding  and  driven  further  general 
ecological  developments.  Thus,  we  are  very 
theoretically  aware  and  it  is  encouraging  to 
find  that  we  use  theory  in  our  research  with 
some  frequency.  It  is  only  the  contribution  to 
general  ecology  that  we  are  lacking,  so  what 
could  we  do  to  encourage  this?  What  to  me 
seems  critical  is  that  we  interact  at  the  highest 
level,  find  paradigms  of  general  applicability 
and  do  not  present  ourselves  as  a phylogenetic 
cul-de-sac  where  no  one  wants  to  stop  and 
visit.  Then,  and  only  then  will  spider  ecology 
cross  over  into  general  ecology  in  a major 
way. 

What  of  the  future  of  experimental  spi- 
der ecology?. — Unlike  physics,  ecological  re- 
lationships are  difficult  to  define  absolutely, 
which  explains  our  addiction  to  statistical 
methods,  but  not  necessarily  to  probabilistic 
tests.  Spider  researchers,  like  other  ecologists, 
are  confronted  with  a complex  world  of  inter- 
actions that  they  have  to  untangle  systemati- 
cally. The  traditional  null  hypothesis  approach 
does  not  serve  ecology  well  when  complexity 
in  nature  is  not  met  with  complexity  in  statis- 
tical theory.  It  is  now  argued  by  an  increasing 
band  of  ecologists,  that  null  hypothesis  testing 
should  be  curtailed  and  the  use  of  P-values 
questioned  when  established  via  traditional 
approaches  in  some  circumstances  (Johnson 
1999;  Anderson  et  al.  2000;  Eberhardt  2003; 
Johnson  & Omland  2004).  These  authors  pro- 
pose an  alternative  called  “model  selection” 


844 


THE  JOURNAL  OF  ARACHNOLOGY 


(MS)  which  allows  up  to  20  multiple  com- 
peting hypotheses  to  be  weighted  and  com- 
pared. Model  selection  allows  the  possibility 
that  more  than  one  hypothesis  might  be  true, 
allowing  the  researcher  to  rank  their  impor- 
tance and  identify  more  than  one  outcome 
(Johnson  & Omland  2004).  This  is  in  stark 
contrast  to  the  rather  simple  dichotomy  of  null 
hypotheses  testing.  I can  hnd  only  one  ex- 
ample where  MS  has  been  used  in  arachnol- 
ogy,  in  which  the  ecological  traits  of  phyto- 
seiid  mites  were  assessed  (Luh  & Croft  1999). 
However,  the  likely  outcome  is  that  MS  will 
become  more  prevalent  in  spider  research,  es- 
pecially in  the  study  of  trophic  relations  and 
competition.  However,  I do  not  believe  that, 
where  clear  and  considered  manipulations  are 
possible,  MS  can  ever  replace  manipulative 
experiments  given  that  MS  is  founded  on  ob- 
servational data  mathematically  expressed. 
Experimental  ecology  is  here  to  stay  and  at 
the  center  of  its  development  is  manipulation, 
albeit  somewhat  scaled-up  to  what  our  fore- 
bears had  in  mind. 

ACKNOWLEDGEMENTS 

The  views  expressed  here  are  my  own  and 
not  necessarily  supported  by  those  from 
whom  I have  sought  help.  This  paper  has  been 
six  years  in  the  making,  but  its  relevance  was 
crystallized  as  a result  of  discussions  first  with 
Margaret  Hodge  (USA)  and  subsequently  with 
Spren  Toft  (Denmark)  who  fuelled  my  enthu- 
siasm to  look  more  closely.  I am  extremely 
grateful  to  the  two  anonymous  referees  who 
have  improved  the  manuscript  and  presented 
an  alternative  view.  I am  appreciative  to 
Emma  Shaw  (UK)  for  her  help  and  thank 
Spren,  Gernot  Bergthaler  (Austria),  and  Sam- 
uel Zschokke  (Switzerland)  for  translations. 
Phil  Wheater  (UK),  Gary  Miller  (USA)  and 
Susan  Riechert  (USA)  are  thanked  for  their 
suggestions.  I also  thank  Chris  Felton  (UK) 
and  the  British  Arachnological  Society  library 
for  providing  me  with  translated  reprints  of 
Tretzel’s  work  and  Peter  Merrett  (UK)  and 
Robert  Suter  (USA)  for  information.  For  pho- 
tographic portraits,  I acknowledge  the  help  of 
Spren  Toft,  University  of  Aarhus  (Denmark), 
Basil  Harley  (UK),  John  Parker  (UK),  Jamie 
Owen  of  the  Natural  History  Museum,  Lon- 
don (UK),  Gavin  Ross,  Rothamsted  Research 
(UK),  University  of  Lund  (Sweden),  Sven 
Almquist  (Sweden),  Kaj  Palmgren  through  the 


help  of  the  Tvarminne  Zoological  Station, 

University  of  Helsinki  (Finland).  Thanks  to 

Alison  Haughton  for  proof  reading  the  MS. 

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Manuscript  received  1 October  2005,  revised  10 

November  2005. 


2005.  The  Journal  of  Arachnology  33:850-851 


SHORT  COMMUNICATION 

FOOD  STORAGE  BY  A WANDERING  GROUND  SPIDER 
(ARANEAE,  AMMOXENIDAE,  AMMOXENUS) 


Ansie  S.  Dippenaar-Schoeman:  ARC-Plant  Protection  Research  Institute,  Private 
Bag  XI 34,  Pretoria,  0001  South  Africa 

Rupert  Harris:  99  Colonel  Trichardt  Street,  Welgelegen,  Pietersburg,  0699  South 
Africa 

ABSTRACT.  Members  of  genus  Ammoxenus  are  known  predators  of  harvester  termites  (Hodotermes 
mossambicus).  An  A.  amphalodes  female  was  observed  catching  and  paralyzing  a termite  in  the  field.  The 
paralyzed  termite  was  deposited  in  a silk  sac  with  other  paralyzed  termites.  This  confirms  that  Ammoxenus 
spp.  use  different  methods  of  catching  and  utilizing  prey.  Termites  are  either  killed  and  fed  upon  or 
paralyzed  and  stored  for  feeding  at  a later  time. 

Keywords:  Termites,  Africa  feeding  behavior 


Ammoxenus  Simon  1892  are  known  predators  of 
the  harvester  termite,  Hodotermes  mossambicus 
(Hagen  1858)  in  southern  Africa  (Wilson  & Clark 
1977;  Van  den  Berg  & Dippenaar-Schoeman  1991; 
Dippenaar-Schoeman  et  al.  1996a,  b).  Harvester  ter- 
mites forage  in  sporadic  bursts  of  activity  on  the 
soil  surface  from  subterranean  nests.  When  present 
in  high  numbers  they  can  cause  severe  damage  to 
grassland,  especially  during  long  periods  of 
drought.  Ammoxenid  spiders  are  free-living  soil- 
dwellers,  also  known  as  sand  divers  due  to  their 
ability  to  dive  headfirst  into  sand  when  disturbed. 
Ammoxenus  are  known  only  from  southern  Africa, 
with  six  described  species  occurring  throughout  the 
region  (Dippenaar  & Meyer  1980).  They  are  com- 
monly found  in  high  numbers  in  areas  infested  with 
harvester  termites. 

Ammoxenus  are  regarded  as  specialist  predators 
of  harvester  termites  (Dippenaar-Schoeman  et  al. 
1996b).  They  are  invariably  found  in  the  soft  soil 
mounds  left  after  excavation  by  the  termites  in 
close  proximity  to  the  nest  entrance.  They  are  able 
to  detect  termite  foraging  activity  either  through 
soil  vibration  or  chemical  cues.  According  to  Dean 
(1988)  the  spiders  use  tactile  cues  to  select  optimal 
prey  items  after  initial  handling  of  the  prey.  During 
prey  capture,  the  termite  is  grabbed  and  bitten  be- 
tween the  head  capsule  and  the  cephalothorax.  The 
dead  termite  is  pulled  below  the  soil  surface  by  the 
spider  before  feeding  commences.  Prey  is  sucked 
out  and  not  chewed.  Van  den  Berg  & Dippenaar- 
Schoeman  (1991)  observed  that  members  of  Am- 
moxenus amphalodes  Dippenaar  & Meyer  1988 
spend  inactive  periods  in  sac-like  retreats  made  in 


the  soft  soil  humps  left  by  the  termites  during  ex- 
cavations of  their  subterranean  nests.  Along  with 
the  retreat  sacs,  other  soft  silk  sacs  containing  dead 
harvester  termites  (4-8  termites  per  sac)  were  col- 
lected from  the  soil  mounds  at  Rietondale  Research 
Station,  Pretoria  (25°14'S,  28°  15'E).  Van  den  Berg 
& Dippenaar-Schoeman  (1991)  speculated  that 
these  termites  might  serve  as  a food  reserve  for  the 
spiders  during  the  long  periods  when  the  termites 
are  inactive.  The  observations  described  here  con- 
firm this. 

On  2 1 April  1 998  an  A.  amphalodes  female  was 
observed  in  a grassy  field  near  Pietersburg 
(23°54'S,  29°28'E)  in  the  Limpopo  Province  of 
South  Africa.  She  ran  with  great  speed  amongst 
workers  of  the  harvester  termite  and  then  suddenly 
ran  towards  a termite  worker,  leaped  onto  it  and 
delivered  a bite  to  the  side  of  the  termite’s  body 
just  above  the  base  of  the  second  leg.  The  spider 
flexed  her  legs  backward  while  administering  the 
bite.  Within  30  sec  the  struggling  termite  slowed 
down.  The  spider  released  the  termite  for  less  than 
a sec  to  administer  a second  bite  to  one  of  the  legs 
of  the  termite  that  lasted  about  20  sec.  The  spider 
then  dragged  the  still-living,  but  paralyzed,  termite 
about  40  cm  to  a soft  sandy  area.  She  entered  a soft 
sac-like  structure  on  the  soil  surface  that  was  well 
camouflaged  with  sand  particles.  The  form  of  the 
sac,  with  its  flap-like  entrance,  was  similar  to  that 
of  a sleeping  bag  lying  flat  on  the  soil  surface.  The 
spider  used  her  front  legs  to  open  the  sac  and 
dragged  the  termite  into  the  sac.  Movement  within 
the  sac  continued  for  about  5 min. 

At  this  stage  the  sac  with  its  contents  was  col- 


850 


DIPPENAAR-SCHOEMAN  & HARRIS— FOOD  STORAGE  BY  A SPIDER 


851 


lected  along  with  the  female  spider.  The  sac  con= 
tained  four  termites  which  appeared  dead  but,  when 
touched,  movement  of  their  legs  was  observed. 
There  was  no  indication  that  they  had  been  fed 
upon.  The  sac  was  about  10  cm  in  diameter  and  the 
interior  consisted  of  a white,  slightly  shiny  smooth 
silk  layer  while  the  outside  was  slightly  sticky  and 
covered  with  sand  particles.  The  spiders  and  ter- 
mites are  voucher  specimens  housed  in  the  National 
Collection  of  Arachnida  at  the  ARC-Plant  Protec- 
tion Research  Institute  in  Pretoria. 

Harvester  termites  have  erratic  bursts  of  activity. 
The  ammoxenids  are  able  to  detect  these  bursts 
whether  they  occur  nocturnally  or  diurnally  (Wilson 
& Clark  1977;  Dippenaar-Schoeman  et  al.  1996a, 
b).  The  termites  are  thus  available  sporadically,  for 
short  periods,  above  ground  to  the  spiders.  Web 
building  spiders  have  been  observed  storing  termite 
prey  during  at  least  short  periods  when  food  is 
abundant.  The  theridiid  Chrosiothes  tonala  Levi 
1954,  which  is  also  a termite  specialist,  could  cap- 
ture during  a single  burst  of  termite  activity  20  prey 
or  more  before  carrying  them  all  off  in  one  prey 
mass  (Eberhard  1991).  In  the  field  these  spiders 
were  observed  feeding  on  the  prey  mass  for  up  to 
a day.  The  extra  prey  captured  therefore  enabled  the 
spiders  to  feed  over  a longer  period. 

This  observation  of  food  storage  strengthens  the 
assumption  that  members  of  Ammoxenus  are  spe- 
cialist predators  of  termites  (Dippenaar-  Schoeman 
et  al.  1996b).  They  seem  to  use  two  different  meth- 
ods of  catching  and  utilizing  prey.  The  termite 
workers  are  either  killed,  pulled  immediately  below 
the  soil  surface  and  fed  upon  or  they  are  paralyzed 
and  stored  in  silk  sacs  just  below  the  soil  surface 
for  feeding  at  a later  stage. 


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Dippenaar-Schoeman,  A.S.,  M,  de  Jager  & A.  van 
den  Berg.  1996b.  Ammoxenus  species  (Araneae: 
Ammoxenidae)  specialist  predators  of  harvester 
termites  in  South  Africa.  African  Plant  Protec- 
tion 2:103-109. 

Eberhard,  W.G.  1991.  Chrosiothes  tonala  (Araneae, 
Theridiidae):  A web-building  spider  specializing 
on  termites.  Psyche  98:7-19. 

Van  den  Berg,  A.  & A.S.  Dippenaar-Schoeman. 
1991.  Ground-living  spiders  from  an  area  where 
the  harvester  termite  Hodotermes  mossambicus 
occurs  in  South  Africa.  Phytophylactica  23:247- 
253. 

Wilson,  D.S.  & A.B.  Clark.  1977.  Above  ground 
predator  defense  in  the  harvester  termite,  Hodo- 
termes mossambicus(\ldLg&n).  Journal  of  the  En- 
tomological Society  of  Southern  Africa  40:271- 
282. 

Manuscript  received  1 June  2000,  revised  5 Janu- 
ary 2005. 


2004.  The  Journal  of  Arachnology  32:852-856 


SHORT  COMMUNICATION 

PARTHENOGENESIS  THROUGH  FIVE  GENERATIONS 
IN  THE  SCORPION  LIOCHELES  AUSTRALASIAE 
(FABRICIUS  1775)  (SCORPIONES,  ISCHNURIDAE) 

Kazunori  Yamazaki^:  Institute  of  Life  and  Environmental  Sciences,  University  of 
Tsukuba,  Tsukuba,  Ibaraki  305-8572,  Japan 

Toshiki  Makioka^:  Institute  of  Biological  Sciences,  University  of  Tsukuba,  Tsukuba, 
Ibaraki  305-8572,  Japan 

ABSTRACT,  Females  of  Liocheles  aiistralasiae  (Fabricius  1775)  collected  from  a maleless  population 
on  Iriomote  Island,  Ryukyu,  Japan,  and  separately  reared  in  the  laboratory  have  parthenogenetically  pro- 
duced five  successive  generations  in  seven  years.  Many  individuals  of  the  first  generation  collected  in  July 
1994,  gave  birth  to  the  second  generations  from  1994-1998,  and  some  of  the  second  generation  gave 
birth  to  the  third  generation  from  1997-1999.  The  fourth  generations  were  born  from  1999-2001,  and  the 
fifth  generations  were  born  in  January-August  2001.  Most  females  of  all  generations  gave  birth  to  about 
20  neonates  after  approximately  an  eight-month  pregnancy.  In  the  ovary  of  a fourth  generation  female, 
as  well  as  in  those  of  most  of  the  second  generation  females,  there  were  growing  embryos  and  a number 
of  oocytes  of  various  sizes,  suggesting  a possibility  of  the  sixth  generation  or  subsequent  generations  by 
parthenogenesis. 

Keywords:  Thelytokous  parthenogenesis,  successive  generations,  histological  section 


Among  1259  scorpion  species  described  in  the 
world  (Fet  et  al.  2000),  thelytokous  parthenogenesis 
has  been  reported  only  in  seven  species  (Matthiesen 
1962,  1971;  San  Martin  & Gambardella  1966;  Mak- 
ioka  & Koike  1984,  1985;  Zolessi  1985;  Lourengo 
1991;  Lourengo  & Cuellar  1994;  Makioka  1993; 
Maury  1997;  Lourengo  et  al.  2000).  In  some  of 
these  species,  parthenogenesis  has  been  presumed 
based  on  the  absence  of  males  in  the  populations 
(Lourengo  1991;  Lourengo  & Cuellar  1994),  female 
biased  sex  ratios  (Maury  1997)  and  all  female  ne- 
onates (Lourengo  1991;  Lourengo  & Cuellar  1999). 
However,  one  of  the  best  evidences  of  parthenogen- 
esis is  an  achievement  of  independent  rearing,  i.e., 
being  raised  alone  without  the  presence  of  males, 
through  successive  generations.  In  only  three  scor- 
pion species,  has  parthenogenesis  been  confirmed 
by  means  of  independent  rearing  through  three  or 
four  successive  generations;  this  was  seen  in  two 
buthids,  Tityus  sernilatus  Lutz  & Mello  1922  (Mat- 

' Present  address:  Department  of  Biological  Sci- 
ences, Graduate  School  of  Science,  University  of 
Tokyo,  7-3-1  Hongo,  Bunkyo-ku,  Tokyo,  1 13-0033, 
Japan. 

2 Present  address:  4-31-13  Kitami,  Setagaya,  Tokyo 
157-0067,  Japan. 


thiesen  1962,  1971;  San  Martin  & Gambardella 
1966)  and  T.  bolivianus  uruguayensis  (Borelli 
1900)  (Zolessi  1985)  and  an  ischnurid,  Liocheles 
australasiae  (Fabricius  1775)  (Makioka  1993). 

Matthiesen  ( 1 962)  found  in  Tityus  serrulatus  that 
three  individuals  of  the  second  generation,  born 
from  the  first  field-collected  generation,  partheno- 
genetically gave  birth  to  the  third  generations  when 
reared  separately.  Later  he  reported  that  one  of  the 
third  generation  individuals,  reared  separately,  gave 
birth  to  a total  of  33  fourth  generation  offspring 
(Matthiesen  1971).  In  T.  serrulatus,  San  Martin  & 
Gambardella  (1966)  also  reported  that  two  second 
generation  females  gave  birth  to  22  third  generation 
offspring,  only  two  of  which  gave  birth  to  eight 
fourth  generation  offspring.  Zolessi  (1985)  stated 
that,  for  T.  bolivianus  uruguayensis  he  successively 
obtained  second  and  third  generations  when  females 
were  reared  separately,  but  he  did  not  show  the 
numbers  of  mothers  and  neonates.  In  Liocheles  aus- 
tralasiae Makioka  (1993)  obtained  many  third  gen- 
eration offspring  under  separate  rearing  conditions. 
In  these  previous  works,  however,  only  a few  of  the 
second  or  third  generations  produced  offspring  par- 
ticularly in  the  Tityus  species,  and  no  neonates  of 
the  third  or  the  fourth  generations  became  mature 
to  produce  offspring,  leaving  unanswered  the  ques- 


852 


YAMAZAKI  & MAKIOKA— PARTHENOGENESIS  IN  A AUSTRALASIAE 


853 


Figure  1. — Separate  rearing  in  Liocheles  australasiae.  Scale  = 2 cm. 


tion  as  to  whether  parthenogenesis  is  an  evolution- 
ary strategy  in  these  species  or  whether  the  phe- 
nomenon is  limited  to  only  a few  generations.  In 
the  present  study,  we  have  attempted  to  answer  this 
question  in  L.  australasiae  by  rearing  them  through 
more  than  four  generations. 

A total  of  413  females  of  Liocheles  australasiae 
were  collected  from  a maleless  population  (Mak- 
ioka  & Koike  1984,  1985;  Makioka  1992a,  1992b, 
1993)  on  Iriomote  Island,  one  of  the  Ryukyu  Is- 
lands, Japan,  in  July  1994.  These  specimens  are  de- 
posited in  the  collections  of  the  Biological  Sciences 
of  University  of  Tsukuba  (TKB-anim.  1008-1421). 
First  generations  derived  from  the  collected  speci- 
mens were  serially  numbered  and  kept  separate  in 
glass  vials  (27  mm  in  diameter  and  55  mm  in 
height)  with  a piece  of  wet  filter  paper  (Fig.  1)  at 
28  ± 1 °C  in  a dark  incubator,  and  fed  termites  once 
a week. 

The  first  instar  juveniles  of  the  second  generation 
bom  from  those  females  immediately  climbed  onto 
their  mother’s  back,  stayed  there  without  eating  for 
about  a week  (Fig.  2),  and  then  molted  into  second 
instar  juveniles  (Fig.  3)  which  left  their  mother  and 
took  food  by  themselves.  Each  of  the  second  instar 
juveniles  was  kept  separate  in  a new  glass  vial  soon 
after  the  first  molt,  and  serially  numbered.  The  ju- 
veniles were  fed  termites  once  a week,  the  number 
of  which  was  varied  with  the  scorpion’s  instar.  We 
took  special  care  not  to  give  soldier  termites  to  the 
young  scorpions,  because  the  soldiers  can  wound  or 
kill  young  scorpions.  All  specimens  were  watered 
daily  and  their  conditions  (molt,  parturition,  death, 
etc.)  were  checked  and  recorded. 

Ten  females  of  the  second  generation  that  expe- 
rienced parturitions  at  least  once  and  a female  of 


the  fourth  generation  that  experienced  parturition 
once  were  dissected  in  physiological  saline  solution 
for  histological  observations.  The  ovaries  were  re- 
moved, fixed  with  Bouin’s  solution,  dehydrated  in 
a graded  ethanol-n-butaeol  series,  embedded  in  par- 
affin and  serially  sectioned  at  5 fxm  thickness.  The 
sections  were  stained  with  Mayer’s  hematoxylin 
and  eosin,  and  the  number  of  oocytes,  embryos 
growing  in  the  ovarian  diverticula,  and  empty  ovar- 
ian diverticula  (remnants  of  previous  parturitions) 
was  counted  under  a light  microscope. 

A total  of  147  of  the  413  first-generation  females 
experienced  165  parturitions  to  produce  1118  sec- 
ond generation  offspring  during  the  period  from 
1994-1998.  From  these  second  generation  off- 
spring, 46  females  became  mature  and  experienced 
98  parturitions  to  produce  493  third  generation  off- 
spring, 19  of  which  experienced  28  parturitions  to 
produce  180  fourth  generation  offspring.  From  the 
fourth  generations,  only  seven  females  became  ma- 
ture and  gave  birth  to  78  fifth  generation  offspring 
through  six  parturitions. 

The  ovary  of  each  female  dissected  consisted  of 
three  longitudinal  and  four  transverse  ovarian  tubes, 
which  bore  many  growing  ovarian  diverticula  con- 
taining oocytes  or  embryos  and  empty  ovarian  di- 
verticula which  had  lost  their  embryos  in  the  pre- 
vious parturitions.  In  adult  ovaries,  as  described  in 
previous  papers  (Makioka  1992a;  Yamazaki  & 
Makioka  2001),  there  were  neither  oogonia  nor  oo- 
cytes in  the  walls  of  the  ovarian  tubes  and  all  the 
oocytes  were  contained  in  their  own  ovarian  diver- 
ticula, waiting  to  develop  into  embryos. 

In  the  ovary  of  the  fourth  generation  female  ex- 
amined immediately  after  her  death,  there  were  20 
large  empty  ovarian  diverticula  that  had  newly  lost 


854 


THE  JOURNAL  OF  ARACHNOLOGY 


Figure  2-3. — First  instar  juveniles  of  Lioclieles  aiistrakisiae  mounted  on  their  mother’s  back.  Scale  = 
1 cm.  3.  Second  instar  juveniles  of  Liocheles  aiistralasiae  immediately  after  the  first  molt  on  their  mother’s 
back.  Scale  = 1 cm. 


their  embryos  at  the  last  parturition  (Fig.  4)  and  86 
smaller  ovarian  diverticula  containing  oocytes  of 
various  sizes  (Fig.  5).  No  growing  ovarian  divertic- 
ula containing  growing  embryos  were  found.  Two 
neonates  corresponding  to  the  difference  in  number 


between  20  empty  ovarian  diverticula  and  18  neo- 
nates counted  at  birth,  may  have  been  eaten  by  the 
mother  (see  Polis  & Sissom  1990).  Neither  male 
gonadal  tissues,  such  as  ovotestes,  nor  sperm  re- 
ceiving structures,  such  as  spermathecae,  were 


Figures  4-5. — Ovarian  sections  of  the  fourth  generation  in  Liocheles  aiistralasiae . 4.  Ovarian  diverticula 
containing  a primary  oocyte  (arrows)  and  empty  ovarian  diverticula  (ed).  ot,  ovarian  tube.  Scale:  500  pm. 
5.  Enlargement  of  small  ovarian  diverticula  containing  primary  oocyte  (po).  f;  follicle  epithelium.  Scale 
= 50  pm. 


YAMAZAKI  & MAKIOKA— PARTHENOGENESIS  IN  L.  AUSTRALASIAE 


855 


found  in  the  ovaries  of  the  second  and  the  fourth 
generation  females. 

Some  authors  have  attempted  to  rear  scorpions 
from  neonates  to  adults  in  order  to  ascertain  their 
life  histories  (Rosin  & Shulov  1963;  Smith  1966; 
Matthiesen  1970;  Francke  1976;  Sissom  & Francke 
1983;  Francke  & Sissom  1984;  Benton  1991; 
Brown  1997)  and  to  confirm  parthenogenetic  repro- 
duction (Matthiesen  1962,  1971;  San  Martin  & 
Gambardella  1966;  Zolessi  1985;  Makioka  1993; 
Lourengo  & Cuellar  1999).  In  most  cases,  however, 
none  or  only  a few  of  neonates  reached  the  adult 
stage  (Matthiesen  1962,  1970,  1971;  Rosin  & Shu- 
lov 1963;  San  Martin  & Gambardella  1966;  Smith 
1966;  Francke  1976;  Sissom  & Francke  1983; 
France  & Sissom  1984;  Zolessi  1985;  Benton  1991; 
Brown  1997).  Among  them,  only  three  partheno- 
genetic scorpions  successively  continued  to  produce 
subsequent  generations  under  the  separate  rearing 
conditions  (Matthiesen  1962,  1971;  San  Martin  & 
Gambardella  1966;  Zolessi  1985;  Makioka  1993). 

Matthiesen  (1971)  succeeded  in  obtaining  33  ne- 
onates of  the  fourth  generation  from  a mother  of 
the  third  generation  in  Tityus  serrulatus  and  Zolessi 
(1985)  obtained  an  unspecified  number  of  neonates 
of  the  third  generation  from  the  second  generation 
in  T.  bolivianus  uruguayensis,  but  they  did  not 
mention  the  fates  of  these  neonates.  In  Liocheles 
australasiae,  Makioka  (1993)  obtained  a number  of 
neonates  of  the  third  generation  from  four  mothers 
of  the  second  generation,  but  rearing  was  then  ter- 
minated by  an  incubator  accident.  Thereafter,  in 
1994,  we  began  the  present  study  and  have  suc- 
ceeded in  obtaining  a number  of  individuals  of  five 
successive  generations  of  L.  australasiae.  At  pres- 
ent, 78  second  instars  of  the  fifth  generation  are 
being  raised.  At  the  same  time,  in  a fourth  gener- 
ation female  after  the  first  parturition,  the  ovary 
contained  a number  of  oocytes  of  various  sizes.  It 
seems  likely  therefore,  that  the  present  specimens 
of  L.  australasiae  will  continue  to  reproduce  par- 
thenogenetically  through  further  generations  under 
the  present  laboratory  conditions,  as  well  as  in  their 
native  population  of  Iriomote  Island,  and  that  our 
separate  rearing  method  is  well  suited  to  L.  austra- 
lasiae. We  suggest  that  because  of  the  number  of 
offspring  produced  by  parthenogenesis  and  because 
of  the  number  of  generations  we  have  now  reared, 
parthenogenesis  is  indeed  a stable  reproductive 
strategy  in  this  species. 

We  wish  to  thank  Dr.  Koji  Tojo,  University  of 
Tsukuba,  for  his  helpful  advice  on  preparing  the 
present  paper.  We  also  thank  Dr.  Hiroshi  Ando,  Tsu- 
rumi  University,  and  Mr.  Yuji  Takayama  and  Mr. 
Hiroyuki  Mitsumoto,  University  of  Tsukuba,  for 
their  assistance  in  collecting  and  rearing  specimens. 

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Manuscript  received  18  March  2002,  revised  22 
October  2003. 


2005.  The  Journal  of  Arachnology  33:857--861 


SHORT  COMMUNICATION 

THE  EFFECTS  OF  MOISTURE  AND  HEAT  ON  THE  EFFICACY 
OF  CHEMICAL  CUES  USED  IN  PREDATOR  DETECTION 
BY  THE  WOLF  SPIDER  PARDOSA  MILVINA 
(ARANEAE,  LYCOSIDAE) 


Shawn  M.  Wilder  and  Jill  DeYito:  Department  of  Zoology,  Miami  University, 
Oxford,  OH  45056 

Matthew  H.  Persons:  Department  of  Biology,  Susquehanna  University,  Selinsgrove, 
PA  17870 

Ann  L«  Rypstra:  Department  of  Zoology,  Miami  University,  Hamilton,  OH  45011 

ABSTRACT*  Little  is  known  about  how  eovironmentai  conditions  affect  the  relative  efficacy  of  infor- 
mation present  in  chemical  cues.  The  wolf  spider,  Pardosa  milvina,  responds  to  silk  and  excreta  from  a 
larger  species  of  wolf  spider,  Hogna  helluo,  with  effective  antipredator  behavior.  We  investigated  whether 
wetting  or  heating  chemotactile  cues  of  Hogna  helluo  would  reduce  the  amount  of  antipredator  behavior 
displayed  by  Pardosa  milvina  relative  to  unmanipulated  cues.  Pardosa  milvina  showed  less  antipredator 
behavior  on  chemotactile  cues  that  had  been  wetted  then  dried  but  did  not  respond  differently  in  the 
presence  of  cues  that  had  been  heated  and  then  cooled.  The  results  suggest  rhat,  in  the  field,  morning  dew 
may  degrade  some  of  the  cues  deposited  by  H.  helluo  at  night  and  reduce  the  ability  of  P.  milvina  to 
avoid  predation.  However,  typical  periods  of  daily  heating  of  cues  may  not  affect  the  efficacy  of  predator 
detection  by  F.  milvina. 

Keywords:  Antipredator  behavior,  chemotactile  cues,  moisture,  heat 


Many  animals  have  evolved  behaviors  that  re- 
duce the  risk  of  predation,  often  at  the  cost  of  lost 
foraging  opportunities  (Sih  1980;  Stephens  & Krebs 
1986),  To  minimize  the  costs  of  antipredator  be- 
havior, some  animals  adjust  their  behavioral  re- 
sponse to  a predator  depending  on  the  relative  mag- 
nitude of  the  threat  (Kats  & Dill  1998;  Dicke  & 
Grostal  2001).  A variety  of  cues,  including  visual 
information,  vibrations,  and  chemicals,  may  be  used 
to  detect  the  presence  of  and  threat  posed  by  a pred- 
ator (Lima  & Dill  1990).  Chemotactile  cues  may  be 
especially  important  for  predator  detection  by  the 
wolf  spider  Pardosa  milvina  (Hentz  1844)  (Ara- 
neae,  Lycosidae;  Persons  et  al.  2002).  This  relative- 
ly small  wolf  spider  (ca.  20  mg)  significantly  re- 
duces movement  in  the  presence  of  silk  and  excreta 
from  the  larger  (adult  female,  ca.  300-800  mg)  syn- 
topic  wolf  spider  Hogna  helluo  (Walckenaer  1837) 
(Araneae,  Lycosidae;  Persons  & Rypstra  2001; 
Bames  et  al.  2002).  This  reduction  in  movement 
results  in  a lower  probability  of  predation  for  P. 
milvina  (Persons  et  al.  2002).  However,  long  term 
exposure  to  cues  can  have  significant  costs,  includ- 


ing weight  loss  and  lower  egg  production  (Persons 
et  al.  2002).  Thus,  P.  milvina  finely  adjusts  its  an- 
tipredator behavior  depending  on  the  size  of  the 
predator  (Persons  & Rypstra  2001),  the  diet  of  the 
predator  (Persons  et  al.  2001),  and  the  length  of 
time  since  predator  cues  were  deposited  (Barnes  et 
al.  2002). 

The  level  of  antipredator  behaviors  exhibited  (i.e. 
reductions  in  activity)  may  depend  on  the  reliability 
of  cues  present  in  the  environment.  Past  studies  of 
the  response  of  P.  milvina  to  cues  of  H.  helluo  have 
been  conducted  in  controlled  laboratory  environ- 
ments (Barnes  et  al.  2002;  Persons  et  al.  2002).  Yet, 
in  nature,  cues  may  be  exposed  to  a variety  of  en- 
vironmental conditions  that  may  affect  the  quality 
of  cues  and  the  information  they  contain  about  a 
predator.  Even  within  a single  day,  conditions  may 
change  from  cool  and  wet  (e.g,  from  dew)  in  the 
morning,  to  hot  and  dry  during  the  middle  of  the 
day.  Information  is  needed  on  how  environmental 
conditions  may  affect  predator  cues  in  order  to  ex- 
trapolate the  results  of  laboratory  studies  to  the  nat- 
ural environment.  The  purpose  of  the  study  was  to 


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examine  the  impact  of  two  potentially  important  en- 
vironmental variables,  moisture  and  heat,  on  the  rel- 
ative efficacy  of  chemotactile  cues  that  induce  an- 
tipredator behavior  by  P.  milvina. 

All  P.  milvina  used  as  experimental  subjects  were 
collected  in  the  soybean  fields  at  the  Miami  Uni- 
versity Ecology  Research  Center  (Oxford,  Butler 
County,  Ohio,  USA)  between  June  and  August 
2003.  We  used  field  caught  adult  female  P.  milvina 
in  the  experimental  trials.  None  of  the  females  used 
in  the  trials  had  produced  an  egg  sac  in  the  week 
prior  to  testing.  Hogna  helluo  used  for  cue  collec- 
tion were  adult  and  late  instar  immature  females, 
all  of  which  had  been  either  field-caught  or  lab- 
reared  from  populations  originating  at  the  Ecology 
Research  Center. 

Both  species  were  maintained  in  covered  plastic 
cups  {P.  milvina:  5 cm  high  X 8 cm  wide,  H.  hel- 
luo: 8 cm  high  X 12  cm  wide)  with  a moist  peat 
moss  substrate  in  the  laboratory  on  a 13:11  light: 
dark  cycle  at  approximately  25  °C  and  70%  humid- 
ity. Both  F.  milvina  and  H.  helluo  were  maintained 
on  a diet  of  two  appropriately  sized  domestic  crick- 
et nymphs  (Acheta  domesticus)  once  a week.  The 
predators  to  be  used  as  a source  of  chemotactile 
stimuli,  H.  helluo,  were  fed  to  satiation  with  eight 
juvenile  crickets  in  the  24  hours  preceding  cue  col- 
lection. This  served  to  equalize  the  potential  vol- 
ume of  silk  and  feces  deposited  on  the  substrate. 

We  collected  predator  silk  and  excreta  cues  on 
white  filter  paper  (18.5  cm  diameter)  housed  in  cov- 
ered, round  plastic  containers  (20  cm  in  diameter  X 
8 cm  high).  Chambers  were  swabbed  with  alcohol 
and  allowed  to  dry  before  we  added  the  filter  paper. 
A cotton  dental  wick  saturated  with  double-distilled 
water  was  taped  to  the  inside  of  each  container  lid 
to  prevent  spider  desiccation.  A single  H.  helluo 
was  housed  in  each  chamber  for  a minimum  of  24 
h (i.e.,  preceding  the  first  trial  run  on  a given  day). 
Because  the  level  of  P.  milvina  response  to  H.  hel- 
luo cues  declines  with  cue  age  (Barnes  et  al.  2002), 
we  did  not  remove  the  stimulus  spider  from  the  cue 
collection  chamber  until  we  were  ready  to  treat  the 
cue-laden  filter  paper  with  water  or  heat  two  hours 
before  each  trial. 

The  testing  arena  consisted  of  the  same  container 
type  used  for  cue  collection,  except  that  the  lid  was 
removed  to  allow  video  recording  of  each  trial  from 
above.  For  each  trial,  we  lined  one  side  of  the  arena 
with  unmanipulated  H.  helluo  cues  (control)  and  the 
other  side  with  H.  helluo  cues  that  had  been  ex- 
posed to  one  of  our  experimental  treatments.  Before 
handling  filter  paper,  and  between  handling  filter 
paper  with  unmanipulated  cues  and  experimentally- 
manipulated  cues,  we  cleaned  our  hands  by  washing 
them  with  soap  and  water  and  then  sterilizing  them 
with  alcohol.  Experimental  vs.  control  sides  were 
alternated  between  trials  during  each  experiment 
(i.e.,  the  left  side  of  the  arena  was  designated  as  the 


control  in  approximately  50%  of  the  trials  and  vice 
versa).  Arenas  were  swabbed  with  alcohol  and  al- 
lowed to  dry  between  trials.  Individual  P.  milvina 
were  introduced  to  the  center  of  the  test  chamber 
under  a clear  glass  vial  (2,5  cm  in  diameter  X 6.5 
cm  high)  on  a small  round  circle  of  filter  paper 
(diameter  = 4.5  cm)  which  had  not  been  exposed 
to  predator  cues.  After  an  acclimation  period  of  two 
minutes,  we  removed  the  glass  vial  and  recorded  P. 
milvina  behavior  remotely  using  a video  camera. 

We  conducted  trials  from  25  August-5  Septem- 
ber 2003,  between  0930  h and  1630  h.  The  behavior 
of  P,  milvina  was  recorded  from  another  room  to 
minimize  human  disturbance  during  the  trials.  The 
video  camera  was  mounted  1 m above  the  test 
chamber  and  the  area  was  illuminated  with  fluores- 
cent lighting;  room  temperature  was  ca.  25  °C.  We 
quantified  locomotor  activity  of  the  experimental  P. 
milvina  using  an  automated  digital  data  collection 
system  (Videomex-V,  Columbus  Instruments)  con- 
nected to  a Sony©  Hi8  video  camera.  The  system 
recorded  spider  movements  on  each  side  of  the  are- 
na for  one-minute  intervals  throughout  each  30  min 
trial.  We  compared  the  following  parameters  be- 
tween treatment  and  control  sides  of  the  arenas:  dis- 
tance traveled,  time  spent  resting,  time  walking,  res- 
idence time  on  each  side  of  the  arena,  and  time 
spent  in  non-forward  movement  (e.g,  leg  move- 
ments or  turning).  We  discarded  data  from  several 
animals  that  failed  to  move  more  than  100  cm  dur- 
ing the  30  minute  trial  because  these  individuals 
may  not  have  had  sufficient  experience  sampling 
both  sides  of  the  arena.  Typical  distances  traveled 
by  P.  milvina  for  30  min  in  equivalent  test  arenas 
range  from  300-1000  cm  (Persons  et  al.  2001).  We 
summed  data  over  the  30  min  trial  and  used  paired 
t-tests  to  compare  movement  behaviors  on  the  cue 
and  control  sides  of  the  arena. 

In  our  first  experiment,  F.  milvina  were  given  a 
choice  between  filter  paper  with  H.  helluo  cues  that 
had  been  saturated  with  water  then  allowed  to  dry 
for  two  hours  (experimental  treatment)  vs.  filter  pa- 
per with  cues  collected  from  the  same  spider,  not 
treated  with  water  but  allowed  to  age  for  the  same 
two  hour  period  (control  treatment).  Two  hours  be- 
fore each  trial,  we  removed  the  stimulus  spider 
from  the  cue  collection  chamber,  cut  the  filter  paper 
in  half  with  scissors,  and  wet  the  experimental  sec- 
tion with  1,5  mL  double-distilled  water,  dripped 
evenly  across  the  cue-laden  surface.  Both  experi- 
mental and  control  treatments  {n  = 14)  were  left 
open  to  the  air  (at  room  temperature  ca.  22,5  °C; 
humidity  ca.  60%)  to  allow  the  wet  side  to  dry  for 
2 hours. 

Our  second  experiment  consisted  of  a choice  test 
between  H.  helluo  cue-laden  filter  paper  that  had 
been  heated  to  40  °C,  then  cooled  to  room  temper- 
ature (experimental  treatment)  vs.  filter  paper  with 
cues  collected  from  the  same  spider,  not  heated  but 


WILDER  ET  AL.— ENVIRONMENTAL  EFFECTS  ON  CUES 


859 


1400  n 

E 

1200 

o 

o 

c 

1000 

(0 

800 

o 

k. 

o 

600 

2 

400 

0) 

E 

200 

P 

0 

□ Wetted  cues 
■ Control  cues 


ri.n 


NF  W I R D 


Behavior 

Figure  1. — Comparisons  of  the  behavior  of  P.  milvina  H.  helliio  cues  that  were  wetted  then  dried. 
Behaviors  are  denoted  as  follows:  NF  = time  in  non-forward  movement,  W = time  walking,  I = time 
immobile,  R = residence  time  (on  half  of  arena),  D = Distance  traveled.  * indicates  P < 0.05. 


allowed  to  age  for  the  same  two  hour  period  (con- 
trol treatment).  Mean  daily  soil  surface  tempera- 
tures range  between  20  and  30  °C  from  June-Au- 
gust  in  corn  and  soybean  fields,  where  P.  milvina 
and  H.  helluo  are  found  in  high  abundance  (NSIDC 
2002).  Occasionally,  temperatures  may  rise  above 
40  °C  for  brief  periods.  However,  a temperature  of 
40  °C  was  chosen  for  this  study  to  evaluate  if  typ- 
ical periods  of  heating  during  the  summer  would  be 
sufficient  to  degrade  the  information  contained  in 
H.  helluo  cues.  We  removed  the  stimulus  H.  helluo 
from  each  chamber  and  divided  the  filter  paper;  the 
experimental  half  was  placed  in  a drying  oven  pre- 
heated to  40  °C  for  1.5  h,  while  the  control  half 
aged  at  room  temperature  (ca.  22.5  °C;  humidity  ca. 
60%).  The  experimental  filter  paper  was  kept  cov- 
ered during  heating  to  minimize  the  effect  of  the 
drying  oven  on  the  water  content  of  the  cue-laden 
paper.  Each  control  filter  paper  was  kept  covered 
while  the  corresponding  paper  in  the  experimental 
treatment  was  in  the  oven.  Containers  with  both 
treatments  were  left  open  to  the  air  at  room  tem- 
perature during  the  30  minute  cooling  period. 

Wetting  then  drying  the  predator  cues  had  a sig- 
nificant effect  on  the  movements  of  P.  milvina  (Fig. 
1).  Spiders  spent  less  time  in  non-forward  move- 
ment (e.g.  turning  and  appendage  movements)  on 
the  wetted  side  of  the  arena  than  the  control  side 
{df=  8,  t - 4.40,  P = 0.002,  Fig.  1).  In  addition, 
P.  milvina  spent  significantly  less  time  immobile  {df 
= 8,  / = 2.58,  P = 0.03)  and  had  a lower  residence 
time  {df  = 8,  / = 3.09,  P = 0.02)  on  the  treatment 
side  of  the  arena  that  had  previously  been  wet  (Fig. 
1).  There  was  no  effect  of  wetting  the  cues  on  time 


spent  walking  {df  = 8,  r = 1.37,  P = 0.21)  or  dis- 
tance traveled  {df  = 8,  t = 0.23,  P = 0.83). 

In  contrast  to  the  effects  of  water  on  cue  efficacy, 
heating  then  cooling  the  predator  cues  had  no  effect 
on  the  movement  of  P.  milvina  (Fig.  2).  There  were 
no  differences  in  non-forward  movement  {df  = 12, 
t = 1.55,  P = 0.15),  time  spent  walking  {df  = 12, 
t = 0.03,  P = 0.98),  time  immobile  {df  = 12,  r = 
1.21,  P = 0.25),  residence  time  {df  = 12,  t = 1.36, 
P = 0.20)  and  distance  traveled  {df  = \2,  t = 0.79, 
P — 0.44)  of  P.  milvina  between  previously  heated 
and  control  predator  cues. 

Previous  studies  have  shown  that  P.  milvina  re- 
sponds to  H.  helluo  silk  and  excreta  with  greater 
time  spent  immobile  and  greater  residence  time  on 
cue  substrates  relative  to  controls  (Persons  et  al. 
2001;  Barnes  et  al.  2002).  Immobility  has  been 
shown  to  be  an  effective  means  of  reducing  pre- 
dation risk  from  H.  helluo,  which  may  hunt  using 
visual  and/or  vibratory  cues  (Persons  et  al.  2002). 
Thus  the  increase  in  activity  we  observed  on  the 
side  of  the  arena  that  had  been  treated  with  water 
suggests  that  the  cues  deposited  by  H.  helluo  are 
significantly  less  effective  in  producing  anti-preda- 
tor behavior  in  P.  milvina.  Likewise,  the  greater 
amount  of  time  that  the  spiders  spent  immobile  on 
the  control  side  of  the  arena  where  there  were  more 
effective  chemical  cues  likely  resulted  in  the  coun- 
terintuitive observation  they  actually  had  longer 
residence  times  on  the  side  of  the  arena  where  they 
perceived  greater  risk.  We  suspect  that  the  greater 
time  spent  in  non-forward  movement  (e.g.  turning 
and  appendage  movements)  in  the  presence  of  cues 
may  constitute  directional  sampling  of  predator 


860 


THE  JOURNAL  OF  ARACHNOLOGY 


E 

o 

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(j2 


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1400  n 

1200 

1000 

800 

600 

400 

200 

0 


□ Heated  cues 
■ Control  cues 


nm  n 


NF  W 


Behavior 

Figure  2. — Comparisons  of  behavior  of  P.  milvina  on  H.  helluo  cues  that  were  heated  then  cooled. 
Behaviors  are  denoted  as  follows:  NF  = time  in  non-forward  movement,  W = time  walking,  I = time 
immobile,  R = residence  time  (on  half  of  arena),  D = Distance  traveled. 


cues  and  visual  searching  for  nearby  predators. 
Thus,  less  time  in  non-forward  movement  and  less 
time  immobile,  and  lower  residence  time  on  the 
previously  wet  substrate  relative  to  control  H.  hel- 
luo cues,  may  indicate  that  water  either  reduces  or 
completely  eliminates  the  efficacy  of  the  chemical 
cues  used  in  predator  detection  by  P.  milvina. 

The  effects  of  water  on  predator  cue  efficacy  may 
have  important  implications  for  P.  milvina.  Hogna 
helluo  are  primarily  nocturnal  and  may  deposit 
dense  accumulations  of  silk  and  excreta  around  the 
entrance  to  their  burrows,  where  they  spend  much 
of  their  time  during  the  day  (Walker  et  al.  1999a; 
b).  Morning  dew  may  then  degrade  much  of  the 
cues  that  were  deposited  at  night  and  limit  the  abil- 
ity of  diurnal  P.  milvina  to  avoid  or  reduce  move- 
ment in  the  proximity  of  H.  helluo  burrows.  Periods 
after  brief  rainfall  may  also  be  dangerous  to  P.  mil- 
vina. In  addition  to  degrading  predator  cues,  there 
is  evidence  that  water  degrades  female  sex  phero- 
mones, which  may  decrease  the  ability  of  males  to 
find  and  mate  with  females  (Dondale  & Hegdekar 
1973).  Thus,  the  frequency  of  rainfall  in  a region 
may  have  implications  for  predator-prey  interac- 
tions among  P.  milvina  and  H.  helluo. 

A temperature  of  40  °C  appeared  to  have  no  ef- 
fect on  the  efficacy  of  H.  helluo  chemical  cues. 
Lack  of  an  effect  of  heating  may  be  because  the 
chemical  cues  in  silk  and  excreta  are  tolerant  of 
high  temperatures,  or  because  the  heating  period  of 
the  experiment  was  too  short  or  of  too  low  of  a 
temperature  to  create  a detectable  difference.  Fur- 
ther studies  are  needed  to  determine  if  longer  pe- 
riods of  heating  or  higher  temperatures,  such  as 
those  experienced  on  some  sunny  summer  after- 


noons on  barren  ground,  where  cues  may  be  ex- 
posed to  short  periods  (ca.  1-2  hours)  of  tempera- 
tures in  excess  of  40  °C,  affect  the  efficacy  of  H. 
helluo  chemical  cues. 

It  is  not  known  what  chemical,  group  of  chemi- 
cals or  tactile  information  in  the  silk  or  excreta  of 
H.  helluo  is  responsible  for  eliciting  antipredator 
behaviors  in  P.  milvina.  However,  the  results  of  this 
study  suggest  that  the  cue  responsible  for  changes 
in  behavior  by  P.  milvina  may  degrade  in  the  pres- 
ence of  water.  Further  studies  of  the  properties  of 
predator  cues  may  aid  in  identifying  the  specific  cue 
responsible  for  eliciting  antipredator  behavior  in  H. 
helluo  silk  and  excreta. 

ACKNOWLEDGMENTS 

This  manuscript  was  improved  by  comments 
from  J.  Rovner  and  an  anonymous  reviewer.  We 
would  like  to  thank  the  many  undergraduates  in  the 
Miami  University  Spider  Lab  for  collecting,  raising 
and  maintaining  the  spiders  used  in  this  study. 
Funding  was  provided  by  NSF  grants  DBI  0216776 
& DBI  0216947  to  M.H.  Persons  and  A.L.  Rypstra, 
an  Ohio  Plant  Biotechnology  Consortium  grant  to 
C.M.  Buddie  and  A.L.  Rypstra,  and  the  Ecology 
Research  Center  and  Department  of  Zoology  at  Mi- 
ami University.  Voucher  specimens  of  P.  milvina 
and  H.  helluo  from  the  population  at  the  Miami 
University  Ecology  Research  Center  have  been  de- 
posited in  Miami  University’s  Hefner  Zoology  Mu- 
seum. 

LITERATURE  CITED 

Barnes,  M.C.,  M.H.  Persons  & A.L.  Rypstra.  2002. 

The  effect  of  predator  chemical  cue  age  on  an- 


WILDER  ET  AL.— ENVIRONMENTAL  EFFECTS  ON  CUES 


861 


tipredator  behavior  in  the  wolf  spider  Pardosa 
milvina  (Araneae:  Lycosidae),  Journal  of  Insect 
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Dicke,  M.  & P.  Grostal.  2001.  Chemical  detection 
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Dondale,  C.D.  & B.M.  Hegdekar.  1973.  The  contact 
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Persons,  M.H.,  S.E.  Walker,  A.L.  Rypstra  & S.D. 
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imal Behaviour  61:43-51. 

Persons,  M.H.,  S.E.  Walker  & A.L.  Rypstra.  2002. 
Fitness  costs  and  benefits  of  antipredator  behav- 
ior mediated  by  chemotactile  cues  in  the  wolf 
spider  Pardosa  milvina  (Araneae,  Lycosidae). 
Behavioral  Ecology  13:386-392. 

Sih,  A.  1980.  Optimal  behavior;  can  foragers  bal- 
ance two  conflicting  demands?  Science  210: 
1041-1043. 

Stephens,  D.W.,  & J.R.  Krebs.  1986.  Foraging  The- 
ory. Princeton  University  Press,  Princeton,  NJ. 
Walker,  S.E.,  S.D.  Marshall,  A.L.  Rypstra  & D.H. 
Taylor.  1999a.  The  effects  of  hunger  on  loco- 
motory  behaviour  in  two  species  of  wolf  spider 
(Araneae,  Lycosidae).  Animal  Behaviour  58: 
515-520. 

Walker,  S.E.,  S.D.  Marshall  & A.L.  Rypstra.  1999b. 
The  effect  of  feeding  history  on  retreat  construc- 
tion in  the  wolf  spider  Hogna  helluo  (Araneae, 
Lycosidae).  Journal  of  Arachnology  27:689-691. 

Manuscript  received  30  October  2003,  revised  22 
March  2004. 


2004.  The  Journal  of  Arachnology  32:862-865 


SHORT  COMMUNICATION 


DESCRIPTION  OF  MALE  PHRYNUS  ASPERATIPES 
(AMBLYPYGI,  PHRYNIDAE)  FROM 
BAJA  CALIFORNIA  SUR,  MEXICO 


Maria-Luisa  Jimenez  and  Jorge  Llinas-Gutierrez:  Laboratorio  de  Aracnologia  y 
Entomologia,  Centro  de  Investigaciones  Biologicas  del  Noroeste  (CIBNOR)  Apdo. 
Postal  128,  La  Paz,  B.C.S.  23000,  Mexico.  E-mail:  ljimenez04@cibnor.mx 

ABSTRACT.  The  first  known  male  of  the  whip  spider  Phrynus  asperatipes  (Wood)  is  described  from 
two  oases  and  other  regions  of  Baja  California  Sur,  Mexico.  It  differs  from  the  females  as  follows:  males 
have  the  carapace  (6. 5-7. 9 mm)  and  abdomen  (1 1.0-12.4  mm)  smaller  than  females.  Also  on  an  average, 
the  femora  (2.3  mm)  and  tibiae  (7.2  mm)  of  the  antenniform  legs  are  shorter  than  in  females. 

Keywords:  Whip  spiders,  Phrynus,  Mexico,  Baja  California,  taxonomy 


At  present,  amblypygids  of  the  Baja  California 
Peninsula  are  represented  by  two  species:  Acantho- 
phrymis  coronatus  (Butler  1873)  from  Sierra  de  San 
Lazaro  (Quintero  1980)  and  Phiynus  asperatipes 
(Wood  1863)  from  several  localities  in  the  state  of 
Baja  California  Sur  (Quintero  1981;  Vazquez-Rojas 
1996;  Avila-Calvo  & Armas  1997).  Vazquez-Rojas 
(1996)  agreed  with  Mello-Leitao  (1931),  recording 
Acanthophrynus  spinifrons  (Pocock  1894)  from  this 
region.  Quintero  (1980),  in  his  review  of  the  genus 
Acanthophrynus,  considered  this  species  to  be  syn- 
onymous with  A.  coronatus. 

Originally,  the  whip  spider  P.  asperatipes  was 
described  by  Wood  (1863)  from  Baja  California, 
probably  from  Baja  California  Sur,  Mexico,  based 
on  a specimen  of  sex  not  determined  in  the  original 
description  and  which  was  lost  (Quintero  1981). 
Kraepelin  (1895)  determined  this  species  as  Neo- 
phrynus  whitei  Kraepelin  1895  and  later  (1899)  as 
Tarantula  whitei.  Quintero  (1981),  in  his  review  of 
the  genus  Phrynus,  designated  a topotypic  female 
as  the  neotype  of  P.  asperatipes.  In  1983,  he  clas- 
sified Hemiphrynus  machadoi  Page  1951  from 
southern  Africa  in  the  genus  Phrynus  and  consid- 
ered the  former  as  the  sister  group  to  P.  asperatipes. 
Weygoldt  (1996)  in  his  study  on  African  ambly- 
pygids assigned  the  first  species  as  unique  in  the 
genus  Xerophrynus  of  the  Phrynichidae  and  tenta- 
tively considered  it  as  an  ancestral  descendant  in 
the  line  that  conduced  this  family. 

Phrynus  asperatipes  is  endemic  to  Baja  Califor- 
nia Sur  and  has  been  collected  from  creeks,  a palm 
oasis,  under  rocks  on  a hillside  and  in  a sand  dune 
area,  representing  the  most  xeric  conditions  under 


which  a species  of  Phrynus  has  been  found  (Quin- 
tero 1981).  Previously,  only  females  of  P.  aspera- 
tipes have  been  known  from  Baja  California.  We 
here  present  a description  of  the  first  males  of  this 
species.  The  specimens  were  collected  near  two  oa- 
ses and  from  several  localities  in  the  central  and 
southern  areas  of  the  state  of  Baja  California  Sur. 
The  measurements  (in  mm)  were  made  using  a stan- 
dard ocular  grid  in  a Zeiss  dissecting  stereomicro- 
scope (Quintero  1981;  Armas  & Perez-Gonzalez 
2001).  Drawings  were  made  with  a camera  lucida 
using  magnifications  of  1.2-3.2X  for  the  pedipalp, 
trichobothria  and  genitalia.  Abbreviations  were 
used  following  Quintero  (1981)  and  Weygoldt 
(2000).  Specimens  are  lodged  in  the  following  in- 
stitutions: National  Collection  of  Arachnids 
(CNAN)  at  the  Instituto  de  Biologia,  Universidad 
Autonoma  de  Mexico;  Museum  of  Comparative 
Zoology,  Harvard  University  (MCZ),  American 
Museum  of  Natural  History,  New  York  (AMNH); 
and  the  Arachnid  Collection  at  the  Centro  de  In- 
vestigaciones Biologicas  del  Noroeste  (CARCIB). 

Phrynus  asperatipes  (Wood  1863) 

Figs.  1-8 

Material  examined. — MEXICO:  Baja  Califor- 
nia Sur.  4 6,  La  Purfsima,  26°12'N,  112°03'W,  el- 
evation 291  m,  25  & 27  August  2002,  6 April  2003, 

l.  Posada,  G.  Nieto,  M.  Correa  (CNAN);  2 6 , San 
Jose  Comondu,  26°04'N,  111°49'W,  elevation  300 

m,  29  September  2002,  7 April  2003,  I.  Posada,  G. 
Nieto,  M.  Correa  (MCZ);  2 3,  at  116  and  1 17  km 
Transpeninsular  Highway  19  (Todos  Santos-Cabo 
San  Lucas),  22°55'N,  109°59'W,  April-February 


862 


JIMENEZ  & LLINAS-GUTIERREZ— DESCRIPTION  OF  MALE  PHRYNUS  ASPERATIPES 


863 


Figures  1-8. — Phrynus  asperatipes  Wood,  male.  1,  Left  trochanter,  anterodorsal  view.  2.  Left  femur 
dorsal.  3.  Left  femur  ventral.  4.  Left  tibia  ventral.  5.  Left  tibia  dorsal.  6.  Basitarsus  and  tarsus,  inner  lateral 
view.  7.  Genitalia  ventral  view.  8.  Genitalia  dorsal  view. 


1988,  B.  Merrill,  D.  Ward  Jr.  (AMNH);  1 d,  Buena 
Vista,  23°0rN,  110°11'W,  26  January  1988,  V.R. 
Roth  (CARCIB). 

Diagnosis. — Phrynus  asperatipes  differs  from 
other  species  of  Phrynus  in  having  a distinct  suture 
between  the  pedipalpal  tarsus  and  post-tarsus, 
which  in  ventral  view  has  a “V”  form;  cleaning 
organ  without  a dorso-medial  row  of  minute  bris- 


tles, basitibia  of  leg  IV  not  articulated;  color  of 
some  populations  is  yellowish  brown,  not  seen  in 
other  species  of  Phrynus.  As  in  P.  operculatus  Po- 
cock  1902,  P.  asperatipes  has  distinct  sexual  di- 
morphism in  the  size  of  the  genital  operculum  and 
males  have  a larger  operculum  than  females. 

Description. — Males  (n  = 9):  Total  length  17.4 
mm  (13.5-17.8  mm),  carapace,  chelicerae,  and  ped- 


864 


THE  JOURNAL  OF  ARACHNOLOGY 


ipalps  yellowish  brown.  Carapace  with  two  orange- 

brown  spots  posterior  to  the  frontal  area  and  five 
dark  spots  on  each  side;  frontal  area  light  yellow 
with  a black  ocular  tubercle  rounded  with  a brown 
circle;  sulcus  dark  brown  from  which  radiate  four 
shallow  grooves.  Carapace  edge  dark  orange- 
brown.  Legs  1-4  yellowish  brown  with  many  dark- 
er setiferous  tubercles;  patella  darker  than  the  other 
segments.  Carapace  with  uniformly  scattered  seti- 
ferous tubercles.  Frontal  area  narrow,  with  anterior 
edge  lightly  curved  and  tuberculated;  frontal  pro- 
cess hidden.  Ocular  tubercle  small  0.7  mm  (0.6-0. 8 
mm),  separated  0,5  mm  from  anterior  edge.  Lateral 
eyes  separated  3.4  mm  (2. 8-3.9  mm),  by  1.2  mm 
(0.98-1.47  mm)  from  the  anterior  edge  and  by  1.5 
mm  (1.5  mm)  from  the  lateral  edge  of  the  carapace. 
Carapace  length  6.5  mm  (5. 5-6. 9 mm)  and  width 

10.0  mm  (8.3-10.2  mm).  Dorsal  surface  of  the  bas- 
al segment  of  the  chelicerae  without  distal  tuber- 
cles; with  a single  tooth  on  external  margin  of  basal 
segment  and  two  ridges.  Mobil  finger  with  four 
teeth  in  ventral  surface.  Pedipalps:  Trochanter  with 
four  anterior  spines  and  setiferous  tubercles  (Fig. 
1).  Femur  Fdl  small;  Fd2  shorter  than  Fd3,  and 
they  do  not  share  a common  base;  Fd4  smaller  than 
Fdl;  Fd5  longer  than  Fd6;  Fvl  longer  than  Fv2; 
Fv3  longer  than  Fv4;  Fv5  longer  than  Fv6  (Figs.  2, 
3).  Tibia  Tdl  small;  Td2  longer  than  Td5;  Td4  not 
longer  than  Td3  and  Td6;  Tvl  longer  than  Tv7;  Tv2 
is  not  almost  the  same  size  as  Tv3  but  much  longer; 
Tv5  longer  than  Tv4  and  Tv6  (Figs.  4,  5).  Basitar- 
sus  Bdl  very  small,  1/5  part  of  the  size  of  Bd3; 
Bvl  and  Bv3  small,  Bv2  well  developed  and  longer 
than  Bv3  (Fig.  6).  Tarsus  and  post-tarsus  of  the  ped- 
ipalp  not  fused,  with  a visible  suture,  that  in  ventral 
view,  has  a “V”  form.  Femur  5.4  mm  (4.4-6. 7 
mm)  long;  tibia  6.4  mm  (4. 5-6. 6 mm)  long  and  1.8 
mm  (1.8  mm)  wide;  basitarsus  2.7  mm  (2. 0-2. 7) 
long  and  1.2  mm  (L2-L8  mm)  wide.  Tarsus  2.5 
mm  (2. 0-2. 5 mm)  long.  Legs:  Second  tarsomere  of 
all  tarsi  without  a tranverse  line  on  distal  end.  Fla- 
gellum of  the  antenniform  leg  with  92  segments:  29 
tibial  subarticles  and  63  tarsal  subarticles.  Femur 

13.8  mm  (10.6-15.6  mm),  tibia  23.8  mm  (19.3- 

23.8  mm),  tarsus  24.3  mm  (20.0-24.3  mm).  Leg  II: 
Femur  8.6  mm  (8.2-10.0  mm),  tibia  8.5  mm  (7.6- 
10.2  mm).  Leg  III:  Femur  9.8  mm  (7.6-11.3  mm), 
tibia  9.5  mm  (7.4-11.9  mm).  Leg  IV:  Femur  8.0 
mm  (6.8-9.8  mm),  tibia  (5.9/0. 1/2.9/4.9)  (8.9/1. 6/ 
4.0/6.2)-(5.8/0.1/2.5/4.5),  tarsus  (1 .0/0.4/0. 1/0.8) 
(0.8/0.2/0.4/Ll)-(0.6/0.1/0.3/0.7).  Basitibia  of  leg 
IV  not  articulated;  trichobothrial  ratios:  bt  0.2,  bf 
0.1,  be  0.4,  sci  1.8.  Sternum  tripartite,  anterior  ster- 
nite  thin  and  short  with  three  long  middle  setae  and 
18  basal  setae  of  different  sizes;  median  and  pos- 
terior sternites  not  conspicuous,  first  with  four  setae 
and  last  with  three  setae.  Abdomen  11.0  mm  (7.8- 

1 1 .0  mm)  long,  with  light  yellow  segments  and  two 
middle  darker  spots,  anterior  segment  with  two 


brown  depressions,  lateral  sides  dark  yellow,  venter 
light  yellow.  Genital  operculum  3.8  mm  (2.9-3.9 
mm)  long  and  5.4  mm  (3. 9-5. 4 mm)  wide  with  a 
curved  posterior  edge;  genitalia  as  in  Figs.  7,  8. 

Variation. — Coloration  from  light  yellow  to 
dark  brown.  Measurements  of  distance  of  ocular  tu- 
bercle to  external  edge  of  carapace,  distance  be- 
tween lateral  eyes  to  lateral  edge  of  carapace  and 
width  of  pedipalpal  tibia  were  constant.  The  range 
of  the  trichobothria  of  tibia  IV  was  sbe  0. 3-0.4,  and 
sci  0.5-0. 6. 

Distribution. — This  species  is  known  only  from 
Baja  California  Sur. 

Natural  history. — Specimens  were  mainly  col- 
lected with  pitfall  traps  and  by  hand  under  rocks  in 
xeric  vegetation  surrounding  La  Purisima  and  San 
Jose  Comondu  oases  and  in  lesser  proportion  in  me- 
sic  vegetation  in  these  localities.  Both  sexes  were 
more  abundant  during  summer  (August-Septem- 
ber),  although  some  adults  were  captured  in  April. 
Specimens  were  more  common  in  San  Jose  Com- 
ondu than  in  La  Purisima.  Some  specimens  have 
been  seen  in  houses,  where  local  people  call  them 
“vinagrillos”  and  considered  them  “poisonous.” 

We  are  grateful  to  Oscar  Armendariz  for  help 
with  the  drawings,  Carlos  Palacios  for  his  help  dur- 
ing field  collections,  and  also  to  the  editor  and 
anonymous  reviewers  for  their  comments  to  this 
manuscript.  The  editing  staff  at  CIBNOR  improved 
the  English  text.  This  paper  received  financial  sup- 
port from  Consejo  Nacional  de  Ciencia  y Tecnolo- 
gia  (CONACyT)  (SEMARTNAT-2002-C0 1-0052) 
Mexico. 

LITERATURE  CITED 

Armas,  L.E  de  & A.  Perez-Gonzalez.  2001.  Los 
amblipigidos  de  Republica  Dominicana  (Arach- 
nida:Amblypygi).  Revista  Iberica  de  Aracnologia 
3:47-66. 

Avila-Calvo,  A.E  & L.E  de  Armas.  1997.  Lista  de 
los  amblipigidos  (Arachinida:Amblypygi)  de 
Mexico,  Centroamerica  y las  Antillas.  Cocuyo 
(La  Habana)  6:31-32. 

Kraepelin,  K.  1895.  Revision  der  Tarantuliden  Fabr. 
Verhandlungen  des  Naturwissenschaftlichen  Ver- 
eins  in  Hamburg  13(3):3-53. 

Kraepelin,  K.  1899.  Scorpiones  und  Pedipalpi.  Tier- 
reich  8:I-xiii,l-265. 

Mello-Leitao,  C.  1931.  Pedipalpos  do  Brasil  e al- 
gumas  notas  sobre  a Ordem.  Arachos  Museum 
Nacional  Rio  de  Janeiro  33:7-72. 

Quintero,  D.  1980.  Systematics  and  evolution  of 
Acanthophrynus  Kraepelin  (Amblypygi,  Phryni- 
dae).  Verhandlungen  des  8.  Intemationalen  Ar- 
achnologen-Kongress,  Wien.  (J.  Gruber  ed.).  H, 
Egermann,  Wien. 

Quintero,  D.  1981.  The  amblypygid  genus  Phrynus 

in  the  Americas  (Amblypygi,  Phrynidae).  Jour- 
nal of  Arachnology  9:117-166. 


JIMENEZ  & LLINAS=GUTIERREZ— DESCRIPTION  OF  MALE  PHRYNUS  ASPERATIPES 


865 


Quintero,  D.  1983.  Revision  of  the  amblypygid  spi- 
ders of  Cuba  and  their  relationship  with  the  Ca- 
ribbean and  continental  American  amblypigid 
fauna.  Studies  on  the  Fauna  of  Curagao  and  other 
Caribbean  Islands  65:1-54. 

Vazquez-Rojas,  1.  1996.  Amblypygi.  Pp.  71-72.  In 
Biodiversidad  Taxonomia  y Biogeografia  de  Ar- 
tropodos  de  Mexico:  Hacia  una  smtesis  de  su 
conocimiento.  (J.  Llorente-Bousquets,  A.  Garcia- 
Aldrete,  E.  Gonzalez-Soriano,  eds.).  Institute  de 
Biologfa,  Universidad  Nacional  Autonoma  de 
Mexico  Mexico  City,  D.F.,  Mexico. 

Weygoldt,  P.  1996.  The  relationships  of  the  south 
east  African  whip  spiders  Hemiphrynus  macha- 


doi  Fage  1951  and  Phrynichus  scullyi  Purcell, 
1901:  introduction  of  the  new  generic  names  Xe- 
rophrynus  and  Phrynichodamon  (Chelicerata: 
Amblypygi).  Zoologischer  Anzeiger  235:117- 
130. 

Weygoldt,  P.  2000.  Whip  Spiders.  Their  Biology, 
Morphology  and  Systematics.  Apollo  Books, 
Stenstrup. 

Wood,  H.C.  1863.  On  the  Pedipalpi  of  North  Amer- 
ica. Journal  of  the  Academy  of  Natural  Sciences. 
Philadelphia  5:357-376. 

Manuscript  received  15  June  2003,  revised  23  Oc- 
tober 2003. 


2004.  The  Journal  of  Arachnology  32:866-869 


SHORT  COMMUNICATION 

CONFIRMATION  OF  PARTHENOGENESIS  IN 
TITYUS  TRIVITTATUS  KRAEPELIN  1898 
(SCORPIONES,  BUTHIDAE) 

Carlos  A.  Toscano-Gadea:  Seccion  Entomologia,  Facultad  de  Ciencias,  Igua  4225 
and  Laboratorio  de  Etologia,  Ecologia  y Evolucion,  Institute  de  Investigaciones 
Biologicas  Clemente  Estable,  Avenida  Italia  3318.  Montevideo,  Uruguay.  E-mail: 
cat@fcien.edu. uy 

ABSTRACT.  The  parthenogenesis  in  Tityus  trivittatus  Kraepelin  1898,  is  confirmed  for  the  first  time, 
based  on  the  progeny  of  three  virgin  females  raised  in  isolation  since  their  birth.  The  possible  and  occa- 
sional introduction  of  this  species  into  Uruguay  is  discussed. 

Keywords:  Scorpions,  asexual  reproduction,  Uruguay 


Just  seven  species  of  scorpions,  from  a total  of 
approximately  1500  known  (Fet  et  al.  2000),  have 
been  documented  as  parthenogenetic.  Of  these  sev- 
en species,  six  belong  to  the  family  Buthidae:  Hot- 
tentotta  hottentotta  (Fabricius  1787),  Ananteris  coi- 
neaui  Lourengo  1982  (following  Louren90  1994 
and  Lourengo  & Cuellar  1999,  respectively)  and 
four  species  of  the  neotropical  genus  Tityus  Koch 
1836:  T.  serrulatus  Lutz  & Mello  1922,  T.  Uru- 
guay ensis  Borelli  1901,  T.  colombianus  (Thorell 
1876)  and  T.  metuendus  Pocock  1897  (Matthiesen 
1962;  Zolessi  1985;  Louren^o  1991  & Lourengo  & 
Cuellar  1999,  respectively).  However,  the  unisexual 
condition  of  populations  of  T.  uruguayensis  has 
been  disputed  (Toscano-Gadea  2001).  The  remain- 
ing species  belongs  to  Ischnuridae:  Liocheles  aus- 
tralasiae  (Fabricius  1775)  according  to  Makioka  & 
Koike  (1984,  1985),  Makioka  (1992,  1993)  and  Ya- 
mazaki  et  al.  (2001).  In  general,  this  kind  of  asexual 
reproduction  can  be  considered  unusual  (converse- 
ly, see  Lourengo  2000). 

Tityus  trivittatus  Kraepelin  1898  is  a medium- 
sized scorpion,  growing  up  to  65  mm  long,  pre- 
senting an  orange-yellow  or  reddish  coloration, 
with  three  dark  brown  longitudinal  bands  that  go 
from  tergite  I to  IV  (a  detailed  description  was  in- 
cluded in  Maury  1970,  1997).  The  distribution  of 
this  species  includes  Argentina,  Paraguay,  Brazil 
and  Uruguay;  bisexual  populations  are  found  in 
Paraguay,  Brazil  and  northern  Argentina  (Maury 
1970,  1997). 

Knowledge  of  the  biology  of  this  species  is  im- 
portant due  to  the  possible  medical  significance  of 
its  venom,  its  synanthropic  character  and  its  appar- 
ent proclivity  for  asexual  reproduction.  The  possi- 


bility of  parthenogenesis  in  Tityus  trivittatus  was 
first  suggested  by  Maury  (1970,  1997)  and  later  by 
Peretti  (1994,  1997).  Maury  (1970)  suggested  that 
this  species  is  parthenogenetic  after  finding  a dis- 
proportionate sex-ratio  of  1 male:  145  females.  In 
1997,  the  same  author  surveyed  236  individuals, 
finding  only  two  males.  He  also  held  in  isolation 
two  individuals  captured  in  the  city  of  Buenos  Ai- 
res, Argentina,  which  gave  birth  to  8 and  13  young 
scorpions,  respectively,  after  molting  into  adult- 
hood. Thus,  there  is  strong  indirect  evidence  of  the 
existence  of  facultative  parthenogenesis  in  this  spe- 
cies. However,  as  females  of  Tityus  can  molt  after 
giving  birth  (Toscano-Gadea  2001),  and  eventually 
maintain  sperm  in  their  reproductive  tract,  the  prog- 
eny obtained  by  Maury  would  not  necessarily  be  an 
evidence  of  parthenogenesis.  Later  on,  Maury 
(1997)  tried  to  raise  this  species  in  captivity  but 
failed,  due  to  difficulties  presented  in  the  breeding. 
Even  raised  under  strict  temperature,  humidity  and 
feeding  conditions,  the  scorpions  rarely  survived 
for  more  than  the  second  or  third  instar. 

The  objective  of  this  study  was  to  test  the  par- 
thenogenetic condition  of  T.  trivittatus  through  suc- 
cessive generations  and  describe  the  development 
in  captivity  of  the  progeny. 

In  1999,  one  female  of  T.  trivittatus  was  captured 
in  the  city  of  Cordoba,  Argentina  and  donated  to 
the  author  by  Dr.  Alfredo  Peretti.  This  female  gave 
birth  to  sixteen  young  scorpions  in  January  2000 
and  died  in  February  2001,  with  eleven  scorpions 
ready  to  be  born.  The  second  instar  juveniles  were 
separated  from  their  mother  after  the  first  molt,  ap- 
proximately sixteen  days  after  their  birth,  and  from 
that  moment  on,  were  kept  in  individual  Petri  dishes 


866 


TOSCANO-GADEA— PARTHENOGENESIS  IN  TITYUS  TRIVITTATUS 


867 


Table  1. — Duration  of  each  juvenile  stage  in  T.  trivitattus  Kraepelin  1898.  All  the  individuals  first 
molted  14-18  days  after  their  birth.  The  numbers  that  appear  under  the  second,  third  and  fourth  molt 
columns  correspond  to  intermolt  periods.  Only  the  individuals  that  survived  after  the  second  molt  were 
considered.  The  ( — ) represents  no  data  available. 


Number  of  the 
individual 

First  molt 

Second  molt 

Third  molt 

Fourth  molt 

1 

14-18  days 

299  days 

391  days 

— 

2 

14-18  days 

297  days 

399  days 

361  days 

3 

14-18  days 

343  days 

349  days 

Died;  6 Oct.  2001 

4 

14-18  days 

304  days 

Died;  12  Feb.  2001 

— 

5 

14-18  days 

342  days 

Died;  4 Nov.  2001 

— 

6 

14-18  days 

347  days 

Died;  12  Feb.  2001 

— 

7 

14-18  days 

324  days 

Died;  17  April  2001 

— 

8 

14-18  days 

295  days 

410  days 

345  days 

9 

14-18  days 

342  days 

368  days 

— 

Mean 

16  days 

321.4  days 

383.4  days 

353  days 

of  8.5  cm  diameter  and  1 cm  height.  I used  flattened 
soil  as  substrate  (with  stones  providing  refuges)  and 
a fresh  water  supply.  After  the  second  molt,  they 
were  placed  in  bigger  containers  (9.5  cm  diameter 
X 11  cm  height),  with  the  same  substrate.  In  both 
containers,  the  substrate  was  changed  every  30-45 
days.  The  alimentation  consisted  principally  of  ju- 
venile and  adult  spiders:  Schizocosa  malitiosa 
(Tullgren  1905),  Lycosa  thorelli  (Keyserling  1877) 
and  Metaltella  simoni  (Keyserling  1877),  cock- 
roaches: Periplaneta  americana  (Linnaeus),  Blatta 
sp.  and  Blattella  sp.,  and  green  grasshoppers  be- 
longing to  the  family  Decticinidae.  All  juvenile 
scorpions  were  fed  at  the  same  time,  with  the  same 
kind  of  prey,  at  least  every  15  days.  The  remnants 
of  prey  were  immediately  taken  away  to  avoid  the 
appearance  of  fungi  and  mites.  The  containers  were 
kept  in  a room  with  natural  illumination  and  a tem- 
perature of  23.9  °C  ± 5.0.  The  humidity  varied 
from  60-80  %.  The  female  and  the  individuals  that 
died  during  their  development  were  deposited  in  the 
Arachnological  Collection  of  the  Seccion  Entomo- 
logfa  of  Facultad  de  Ciencias,  Montevideo. 

The  results  of  the  juvenile  stage  duration  are 
shown  in  Table  1 . Seven  individuals  died  before  the 
second  molt,  four  died  after  the  second  and  one 
individual  died  after  the  third  molt.  Of  the  remain- 
ing 4,  one  female  (number  one)  gave  birth  to  twelve 
offspring  after  the  third  molt,  produced  a second 
clutch  and  then  died.  When  she  was  dissected,  only 
ovaries  were  found.  Two  other  females  (numbers 
two  and  eight)  gave  birth  to  six  and  11  offspring, 
respectively,  after  the  fourth  molt.  The  remaining 
individual  (number  nine),  is  alive  after  three  molts, 
without  any  progeny  yet  (Table  2).  From  these  data, 
we  are  able  to  confirm  the  thelytokous  partheno- 
genesis in  T.  trivittatus.  This  species  should  be  add- 
ed to  the  list  of  parthenogenetic  scorpions,  increas- 
ing the  number  to  eight  in  this  order. 


In  addition,  the  second  clutch  of  female  number 
one  confirmed  the  capacity  of  multiple  parturition 
in  T.  trivittatus,  already  pointed  out  by  Peretti 
(1997).  According  to  Polis  & Sissom  (1990),  this 
peculiarity  is  shared  with  the  parthenogenetic  T. 
serrulatus  but  probably  not  with  T.  uruguayensis 
(Toscano-Gadea  2001  and  unpub.  data). 

Approximately  95%  of  all  living  species  repro- 
duce sexually  (Louren90  2000).  However,  parthe- 
nogenesis would  offer  advantages  for  the  species 
that  practice  it,  namely  the  foundation  of  a new 
population  by  only  one  individual  and  rapid  colo- 
nization of  new  habitats  (San  Martin  & Gambar- 
della  1966;  Cuellar  1977,  1994;  Maury  1997;  Lour- 
engo  & Cuellar  1995,  1999;  Lourengo  2000).  Tityus 
trivittatus  would  appear  to  be  a good  colonizer  in 
new  environments,  based  on  the  possibility  of  uni- 
sexual reproduction,  but  also  because  of  their  abil- 
ity to  reproduce  after  fewer  molts  (three  or  four) 
than  other  Tityus  species  as  T.  serrulatus  and  T. 
uruguayensis  which  need  five  molts  to  become 
adults  (Matthiesen  1962;  Zolessi  1985). 

The  presence  of  T.  trivitattus  in  Uruguay  was 
pointed  out  by  Maury  (1997)  based  on  three  indi- 
viduals collected  in  Colonia,  Uruguay  (“Estancia 
del  Dr.  Rebuffo”,  15  km  from  Colonia  City,  II- 
1985,  D.J.  Carpintero  coll.)  a neighboring  province 
of  Buenos  Aires,  Argentina,  separated  only  by  a 
narrow  section  of  the  Rio  de  la  Plata.  If  we  consider 
the  abundant  information  about  scorpions  that  col- 
onize new  areas  by  anthropogenic  means  (Goyffon 
1992;  Louren^o  et  al.  1994;  Lourengo  & Cuellar 
1995;  Toscano-Gadea  1998)  and  the  great  quantity 
of  tourists  from  Argentina  that  visit  the  city  of  Co- 
lonia from  December-March  (similar  period  of  ma- 
jor activity  for  this  species  according  Maury 
(1997))  we  consider  reasonable  that  this  species 
could  have  entered  Uruguay  by  human  transport. 
Conversely,  there  have  not  been  any  new  records 


Table  2. — Development  of  the  progeny  of  the  female  T.  trivitattus  Kraepelin  1898,  born  on  the  of  January  2000.  The  question  mark  in  the  last  column 
for  individual  number  9 represents  no  progeny  at  the  present.  Only  the  individuals  that  survived  after  the  second  molt  were  considered.  The  ( — ) represents 
no  data  available. 


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for  this  species  in  Uruguay  during  the  last  18  years, 
and  never  in  the  departaments  of  Maldonado  and 
Rocha,  that  are  the  most  visited  by  tourists.  Finally, 
the  introduction  of  this  species  in  Uruguay  seems 
to  have  been  occasional,  and  the  transport  method, 
for  the  moment,  an  enigma. 

Thanks  to  Alfredo  Peretti  for  kindly  donating  the 
female  of  T.  trivittatus,  to  Fernando  Costa  for  the 
critical  reading  of  the  manuscript  and  his  continu- 
ous support,  Estrellita  Lorier  and  Alba  Bentos  for 
identifying  the  insects.  I am  especially  grateful  to 
Anita  Aisenberg  for  her  help  with  the  English  and 
two  anonymous  reviewers  for  their  helpful  com- 
ments. 


LITERATURE  CITED 

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Goyffon,  M.  1992.  Le  role  de  I’homme  dans  lex- 
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Lourengo,  W.R.  2000.  Reproduction  in  scorpions, 
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Louren^o,  W.R.  & O.  Cuellar.  1995.  Scorpions, 
scorpionism,  life  history  strategies  and  parthe- 
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27:149-153. 

Louren^o,  W.R.,  M.  Knox  & M.  Yoshizawa.  1994. 
U invasion  d’une  communaute  au  stade  initial 
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thenogenetique  de  scorpion.  Biogeographica  70: 

77-91. 

Makioka,  T.  1992.  Reproductive  biology  of  the  vi- 
viparous scorpion,  Liocheles  australasiae  (Fabri- 
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Repeated  pregnancies  in  virgins.  Invertebrate  Re- 
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Makioka  T.  1993.  Reproductive  biology  of  the  vi- 
viparous scorpion,  Liocheles  australasiae  (Fabri- 
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869 


notes  on  juvenile  stage  duration.  Invertebrate  Re- 
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Makioka,  T.  & K,  Koike.  1984.  Parthenogenesis  in 
the  viviparous  scorpion,  Liocheles  australasiae . 
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374-376. 

Makioka,  T.  & K.  Koike.  1985.  Reproductive  bi- 
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Matthiesen,  EA.  1962,  Parthenogenesis  in  scorpi- 
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Maury,  E.A.  1970.  Redescripcion  y distribucion  en 
la  Argentina  de  Tityus  trivittatus  trivittatus  Krae- 
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Maury,  E.A.  1997.  Tityus  trivittatus  en  la  Argenti- 
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Ciencias  Naturales  24:1-24. 

Peretti,  A.V.  1994.  Comportamiento  de  relacion 
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de  Biologia  de  Concepcion  65:9-21. 

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Polls  G.A.  & W.D.  Sissom,  1990.  Life  history.  Pp, 
161-223.  In  The  Biology  of  Scorpions  (G.A.  Po- 
lls ed.)  Stanford  University  Press,  Stanford, 

San  Martin  P.  & L.A.  de  Gambardella.  1966.  Nueva 
comprobacion  de  la  partenogenesis  en  Tityus  ser- 
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la  Sociedad  Entomologica  Argentina  XXVIII: 
79-84. 

Toscano-Gadea,  C.A.  1998.  Euscorpius  flavicaudis 
(Degeer,  1778)  in  Uruguay:  first  record  from  the 
New  World  (Scorpiones,  Chactidae).  Newsletter 
of  the  British  Arachnological  Society  81:6. 

Toscano-Gadea,  C.A.  2001.  Is  Tityus  uruguayensis 
Boreili,  1901  really  parthenogenetic?  Pp.  359- 
364.  In  Scorpions  2001:  In  Memoriam  of  Gary 
A.  Polis.  (V.  Fet  & P.  Selden,  eds.).  British  Ar- 
achnologicai  Society,  Burnham  Beeches,  Bucks. 

Yamazaki  K.,  H.  Yahata,  N.  Kobayashi  & Makioka 
T.  2001.  Egg  maturation  and  parthenogenetic  re- 
covery of  diploidy  in  the  scorpion  Liocheles  aus- 
tralasiae (Fabricius)  (Scorpions,  Ischnuridae). 
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Manuscript  received  31  March  2003,  revised  17 
October  2003. 


2005.  The  Journal  of  Arachnology  33:870-872 


SHORT  COMMUNICATION 

ALLOMETRY  OF  GENITALIA  AND  FIGHTING  STRUCTURES 
IN  LINYPHIA  TRIANGULARIS  (ARANEAE,  LINYPHIIDAE) 

Sebastian  Funke:  Pastor-Fischer  Weg  6,  58708  Menden,  Germany. 

Bernhard  A.  Huber^:  Zoological  Research  Institute  and  Museum  Alexander  Koenig, 
Adenauerallee  160,  53113  Bonn,  Germany.  E-mail:  b.huber.zfmk@uni-bonn.de 

ABSTRACT.  Allometric  scaling  is  a powerful  approach  for  studying  the  relationship  between  size, 
shape  and  function.  We  studied  allometric  slopes  in  Linyphia  triangularis,  measuring  two  male  and  one 
female  genital  characters  and  several  male  and  female  non-genital  characters  including  male  chelicerae 
that  are  used  for  fighting.  As  predicted  from  theory,  genitalia  had  the  lowest  allometric  values,  fighting 
structures  the  highest. 

Keywords:  Copulatory  organs,  sexual  selection,  Linyphia,  allometry 


“Mr.  Locket  tells  me  that,  from  preliminary  in- 
vestigations ...  of  males  of  the  species  Linyphia 
triangularis  ...  he  does  not  believe  that  large  spec- 
imens have  relatively  larger  jaws  than  smaller  spec- 
imens” (Bristowe  1929:  339). 

In  most  animals  studied,  structures  used  as  weap- 
ons or  display  devices  show  steeper  regression 
slopes  (higher  allometric  values)  than  other  body 
parts  in  relation  to  body  size  (Tatsuta  et  al.  2001; 
Eberhard  2002a;  further  references  in  Eberhard 
2002b).  This  may  result  from  small  individuals  hav- 
ing relatively  little  to  gain  from  investing  in  such 
structures  (Baker  & Wilkinson  2001).  In  contrast, 
genitalia  often  have  remarkably  low  slopes  (Eber- 
hard et  al.  1998;  Palestrini  et  al.  2000;  Tatsuta  et 
al.  2001;  Kato  & Miyashita  2003),  presumably  re- 
sulting from  selection  to  fit  all  variants  of  the  op- 
posite six  (‘one-size-fits-air  model,  Eberhard  et  al. 
1998).  This  short  note  focuses  on  the  relationships 
between  chelicerae  (fighting  structures),  genitalia 
and  body  size  in  Linyphia  triangularis  (Clerck 
1757). 

Adult  males  and  females  of  the  holarctic  L.  tri- 
angularis appear  from  July  to  late  August  with 
males  molting  to  maturity  about  1-3  weeks  earlier 
than  females  (Toft  1989;  Stumpf  & Linsenmair 
1996).  First  male  sperm  precedence  has  been  doc- 
umented in  closely  related  species  (Watson  1991; 
Stumpf  & Linsenmair  1996)  and  this  probably  ex- 
plains mate-guarding  of  penultimate  females  (Toft 
1989;  Stumpf  & Linsenmair  1996).  Despite  the  ex- 
istence of  an  alternative  male  mating  strategy, 
where  the  smaller  male  attempts  to  induce  the  dom- 

' Corresponding  author. 


inant  male  to  leave  the  female  by  chasing  him  out 
of  the  web  (‘interference  strategy’,  Nielsen  & Toft 
1990),  observations  on  this  and  a related  species 
(Rovner  1968;  Stumpf  & Linsenmair  1996;  Watson 
1990)  suggest  that  fighting  ability  largely  predicts 
reproductive  success.  Linyphia  triangularis  males 
use  their  chelicerae  in  aggressive  interactions  (Rov- 
ner 1968)  leading  to  the  prediction  that  these  should 
be  under  strong  directional  selection. 

Our  measurements  are  based  on  a sample  of  33 
adult  cohabiting  male/female  pairs  collected  in  Aus- 
tria (Upper- Austria,  Walding,  48°2LN,  14°12'E,  4 
August  2003).  The  spiders  are  deposited  at  the  Zoo- 
logical Research  Institute  and  Museum  Alexander 
Koenig  (ZFMK),  Bonn.  We  measured  male  and  fe- 
male carapace  length  and  width,  abdomen  length 
and  width,  tibia  1 length,  paturon  and  cheliceral 
fang  lengths,  as  well  as  epigynum  width  and  the 
length  of  two  bulbal  structures,  lamella  and  tegulum 
(Figs.  1-5).  Measurements  were  to  the  nearest  0.01 
mm  (genitalia)-0.03  mm  (legs).  Statistical  analysis 
was  made  with  SPSS  11.0,  using  both  ordinary 
least  squares  (OLS)  and  reduced  major  axis  (RMA) 
regressions  of  log-transformed  data.  Carapace  width 
was  taken  as  an  indicator  of  body  size,  i.e.  all  OLS 
regression  values  are  of  the  respective  structure  on 
log  carapace  width.  Both  regression  techniques  sup- 
ported the  same  conclusions,  so  we  will  present 
OLS  values  only. 

Our  data  clearly  show  the  dichotomy  between 
fighting  structures  and  genitalia.  The  slopes  of  male 
chelicerae  (paturon:  1.740,  fang:  2.319,  both  P < 
0.001)  were  high  in  comparison  to  the  slopes  of 
tibia  and  opisthosoma  measures  (0.607-0.973,  P < 
0.003).  Interestingly,  female  chelicerae  also  had  rel- 


870 


FUNKE  & HUBER— ALLOMETRY  IN  LINYPHIA  TRIANGUI^RIS 


871 


Figures  1-5. — Linyphia  triangularis^  illustrations  of  some  of  the  characters  measured.  1,  2.  Frontal 
views  of  large  male  and  medium  size  female,  drawn  at  same  scale.  3,  4.  Left  genital  bulb,  prolateral  (3) 
and  retrolateral  (4)  views.  5,  Epigynum,  posterior  view,  e — epigyn,um  width,  f = fang  length,  1 = bulbal 
lamina  length,  p = paturon  length,  t = tegulum  length. 


atively  steep  slopes,  though  much  lower  than  in 
males  (paturon:  1.070,  fang:  1.410,  both  P < 
0.001).  Genitalia,  on  the  other  hand,  showed  very 
low  slopes  for  both  bulbal  structures  (lamella: 
0.296,  P < 0.001,  tegulum:  0.257,  P = 0.004),  and 
for  the  epigynum  (0.422,  P = 0.016).  Evidently, 
there  is  stabilizing  selection  on  standard  size  geni- 
talia in  L.  triangularis  like  in  many  other  arthropods 
(Eberhard  et  ah  1998). 

Apart  from  these  main  results,  we  incidentally 
found  a surprising  relationship  between  male  and 
female  sizes:  males  (carapace  width)  in  our  sample 
were  not  larger  than  females  (paired  t-test,  P = 
0.30).  Lang  (2001),  working  on  Swedish  popula- 
tions of  the  same  species,  reported  that  males  were 
on  average  5-22%  larger  than  females  in  1 1 out  of 
his  12  samples.  We  suggest  that  the  absence  of  body 
size  dimorphism  in  our  sample  might  be  explained 
by  a bias  in  our  sample.  We  collected  only  cohab- 
iting adult  pairs,  i.e.  females  that  were  probably 
non-virgin.  If  L.  triangularis  has  first  male  sperm 
precedence  like  its  close  relatives  (Watson  1991; 
Stumpf  & Linsenmair  1996),  then  the  females  in 
these  pairs  had  a lower  reproductive  value  than  vir- 
gin females.  Large,  dominant  males  might  rather 
invest  in  searching  for  virgin  females,  so  we  might 
have  missed  them.  Apart  from  explaining  the  ab- 
sence of  a sexual  size  dimorphism  in  carapace 
width  in  our  sample,  this  finding  hints  to  yet  anoth- 
er alternative  mating  strategy  of  smaller  males: 
small  males  might  employ  a post-copulation  cohab- 
itation strategy  to  profit  from  the  residual  female 
reproductive  value  that  is  left  for  second  males  in 
Linyphia. 


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R.D.  Briceno,  1.  Salas  and  V.  Rodriguez.  1998. 
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Toft,  S.  1989.  Mate  guarding  in  two  Linyphia  spe- 
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Manuscript  received  10  March  2004,  revised  10 
June  2004. 


2005.  The  Journal  of  Arachnology  33:873-877 


SHORT  COMMUNICATION 

MATRIPHAGY  IN  THE  NEOTROPICAL  PSEUDOSCORPION 
PARATEMNOIDES  NIDIFICATOR  (BALZAN  1888)  (ATEMNIDAE) 


Everton  Tizo-Pedroso  and  Kleber  Del-Claro:  Laboratorio  de  Ecologia 

Comportamental  e de  Interagoes,  Institute  de  Biologia,  Universidade  Federal  de 
Uberlandia.  C.R593,  Cep  38400-902,  Uberlandia,  MG,  Brasil.  Telfax: 

55(34)32182243.  E-mail:  delclaro@ufu.br. 

ABSTRACT.  We  studied  the  natural  history  and  social  behavior  of  Paratemnoides  nidificator  (Balzan 
1888)  in  a tropical  savanna  system.  Females  were  responsible  for  all  nymphal  care.  We  observed,  for  the 
first  time  in  pseudoscorpions,  the  occurrence  of  matriphagy  behavior  by  the  offspring.  During  conditions 
of  food  deprivation,  the  mother  went  out  of  the  nest  and  passively  awaited  the  protonymphs’  attack,  not 
reacting  to  the  capture  nor  to  the  nymphs  feeding  on  her  body.  We  suggest  that  this  extreme  form  of 
parental  care,  matriphagy,  can  reduce  cannibalism  among  protonymphs  and  facilitate  the  evolution  of 
social  behavior  in  pseudoscorpions. 

RESUMO,  Nos  estudamos  a historia  natural  e o comportamento  social  de  Paratemnoides  nidificator 
(Balzan  1888)  na  regiao  dos  cerrados.  As  femeas  foram  responsaveis  por  todo  o cuidado  as  ninfas.  Nos 
observamos,  pela  primeira  vez  em  pseudoescorpioes,  a ocorrencia  de  matrifagia  pela  prole.  Em  condigoes 
de  fome,  a mae  deixa  o ninho  e passivamente  espera  que  as  protoninfas  a ataquem,  nao  reagindo  nem  a 
captura,  nem  a alimentagao  das  ninfas  sobre  seu  corpo.  Nos  sugerimos  que  esta  forma  extrema  de  cuidado 
parental,  matrifagia,  possa  reduzir  o canibalismo  entre  as  protoninfas  e assim  facilitar  a evolugao  de 
comportamento  social  em  pseudoescorpioes. 

Keywords:  Social  behavior,  maternal  care,  Arachnida,  cannibalism,  tropical  savanna 


The  order  Pseudoscorpiones  is  highly  diversified 
with  more  than  3,239  described  species  in  425  gen- 
era and  24  families,  representing  around  3.3%  of  all 
arachnids  (Harvey  1991,  2002).  In  general,  pseu- 
doscorpions are  small  (2-8  mm)  and  are  non-social 
animals  that  behave  aggressively  in  intraspecific 
contacts  (Weygoldt  1969;  Zeh  1987).  Zeh  (1987) 
reported  fights  between  males  of  a Chemetidae  spe- 
cies during  contests  for  food  or  females,  resulting 
in  cannibalism.  Some  Atemnidae  species,  however, 
show  a high  level  of  sociality,  living  in  groups, 
sharing  food  and  hunting  cooperatively  (Brach 
1978;  Zeh  & Zeh  1990). 

All  pseudoscorpion  species  present  some  level  of 
parental  care.  Indeed,  females  of  all  species  take 
care  of  embryos  that  are  maintained  inside  a brood 
sac  attached  to  her  genital  opening  (Levi  1953;  Ga- 
butt  1970b;  Weygoldt  1969).  Females  can  also  build 
silk  chambers  in  which  they  rest  with  the  brood  sac 
until  the  emergence  of  the  protonymphs  (Brach 
1978;  Gabbutt  1962,  1966,  1970a;  Levi  1948,  1953; 
Harvey  1986;  Zeh  & Zeh  2001).  In  Neobisium  ma- 
ritimum  (Leach  1812)  the  silk  chamber  is  built  and 
occupied  by  one  individual,  and  several  chambers 


may  occur  in  the  same  rock  fissure  (Gabbutt  1962, 
1966).  Females  of  Neobisium  muscorum  (Leach 
1817)  can  have  chambers  placed  side  by  side  (Wey- 
goldt 1969).  In  Paratemnoides  elongatus  (Banks 
1895)  and  P.  minor  (Balzan  1892),  both  species  that 
occur  beneath  tree  bark,  nymphs  can  build  molt 
chambers  cooperatively  and  adult  females  bearing 
a brood  sac  can  use  molt  chambers  for  brood  care 
as  well  (Brach  1978;  Hahn  & Matthiesen  1993b). 
This  cooperative  building  of  nests  saves  time  and 
silk,  maintains  appropriate  humidity  conditions  and 
protects  the  brood  from  predators  (Brach  1978),  In 
both  those  Paratemnoides  species  females  in  the 
nest  remove  the  brood  sac  from  the  genital  opening 
after  secreting  the  nutritive  fluid  to  the  embryos 
(Brach  1978;  Hahn  & Matthiesen  1993a).  Pro- 
tonymphs of  Pseiaphochernes  scorpioides  (Herman 
1804)  remain  2-3  days  inside  the  nest  receiving 
care  until  they  disperse  (Weygoldt  1969). 

Pseudoscorpions  are  widespread.  For  instance,  in 
Central  Amazon,  Adis  & Mahnert  (1985)  recorded 
60  species  belonging  to  25  genera  in  10  families. 
The  Brazilian  cerrado  savanna  originally  covered 
approximately  25%  of  the  country  and  is  currently 


873 


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Table  1 . — Composition  of  all  colonies  (by  sex  and  age  classes)  of  Paratemnoides  nidificator  (Atemni- 
dae)  studied. 


Colony 

Males 

Females 

Tritonymphs 

Deutonymphs 

Protonymphs 

Total 

1 

3 

4 

8 

— 

— 

15 

2 

4 

5 

16 

14 

3 

42 

3 

8 

12 

15 

5 

— 

40 

4 

7 

5 

4 

12 

21 

49 

5 

9 

10 

4 

— 

— 

23 

6 

4 

7 

1 

28 

30 

70 

7 

12 

11 

7 

3 

— 

33 

X ± SD 

6.71  ± 3.25 

7.71  ± 3.25 

7.85  ± 5.7 

8.86  ± 10.08 

7.71  ± 12.47 

38.86  ± 17.98 

one  of  the  most  endangered  tropical  ecosystems 
(Oliveira  & Marquis  2002).  To  our  knowledge  there 
is  no  study  about  pseudoscopions  in  the  cerrado. 
Here,  we  studied  the  biology  and  natural  history  of 
Paratemnoides  nidificator  (Balzan  1888)  an  atem- 
nid  species  that  occurs  under  the  bark  of  living  trees 
of  Caesalpinia  pelthophoroides  (Caesalpiniaceae), 
a tree  found  throughout  the  cerrado  domain. 

Observations  for  this  study  were  conducted  from 
October  2001  to  December  2003  in  Uberlandia, 
Brazil  (18°  53'S,  48°  15'W;  863  m eh),  in  the  south- 
eastern limit  of  the  cerrado  distribution.  Seven  col- 
onies of  pseudoscorpions  (Table  1)  were  collected 
from  the  field  and  maintained  in  captivity  during  all 
the  study.  Each  colony  was  kept  in  a glass  bottom 
culture  dish  (12  cm  of  diameter)  having  the  original 
piece  of  tree  bark  and  was  fed  twice  a week  with 
live  termites  (Armithermes  sp.)  and  beetles  (Acant- 
hocelides  obtectus,  Bruchidae).  Moisture  was  pro- 
vided by  a small  piece  of  water-soaked  cotton.  Be- 
havioral observations  were  made  using  the  “all 
occurrence  samples”  method  (Altmann  1974).  Us- 
ing this  method,  everything  that  a group  or  individ- 
ual does  during  an  observation  session  is  recorded 
ad  libitum.  This  method  is  particularly  useful  to  be- 
gin a study  or  to  observe  rare  or  fortuitous  behav- 
iors (see  also  Martin  & Bateson  1993;  Del-Claro 
2004).  Individual  observation  sessions  lasted  30- 
40  min  and  were  made  during  the  day  (mainly  be- 
tween 09:00h  and  15:00h)  using  natural  light.  As 
colonies  are  built  under  the  bark  of  trees,  during  the 
observation  sessions  the  petri  dishes  with  the  col- 
onies were  put  on  a wire  stand  with  a mirror  below 
that  enable  the  observations  without  be  disturbing 
the  animals.  In  the  present  paper  we  describe  the 
social  and  reproductive  behavior  of  P.  nidificator 
based  on  50  observation  sessions  (34  hours  total 
observations).  Voucher  specimens  have  been 
lodged  with  the  Museu  de  Zoologia  de  Sao  Paulo 
(MZUSP). 

We  observed  that  females  wove  the  reproductive 
nest  alone.  Inside  the  chambers,  the  female  provid- 
ed parental  care  continuously  to  embryos  and 
nymphs  by  feeding  and  grooming  them.  This  lasted 


until  the  nymphs  were  adults  or  were  forced  from 
the  nest.  The  female  also  guarded  the  nest  entrance 
against  enemies.  In  some  cases,  the  female  pro- 
duced an  additional  brood  and  then  forced  nymphs 
from  the  first  brood  out  of  the  chamber  by  touching 
them  with  her  pedipalps.  After  chasing  the  original 
brood,  the  female  sealed  the  exit  with  new  silk  and 
produced  the  new  brood  sac.  The  “displaced” 
nymphs  then  cooperatively  built  another  chamber 
in  which  they  molted.  The  reproductive  and  the 
molting  chambers  were  built  side  by  side  sharing 
the  vertical  walls.  This  behavior  has  also  been  ob- 
served in  P.  elongatus  (Banks  1895)  and  P.  minor 
(Balzan  1892)  (Brach  1978;  Hahn  & Matthiesen 
1993a).  In  the  field,  we  found  colonies  of  P.  nidi- 
ficator with  nests  composed  of  3-20  chambers. 

We  identified  95  distinct  behavioral  acts,  of 
which  16  were  related  to  reproductive  behavior, 
mainly  parental  care  (Table  2).  Parental  behaviors 
comprised  10. 13%  of  the  behaviors  seen  in  this  spe- 
cies. However,  the  acts  in  this  category  are  per- 
formed only  by  adult  females,  so  more  than  75% 
of  adult  female  behaviors  are  related  to  taking  care 
of  embryos  and  young.  Other  important  behavioral 
acts  of  females  were  self-grooming  and  feeding. 
Males  directly  cooperated  in  parental  care  by  catch- 
ing and  offering  prey  to  all  members  of  the  colony 
(94  records  during  50  observation  sessions).  How- 
ever, nymphs  in  general  were  fed  by  the  mother. 
Our  data  revealed  that  females  left  the  nest  to  hunt 
prior  to  feeding  the  brood  (56%,  or  in  42  out  of  75 
times  that  we  observed  females  leaving  the  nest 
during  the  observations).  The  mother  ate  the  rest  of 
the  carrion  left  by  the  nymphs.  Tritonymphs  hunted 
cooperatively  with  the  mother  (3  in  42  observations 
of  the  mother  hunting),  or  without  the  mother  {n  = 
14  records  during  50  observation  sessions). 

At  the  end  of  our  observations  we  recorded  col- 
ony behavior  under  food  deprivation  by  depriving 
the  colony  food  for  one  week.  On  the  seventh  day 
we  observed  matriphagy  behavior  in  three  of  the 
seven  colonies.  The  mother  exited  the  nest,  raised 
her  pedipalps  and  passively  waited  for  her  nymphs 
to  attack.  Nymphs  (9  ± 3 protonymphs,  X ± SD, 


TIZO-PEDROSO  & DEL-CLARO— MATRIPHAGY  IN  A PSEUDOSCORPION 


875 


Table  2. — Behavioral  acts  of  Paratemnoides  nidificator  (Atemnidae)  associated  with  “Parental  Care”. 
Data  recorded  from  a clutch  of  90  individuals  (33  adults  and  57  nymphs)  reared  in  captivity  (n  ^ 34 
hours  of  observations). 


Behavioral  act 

Number  of 
observations 

Percent  frequency  of 
the  behavioral  act 
(total  453  acts) 

1 -Female  weaving  chamber. 

179 

30.4 

2-Female  occupying  a woven  chamber  previously  built  by  anoth- 
er individual. 

5 

0.85 

3-Female  excluding  conspecifics  from  chamber. 

4 

0.68 

4-Female  resting  in  the  nest. 

76 

12.9 

5-Female  moving  in  the  nest. 

19 

3.23 

6-Female  touching  the  nest  wall  with  pedipalps. 

10 

1.7 

7-Female  touching  the  embryos  with  pedipalps. 

84 

14.3 

8-Female  touching  the  protonymphs  with  pedipalps. 

29 

4.92 

9-Female  transporting  wood  pieces  inside  the  nest. 

4 

0.68 

10-Female  inserting  fragments  of  wood  in  the  nest  walls. 

4 

0.68 

11 -Female  stopping  in  the  nest  above  in  second  instar  embryos. 

4 

0.68 

12-Female  stopping  in  the  nest  together  with  the  protonymphs. 

29 

4.92 

13-Female  excluding  conspecifics  from  previously  built  chamber. 

3 

0.51 

14-Matriphagy. 

3 

0.51 

15 -Female  bringing  food  to  her  nymphs 

42 

7.13 

16-Males  offering  prey  to  nymphs 

94 

16 

Total 

589 

100 

n = 3)  left  the  nest  and  gathered  around  the  mother 
and  attacked  by  grasping  the  mother’s  legs  and  ped- 
ipalps  (3  ± 1 min,  X ± SD,  n — 3;  time  to  attack). 
The  young  fed  through  the  leg  joints  of  the  mother. 
The  mother  remained  motionless  as  she  was  con- 
sumed (40  ± 5 min,  X ± SD,  n — 3;  time  used  by 
nymphs  feeding  on  mother’s  body.  Figs.  1-4).  Im- 
mediately, in  the  next  step,  the  mother’s  exoskele- 
ton was  thrown  out  of  the  bark  piece  by  the 
nymphs.  Without  the  mother,  nymphs  began  to  hunt 
cooperatively. 

In  the  classic  definition  of  degrees  of  social  be- 
havior by  Wilson  (1971),  eusocial  species  are  char- 
acterized as  having  members  of  the  same  generation 
using  a composite  nest,  cooperation  in  brood  care, 
overlap  of  generations  with  offspring  assisting  par- 
ents and  reproductive  division  of  labor.  In  P.  nidi- 
ficator we  did  not  identify  a worker  caste.  Never- 
theless, we  consider  this  pseudoscopion  as  a 
permanent  social  species.  In  arachnids,  Plateaux- 
Quenu  et  al.  (1997)  defined  as  permanent  social 
species,  “a  group  of  individuals  of  both  sexes  gen- 
erally with  overlapping  generations  which  cooper- 
ate in  the  construction  of  a common  nest,  prey  cap- 
ture and  care  of  the  young.”  These  authors  consider 
permanent  social  species  as  synonymous  with  co- 
operative, non-territorial  permanently  social  species 
(Plateaux-Quenu  et  al.  1997). 

The  trade  off  between  individual  sacrifice  and 
colony  welfare  is  well  evident  in  the  case  of  de- 
fense, and  sometimes  this  altruistic  behavior  is  ac- 


companied by  anatomical  specialization  (Holldobler 
& Wilson  1990).  The  presence  of  a sting,  used  to 
defend  the  colony  against  vertebrates  in  the  honey 
bees,  some  genera  of  ants,  social  polistine  and  poly- 
biine  wasps,  constitutes  a remarkable  example  of 
convergence  in  social  behavior  (Hermann  & Blum 
1981).  There  is  no  anatomical  specialization  in  P. 
nidificator  or  other  arachnids  to  facilitate  matri- 
phagy.  However,  the  simple  occurrence  of  matri- 
phagy  in  pseudoscorpions  and  other  invertebrates 
(e.g.  Evans  et  al.  1995;  Kim  et  al.  2000),  can  be 
also  pointed  out  as  example  of  convergence  in  so- 
cial behavior. 

According  to  Evans  et  al.  (1995),  extreme  forms 
of  parental  care,  such  as  matriphagy,  may  be  fre- 
quent among  spiders  that  typically  produce  single 
clutches.  We  did  additional  laboratory  observations 
in  38  colonies  of  P.  nidificator  during  the  repro- 
ductive season  of  2003.  Of  these  38  colonies,  in  7 
the  female  was  maintained  alone  and  she  was  able 
to  produce  only  one  brood.  In  the  other  3 1 colonies, 
females  were  maintained  in  the  colony  and  they 
produced  two  or  more  additional  clusters,  in  general 
three  {n  = 26).  The  observation  that  females  alone 
did  not  produce  additional  broods  suggests  that  sol- 
itary females  may  have  a smaller  reproductive  out- 
put than  that  females  living  in  groups.  We  suggest 
that  the  social  life  in  P.  nidificator,  with  adults 
hunting  cooperatively,  can  reduce  the  chances  of 
cannibalism  and  improve  reproductive  conditions 
for  many  individuals.  In  Araneae,  Elgar  & Crespi 


Figures  1-4. — Schematic  illustrations  of  matriphagy  in  the  pseudoscorpion  Paratemnoides  nidificator. 
1.  Female  and  protonymphs  resting  inside  the  silk  chamber  (sc),  near  entrance  hole  (eh);  2.  The  mother 
goes  out  to  the  nest  and  raises  her  pedipalps.  The  brood  begin  to  leave  the  nest;  3.  Nymphs  gather  around 
the  mother  and  attack  by  grasping  the  mother’s  legs  (arrow)  and  pedipalps;  4.  The  young  feed  through 
the  joints  of  mother’s  pedipalps  (a),  legs  (b)  and  abdome  (c).  Scale  =1.0  mm. 


(1992)  suggested  that  by  reducing  cannibalism 
among  groups  of  siblings,  matriphagy  may  facilitate 
the  evolution  of  social  behavior  (Crespi  1992).  We 
suggest  that  here  also,  matriphagy  may  be  an  im- 
portant part  of  the  evolution  of  sociality  in  this 
group. 

To  our  knowledge  this  is  the  first  record  of  ma- 
triphagy in  pseudoscorpions  and  P.  nidificator 
serves  as  a good  model  for  the  difficult  assessment 
of  the  costs  and  benefits  of  altruistic  behavior 
(Krebs  & Davies  1993).  Further  studies  could  help 
to  clarify  proximate  and  evolutionary  causes  of  ma- 
triphagy in  pseudoscorpions.  Many  questions  de- 


serve further  research.  For  example,  do  nymphs 
survive  better  as  a consequence  of  matriphagy? 
Does  matriphagy  occur  in  starving  colonies  in  the 
same  mannner  as  it  occurs  with  isolated  females? 
Could  the  P.  nidificator  mother  be  maximiting  her 
ultimate  number  of  offspring  by  this  extreme  form 
of  altruism,  similar  to  that  reported  to  spiders  (Kim 
et.  al  2000)?  These  and  other  questions  confirm 
there  is  still  much  to  be  learned. 

We  thank  Gail  Stratton,  Heraldo  L.  Vasconcelos, 
Paula  E.  Cushing,  Paulo  E.  Oliveira,  Paulo  S.  Oli- 
veira, Peter  Weygoldt,  Renata  de  Andrade  as  well 
as  an  anonymous  reviewer,  for  helpful  comments 


TIZO-PEDROSO  & DEL=CLARO--=MATRIPHAGY  IN  A PSEUDOSCORPION 


877 


on  the  manuscript.  We  thank  Paula  E.  Cushing  also 
for  suggesting  further  questions  to  this  study.  We 
thank  Volker  Manhert  for  identifing  the  pseudo- 
scorpion,  Luciaea  Zukovski  for  identifing  the  beetle 
and  Jorge  J.  de  Faria  Neto  for  drawings.  We  thank 
CNPq  and  Fapemig  for  financial  support. 

LITERATURE  CITED 

Adis,  J.  & V.  Mahniert.  1985.  On  the  natural  history 
and  ecology  of  pseudoscorpioes  (Arachnida) 
from  an  Amazonian  blackwater  inundation  for- 
est. Amazoniana  9(3): 297-3 14. 

Altmann,  J.  1974.  Observational  study  of  behav- 
iour; sampling  methods.  Behaviour  49:227-265. 
Brach,  V.  1978.  Social  behavior  in  the  pseudoscor- 
pioE  Paratemnus  elongatus  (Banks)  (Pseudos- 
corpionida:  Atemnidae).  Insectes  Sociaux  25(1): 
3-11. 

Crespi,  B.J,  1992.  Cannibalism  and  trophic  eggs  in 
subsocial  and  eusocial  insects.  Pp  176-213.  In 
Cannibalism:  Ecology  and  Evolution  Among  Di- 
verse Taxa.  (Elgar,  M.A.  & B.J.  Crespi,  eds.). 
Oxford  University  Press. 

DekClaro,  K.  2004.  Comportamento  Animal:  Uma 
Introdugao  a Ecologia  Comportamental.  Editora 
e Livraria  Conceito,  Jundiai.  132pp. 

Elgar,  M.A.  & B.J.  Crespi.  1992.  Ecology  and  evo- 
lution of  cannibalism.  Pp  1-12.  In  Cannibalism: 
Ecology  and  Evolution  Among  Diverse  Taxa. 
(Elgar,  M.A.  & BJ.  Crespi,  eds.).  Oxford  Uni- 
versity Press. 

Evans,  T.A.,  E.J.  Wallis  & M.A.  Elgar.  1995.  Mak- 
ing a meal  of  mother.  Nature  376:299. 

Gabbutt,  P.D.  1962.  ‘Nests’  of  the  marine  false- 
scorpion.  Nature  19rj‘ 87-89. 

Gabbutt,  P.D.  1966.  An  investigation  of  the  silken 
chambers  of  die  marine  pseudoscorpion  NeobP 
Slum  maritimum.  Journal  of  Zoology  149:337- 
343. 

Gabbutt,  P.D.  1970a.  Sampling  pioblems  and  the 
validity  of  life  history  analyses  of  pseudoscor- 
pions. Journal  of  Natural  Hisioiy  4:1-15. 
Gabbutt,  P.D.  1970b.  The  external  morphology  of 
the  pseudoscorpion  Dactylochelifer  latreillei. 
Journal  of  Zoology  160:313-335. 

Hahn,  N.S.  & EA.  Matthiesen.  1993a.  Desenvol- 
vimento  pos-embrionMo  de  Paratemnus  minor 
(Pseudoscorpiones,  Atemnidae).  Revista  Brasi- 
ieira  de  Biologia  53(3):345-353. 

Hahn,  N.S.  & EA.  Matthiesen.  1993b  Notas  bio- 
logicas  sobre  Paratemnus  minor  (Pseudoscorpio- 
nes, Atemnidae).  Revista  Brasileiia  de  Biologia 
53(4):57 1-574. 

Harvey,  M.S.  1986,  The  systematics  and  biology  of 
pseudoscorpions.  Pp.  75-85.  In  Australian 
Arachnology.  (Austin,  A.D.  & N.W.  Heather). 
Australian  Entomological  Society,  Brisbane. 


Harvey,  M.S.  1991.  Catalogue  of  the  Pseudoscor- 
pionida.  Manchester  University  Press,  Manches- 
ter. 

Harvey,  M.S.  2002.  The  neglected  cousins:  What 
do  we  know  about  the  smaller  arachnid  orders? 
Journal  of  Arachnology  30:357-372. 

Elermann,  H.R.  & M.S.  Blum.  1981.  Defensive 
mechanisms  in  the  social  Hymenoptera.  Pp  77- 
197.  In  Social  Insects,  Vol.  2,  (Hermann  H.R., 
ed.).  Academic  Press,  New  York. 

Holldobler,  B.  & E.O.  Wilson.  1990.  The  Ants.  The 
Belknap  Press  of  Harvard  University  Press, 
Cambrigde.  732pp. 

Kim,  K.W.,  C.  Roland  & A.  HoreL  2000.  Function- 
al value  of  matriphagy  in  the  spider  Amaurobius 
ferox.  Ethology  106:729-742. 

Krebs,  J.R.  & N.B.  Davies.  1993.  An  Introduction 
to  Behavioral  Ecology.  3rd  ed.  Blackwell  Sci- 
entific Publications,  Oxford.  482pp. 

Levi,  H.W.  1948.  Notes  on  the  life  history  of  the 
pseudoscorpion  Chelifer  cancroides  (Linn.) 
(Cheionethida).  Transactions  of  the  American 
Microscopical  Society  67:290-290. 

Levi,  H.W.  1953.  Observations  on  two  species  of 
pseudoscorpions.  Canadian  Entomologist  85:55- 
62. 

Oliveira,  P.S  & R.J.  Marquis.  2002.  The  Cerrados 
of  Brazil:  Ecology  and  Natural  History  of  a Neo- 
tropical Savanna.  Columbia  University  Press, 
New  York.  398pp. 

Martin,  P.  & P Bateson.  1993.  Measuring  Behav- 
iour: An  Introductory  Guide.  2nd  ed.  Cambridge 
University  Press,  Cambridge.  222pp. 

Plateaux-Quenu,  A.,  A,  Horel  & C.  Roland.  1997. 
A on  social  evolution  in  two  different 

groups  of  arthropods:  halictines  bees  (Hymenop- 
tera) and  spiders  (Arachnida).  Ethology  Ecology 
& Evolution:  9:183-196. 

Weygoldt,  P.  1969.  The  Biology  of  Pseudoscorpi- 
ons.  Harvard  University  Press,  Cambridge. 
145pp. 

Wilson,  E.O.  1971.  The  Insect  Societies.  Harvard 
University  Press,  Cambridge.  548pp. 

Zeh,  D.W.  1987.  Aggression,  density  and  sexual  di- 
morphism in  chernetid  pseudoscorpions  (Arach- 
nida: Pseudoscorpioiiida).  Evolution  41(5):  1072- 
1087. 

Zeh.  J.A.  & D.W.  Zeh.  1990.  Cooperative  foraging 
for  large  prey  by  Paratemnus  elongatus  (Pseu- 
doscorpionida,  Atemnidae),  Journal  of  Arachn- 
mology  18:307-311. 

Zeh,  J.A.  & D.W.  Zeh.  2001.  Spontaneous  abortion 
depresses  female  sexual  receptivity  in  a vivipa- 
rous arthropod.  Animal  Behaviour  62:427-433. 

Manuscript  received  15  September  2003,  revised  20 
February  2004. 


2005.  The  Journal  of  Arachnology  33:878-879 


BOOK  REVIEW 


Review  of  Fossil  Spiders  in  Amber  and  Copal  by  Joerg  Wunderlich.  Pub- 
lished by  the  author  (Verlag  J.  Wunderlich)  in  two  volumes  under  the  ref- 
erence Beitrage  zur  Araneologie  3a  (Volume  1 with  848  pages)  and  3b 
(Volume  2 with  1060  pages).  ISBN  3-931473-10-4.  Cost  for  each  volume 
is  48  Euro  with  orders  to  be  placed  with  the  author  at  Ober  Hauselbergweg 
24,  Hirschberg,  69493,  Leutershausen,  Germany. 


This  voluminous  work  covers  every  con- 
ceivable aspect  of  fossil  spiders  in  amber  and 
copal,  from  systematics  and  evolution  to  be- 
havior and  ecology.  Since  our  conceptions  of 
fossils  are  based  on  our  knowledge  of  extant 
forms,  many  examples  of  modern  day  taxa  are 
used  to  interpret  the  behavior  of  fossil  taxa 
(Boucot  1990).  The  present  work  differs  from 
the  authors  two  earlier  books  on  fossil  spiders 
(Spinnenfauna  gestern  und  heute  [1986]  and 
Die  fossilen  Spinnen  im  Dominikanischen 
Bernstein  [1988])  by  being  written  in  both  En- 
glish and  German,  thus  making  it  accessible 
to  a wider  audience. 

Reviewing  a book  of  1908  pages  is  no 
small  task  and  I apologize  if  some  aspects, 
which  have  special  significance  to  certain 
readers,  are  omitted.  Since  pagination  contin- 
ues sequentially  in  both  volumes,  I will  refer 
to  the  two  as  a single  work.  To  begin,  this 
definitely  is  a “one  of  a kind  book”  which 
has  its  own  unique  type  of  presentation.  Most 
of  the  chapters  appear  as  separate  publications 
with  a title,  author,  abstract,  introduction,  ref- 
erences and  figures,  so  they  can  be  cited  sep- 
arately. Some  of  the  final  chapters  are  au- 
thored by  others. 

This  book  presents  a wealth  of  information 
on  all  aspects  of  fossil  spiders  in  amber  and 
copal,  although  most  of  the  new  taxa  and  ex- 
amples presented  are  in  Baltic  and  Dominican 
amber  and  Madagascar  copal.  While  the  major 
part  of  the  book  covers  systematic  placement 
and  taxonomic  descriptions  of  fossil  spiders, 
a large  and  significant  section  deals  with  fossil 
evidence  of  spider  biology  and  behavior.  Top- 


ics in  this  portion  include  leg  amputation  and 
regeneration,  ballooning,  bleeding,  camou- 
flage, webs,  sperm  and  sperm  webs,  courtship 
behavior,  egg  sacs,  enemies,  fecal  remains,  ex- 
uviae, ant  mimicry,  wound  healing,  molting, 
cannibalism,  parasitism,  phoresis  and  preda- 
tion by  spiders  on  a wide  range  of  other  or- 
ganisms (including  beetles,  flies,  bark  lice, 
ants,  planthoppers,  termites,  other  spiders, 
caddis  flies,  parasitic  wasps,  scale  insects, 
spring  tails,  roaches,  aphids,  mites,  a web 
spinner,  weevils,  bristle  tails,  insect  larvae, 
myriapods  and  pseudoscorpions). 

Of  special  interest  are  the  author’s  compar- 
isons of  extant  and  extinct  spiders  in  Europe 
and  the  Dominican  Republic  based  on  present 
day  records  and  amber  taxa.  While  amber 
only  entraps  a small  percentage  of  spiders  in 
any  ecosystem,  it  is  amazing  how  many  spe- 
cies have  been  found.  In  Dominican  amber, 
there  are  some  152  spider  species  in  compar- 
ison with  296  extant  ones  in  the  Dominican 
Republic  while  Baltic  amber  has  some  500 
species  in  comparison  with  some  1300  extant 
ones  in  Northern  Europe.  At  the  higher  level, 
there  are  more  spider  families  in  Baltic  amber 
(51)  than  in  Europe  today  (46). 

Findings  show  that  Theridiidae  is  the  dom- 
inant family  in  both  Baltic  and  Dominican 
amber,  thus  reflecting  the  tropical-subtropical 
conditions  at  both  of  those  sites  in  the  mid- 
Tertiary.  In  contrast,  the  Linyphiidae  is  the 
most  diverse  family  in  central  Europe  today, 
reflecting  the  temperate  climate.  Spiders  in 
Baltic  amber  are  over  twice  as  diverse  as  in 
Dominican  amber.  This  is  probably  due  to  the 


878 


BOOK  REVIEW 


879 


different  ecotypes  in  the  Baltic  amber  forest, 
including  not  only  subtropicahtropical,  but 
also  warm  temperate  forms  (Larssoe  1978). 
This  diversity  is  also  reflected  in  the  plant 
genera  reported  from  Baltic  amber.  The  trop- 
icahsubtropical  and  many  warm  temperate 
forms  undoubtedly  disappeared  during  the 
post-Eocene  cooling  events  (Prothero  1994). 
In  contrast,  the  climate  in  Hispaniola  re= 
maieed  fairly  constant  until  the  Pliocene- 
Pleistocene  cooling  period,  which  eliminated 
the  strictly  tropical  forms  (Poinar  & Pomar 
1999).  This  explains  why  approximately  88% 
of  the  spider  taxa  in  Baltic  amber  are  now 
extinct,  compared  with  only  33%  in  Domini- 
can amber. 

Since  fossilized  resin  is  the  best  medium  for 
preserving  taxonomic  characters,  a wealth  of 
new  fossil  taxa  have  been  described  from 
specimens  preserved  in  amber  and  copal.  A 
number  of  new  spider  species  and  genera  are 
described  in  the  present  work,  mostly  from 
Baltic  and  Dominican  amber,  but  a few  also 
in  Lebanese  and  Burmese  amber.  Each  chapter 
in  volume  2 deals  with  a specific  spider  fam- 
ily, usually  beginning  with  a key  to  the  amber 
species  and  thee  describing  new  taxa. 

Of  all  the  spiders  covered  in  this  work,  one 
group  in  particular  is  especially  interesting  be- 
cause of  its  phylogeny,  appearance  and  bio- 
geography. These  spiders  belong  to  the  prim- 
itive family  Archaeidae,  the  “Dawn”  or 
“Long-  necked  spiders”.  Wunderlich  lists  two 
subfamilies,  the  Mecysmaucheeiieae,  from 
Australia,  New  Zealand  and  South  America 
and  the  Archaeinae  from  South  Africa,  Mad- 
agascar and  the  Australian  Region.  Five  gen- 
era in  the  subfamily  Archaeinae  occur  in  Bal- 
tic and  Bitterfeld  amber,  the  most  common 
fossil  being  Archaea  paradoxa  Koch  & Ber- 
endt  1854  in  Baltic  amber.  Members  of  the 
genus  Archaea  have  an  elongated  prosoma 
and  long  chelicerae,  the  inner  edges  of  which 
are  lined  with  peg  teeth  to  grasp  prey.  All  ex- 
tant members  of  this  subfamily  prey  on  spi- 
ders and  the  long  chelicerae  hold  the  prey  far 
enough  away  to  avoid  receiving  injury.  Dawn 
spiders  are  quite  small  (usually  less  than  4 
mm  in  length);  do  not  make  capture  nets,  live 


among  dead  leaves  or  moss  and  lichens  on 
tree  limbs  and  carry  around  their  egg  sacs. 
Wunderlich  shows  an  Arachaea  sp.  in  Baltic 
amber  holding  a member  of  the  family  Ther- 
idiidae  as  prey.  The  descendants  of  Archaea 
are  long  gone  from  the  Northern  Hemisphere 
but  can  be  found  in  Madagascar  copal,  a prod- 
uct of  the  legume  tree,  Hymenaea  verrucosa. 
Today,  most  copal  from  Madagascar  is  less 
than  100  years  old,  yet  at  the  rate  of  habitat 
destruction  in  that  land,  it  is  an  important 
source  of  rare  and  endangered  and  probably 
even  extinct  species  (Poinar  et  al  2001). 

Volume  one  contains  696  color  photos  of 
spiders  covered  in  the  text  and  numerous  ex- 
amples of  spider  behavior.  Also  included  are 
color  photos  of  the  only  known  Baltic  amber 
solfugid  and  opilioacarid.  The  unique  type  of 
presentation  and  some  spelling  errors  in  this 
work  should  not  detract  from  its  wealth  of  in- 
formation, which  will  be  of  interest  not  only 
to  arachnologists,  but  amber  enthusiasts  in 
general,  since  the  color  plates  are  quite  fas- 
cinating and  the  keys  can  be  used  for  the  iden- 
tification of  amber  and  copal  spiders. 

LITERATURE  CITED 

Boucot,  A.  1990.  Evolutionary  Paleobiology  of  Be- 
havior and  Coevolution.  Elsevier,  Amsterdam. 
725  pp. 

Larsson,  S.G.  1978.  Baltic  Amber — a Palaeobio- 
logical  Study.  Entomonograph  1:1-192. 

Poinar,  Jr.,  G.O.,  A.  Brown,  S.  Brown  & R.  Poinar. 
2001.  Stuck  in  Time  (Madagascar  copal).  Fauna 
2:70-76. 

Poinar,  Jr.,  G.O.  & R.  Poinar.  1999.  The  Amber  for- 
est. Princeton  University  Press,  Princeton.  239 

pp. 

Prothero,  D.R.  1994.  The  Eocene-Oligocene  Tran- 
sition. Columbia  University  Press,  New  York. 
291  pp. 

Wunderlich,  J.  1986.  Spinnenfauea  gestern  und 
heute.  Erich  Bauer  Verlag,  Wiesbaden.  283  pp. 
Wunderlich,  J.  1988.  Die  fossilen  Spinnen  (Ara- 
neae)  im  Baltischen  Bernstein.  Beitr^e  zur  Ar- 
aneologie  3:280  pp. 

George  Poinar,  Jr,:  Department  of  Zoolo- 
gy, Oregon  State  University,  Corvallis, 
OR  97331  Email:  poinarg@  science. 
oregonstate.edu 


INSTRUCTIONS  TO  AUTHORS 

(revised  October  2003) 


General:  Manuscripts  are  accepted  in  English  only.  Authors 
whose  primary  language  is  not  English  may  consult  the  editors 
for  assistance  in  obtaining  help  with  manuscript  preparation. 
All  manuscripts  should  be  prepared  in  general  accordance 
with  the  current  edition  of  the  Council  of  Biological  Editors 
Style  Manual  unless  instructed  otherwise  below.  Authors  are 
advised  to  consult  a recent  issue  of  the  Journal  of  Arachnology 
for  additional  points  of  style.  Manuscripts  longer  than  three 
printed  journal  pages  should  be  prepared  as  Feature  Articles, 
shorter  papers  as  Short  Communications.  One  invited  Review 
Article  per  year  will  be  solicited  by  the  editors  and  published 
in  the  third  issue  at  the  discretion  of  the  editors.  Suggestions 
for  review  articles  may  be  sent  to  the  Managing  Editor. 

Submission:  Send  one  electronic  version  of  the  entire  man- 
uscript (in  PDF  or  Microsoft  Word  format)  or  send  four  iden- 
tical copies  of  the  typed  material  together  with  copies  of  illus- 
trations to  the  Managing  Editor  of  the  Journal  of  Arachnology: 
Paula  E.  Cushing,  Managing  Editor,  Denver  Museum  of 
Nature  and  Science,  Zoology  Department,  2001  Colorado 
Blvd.,  Denver,  CO  80205=5798  USA  [Telephone:  (303)  370- 
6442;  FAX:  (303)  331-6492;  E-mail:  PCusWg@dmns.org  or 
PECushing@juno.com]. 

The  Managing  Editor  will  forward  your  manuscript  to  one 
of  the  Subject  Editors  for  the  review  process.  You  will  receive 
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from  the  Managing  Editor,  with  the  manuscript  number  of 
your  manuscript.  Please  use  this  number  in  all  correspondence 
regarding  your  manuscript.  Correspondence  relating  to  manu- 
scripts should  be  directed  to  the  appropriate  Subject  Editor. 
After  the  manuscript  has  been  accepted,  the  author  will  be 
asked  to  submit  the  manuscript  on  a PC  computer  disc  in  a 
widely-used  word  processing  program.  The  file  also  should  be 
saved  as  a text  file.  Indicate  clearly  on  the  computer  disc  the 
word  processing  program  used. 

Voucher  Specimens:  Voucher  specimens  of  species  used  in 
scientific  research  should  be  deposited  in  a recognized  scien- 
tific institution.  All  type  material  must  be  deposited  in  a rec- 
ognized collection/institution. 

FEATURE  ARTICLES 

Title  page. — The  title  page  will  include  the  complete  name, 
address,  and  telephone  number  of  the  author  with  whom 
proofs  and  correspondence  should  be  exchanged,  a FAX  num- 
ber and  electronic  mail  address  if  available,  the  title  in  capital 
letters,  and  each  author’s  name  and  address,  and  the  running 
head  (see  below). 

Abstract.  — The  heading  in  bold  and  capital  letters  should 
be  placed  at  the  the  beginning  of  the  first  paragraph  set  off  by 
a period,  A second  abstract,  in  a language  pertinent  to  the 
nationality  of  the  author(s)  or  geographic  region(s)  empha- 
sized, may  be  included. 

Keywords.  — Give  3-5  appropriate  keywords  following 
the  abstract. 

Text.  — Double-space  text,  tables,  legends,  etc.  throughout. 
Three  levels  of  heads  are  used. 

• The  first  level  (METHODS,  RESULTS,  etc.)  is  typed  in 
capitals  and  on  a separate  line. 

• The  second  level  is  bold,  begins  a paragraph  with  an 
indent  and  is  separated  from  the  text  by  a period  and  a 
dash. 

• The  third  level  may  or  may  not  begin  a paragraph  but  is 
italicized  and  separated  from  the  text  by  a colon. 

Use  only  the  metric  system  unless  quoting  text  or  referencing 
collection  data.  All  decimal  fractions  are  indicated  by  the  peri- 
od (e.g.,  -0.123). 

Citation  of  references  in  the  text:  Cite  only  papers  already 
published  or  in  press.  Include  within  parentheses  the  surname 
of  the  author  followed  by  the  date  of  publication.  A comma 
separates  multiple  citations  by  the  same  author(s)  and  a semi- 
colon separates  citations  by  different  authors,  e.g.,  (Smith 
1970),  (Jones  1988;  Smith  1993),  (Smith  1986,  1987;  Smith  & 
Jones  1989;  Jones  et  al.  1990).  Include  a letter  of  permission 
from  any  person  who  is  cited  as  providing  unpublished  data  in 
the  form  of  a personal  communication. 

Citation  of  taxa  in  text:  Please  include  the  complete  taxonom- 
ic citation  for  each  arachnid  taxon  when  it  appears  first  in  the 
paper.  For  Araneae,  this  taxonomic  information  can  be  found 
on-line  at  http://research.amnh.org/entomology/spiders/cata- 
log81-87/INTR02.html.  For  example,  Araneus  diadematus 
Clerck  1757. 

Literature  cited  section. — Use  the  following  style  and 
include  the  full  unabbreviated  journal  title. 

Opell,  B.D.  2002.  How  spider  anatomy  and  thread  configura- 
tion shape  the  stickiness  of  cribellar  prey  capture 
threads.  Journal  of  Arachnology  30:10-19. 

Krafft,  B.  1982.  The  significance  and  complexity  of  communi- 
cation in  spiders.  Pp.  15-66.  In  Spider  Communications: 
Mechanisms  and  Ecological  Significance.  (P.N.  Witt  & 
J.S.  Rovner,  eds.).  Princeton  University  Press,  Princeton, 
New  Jersey. 


Footnotes. — Footnotes  are  permitted  only  on  the  first 
printed  page  to  indicate  current  address  or  other  information 
concerning  the  author.  All  footnotes  are  placed  together  on  a 
separate  manuscript  page.  Tables  and  figures  may  not  have 
footnotes. 

Running  head. — The  author’s  sumame(s)  and  an  abbrevi- 
ated title  should  be  typed  all  in  capital  letters  and  must  not 
exceed  60  characters  and  spaces.  The  running  head  should  be 
placed  near  the  top  of  the  title  page. 

Taxonomic  articles. — Consult  a recent  taxonomic  article 
in  the  Journal  of  Arachnology  for  style  or  contact  the  Subject 
Editor  for  Systematics.  Papers  containing  the  original  taxo- 
nomic description  of  the  focal  arachnid  taxon  should  be  given 
in  the  Literature  Cited  section. 

Tables. — Each  table,  with  the  legend  above,  should  be  placed 
on  a separate  manuscript  page.  Only  horizontal  lines  (usually 
three)  should  be  included.  Tables  may  not  have  footnotes; 
instead,  include  all  information  in  the  legend.  Make  notations  in 
the  text  margins  (if  possible)  to  indicate  the  preferred  location 
of  tables  in  the  printed  text.  Must  be  double  spaced. 

Illustrations. — Original  illustrations  should  not  be  sent 
until  the  article  is  accepted  for  publication.  Electronic  submis- 
sions of  illustrations  is  acceptable  for  review  of  the  manuscript. 
However,  final  versions  of  illustrations  of  accepted  manu- 
scripts must  still  be  submitted  in  hard  copy  (camera-ready, 
instructions  below).  Address  all  questions  concerning  illustra- 
tions to  the  Editor  of  the  Journal  of  Arachnology:  Dan  Mott, 
Editor-In-Chief  Department  of  Biology  & Chemistry, 
Texas  A&M  International  University,  5201  University 
Blvd.,  Laredo,  TX  78041=1900  USA  [Telephone  (956)  326- 
2583;  FAX:  (956)  326-2439;  E-mail:  dmott@tamiu.edu].  All 
art  work  must  be  camera-ready  — i.e.,  mounted  and  labeled  — 
for  reproduction.  Figures  should  be  arranged  so  that  they  fit 
(vertically  and  horizontally)  the  printed  journal  page,  either  one 
column  or  two  columns,  with  a minimum  of  wasted  space. 
When  reductions  are  to  be  made  by  the  printer,  pay  particular 
attention  to  width  of  lines  and  size  of  lettering  in  line  drawings. 
Multiple  photos  assembled  on  a single  plate  should  be  mount- 
ed with  only  a minimum  of  space  separating  them.  In  the  case 
of  multiple  illustrations  mounted  together,  each  illustration 
must  be  numbered  sequentially  rather  than  given  an  alphabetic 
sequence.  Written  on  the  back  should  be  the  name(s)  of 
author(s)  and  an  indication  of  top  edge.  Indicate  whether  the 
illustration  should  be  one  column  or  two  columns  in  width.  The 
overall  dimensions  should  be  no  more  than  1 1 inches  (28  cml 
X 14  inches  (36  cml.  Larger  drawings  present  greater  difficul- 
ty in  shipping  and  greater  risks  of  damage  for  which  the 
Journal  of  Arachnology  assumes  no  responsibility.  In  manu- 
scripts for  review,  photocopies  should  be  included,  and  should 
be  reduced  to  the  exact  measurements  that  the  author  wants  to 
appear  in  the  final  publication.  Make  notations  in  the  text  mar- 
gins to  indicate  the  preferred  position  of  illustrations  in  the 
printed  text.  Color  plates  can  be  printed,  but  the  author  must 
assume  the  full  cost,  currently  about  $600  per  color  plate. 

Legends  for  illustrations  should  be  placed  together  on  the 
same  page(s)  and  separate  from  the  illustrations.  Each  plate 
must  have  only  one  legend,  as  indicated  below: 

Figures  1-4. — A-us  x-us,  male  from  Timbuktu:  1.  Left  leg; 
2.  Right  chelicera;  3.  Dorsal  aspect  of  genitalia;  4.  Ventral 
aspect  of  abdomen. 

Figures  27-34. — Right  chelicerae  of  species  of  A-us  from 
Timbuktu:  27,  29,  31,  33.  Dorsal  views;  28,  30,  32,  34. 
Prolateral  views  of  moveable  finger;  27,  28.  A-us  x-us,  holo- 
type  male;  33,  34.  A-us  y-us,  male.  Scale  = 1.0  mm. 

Assemble  manuscript  for  mailing. — Assemble  the  sepa- 
rate sections  or  pages  in  the  following  sequence;  title  page, 
abstract,  text,  footnotes,  tables  with  legends,  figure  legends, 
figures. 

Page  charges,  proofs  and  reprints. — Page  charges  are  vol- 
untary, but  non-members  of  AAS  are  strongly  encouraged  to 
pay  in  full  or  in  part  for  their  article  ($75/Joumal  page).  The 
author  will  be  charged  for  changes  made  m the  proof  pages. 
Reprints  are  available  only  from  the  Allen  Press  and  should  be 
ordered  when  the  author  receives  the  proof  pages.  Allen  Press 
will  not  accept  reprint  orders  after  the  paper  is  published.  The 
Journal  of  Arachnology  also  is  published  by  BioOne. 
Therefore,  you  can  download  the  PDF  version  of  your  article 
from  the  BioOne  site  or  the  AAS  site  if  you  are  a member  of 
AAS  or  if  your  institute  is  a member  of  BioOne.  PDF’s  of  arti- 
cles older  than  one  year  will  be  freely  available  from  the  AAS 
website. 

SHORT  COMMUNICATIONS 

Short  Communications  are  usually  limited  in  length  to  three 
journal  pages,  including  tables  and  figures.  They  will  be  print- 
ed in  a smaller  (10  point)  typeface.  The  format  for  these  is 
less  constrained  than  for  feature  articles:  the  text  must  still 
have  a logical  flow,  but  formal  headings  are  omitted  and  other 
deviations  from  standard  article  format  can  be  permitted  when 
warranted  by  the  material  being  covered. 


Short  Communications 

Food  storage  by  a wandering  ground  spider  (Araneae,  AmmoxQmdidiQ,  Ammoxenus) 


by  Ansie  S.  Dippenaar-Schoeman  & Rupert  Harris 850 

Parthenogenesis  through  five  generations  in  the  scorpion  Liocheles  australasiae 
(Fabricius  1775)  (Scorpiones,  Ischnuridae)  by  Kazunori  Yamazaki  & 

Toshiki  Makioka 852 


The  effects  of  moisture  and  heat  on  the  efficacy  of  chemical  cues  used  in  predator 
detection  by  the  wolf  spider  Pardosa  milvina  (Araneae,  Lycosidae) 

by  Shawn  M.  Wilder,  Jill  DeVito,  Matthew  H.  Persons  & Ann  L.  Rypstra  . . 857 

Description  of  male  Phrynus  aspemtipes  (Amblypygi,  Phrynidae) 

by  Maria-Luisa  Jimenez  & Jorge  Llinas-Gutierrez 862 

Confirmation  of  parthenogenesis  in  Tityus  trivittatus  Kraepelin  1898  (Scorpiones, 

Buthidae)  by  Carlos  A.  Toscano-Gadea 866 

Allometry  of  genitalia  and  fighting  structures  in  Linyphia  triangularis  (Araneae, 

Linyphiidae)  by  Sebastian  Funke  & Bernhard  A.  Huber 870 

Matriphagy  in  the  neotropical  pseudoscorpion  Paratemnoides  nidificator  (Balzan 

1888)  (Atemnidae)  by  Everton  Tizo-Pedroso  & Kleber  Del-Claro 873 

Book  Review 

Review  of  Fossil  Spiders  in  Amber  and  Copal  (by  Joerg  Wunderlich)  reviewed  by 

George  Poinar,  Jr. 878 


USERNAME:  akron05 


PASSWORD:  spider05 


CONTENTS 

The  Journal  of  Arachnology 


1 

III 

III 

mill 

3 908e 

101181  205< 

, 

Volume  33  Featured  Articles  Number  3 

The  male  genitalia  of  the  family  Atemnidae  (Pseudoscorpiones) 

by  Finn  Erik  Klausen 641 

Extremely  short  copulations  do  not  affect  hatching  success  in  Argiope  bruennichi 
(Araneae,  Araneidae)  by  Jutta  M.  Schneider,  Lutz  Fromhage  & 

Gabriele  Uhl 663 


Parameters  affecting  fecundity  of  Loxosceles  intermedia  Mello-Leitao  1934 

(Araneae,  Sicariidae)  by  Marta  L.  Fischer  & Joao  Vasconcellos-Neto 670 

Refining  sampling  protocols  for  inventorying  invertebrate  biodiversity:  influence 
of  drift-fence  length  and  pitfall  trap  diameter  on  spiders  by  Karl  E.C. 


Brennan,  Jonathan  D.  Majer  & Melinda  L.  Moir 681 

Male  residency  and  mating  patterns  in  a subsocial  spider  by  Barrett  A.  Klein, 

Todd  C.  Bukowski  & Leticia  Aviles 703 

A redescription  of  Chrysso  nigriceps  (Araneae,  Theridiidae)  with  evidence  for 

maternal  care  by  Jeremy  Miller  & Ingi  Agnarsson 711 

A ' sWimmmg'  Heteropoda  species  from  Borneo  (Araneae,  Sparassidae, 

Heteropodinae)  by  Peter  Jager 715 

Three  new  species  of  Solifugae  from  North  America  and  a description  of  the 
female  of  Branchia  brevis  (Arachnida,  Solifugae)  by  Jack  O.  Brookhart 
& Paula  E.  Cushing 719 

Visual  acuity  of  the  sheet-web  building  spider  Badumna  insignis  (Araneae, 

Desidae)  by  Christofer  J.  Clemente,  Kellie  A.  McMaster,  Liz  Fox, 

Lisa  Meldrum,  Barbara  York  Main  & Tom  Stewart  726 

A new  species  of  Bothriurus  from  Brazil  (Scorpiones,  Bothriuridae) 

by  Camilo  Ivan  Mattoni  & Luis  Eduardo  Acosta 735 

Diel  activity  patterns  and  microspatial  distribution  of  the  harvestman  Phalangium 
opilio  (Opiliones,  Phalangiidae)  in  soybeans  by  Cora  M.  Allard  & 

Kenneth  V.  Yeargan 745 

Identity  and  placement  of  species  of  the  orb  weaver  genus  Alcimosphenus 

(Araneae,  Tetragnathidae)  by  Herbert  W.  Levi 753 

Development  and  life  tables  of  Loxosceles  intermedia  Mello-Leitao  1934 

(Araneae,  Sicariidae)  by  Marta  L.  Fischer  & Joao  Vasconcellos-Neto 758 

Mate  choice  and  sexual  conflict  in  the  size  dimorphic  water  spider  Argyroneta 
aquatica  {Araneae,  Argyronetidae)  by  Dolores  Schiitz  & 

Michael  Taborsky 767 


Molecular  insights  into  the  biogeography  and  species  status  of  New  Zealand’s 
endemic  Latrodectus  spider  species;  L.  katipo  and  L.  atritus  (Araneae, 

Theridiidae)  by  James  W.  Griffiths,  Adrian  M.  Paterson  & Cor  J.  Vink . . 776 

Revision  of  the  spider  genus  Hesydrus  (Araneae,  Lycosoidea,  Trechaleidae) 


by  James  E.  Carico 785 

Description  of  two  new  spider  genera  of  Trechaleidae  (Araneae,  Lycosoidea)  from 

South  America  by  James  E.  Carico 797 

Living  with  the  enemy:  jumping  spiders  that  mimic  weaver  ants  by  Ximena  J. 

Nelson,  Robert  R.  Jackson,  G.B.  Edwards  & Alberto  T.  Barrion 813 

A new  technique  for  examining  surface  morphosculpture  of  scorpions 

by  Erich  S.  Volschenk 820 

Review  Article 

The  emergence  of  manipulative  experiments  in  ecological  spider  research 

(1684-1973)  by  James  R.  Bell 826 


Contents  continued  on  inside  back  cover