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AGRIC. 
LIBRARY 


LIBRARY 


UNIVERSITY  OF  CALIFORNIA 


GIFT  OF" 


Class 


U.  S.'DEP 


. 


VGRICULTURE. 

.lOLOGT. 





«,'. 


INSECTS 


AFFECTING  THE 


AGRICULTURAL 
LIBRARY, 


-OF- 


CALIFORNIA.   I 


O  K  AN  G-E. 


REPORT  ON  THE  INSECTS  AFFECTING  THE  CULTURE  OF  THE  ORANGE 

AND  OTHER  PLANTS  OF  THE  CITRUS  FAMILY,  WITH  PRACTICAL 

SUGGESTIONS  FOR  THEIR  CONTROL  OR  EXTERMINATION, 

MADE,  UNDER  DIRECTION  OF  THE  ENTOMOLOGIST, 


BY 


H.  G-.  HUBBARD. 


TVTTH 


WASHINGTON: 

GOVERNMENT   PRINTING  OFFICE. 

1885. 


JOINT    RESOLUTION    AUTHORIZING    THE    PRINTING    OP    FIVE    THOUSAND    COPIES  OF 
A  SPECIAL  REPORT  ON  INSECTS  AFFECTING  THE  ORANGE  TREE. 

Resolved  by  the  House  of  Representatives  (the  Senate  concurring},  That  there  be  printed 
5,000  copies  of  a  special  report  from  the  Department  of  Agriculture  on  insects  affect- 
ing the  orange  tree,  with  the' necessary  illustrations,  2,500  copies  of  which  shall  be 
for  the  use  of  the  House  of  Representatives,  1,500  for  the  use  of  the  Senate,  and  1,000 
for  the  use  of  the  Department  of  Agriculture. 

JULY  6, 1882. 
II 


TABLE   OF  CONTENTS. 


Tago. 

LETTER  OF  TRANSMITTAL vii 

LETTER  OF  SUBMITTAL '.. ix 

INTRODUCTION. 

INJURIES  BY  INSECTS  DISTINGUISHED  FROM  ORGANIC  DISEASE 1 

Diseases  affecting  the  condition  of  the  plant ; — die-back,  1 — bark  -fungus, 
2 — foot-rot; — sinut,  3 — splitting  of  fruit,  4 — dropping  of  fruit,  5. 

THE  INSECT  FAUNA  or  THE  ORANGE 5 

Attraction  which  the  orange  tree  has  for  insects,  5 — injurious  insects ; — ben- 
eficial insects,  6 — innocuous  insects ; — importance  of  distinguishing  friends 
from  foes,  7 — presence  of  .certain  injurious  insects  indicated  by  ants,  8. 

SYSTEMS  OF  CULTIVATION 8 

Influence  of  shade  upon  the  increase  of  insect  pests,  8 — clean  culture  or 
mulching  preferable  to  cropping  young  groves ; — seasons  of  greatest  in- 
sect activity,  9 — the  proper  months  for  applying  remedies,  10. 


PAET  I.— COCCID^  [SCALE  INSECTS  OK  BAKK-LICE]. 

CHAPTER  I. 

CHARACTERS  OF  THE  COCCID^  AND  COMMENCEMENT  OF  THE  CONSIDERATION 

OF  THE  SUBFAMILY  DIASPIN^E , 13 

General  characters  of  Bark-lice  and  their  relations  to  other  insects; — prod- 
ucts of  Bark-lice,  13— division  into  subfamilies,  14 — life-history  of  the 
Diaspinse  :— the  larva,  15 — growth  of  the  scale,  16— the  females; — the 
males,  17 — periods  of  development ; — nature  of  the  scale-covering,  18 — 
Long  Scale,  19— life-history,  21 — broods,  22— parasites,  23— origin  and 
spread,  24. 

CHAPTER  II. 

DIASPIN.E— Continued 26 

Purple  Scale,  26— Red  Scale  of  Florida,  28— Red  Scale  of  California,  32— 
White  Scale,  35— Chaff  Scale,  37— the  Orange  Chionaspis,  40. 

CHAPTER  III. 

DIASPIN.E — Continued—  RAVAGES  OF  THE  ARMORED  SCALES 42 

Bark-lice  everywhere  present  in  orange  groves,  42— relative  importance  of 
the  several  species  as  pests; — agencies  which  assist  their  distribution, 
43 — influence  of  the  wind,  44 — enfeebled  condition  of  the  plant  favorable 
to  their  increase  ; — usual  course  of  the  pest,  45 — the  popular  belief  that 
the  scales  are  thrown  off  at  the  ends  of  the  branches ; — influence  of  cli- 
mate, 46 — effect  of  frost ; — natural  checks,  47. 

in 


IV  TABLE    OF    CONTENTS. 

CHAPTER  IV. 

Page. 

LECANIN.E — THE  NAKED  OR  WAXY  SCALES 48 

General  characters  and  life-history  of  the  subfamily;— the  Turtle-back 
Scale ; — Broad  Scale,  48— growth ;— habits,  49 — broods ;— honey-dew  and 
ants ; — parasites,  50— the  Black  Scale  of  California,  53 — the  Hemispherical 
Scale,  55— the  Wax  Scale,  56— the  Barnacle  Scale,  59 — extent  of  injuries 
and  relative  importance  of  the  species,  61 — smut,  62. 

CHAPTER  V. 
COGGING — THE  MEALY-BUGS 63 

Characteristics  of  the  subfamily ; — food  plants,  63 — the  Destructive  Mealy- 
bug, 64 — the  Cottony  Cushion  Scale,  66. 

CHAPTER  VI. 

INSECTS  PREYING  UPON  BARK-LICE 69 

Enumeration  of  external  enemies ; — work  of  Mites,  69 — internal  parasites  ;— 
ants  as  friends  and  enemies,  70— Lady- birds,  71 — parasites  of  the  Lady- 
birds, 74 — the  Scale-eating  Epitragus,  75 — the  Scale-eating  Dakruma,  76 — 
the  Pale  Dakruma ; — the  Scale-eating  Tineid,  77— the  Spider-legged  Sol- 
dier-bug, 78— hemipterous  enemies  of  the  Mealy-bug,  79 — Lace-wings, 
80— predatory  Mites,  81— Glover's  Mite,  82 — the  -Hairy  Mite  ; — the  Spear- 
head Mite;— the  Spotted  Mite,  83 — Mites  preying  on  Mealy-bug,  84 — Long- 
bodied  Mite ;— the  Orbicular  Mite,  85. 

CHAPTER  VII. 

MEANS  OF  DEFENSE  AGAINST  SCALE-INSECTS—REMEDIES 86 

Introduction  of  Scale-insects  upon  imported  plants,  86 — infection  from 
nursery  stock,  87— protection  afforded  by  hedges  and  trees,  88 — plants 
available  for  hedges ; — benefits  of  inside  pruning  and  cleanliness,  89 — 
scrubbing  the  trunks ; — palmetto  brushes,  90 — ineffectual  popular  reme- 
dies ; — fumes  of  sulphur  fatal  to  the  plant ;— impossibility  of  introducing 
insecticides  into  the  sap  through  the  roots,  91 — or  by  inoculation  ; — fight- 
ing Scale  with  fertilizers ;— effective  remedies ;— kerosene ;  —milk  and  kero- 
sene emulsion,  92 — soap  and  kerosene  emulsion  ; — unrefined  kerosene  in- 
jurious;— effect  of  kerosene  upon  the  Orange,  94 — applications  best  made  in 
spring; — whale-oil  soap,  95 — potash  and  soda  lyes,  96 — carbolic  acid,  97 — 
sulphurated  lime,  98— bisulphide  of  carbon ; — sulphuric  acid ; — sulphate  of 
iron ; — ammonia ; — silicate  of  soda,  99— various  common  remedies  of  little 
value ; — the  application  of  remedies  ; — fineness  and  force  of  spray  ; — cy- 
clone nozzle,  100 — complete  outfit  mounted  on  a  cart ; — necessity  of  re- 
peated applications,  101 — proper  seasons  for  applying  remedies,  102. 

PAET   II.— MISCELLANEOUS  INSECTS  AFFECTING  THE 

ORANGE. 

CHAPTER  VIII. 

RUST  OF  THE  ORANGE 105 

Nature  of  rust;— discoloration  of  the  fruit ;— not  produced  by  a  fungus, 
105 — origin  of  rust ; — reasons  for  considering  it  the  work  of  a  Mite ; — the 
Mite  on  the  leaves ; — first  appearance  on  the  fruit,  106 — attacks  of  the 
Mite  always  followed  by  rust ; — development  of  rust  subsequent  to  the 
departure  of  the  Mites ; — description  of  the  Rust-mite,  107— growth  from 
the  egg  to  the  adult,  108— food,  habits,  and  numerical  abundance,  109 — 


TABLE    OF    CONTENTS.  V 

Page. 
SUST  OF  THE  ORANGE — Continued. 

effect  of  sunshine  and  shade  upon  the  Mites ; — rust-rings  on  the  fruit, 
110 — influence  of  the  weather ; — means  of  dissemination,  111 — ravages 
of  the  Rust-mite  confined  to  Citrus  plants; — effect  of  attacks  upon  the 
foliage; — rusted  fruit,  112 — origin  and  spread  of  the  Mite; — periods  of  in- 
crease ;— geographical  distribution ;— remedies ;— influence  of  soil,  113 — 
fruit  less  liable  to  rust  on  low  land ; — preventive  measures ; — effect  of  re- 
ducing radiation; — protection  afforded  by  wind-breaks,  114 — application 
of  insecticides; — whale-oil  soap,  115 — sulphur,  116 — natural  sulphur 
water; — kerosene  ;— carbolic  acid,  118 — potash; — pyrethrum,  119 — 
lime ; — ashes ; — caution ; — danger  of  making  applications  during  winter, 
120. 

CHAPTER  IX. 

INSECTS  AFFECTING  THE  ROOT,  CROWN,  TRUNK,  AND  BRANCHES. 

BOOT  AND  CROWN 121 

Tap-root  borers ; — white  ants,  121— description  and  habits  of  the  common 
species; — injuries  to  Orange,  121 — the  work  of  Termites  distinguished 
from  that  of  other  insects ; — buried  wood  and  stumps  a  source  of  danger, 
123 — needful  precautions ; — remedies ; — exposure  to  light ; — applications 
of  hot  water  ;— pyrethrum  ;— kerosene ; — bisulphide  of  carbon,  124 — 
ashes ; — lime  and  sulphur ;— means  of  saving  girdled  trees ; — a  larger 
species  of  Termite,  12a. 

TRUNK  AND  BRANCHES 125 

The  Common  Orange  Sawyer,  125 — injuries  the  result  of  careless  pruning ; — 
the  tree  protected  by  its  gum  ; — precautions  to  be  observed  in  pruning; — 
means  of  destroying  the  borers,  127 — the  Twig-girdler,  128— wood-eat- 
ing habits  of  an  ant  (Solenopsis),  129 — means  of  destroying  their  colonies, 
130— methods  of  preventing  ants  from  ascending  the  trees,  131. 

CHAPTER  X. 

INSECTS  AFFECTING  THE  TWIGS  AND  LEAVES. 

• 

HYMENOPTERA,— A  leaf-eating  ant,  132. 

COLEOPTERA, — Brachys  ovata,  132 — Odontota  rubra ; — the  Orange  Leaf-notcher 
and  other  weevils  slightly  injurious  to  the  leaves,  133. 

ORTHOPTERA, — The  Angular- winged  Katydid,  134 — the  Lubber  Grasshopper, 
135— other  locusts,  136. 

LEPIDOPTERA, — The  Orange  Dog,  137— defensive  measures,  138 — parasites,139 — 
slug  caterpillars  and  stinging  caterpillars ; — Lagoa  opercularis,  140 — the 
Saddle-back  Caterpillar,  141— the  Hag-moth  Caterpillar,  142— the  Skiff 
Caterpillar,  143— Bag- worms; — the  Common  Bag-worm,  145— provision 
made  by  the  female  for  the  safety  of  her  eggs,  145 — construction  of  its 
basket  by  the  young ; — parasites,  146— the  Northern  Bag- worm,  147 — 
the  Cylindrical  Bag- worm ; — the  Orange  Basket- worm,  148 — small  (unde- 
scribed)  Bag- worm,  149 — cocoons  of  Artace  on  Orange  ; — the  Grass- 
worm,  150 — Leaf-rollers,  151 — the  Cork-colored  Leaf-roller,  152 — para- 
sites, 153 — the  Sulphur-colored  Leaf-roller  ;— a  larger  Leaf-roller ;  Web- 
makers  ; — the  Orange-leaf  Nothris,  154 — the  Orange  Web- worm,  155— 
insects  associated  with  the  Orange  Web-worm,  156. 

:HEMIPTERA,— The  Orange  Aphis,  157— birth  of  the  young ;— destructive  pow- 
ers;— enemies  and  parasites,  158 — the  Green  Soldier-bug,  159— account  of 
its  ravages  at  West  Apopka,  Fla.,  160— the  Thick-thighed  Metapodius, 
162— other  sucking  bugs,  163. 


VI  TABLE    OF    CONTENTS. 

CHAPTER  XI. 

INSECTS  AFFECTING  THE  BLOSSOM  AND  FRUIT — SCAVENGER  INSECTS. 

Page. 

AFFECTING  THE  BLOSSOMS 164 

The  Orange  Thrips,  164. 

AFFECTING  THE  FRUIT • 165 

The  Cptton  Stainer,  165— the  Leaf-footed  Bug,  168— the  Mexican  Fruit 
Worm,  169. 

SCAVENGERS 17Q 

Insects  feeding  upon  dead  wood  and  bark ;— tree-inhabiting  ants,  170— the 
Orange  Sawyer  considered  as  a  useful  insect ; — the  Flat-headed  Borer, ' 
171 — the  Cylindrical  Bark-borer,  173 — other  insects  boring  in  orange  wood, 
174 — insects  found  in  bleeding  wounds  and  sores ; — insects  feeding  upon 
decaying  fruit ; — Sap-beetles,  175 — the  Wine-fly  of  the  Orange,  176 — other 
insects  found  in  injured  fruit,  177— insects  in  dry  fruit ; — white  ants  in 

fruit,  178. 

CHAPTER  XII. 

PREDATORY  INSECTS. 

INSECTS  PREYING  UPON  PLANT-LICE 180 

Lady-birds; — Scymnus  caudalis,  180— Syrphus flies;— life-history,  181 — the 
Four-spotted  Apliis-fly,  183 — the  Dusky- winged  Aphis-fly; — the  Ruddy 
Aphis-fly,  184— the  Pruinose  Aphis-fly,  185. 

OTHER  PREDATORY  INSECTS  FREQUENTING  THE  ORANGE 186 

Wasps ; — Polistes  americanus,  186— the  Vase-maker  Wasp,  187 — the  Camel- 
crickets  or  Soothsayers,  188 — the  Carolina  Mantis,  189 — the  Slender  Man- 
tis (Missouriensis?),  190— Soldier-bugs ; — the  Spider-legged  Soldier-bug; — 
the  Rapacious  Soldier-bug,  191 — the  Wheel-bug,  192. 

INNOXIOUS  INSECTS 193 

Case-bearers  on  Orange ; — the  Orange  Case-bearing  Tineid,  193 ; — Bark- 
cleaners,  193 — Psocus  venosus  Burm.,  193 — the  Orange  Psocus,  194, 

APPENDICES. 

APPENDIX  -I. 
THE  MEALY-BUG  AT  ORANGE  LAKE,  FLORIDA 19T 

APPENDIX  II. 

EXPERIMENTS  WITH  INSECTICIDES 199* 

Table  I— Kerosene  emulsions,  199  ;  Table  II— Whale-oil  soap,  202 ;  Table 
III— Lye  solutions,  204;  Table  IV — Crude  carbolic  acid  (oil  of  creosote), 
206 ;  Table  V— Bisulphide  of  carbon,  209 ;  Table  VI— Silicate  of  soda, 

211. 

APPENDIX  III. 

THE  COITION  OF  BAG-WORMS 213 

NOTES. 

Note  1,  Additional  parasites  of  Ceroplastes,  215 — Note  2,  Scale-eating  Tineid, 
215 — Note  3,  Telenomus  from  Leptocorisa  eggs,  215 — Note  4,  Heteroptera 
feeding  on  Dactylopius,  215 — Note  5,  Perilitus  from  cocoon  of  Chrysopa, 
215— Notes  6, 7, 8, 9, 10,  Descriptions  of  Orange  Mites,  216— Note  11,  Compo- 
sition of  sulphurated  lime,  217 — Note  12,  Miotropis  parasitic  on  Platynota, 
217 — Note  13,  Goniozus  parasitic  on  Platynota,  217 — Note  14,  Larger  Leaf- 
roller  of  the  Orange,  217— Note  15,  Orange-eating  Tineid,  218— Note  16, 
Pteromalus  from  Pruinose  Aphis-fly,  218— Note  17,  Chrysis  from  Eumenes 
fraterna,  218. 


LETTER  OF  TRANSMITTAL. 


DEPARTMENT  OF  AGRICULTURE, 
DIVISION  OF  ENTOMOLOGY, 

Washington,  D.  0.,  May  20,  1885. 

SIR:  I  have  the  honor  to  transmit  herewith  a  special  report  which 
was  ordered  by  Congress  upon  the  u  Insects  affecting  the  Orange  Tree." 
This  report  has  been  prepared  by  Mr.  H.  G.  Hubbard,  who  has  been 
employed  as  a  special  agent  at  Crescent  City,  Fla.,  and  who  has  de- 
voted his  time  for  nearly  four  years  in  studying  the  insects  that  affect 
the  Orange,  and  especially  in  practical  experiments  to  counteract  their 
injuries.  It  is  but  uttering  a  deserved  compliment  to  say  that  the  prac- 
tical results  of  his  labors  have  been  most  satisfactory,  and  mark  an  im- 
portant era  in  the  history  of  orange- growing  in  the  United  States. 

The  trees  of  the  Citrus  family  are  particularly  subject  to  the  disas- 
trous ravages  of  various  species  of  Scale-insects,  which  not  infrequently 
thwart  all  effort  to  raise  a  grove.  It  is  to  these  that  the  present  re- 
port is  chiefly  devoted,  and  to  their  control  that  the  greatest  efforts 
were  made. 

Mr.  Hubbard's  work  was  confined  to  Florida,  but  the  remedies  are 
applicable  to  other  orange-growing  sections  of  the  country.  Prof.  J.  H. 
Comstock  had  already  published  much  upon  the  Scale-insects  affecting 
the  Orange  in  California  in  the  report  of  this  Department  for  1880,  and 
his  work  has  been  very  freely  used  in  the  present  report. 

The  delay  in  the  printing  of  the  report  has  been  partly  due  to  the  ill 
health  from  which  Mr.  Hubbard  has  suffered  during  the  past  year,  and 
which  has  necessitated  considerable  office  work,  in  which  I  have  had  the 
assistance,  which  1  take  pleasure  in  acknowledging,  of  Messrs.  Howard, 
Schwarz,  and  Pergande. 
Respectfully, 

0.  Y.  EILBY, 

Entomologist. 

Hon.  NORMAN  J.  COLMAN, 
Commissioner  of  Agriculture. 

vn 


LETTER  OF  SUBMITTAL. 


CRESCENT  CITY,  FLA.,  March  25, 1885. 

SIR  :  I  have  the  honor  to  submit  the  following  report  upon  insects 
that  affect  the  culture  of  the  Orange.  The  investigations  conducted  un- 
der your  direction,  and  which  form  the  basis  of  this  report,  were  begun 
upon  my  arrival  in  the  field  in  Florida,  in  August,  1881,  and  continued 
until  March,  1882.  The  work  was  resumed  in  June,  1882,  and  1  returned 
to  Florida  in  September,  remaining  in  the  field  twenty-three  months, 
or  until  August,  1884. 

At  your  request,  a  preliminary  report  upon  Scale-insects  of  the  Orange, 
with  special  reference  to  Remedies  and  their  application,  was  prepared 
in  advance  of  the  final  report,  and  was  included  in  the  Eeport  of  the 
Entomologist  for  1882. 

A  treatise  upon  Bust  of  the  Orange,  including  the  essential  part  of 
Chapter  VIII  of  this  report,  was  prepared  in  the  spring  of  1883,  and 
short  extracts  from  this  and  other  portions  of  the  final  report  have  ap- 
peared in  the  Bulletins  of  the  Entomological  Division.  The  full  treatise 
upon  Bust,  with  illustrations,  is  included  in  the  Annual  Beport  of  the 
Entomologist  for  1884. 

In  the  preparation  of  the  present  work  a  single  object  has  been  kept 
in  view,  namely,  to  afford  practical  aid  to  the  orange-grower  in  the  war- 
fare which  must  be  waged  with  insect  foes.  Technical  terms,  which 
might  render  the  treatise  unintelligible  to  non-entomological  readers, 
have  been  as  far  as  possible  excluded  from  the  text,  and  in  the  descrip- 
tions of  insects  which  fall  within  the  scope  of  these  investigations  an 
attempt  has  been  made  to  render  the  various  forms  recognizable  to  an 
intelligent  observer,  by  the  use  of  popular  language,  aided  in  many  cases 
by  figures,  and  without  a  resort  to  intricacies  of  description,  such  as 
would  be  imperatively  demanded  for  specific  identification. 

Nevertheless,  that  the  work  may  not  prove  of  less  advantage  to  the 
student  of  entomology,  and  to  the  investigator  who  may  seek  to  correct, 
advance,  or  complete  the  many  imperfect  observations  here  recorded, 
references  to  more  complete  descriptions  elsewhere  published  are 
given  when  deemed  necessary,  and  descriptions  of  new  insects,  with 
other  purely  technical  matters,  are  relegated  to  notes  and  appendices 
at  the  end  of  the  volume. 

Although  my  own  observations  have  not  extended  beyond  the  State 
of  Florida,  and  the  accessible  notes  of  observers  elsewhere  are  few  and 

IX 


X  LETTEE    OF    SUBMITTAL. 

meager,  the  first  part  of  the  work,  that  relating  to  Bark-lice,  will  be 
found  applicable  to  any  region  where  the  Orange  is  grown,  since  these 
universal  enemies  of  the  Orange  are  as  cosmopolitan  as  the  plant  it- 
self. This  part  of  the  work,  moreover,  includes,  in  addition  to  those 
species  which  have  been  the  subjects  of  original  investigation  in  Flor- 
ida, such  notes  as  have  been  published  upon  the  Califoruian  species, 
and  which  have  not  as  yet  made  their  appearance  upon  the  Orange  in 
the  East. 

Of  the  miscellaneous  insects  considered  in  the  second  part  of  this  re- 
port, by  far  the  greater  number  are  known  only  in  Florida  or  Louisi- 
ana, and  are  not  likely  to  make  their  appearance  in  the  Pacific  States. 

In  a  record  of  observations  extending  over  several  years  of  daily  and 
almost  constant  work  in  orange  groves,  it  will  not  seem  strange  if  many 
of  the  facts  observed  by  previous  investigators  are  found  repeated  in 
the  following  pages,  and  if  credit  is  not  always  given  for  priority  of  dis- 
covery in  matters  relating  to  the  habits  of  insects,  such  as  may  be  veri- 
fied in  every  orange  grove,  more  intricate  researches,  or  such  as  have 
not  been  reobserved,  are  always  accompanied  by  the  proper  references. 
In  this  way  contributions  of  interest  to  orange-growers  have  been  ex- 
tracted from  the  writings  of  well-known  entomologists,  and  particularly 
from  notes  and  published  treatises  on  orange  insects  by  Glover,  Ash- 
mead,  and  Comstock. 

Finally,  to  your  direction  and  guidance  is  attributable  much  of  what- 
ever valuable  may  result  from  my  work  ;  and  the  influence  of  your  own 
scientific  researches,  not  less  than  your  personal  co-operation,  has  light- 
ened the  labor  and  made  the  preparation  of  this  report  a  pleasant  task. 

Eespectfully  submitted, 

H.  G.  HUBBAKD, 

Special  Agent. 

Prof.  C.  V.  EILEY, 
Entomologist. 


INTRODUCTION. 


INJURIES  BY  INSECTS  DISTINGUISHED  FROM  ORGANIC  DISEASE 

DISEASES    AFFECTING   THE   CONDITION   OF   THE   PLANT. 

Iii  plants,  as  hi  animals,  the  outward  symptoms  of  disease  do  not  al- 
ways indicate  plainly  the  cause  of  the  physical  disturbance.  There  is 
often  need  of  skilful  diagnosis  before  it  is  possible  to  intelligently  apply 
a  remedy. 

Naturally,  in  exogenous  plants,  whose  vital  growing  parts  are  near 
the  surface,  we  look  for  the  most  part  to  external  enemies  for  the  cause 
of  disease,  and  especially  upon  insects,  the  natural  foes  of  the  vegeta- 
ble world,  suspicion  falls  most  readily  and  with  greatest  reason.  Do  the 
leaves  of  an  orange  tree  turn -yellow  and  fall  to  the  ground,  some 
worm,  we  suspect,  is  gnawing  at  the  root,  or  Scale-insects  are  sapping 
the  vital  fluids  from  the  bark.  Are  the  blossoms  blasted,  the  fruit  drop- 
ping or  splitting,  we  are  inclined  to  lay  the  blame  upon  some  sucking 
bug  or  upon  some,  it  may  be,  harmless  insect  that  we  chance  to  see 
upon  the  plant. 

But  these  phenomena  are  not  always  attributable  to  insect  agencies, 
although  they  are  often  correctly  so  assigned.  They  are  frequently  the 
result  of  pathological  disturbances,  as  obscure  in  their  origin  as  are 
many  diseases  of  animals. 

As  the  object  of  the  present  treatise  is  solely  to  make  known  to  or- 
ange growers  the  insect  enemies  and  friends  with  which  they  have  to 
deal,  we  cannot  h«re  enter  upon  a  discussion  of  the  principles  of  vege- 
table hygiene  as  applied  to  orange  trees. 

There  are,  however,  several  organic  diseases  which  in  their  effect  upon 
the  tree  closely  copy  the  work  of  insects,  and  it  is  desirable  that  they 
should  be  clearly  distinguished.  We  may,  therefore,  at  the  outset 
briefly  examine  the  forms  of  fungus  and  other  affections  most  commonly 
met  with  on  plants  of  the  citrus  family,  and  give  their  distinguishing- 
characters,  with  so  much  as  is  certainly  known  or  can  be  plainly  conjec- 
tured concerning  their  nature  or  origin. 

DIE-BACK. — (Plate  II,  Fig.  1.)  This  is  a  disease  of  the  bark  and  young 
wood,  affecting  chiefly  the  tender  shoots.  These  grow  to  a  length  of  1 
foot  or  18  inches,  and  then  become  stunted,  and  finally  die.  Trees  af- 
fected with  this  disease  continually  push  out  new  growth  which  soon 

1 
6521  o  I 1 


2  INSECTS   AFFECTING   THE    ORANGE. 

dies  back,  and  finally  the  older  portions  of  the  tree  become  affected  and 
gradually  succumb. 

A  morbid  growth  undoubtedly  of  fungus  origin  invariably  accompa- 
nies the  disease  in  its  advanced  stages.  This  appears  first  as  discolored 
patches  or  slight  swellings,  which  gradually  become  confluent,  and  fin- 
ally burst,  forming  an  eruption  of  brownish  color.  The  older  branches 
become  covered  with  ridges  of  exfoliated  bark  and  exudations  of  gum, 
presenting  an  unsightly  appearance,  not  unlike  that  of  "Black-knot"  on 
the  plum. 

The  peculiar  microscopic  fungus  which  causes  "  die-back "  is  undoubt- 
edly well  known  to  mycologists.  The  disease  yields  readily  to  treat- 
ment with  dilute  carbolic  or  creosote  washes,  and  is  curable  by  these 
simple  means,  provided  the  exciting  cause  is  removed.  This  fact  may 
be  regarded  as  confirmatory  of  its  fungus  character.  The  term  "  die- 
back  "  has  been  applied  to  several  other  diseases  of  the  orange,  and 
even  to  injuries  from  frost,  but  the  affection  above  described  is  the  one 
which  is  generally  known  under  this  name. 

The  exciting  cause  of  "die-back"  has  been  variously  ascribed  to  over- 
fertilization,  deep  planting,  imperfect  drainage,  the  presence  of  humic 
acid  in  the  soil,  and  finally  to  insects.  While  there  is  good  reason 
to  suppose  that  conditions  of  the  soil,  or  of  cultivation  unfavorable  to 
the  growth  of  the  plant,  render  it  liable  to  the  attacks  of  fungus  dis- 
eases, there  is  no  evidence  that  in  this  case  its  presence  is  due  to  the 
depredations  of  insects.  It  is  true  that  the  dead  and  dying  branches  of 
trees  affected  with  die-back  attract  boring  insects  of  various  sorts,  but 
these  are  found  to  belong  to  wood-eating  kinds,  which  act  as  scaven- 
gers merely,  and  have  no  connection  with  the  disease  itself.  ^/ 

BARK-FUNGrUS. — (Plate  II,  Fig.  2.)  Many  forms  of  lichens  attach 
themselves  to  the  trunk  of  the  Orange,  in  common  with  other  trees,  and 
flourish  abundantly  in  dark  and  damp  situations.  There  are,  however, 
several  mold-like  fungi  found  more  exclusively  upon  the  Orange  and 
its  allies.  These  bear  a  deceptive  resemblance  to  incrustations  of  Scale- 
insect. 

Of  these  fungi  the  one  most  readily  mistaken  for  Scale-insects  com- 
monly appears  upon  the  trunk  and  branches  as  little  hard  excrescences 
of  gray  color,  which,  in  wet  weather,  burst,  disclosing  a  white  cottony 
interior,  from  which  they  are  often  confounded  with  the  "  Mealy  Bug," 
(Dactylopius).  The  resemblance  to  the  Coccid  is  increased  when  the 
white  spicules,  a  bundle  of  which  fills  each  little  fungus  cup,  are  beaten 
out  by  rains,  and  felted  upon  the  bark  in  a  mold -like  coating.  The 
fungus  is  confined  to  the  surface  of  the  bark,  and  appears  to  germi- 
nate exclusively  among  the  debris  of  Scale-insects.  It  is  always  found 
upon  trunks  that  have  long  been  coated  with  Chaff  Scale  (Parlatoria 
pergandii).  It  may  also  be  found  upon  the  leaves  when  they  have  be- 
come infested  with  this  scale,  and  is  easily  removed  by  gentle  friction 


INJURIES  BY  INSECTS  DISTINGUISHED  FROM  ORGANIC  DISEASE.     3 

between  the  fingers,  coming  off  with  the  scales,  and  showing  no  close 
attachment  to  the  surface  of  the  leaf. 

The  fungus  feeds  upon  the  substance  of  the  dead  or  vacated  scales, 
and  is  not  directly  parasitic  upon  the  plant.  It  is  extremely  injurious, 
however,  by  reason  of  the  closely-felted  coating  which  is  formed,  causing 
the  bark  to  harden  and  the  tree  to  become  u  hide-bound." 

FOOT-ROT. — This  disease  appears  only  upon  sweet  seedling  orange 
trees,  most  frequently  between  the  ages  of  nine  and  twelve  years,  and 
often  bears  a  deceptive  resemblance  to  the  work  of  insects.  It  takes  the 
form  of  cancerous  sores,  which  destroy  the  cambium  layer  of  the  bark. 
The  sores  are  confined,  except  in  rare  instances,  to  the  foot  or  collar 
of  the  tree,  and  begin  as  little  cavities  "filled  with  fermenting  sap  and 
having  an  offensive,  sour  odor.  These  cavities  extend  their  boundaries, 
the  outer  bark  dries  and  cracks,  allowing  the  sap  to  exude  and  run 
down  upon  the  outside.  Sometimes  winding  channels  are  formed  in  the 
inner  bark  by  the  burrowing  of  the  pus,  and  when  these  are  laid  bare 
by  the  knife  the  resemblance  to  the  track  of  a  "  Sawyer,"  or  coleopter- 
ous borer,  is  very  striking.  When  the  sores  become  extensive  the  dead 
outer  bark  above  them  sloughs  away,  exposing  the  dry  wood  beneath. 
At  this  stage  the  disease  is  liable  to  be  mistaken  for  the  work  of  u  Wood- 
lice"  or  White-ants  (Termites),  which  will,  moreover,  very  likely  have 
made  their  appearance.  The  characteristic  mark  by  which  the  galleries 
of  termites  may  most  readily  be  distinguished  from  sores  of  foot-rot  con- 
sists of  a  lining  of  comminuted  wood  with  which  these  insects  always 
smooth  the  wails  of  their  tunnels  and  chambers.  If  this  is  wanting  in 
any  of  the  wounds,  even  though  termites  be  seen  in  the  immediate  vi- 
cinity, they  cannot  be  the  authors  of  the  mischief. 

Foot-rot  usually  ends  by  girdling  and  killing  the  tree.  Like  cancer 
in  animals,  it  is  sometimes  successfully  treated  by  a  free  nse  of  the 
knife,  although  this  frequently  serves  only  to  aggravate  the  difficulty 
and  increase  the  area  of  the  disease. 

Antiseptic  treatment  with  lotions  and  poultices  containing  carbolic 
acid  might  prove  beneficial,  but  seems  never  to  have  been  tried.  A 
remedy  that  has  been  found  practicable,  if  taken  in  time,  is  to  plant  at 
the  foot  of  the  diseased  tree  young  stocks  of  the  Sour  u  range,  which  is 
never  affected  by  the  disease,  and  as  soon  as  they  have  established 
themselves,  to  graft  them  into  the  trunk  two  feet  or  more  above  the  ground. 
These  supplementary  stocks  will  in  time  replace  the  original  roots  and 
form  a  new  crown,  while  supporting  and  preserving  the  life  of  the  tree. 

Many  insects,  attracted  by  the  fermenting  sap,  resort  to  these  sores. 
They  are  all  scavengers,  feeding  only  upon  the  lifeless  bark  and  sap, 
or  else  innocuous  and  predatory  species,  such  as  lurk  in  dark,  cool 
places  everywhere. 

SMUT. — A  deposit  resembling  soot  is  found  upon  the  leaves  and  bark 
of  trees  which  have  been  infested  with  certain  kinds  of  bark-lice.  It 
is  not  confined  to  the  Orange,  but  is  found  upon  the  Oleander,  the  Olive, 


4  INSECTS   AFFECTING   THE    ORANGE. 

and  many  other  plants,  and  always  follows  the  attacks  of  Lecanium, 
Oeroplastes,  and  other  Coccids  which  produce  honey -dew. 

The  Gall-berry,  Ilex  glabra,  a  wild  plant  which  grows  in  great  abund- 
ance in  the  sterile  "  flat  woods"  of  Florida,  and  which  is  much  infested 
by  Oeroplastes  scale,  is  often  blackened  by  it  over  many  acres  in  ex- 
tent. 

Prof.  W.  G.  Farlow,  in  a  paper  entitled  "  On  a  Disease  of  Olive  and 
Orange  Trees  occurring  in  California  in  the  Spring  and  Summer  of 
1875,"  describes  and  figures  this  smut,  and  shows  it  to  be  a  fungus. 
He  determines  it  to  be  Capnodium  citri  Berkeley  &  Desmazieres,  a 
species  occurring  on  Orange,  &c.,  in  Europe,  and  says  that  it  seems 
nearly  or  quite  identical  with  the  Fumago  salicina  of  older  writers. 
(See  Tulasne,  "Carpologia  Fungorum,"  PI.  XXXIY,  Figs.  14  and  20.) 
In  the  same  paper  it  is  shown,  from  botanical  considerations,  that  it 
does  not  feed  on  the  plant,  but  on  the  honey-dew  ejected  by  insects. 

Smut  upon  orange  trees  has  long  been  known,  and  its  nature  and 
origin  have  formed  the  subject  of  many  curious  speculations. 

In -a  rare  work,  published  at  Nice,  in  1806,  and  entitled  "Histoire 
Xaturelle  de  la  Morf6e,  ou  de  I'Infection  de  la  Famille  des  Grangers ;  par 
PAbbe"  Loquez,"  this  fungus  is  described,  and  also  the  Bark-louse  con- 
nected with  it,  and  the  two  are  treated  as  jointly  constituting  a  disease 
of  the  Orange,  which  at  that  -time  ravaged  the  gardens  of  Italy  and 
southern  France.* 

Both  the  fungus  and  the  insect  being  nourished,  according  to  the 
author's  view,  upon  the  superabundant  juices  of  the  plant,  he  proposes 
to  remedy  the  disorders  produced  by  their  combined  attack  by  depriv- 
ing the  tree  of  moisture,  and  by  the  dessication  of  its  juices. 

Smut  probably  does  no  more  injury  than  would  be  occasioned  by  a 
similar  coating  of  soot  or  other  fine  powder  coating  the  leaves  and 
growing  parts  of  the  plant.  But  as  it  is  never  seen  except  in  conjunction 
with  the  destructive  insects  above  mentioned,  it  is  not  very  easy  to 
determine  what  proportion  of  the  damage  is  attributable  to  the  fungus 
alone. 

SPLITTING  OF  FRUIT. — Moore,  in  his  treatise  on  Orange  Culture, 
says:  "The  cracking  of  fruit  is  occasioned  by  any  suspension  of  the 
growth  of  the  fruit,  and  a  consequent  hardening  of  the  rind,  followed 
by  a  sudden  flow  of  sap  from  any  stimulating  cause,  as  highly  fertil- 
izing a  bearing  grove,  especially  during  summer,  or  a  wet  spell  follow- 
ing a  dry."  Certain  sap-loving  beetles  of  the  family  Nitidulid&,  arid 
also  vinegar  or  pomace  flies,  attack  the  spli£  fruit  both  on  the  tree  and 
after  it  has  fallen  to  the  ground.  The  larvre,  which  they  produce  in  vast 
numbers,  penetrate  the  pulp,  and  cause  it  to  rot  with  great  rapidity. 

Many  persons,  finding  the  split  fruit  infested  with  these  grubs  and 


*  The  Bark-louse  is  called  by  the  author  Coccus  Jiesperidum  Linn. ;  but  his  minute 
and  excellent  account  of  the  insect  and  its  habits  clearly  indicate  that  it  was  a 
species  of  Mealy-bug  (Dactylopim). 


THE    INSECT   FAUNA   OF   THE    ORANGE.  f> 

maggots,  are  disposed  to  consider  them  the  originators  of  the  mischief. 
A  sound  orange  is,  however,  most  perfectly  protected  by  its  oily  rind 
against  the  attacks  of  these  and  most  other  insects,  and  it  has  been 
found  that  they  die  of  starvation  rather  than  penetrate  it  to  reach  the 
pulp  within. 

DROPPING  OF  FRUIT. — Sucking-bugs  (Hemiptera)  of  several  kinds  at- 
tack the  orange,  and  their  punctures  invariably  cause  the  fruit  to  drop 
and  rot. 

All  fruit  trees  drop  their  fruit  from  causes  more  or  less  obscure,  but 
in  some  way  connected  with  the  condition  of  the  plant.  The  Orange  is 
no  exception  to  this  rule,  but  whenever  the  loss  of  fruit  is  attributable 
to  the  bites  or  punctures  of  insects,  the  depredators  themselves  may  be 
readily  discovered,  as  all  are  of  large  size  and  easily  seen. 

WINTER-KILLED  BRANCHES. — Borers  and  mining  insects  are  com- 
monly found  in  dead  twigs  and  branches  killed  by  frost  in  severe  win- 
ters. They  need  occasion  no  alarm,  as  they  are  chiefly  scavengers,  sub- 
sisting upon  the  dead  wood  and  bark,  and  seldom  do  injury  to  the 
living  parts  of  the  plant. 

THE  INSECT  FAUNA  OF  THE  ORANGE. 

ATTRACTION  WHICH  THE  ORANGE  TREE  HAS  FOR  INSECTS. — The 
dark  green  and  glossy  foliage  of  the  orange  tree,  its  dense  shade,  vig- 
orous growth,  and  above  all  the  succulence  of  the  young  shoots  and 
leaves,  render  it  unusually  attractive  to  insects,  not  only  of  leaf-eating 
kinds,  which  are  general  feeders,  but  also  to  many  predatory  and 
innocuous  insects  which  lurk  in  cool  and  shady  places  or  seek  pro- 
tection among  sheltering  leaves. 

Thus  many  kinds  of  insects  are  seen  about  the  trees,  some  of  them 
injurious,  some  beneficial,  and  some  occasional  visitants,  whose  pres- 
ence is  without  significance  for  good  or  ill.  In  general,  it  may  be  said 
that  those  which  are  most  visible  to  the  casual  observer,  and  which  ap- 
pear to  seek  no  concealment,  are  not  injurious.  They  are,  as  a  rule, 
predatory  insects,  such  as  the  wasps  and  sucking-bugs,  which  prowl 
about  the  trees  in  search  of  prey,  or  harmless  flies  and  bees,  visiting 
the  flowers  for  nectar,  or  sporting  among  the  foliage. 

The  injurious  species  generally  lie  concealed.  They  hide  in  folded 
leaves,  excrete  a  scale,  or  form  a  covering  of  sticks  and  bark.  Many  of 
them  are  of  small  size,  or,  if  large,  they  have  some  device  for  their 
better  concealment,  and  by  some  peculiarity  of  form  or  of  coloration 
they  are  made  to  resemble  portions  of  the  plant  on  which  they  rest,  and 
thus  escape  observation.  The  large  green  "  Katydid  "  readily  passes  for 
a  leaf,  and  in  spite  of  its  size  is  very  difficult  to  detect  among  the 
foliage.  The  "Orange  Dog,"  a  caterpillar  more  than  2J  inches  long,  is 
so  marked  with  brown  and  white  as  to  be  inconspicuous  when  re'sting 
upon  the  bark,  from  its  resemblance  to  a  lichen -covered  twig.  Its 


6  INSECTS   AFFECTING   THE    ORANGE. 

chrysalis  presents  a  still  more  striking  example  of  the  same  protective 
resemblance. 

INJURIOUS  INSECTS. — First  in  importance  are  the  Bark-lice  (Coccidse). 
These  sap  the  life  of  the  tree  at  its  source.  The  vital  juices  are  sucked 
up,  and  probably  also  poisoned,  as  the  blood  of  animals  sometimes  is 
by  the  sucking  parasites  which  infest  them. 

Of  insects  injuring  the  root,  little  is  known.  As  has  been  shown, 
"  Wood-lice  "  (Termites)  are  very  often  injurious  just  beneath  the  surface 
of  the  ground,  and  there  are  some  as  yet  unknown  larvae  which  are 
said  to  bore  into  the  tap-root  at  a  considerable  depth.  The  trunk  has 
few  enemies,  except  Bark-lice,  some  species  of  which  prefer  to  attack 
that  part. 

The  leaves  and  twigs,  being  those  portions  which  offer  the  greatest 
extent  of  exposed  surface  and  the  greatest  variety  of  food,  support 
also  the  largest  number  of  depredating  enemies.  A  large  proportion 
of  the  leaf  eaters  feed  indiscriminately  upon  many  plants.  Such  are 
nearly  all  the  locusts,  grasshoppers,  and  crickets,  many  caterpillars, 
and  some  true  bugs  which  injure  by  suction.  The  latter,  however,  for 
the  most  part  confine  their  attentions  to  the  tender  shoots,  blossom 
buds  and  fruit. 

With  many  of  these  insects  the  injury  is  limited  to  the  gnawing  of  a 
few  leaves,  and  their  importance  to  the  orange-grower  is  not  great. 
Others,  on  account  of  their  large  size  and  voracity,  defoliate  the  frees 
and  do  appreciable  damage. 

The  tender  budding  stalks  furnish  particular  species  of  insects 
with  their  especial  food ;  certain  other  species  feed  upon  the  budding 
leaves  in  the  earlier  part  of  their  lives,  and,  when  adult,  select  them  as 
places  of  deposit  for  their  eggs.  These  do  especial  harm  in  checking 
the  advancing  growth,  nipping  it  in  the  bud,  and  inflicting  far  greater 
damage  than  those  which  confine  their  attacks  to  mature  parts  of  the 
plant. 

Injury  to  the  blossom  buds  and  young  fruit-  is  caused  by  certain  suck- 
ing-bugs (Hemiptera),  and  the  fruit  as  it  approaches  maturity  is  attacked 
by  insects  of  the  same  family,  whose  punctures  cause  it  to  drop  from  the 
trees  and  rot. 

A  minute  mite,  which  appears  to  be  one  of  the  few  forms  of  insect 
life  peculiar  to  plants  of  the  citrus  family,  infests  the  leaves  and  green 
fruit,  causing  upon  the  rind  of  the  latter  a  discoloration  known  as  "  rust." 

BENEFICIAL  INSECTS. — Under  this  head  are  included  a  great  variety 
of  predaceous  insects  and  parasites,  without  whose  aid  in  checking  the 
horde  of  depredators,  the  cultivation,  not  only  of  the  Orange,  but  of 
most  other  plants,  would  be  an  impossibility. 

Every  order  of  insects  furnishes  its  predatory  species^  which  are  to  a 
greater  or  less  extent  beneficial  in  destroying  the  plant-eating  kinds 
upon  orange  trees.  The  paper  wasps,  which  hang  their  nests  to  the 
braiacke*,  art  employed  in  seeking  out  spiders  and  leaf-roiling  cater- 


THE   INSECT   F4UNA    OP    THE    ORANGE.  7 

pillars,  with  which  to  feed  their  helpless  young.  The  Lady-birds  (Ooc- 
cinellidae)  and  their  soft- bodied  young,  with  other  beetles  seen  upon  the 
trunk  and  branches,  are  busily  engaged  in  the  good  work  of  tearing  off 
the  scales  of  Bark-lice  and  feeding  upon  the  Coccids  and  their  eggs. 
Wherever  is  found  a  tender  shoot  infested  with  a  colony  of  Aphides, 
there,  in  the  midst  of  the  swarming  Plant-lice,  will  be  found  the  slug- 
like  larvte  of  predaceous  flies  (Syrphus,  etc.),  gradually  but  surely  re- 
ducing their  numbers,  in  spite  of  the  marvelous  powers  of  reproduction 
and  fecundity  of  the  Plant-lice.  Upon  the  leaves  the  active  young  of 
the  Lace- wing  (Chrysopa)  may  be  seen  trundling  their  little  heaps  of  re- 
fuse, beneath  which  the  insect  lurks  in  ambush  for  its  prey.  Among 
the  smaller  forms,  whose  operations  are  invisible  to  the  unassisted  eye, 
are  numerous  predatory  mites,  which  swarm  among  the  Bark-lice,  and 
greatly  aid  in  holding  them  in  check. 

First  in  importance  among  beneficial  insects,  although  least  in  size, 
and  most  difficult  of  observation,  are  the  true  parasites,  which  live 
within  the  bodies,  and  even  inhabit  the  eggs  of  other  insects,  and,  after 
having  eaten  and  destroyed  their  host,  issue  as  minute  and  active  winged 
insects.  Few,  if  any,  of  the  insect  depredators  upon  the  Orange  are  with- 
out internal  parasites,  belonging  with  few  exceptions  to  iheUymenopteraj 
an  order  of  four- winged  insects  of  which  the  bees  and  wasps  are  types. 

Owing  to  their  small  size,  and  the  concealment  in  which  they  pass 
the  greater  portion  of  their  lives,  parasites  are  themselves  seldom  seen, 
but  the  extent  of  their  operations  is  sometimes  rendered  apparent  by 
the  great  mortality  which  follows  their  attacks  upon  an  invading  army 
of  plant  enemies.  Sometimes  the  presence  of  a  parasite  within  its  body 
is  indicated  by  a  change  of  form  or  color  which  the  parasitized  insect 
undergoes  before  its  death,  and  in  any  case,  after  death,  the  work  of 
the  parasite  is  plainly  shown  by  the  round  hole  which,  in  issuing,  it 
leaves  behind  in  the  body  or  the  protective  covering  of  its  host. 

INNOCUOUS  INSECTS. — Of  these  little  need  be  said  except  that  their 
number  is  legion.  Their  importance  to  the  agriculturist  consists  in  the 
liability  of  their  being  mistaken  for  noxious  insects,  and  thus  diverting 
attention  from  the  real  depredators. 

Many  harmless  insects,  which  are  so  frequently  seen  upon  the  orange 
tree  that  they  may  be  considered  its  regular  attendants,  are  to  a  certain 
extent  beneficial,  and  either  feed  upon  the  various  mosses  and  fungi 
which  accumulate  upon  the  trunk  and  branches,  or  upon  the  lifeless 
wood  and  bark  of  dead  portions  of  the  tree. 

IMPORTANCE  OF  DISTINGUISHING  FRIENDS  FROM  FOES. — Although 
little  can  be  done  to  increase  the  efficiency  of  beneficial  insects,  much 
good  can  at  times  be  accomplished  by  refraining  from  interference  with 
their  operations.  The  orange-grower  often  does  injury  to  his  own  in- 
terests through  lack  of  knowledge  in  distinguishing  friends  from  foes, 
and  by  the  indiscriminate  killing  of  all  insects  which  he  finds  upon  his 
trees. 


8  INSECTS    AFFECTING*1  THE    ORANGE. 

Horticulturists  cannot  be  expected  to  acquire  a  technical  knowledge 
of  insects  attainable  only  by  specialists,  but  the  entomologist  can  offer 
in  many  cases  practical  suggestions  to  aid  in  protecting  the  beneficial 
while  accomplishing  the  destruction  of  the  injurious  species.  In  these 
pages,  wherever  our  present  knowledge  permits,  the  ways  and  means  of 
securing  this  advantage  will  be  indicated,  and  it  is  hoped,  by  the  aid  of 
plain  descriptions  and  figures,  to  render  recognizable  to  the  orange- 
grower  some  of  the  more  important  beneficial  insects  with  which  he  is 
concerned,  as  well  as  the  destructive  kinds  with  which  he  must  con- 
tend. 

PRESENCE  OF  CERTAIN  INJURIOUS  INSECTS  INDICATED  BY  ANTS.— 
Many  of  the  Bark-lice  (Coccida3),  as  well  as  the  common  Plant-louse 
(Aphis)  of  the  Orange  produce  sweetish  secretions,  which  are  greatly 
relished  by  ants ;  indeed,  with  some  species,  the  honey-dew  ejected  by 
these  insects  appears  to  furnish  the  greater  part  of  their  food.  At  all 
events,  whenever  any  of  these  nectar-giving  insects  exist  upon  an  orange 
tree,  ants  will  be  found  in  attendance  upon  them,  and  a  stream  of  ants 
ascending  and  descending  the  trunk  of  the  tree  is  an  infallible  indica- 
tion of  their  presence. 

The  ascending  line  of  ants  readily  guides  the  eye  to  the  spot  among 
the  twigs  and  leaves  where  these  enemies  lie  concealed,  and  they  are 
especially  useful  in  indicating  the  whereabouts  of  incipient  colonies, 
which  may  thus  be  destroyed  before  they  have  greatly  increased,  and  by 
their  numbers  and  the  extent  of  their  injuries  have  forced  themselves 
upon  our  notice. 

Young  orange  trees  are  particularly  liable  to  suffer  injury  from  Aphis 
and  the  soft-bodied,  nectar-producing  CoccidaB.  In  the  nursery,  where 
the  greatest  attention  should  be  given  to  prevent  stunting  and  loss  of 
growth,  we  may  pass  rapidly  along  the  rows,  and  by  the  presence  of 
ants  upon  the  stocks  detect  at  a  glance  those  plants  upon  which  the 
pests  have  obtained  a  foothold. 

SYSTEMS  OF  CULTIVATION. 

INFLUENCE  OF  SHADE  UPON  THE  INCREASE  OF  INSECT  PESTS.— 
Most  insects  love  shade.  Some,  and  among  the  number  Scale-insects, 
the  worst  pests  of  the  Orange,  prefer  the  darkness  and  dampness  pro- 
duced by  dense  masses  of  foliage.  Plants,  on  the  other  hand,  require 
light  and  air,  for  want  of  which  the  inner  branches  pine  and  lose  vital- 
ity, a  condition  which  also  greatly  favors  the  reproduction  of  Scale-in- 
sects. 

The  good  advice  of  the  horticulturist,  a  Prune  back  excessive  branch 
growth,  give  and  keep  an  open  head  to  the  tree,"  may  be  supplemented 
and  sustained  by  that  of  the  entomologist,  "Let  in  light  and  air."  Let 
this  not,  however,  be  construed  as  indorsing  the  practice  of  trimming 
high  the  trunks,  and  depriving  them  of  their  spreading  lower  branches, 


SYSTEMS    OF    CULTIVATION.  9 

their  best  and  most  natural  protection  against  extremes  of  heat  and 
cold. 

CLEAN  CULTURE  OB  MULCHING  PREFERABLE  TO  CROPPING  YOUNG 
GROVES. — The  practice  of  planting  crops  between  the  rows  of  young 
orange  trees  is  not  without  certain  evil  consequences  in  attracting  dep- 
redators. Many  of  these  do  indirect  damage  only.  Cotton,  for  instance, 
is  attacked  by  the  Cotton  Worm  (Aletia  xylina)  which,  after  stripping 
•the  cotton  plants  of  their  leaves,  gather  upon  the  orange  trees  and  make 
their  cocoons  between  the  leaves.  The  orange  trees  are  fouled  with 
their  webs  and  tangles,  which  foster  Scale-insects. 

A  very  appreciable  amount  of  damage  is  always  inflicted  by  locusts  or 
grasshoppers  (AcrididaB)  when  succulent  plants,  like  Cotton  or  Cow  Pea, 
are  planted  in  young  groves;  and  when  the  system  of  allowing  weeds 
to  grow  about  the  trees  is  pursued,  the  loss  of  growth  from  these  in- 
sects is  sometimes  very  serious.  Older  trees  do  not  greatly  suffer,  and 
are,  moreover,  able  to  spare  a  portion  of  their  foliage ;  but  very  young 
trees  when  surrounded  by  weeds  are  more  or  less  defoliated  and  checked 
in  growth.  The  tops  of  young  trees  being  small  and  low  their  leaders 
and  tender  shoots  are  gnawed  and  destroyed  as  fast  as  they  appear, 
and  most  of  the  summer  growth  may  thus  be  lost. 

Objection  is  sometimes  made  to  mulching  orange  trees  with  leaves  or 
vegetable  refuse,  on  the  ground  that  the  mulch  attracts  and  harbors 
insects.  Most  of  the  insects  which  lurk  in  such  places,  however,  are 
predaceous  species,  and  may  be  considered  either  harmless  or  beneficial. 
Very  few  of  them  are  injurious  to  the  orange  tree. 

White  ants  (Termites)  must  be  considered  an  exception  to  this  rule. 
They  are  attracted  by  decaying  vegetable  matter,  especially  by  dead 
wood,  and  sometimes  attack  the  living  tree  at  or  beneath  the  surface  of 
the  ground.  To  avoid  attracting  such  dangerous  neighbors  care  should 
be  had  in  mulching  to  leave  the  crown  of  the  tree  uncovered  and  ex- 
posed to  the  light  and  air.  It  is  also  best  to  exclude  from  the  mulch 
all  solid  masses  of  wood  material,  such  as  chips  and  branches. 

It  is  to  be  noted  in  regard  to  the  common  practice  of  scattering  in  the 
grove  and  about  the  trees  bits  of  wood,  bark,  branches  or  logs,  and  al- 
lowing them  to  decay  upon  the  ground,  that  the  danger  from  this  sys- 
tem of  fertilizing  is  not  always  immediate,  but  consists  rather  in  attract- 
ing termites  and  inducing  them  to  establish  colonies  in  the  vicinity  of 
the  trees,  which  may  indeed  escape  injury  while  an  abundant  supply  of 
dead  wood  remains,  but  are  liable  to  be  attacked  if  this  should  become 
dry  or  partially  exhausted. 

SEASONS  OF  GREATEST  INSECT  ACTIVITY. — Although  in  Florida  some 
insects  breed  continuously  throughout  the  year,  there  is  a  very  general 
winter  rest  from  November  or  December  to  January  or  February,  ac- 
cording to  the  severity  of  the  season.  The  awakening  in  spring  is 
gradual  and  not  sudden  as  at  the  North. 

In  February  most  of  the  species  of  insects  injurious  to  the  Orange 


10  INSECTS   AFFECTING   THE    ORANGE. 

make  their  appearance,  and  in  May  and  June  attain  their  greatest  ac- 
tivity. 

Daring  July  and  August  there  is  a  marked  lull  in  the  insect  world. 
Many  forms  disappear,  to  return  again  in  September. 

The  most  effective  time  to  wage  a  war  of  extermination  against  insect 
pests  can  only  be  determined  satisfactorily  by  a  special  study  of  each  case, 
but,  if  a  general  rule  be  required,  June  and  September  may  be  indicated 
as  the  months  in  which  especial  efforts  should  be  made  to  rid  the  grovel 
of  insect  enemies.  For  fighting  Scale-insects,  however,  the  month  of 
March  or  April,  if  the  season  be  a  late  one,  will  be  found  the  best  in  all 
the  year. 


I. 


COCCID./E. 


[SCALE-INSECTS    OR    BARK  LICE.] 


11 


CHAPTER  I. 

CHARACTERS  OF  THE  COCCID^B  AND  COMMENCEMENT  OF 
THE  CONSIDERATION  OF  THE  SUBFAMILY  DIASPIN^E. 

GENERAL  CHARACTERS   OF  THE  COCCID^  AND  THEIR  RELATIONS  TO 

OTHER   INSECTS. 

The  Scale-insects  or  Bark-lice,  as  they  are  more  comprehensively 
called,  constitute  a  striking  group  of  insects,  remarkable  for  the  pecu- 
liarities of  their  development.  In  this  family  the  females  never  pro- 
gress to  the  winged  state ;  on  the  contrary,  in  many  of  the  species,  after 
a  short  larval  period,  they  undergo  a  change  of  form,  and  retrograde, 
becoming,  when  adult,  mere  living  egg-sacks,  with  organs  only  of  the 
simplest  sorts,  such  as  are  needed  for  reproducing  their  kind,  and  to 
support  a  degraded,  almost  plant-like  existence. 

The  males,  on  the  other  hand,  advance  further  and  pass  through  the 
usual  metamorphoses  of  insects,  finally  appearing  as  winged  insects. 
They  differ,  however,  from  other  insects  of  the  order  Homoptera  in  pos 
sessing  but  one  pair  of  wings;  the  hind  pair  (halteres)  being  aborted, 
and  reduced  to  stumps,  which  are  provided  with  a  hook  that  grapples 
the  fore- wing,  and  apparently  aids  in  steadying  or  directing  flight.  The 
existence  of  the  male  after  reaching  the  adult  state  is  fleeting ;  he  seeks 
out  and  impregnates  one  or  more  females  of  his  kind,  and  then  dies, 
living  at  most  a  day  or  two,  and  taking  in  the  mean  time  no  food.  In- 
deed, in  this  final  stage  the  insect  is  entirely  unprovided  with  mouth 
organs  or  digestive  apparatus  of  any  sort. 

Bark-lice  commonly  excrete  a  covering,  which  may  be  of  a  horny, 
resinous,  waxy,  or  powdery  nature.  Some  of  these  coverings  afford 
products  of  use  in  the  arts;  the  white  wax  of  commerce  and  lac,  from 
which  shell  lac  is  formed,  are  substances  of  this  sort.  The  dried -up 
bodies  of  certain  other  species  yield  purple  or  red  dyes,  of  which  the 
best  known  in  modern  times  is  cochineal.  Many  of  the  species,  and 
especially  the  naked  kinds,  eject  honey-dew,  a  sweetish  liquid,  which 
is  greedily  lapped  up  by  ants,  bees,  wasps,  and  many  other  insects.  A 
sort  of  solidified  honey-dew,  called  "  manna,"  is  produced  by  a  Bark- 
louse  (Gossyparia  mannipara  Ehrenberg);  it  collects  in  considerable 
quantities  upon  the  tamarix  trees  in  Arabia,  and  is  thought  by  some  to 
have  been  the  heaven-sent  manna  that  nourished  the  Hebrews  in  their 
wanderings.  Even  in  our  day  it  is  given  as  food  to  invalids,  and  has  a 
limited  use  in  pharmacy. 

13 


1 4  INSECTS   AFFECTING   THE  •  ORANGE, 

DIVISION  INTO  SUBFAMILIES. 

The  species  of  Coccidse,  according  to  their  varied  forms  and  the  diverse 
nature  of  their  coverings,  are  divided  into  several  groups  or  subfamilies. 

Three  groups  are  represented  in  the  southern  United  States,  and  em 
brace  all  the  species  doing  injury  to  orange  trees.    The  characters 
given  below  will  suffice  for  the  proper  arrangement  of  the  species  falling 
within  the  scope  of  this  treatise. 

I.  DIASPIN^E. — This  subfamily  embraces  those  species  which  form  a 
thin,  horny  scale,  supplemented  by  the  molted  skins  of  the  insect. 
Example,  the  Long  Scale  of  the  Orange,  Mytilaspis  gloverii. 

II.  LECANIN^E. — The  species  of  this  division  form  no  true  scale ;  they 
are  either  naked  or  covered  with  a  thick  coating  of  waxy  material. 
The  naked  species  have,  however,  toughened  skins,  which,  after  the 
death  of  the  insect,  remain  adhering  to  the  bark,  and  then  somewhat 
resemble  the  scales  of  the  Diaspinae.    Example,  the  Turtle-back  Scale, 
Lecanium  hesperidum. 

III.  COGGING. — This  division  includes  soft-bodied  Bark-lice,  called 
"Mealy-bugs"  because  of  their  loose  coverings  of  white,  fibrous  wax,  in 
the  form  of  a  powder,  or  of  long  and  delicate  plates  and  filaments, 
easily  destroyed  by  a  touch.    Example,  the  common  Mealy-bug,  Dacty- 
lopius  destructor. 

In  the  first  of  these  groups  (Diaspina3)  the  change  from  an  active, 
roving  larva,  possessed  of  legs,  to  a  fixed  and  memberless,  sack-like 
animal,  takes  place  very  soon  after  birth.  The  scale  also  is  a  complete 
and  separate  structure,  permanently  fastened  to  the  bark,  and  large 
enough  to  include  not  only  the  body  of  the  mother  insect,  but  also  her 
eggs. 

In  the  second  group  (Lecaninae)  the  form  of  the  larva  is  retained 
much  longer  than  in  the  first  group,  and  the  insects,  though  very  slug- 
gish in  habit,  do  not  become  absolutely  fixed  upon  the  bark  until  they 
are  distended  with  eggs  or  young.  The  legs  also  are  not  lost,  but 
gradually  become  useless  as  the  insect  increases  in  size,  and  are  finally 
lost  to  sight  under  the  swollen  body. 

In  the  third  group  (Ooccinoa)  the  form  of  the  larva  is  retained  by  the 
females  through  life,  and  is  obscured,  but  not  altered,  by  the  formation 
of  an  egg-sack,  or  by  light  costings  of  wax.*  The  organs  of  locomotion 
are  retained,  and  the  females  in  most  of  the  species  move  about  freely, 
even  after  they  have  begun  to  produce  young. 

Thus  in  structure  and  habits  the  Diaspinse  differ  most  widely  from 
other  insects,  the  Coccinse  least,  while  the  Lecaniua3  hold  in  this  respect 
an  intermediate  position. 

"Except  in  Kermes,  a  genus  with  which  orange-growers  are  not  likely  to  become 
concerned. 


LIFE-HISTORY    OF    THE    ARMORED    SCALES. 


15 


DIASPINJE. 

(THE  ARMORED  SCALES.) 

[Plate  III,  and  Figures  1  and  2.]* 

LIFE-HISTORY  OF  THE  ARMORED  SCALES. 

The  larva. — When  the  young  Bark-louse  first  makes  its  appearance 
from  beneath  the  protecting  scale  of  its  mother,  it  is  a  minute,  oval, 
flattened  creature,  provided  with  all  the  organs  usually  possessed  by 
the  young  of  insects;  namely,  six  legs,  a  pair  of  antennae  in  front  and 


FIG.  1. 

FIG.  1. — 1,  egg — natural  size,  scarcely  Tfoj  inch;  2,  larva  as  it  appears  when  running  over  the  twigs — 
natural  length,  -fa  inch  ;  3,  its  appearance  soon  after  becoming  fixed;  4,  appearance  of  scale  after  the 
second  plate  is  formed  ;  5,  form  of  louse  (ventral  view)  soon  after  losing  its  members;  G,  form  oflonse 
when  full  crown;  7,  fully  formed  scales,  containing  louse,  as  it  appears  from  the  under  side,  when 
raised  ;  8,  highly  magnified  antenna  of  the  larva— by  an  error  eight  joints,  instead  of  seven,  the  cor- 
rect number,  are  shown  in  the  drawing.  (After  Kiley.) 

a  pair  of  bristles  behind,  simple  eyes  on  the  sides  of  the  head,  and  a 
short  sucking  beak. 

At  first  the  young  larva  moves  restlessly 
about,  with  a  lumbering  gait,  by  no  means 
sluggish,  yet  markedly  less  rapid  than  that 
of  the  minute  and  active  mites  which  are 
often  found  in  company  with  it.  The  object 
of  its  wanderings  is  simply  to  find  a  suitable 
spot  upon  the  bark  in  which  to  insert  its  suck- 
ing tube  or  beak.  Usually  within  a  few  hours 
after  leaving  the  parent  scale  the  young  Bark- 
louse  has  become  a  fixture  upon  the  surface  of 
the  plant;  the  sucking  mouth-parts,  which 
consist  of  a  bundle  of  four  slender  hairs,  grow 
rapidly  until  they  greatly  exceed  the  body  of 
the  insect  in  length,  and,  penetrating  deeply 
into  the  tissues  of  the  plant,  can  never  after- 


FIG.  2.— a,  terminal  joint  of  the 
female ;  &,  spines  upon  the  border ; 
c,  excretory  pores ;  d,  pregnant  fe- 
male ;  e,  structure  ot  proboscis, 
showing  four  components;  /.  excre- 
tory scale,  showing  successive  lay- 
ers; <7,  second,  or  medial,  scale;  A, 
larval,  or  first  scale.  ( After  Kiley.) 


^Figures  1  and  2  illustrate  the  mode  of  growth  in  Mytllaspis  pomorum  Bouche", 
the  Oyster-shell  Bark-louse  of  the  Apple.  They  are  reproduced  from  the  First  and 
Fifth  Missouri  Entomological  Reports  (1868  and  1872),  in  which  the  facts  essential  to 
a  complete  knowledge  of  the  life-history  of  Diaspinous  Scale-insects  are  fully  set 
forth  by  Prof.  C.  V,  Riley. 


16  IJS SECTS    AFFECTING    THE    ORANGE. 

wards  be  removed  by  the  Coccid,  but  firmly  anchor  it  in  place.  When 
pulled  by  force  from  the  bark  these  long  bristles  separate  and  curl  up, 
and  the  insect  is  powerless  to  reinsert  them  or  to  again  attach  itself  to 
the  plant,  and  must  inevitably  die  of  starvation. 

As  soon  as  the  young  Bark-louse  begins  to  feed  upon  the  juices  of  the 
plant  excretions  of  wax  commence  to  exude  from  its  body.  There  first 
appear  along  the  sides  and  at  the  end  of  the  body  long  curled  threads 
of  white  wax.  These  form  a  tangled  mass,  enveloping  the  insect ;  but 
this  first  covering  is  very  delicate,  and  after  a  time  it  partially  or  en- 
tirely disappears,  owing  to  the  action  of  the  weather.  It  is  succeeded 
by  a  covering  formed  in  a  similar  manner,  but  of  denser  texture.  This 
second  covering  is  more  persistent;  it  is  in  fact  the  beginning  of  the 
permanent  scale. 

For  two  or  three  weeks  after  the  formation  of  the  infantile  scale  is 
completed  the  external  appearance  of  the  insect  does  not  change,  butv 
within  a  new  body  gradually  forms  and  separates  from  the  larva  skin 
until  the  latter  becomes  a  loosened  envelope,  from  which  finally  the 
new-formed  insect  entirely  withdraws  its  body,  passing  through  a  split 
in  the  under  side.  "The  molted  skin  is  not  abandoned,  however,  but 
remains,  partly  covering  the  Coccid  above,  and  ultimately  forms  the 
summit  or  the  extremity  of  the  permanent  scale. 

With  the  old  larva  skin  are  cast  off  the  now  useless  members  of  the 
larva,  and  the  insect  takes  the  form  of  a  fleshy  sack  of  very  simple  con 
struction.  The  joints  of  the  body  are  indicated  by  fleshy  folds,  and  the 
hair-like  mouth-tube  projects  from  the  under  side  near  one  end  of  the 
body.  The  thin  outer  edge  of  the  last  or  anal  joint  of  the  body  is  fur- 
nished with  minute,  horny  lobes  and  spines,  and  its  upper  and  lower 
surfaces  present  numerous  pores,  through  which  flows  a  viscid  liquid, 
the  material  which  on  hardening  forms  the  protecting  scale.  On  the 
under  side  of  the  last  joint  can  also  be  plainly  seen  the  vaginal  opening, 
through' which  pass  the  eggs  or  young. 

Immediately  after  molting  the  body  of  the  Coccid  expands,  so  that 
•  it  can  no  longer  be  entirely  covered  by  the  cast  skin  of  the  larva,  and  a 
portion  of  the  broad  terminal  joint  projects  beyond  its  'edge  ;  but  the 
exposed  parts  are  soon  flooded  with  a  glutinous  fluid,  issuing  from  the 
pores  that  stud  its  surface,  and  this  in  a  few  minutes  hardens,  and 
forms  an  extension  of  the  covering. 

During  the  growth  of  the  insect  which  follows  the  molting  of  the 
larva  skin,  the  scale  covering  receives  repeated  additions  of  these  thin 
Iamina3,  each  of  which  underlies  and  projects  slightly  beyond  the  pre- 
ceding layer,  and  the  scale  constantly  increases  in  size  and  in  solidity  ; 
while  at  all  times  the  outer  edge  remains  the  thinnest,  and  therefore 
the  most  vulnerable  point.  Thus  the  process  of  growth  at  this  stage  is 
seen  to  be  analogous  to  that  of  snails  or  oysters,  which  form  their  shells 
in  an  exactly  similar  manner. 

A  considerable  interval  having  elapsed  after  the  first  molt,  the  fe- 


LIFE-HISTORY    OF    THE    ARMORED    SCALES.  17 

males  agaiu  cast  their  skins ;  but  their  form  at  this  time  remains  un- 
changed. The  second  skin  like  the  first  remains  in  place  and  forms  a 
part  of  the  scale ;  it  is,  however,  less  distinctly  visible  than  the  first 
larval  skin,  being-  covered  with  more  or  less  of  the  thick  excreted  ma- 
terial. 

Soon  after  the  second  molt  the  females  are  impregnated  by  the 
males.  From  this  time  until  the  scales  reach  their  full  size  their  growth 
is  very  rapid.  In  the  linear  scales  (Mytilaspis)  the  females  not  only 
increase  in  size  as  their  bodies  become  distended  with  eggs,  but  they 
also  shift  somewhat  their  position  under  the  scale,  so  that  finally,  at  the 
smaller  end,  that  portion  which  lies  immediately  under  the  molted  skins 
is  left  vacant.  To  permit  this  movement  sufficient  slack  is  given  the 
flexible  sucking  tube  between  its  junction  with  the  body  and  the  point 
at  which  it  enters  the  bark. 

The  eggs  are  now  laid  under  the  scale,  beginning  at  the  outer  edge. 
As  they  are  deposited,  the  body  of  the  female  shrinks,  and  gradually 
retreats  to  its  former  position,  leaving  the  outer  portion  of  the  scale 
filled  with  eggs.  When  all  her  qggs  are  laid  the  depleted  female  shrivels 
and  dries  up,  and  life  in  her  exhausted  body  gradually  becomes  ex- 
tinct. 

The  Males. — As  crawling  larvae,  and  during  the  time  that  their  scales 
are  forming,  the  males  are  indistinguishable  from  the  females ;  but 
after  the  first  molt  differences  begin  to  appear,  and  the  scales  of  the 
males  become  recognizable  by  their  form  or  color,  although  the  insects 
themselves  are  not  markedly  different  until  after  the  second  molt. 

Shortly  before  the  second  molt  of  the  females  the  males  also  cast 
their  skins  a  second  time,  and  in  so  doing  change  to  the  pupa  state.  In 
the  pupa,  the  legs,  wings,  and  other  parts  of  the  perfect  insect  are  grad- 
ually formed  under  a  mask-like  skin,  in  which  the  new  form  is  obscurely 
outlined. 

At  the  second  molt  the  male  ejects  the  skin  from  its  scale,  while  in 
the  female  it  remains  and  forms  a  part  of  the  scale  itself.  In  the  male 
growth  ceases  with  this  molt ;  but  the  scale  of  the  female  is  at  this 
stage  less  than  half  its  full  size;  the  male  scale  is  therefore  much 
smaller  and  thinner  than  that  of  the  other  sex,  and  the  first  larva  skin, 
but  not  the  second,  forms  part  of  its  structure. 

After  remaining  a  week  or  sometimes  less  in  the  pupa  state  the  pupal 
envelope  is  rent  and  torn  from  its  limbs  by  the  perfect  insect.  This  oper- 
ation takes  place  under  the  scale,  and  the  winged  fly  leaves  its  shelter 
only  after  a  rest  of  several  hours,  which,  indeed,  may  be  prolonged  into 
days  if  the  weather  does  not  happen  to  be  propitious.  The  exit  of  the 
fly  is  made  by  pushing  up  a  portion  of  the  outer  edge  of  the  scale.  In 
the  elongate  scales  of  Mytilaspis,  the  escape  of  the  male  is  facilitated 
by  a  thin  joint  in  the  scale,  which  permits  the  broad  end  to  be  lifted  as 
a  flap.  The  body  of  the  male  terminates  in  a  spine-shaped  organ,  by 
(J521  o  I -2 


18  INSECTS    AFFECTING   TH&    ORANGE. 

means  of  which  it  is  enabled  to  reach  and  fertilize  the  females  under 
their  scales. 

Prof.  J.  H.  Comstock,  whose  minute  and  exhaustive  study  of  the  life- 
histories  of  certain  of  our  common  Scale-insects  has  left  little  to  be  added 
by  subsequent  observers,  has  pointed  out  that  the  lives  of  these  insects 
are  divided  by  their  metamorphoses  into  nearly  equal  intervals.  In 
the  words  of  this  author,  "  the  three  intervals  between  the  birth  of  the 
female  and  the  first  molt,  between  the  latter  and  the  second  molt,  and 
between  this  and  the  beginning  of  ovipositiou  are  about  equal."*  The 
first  molt  in  the  male,  and  also  its  second  molt,  or  entrance  into  pupa, 
take  place  at  nearly  the  same  time  with  the  molts  of  the  female.  The 
existence  of  the  male,  however,  terminates  before  the  completion  of  the 
third  interval  by  the  female. 

The  interval  in  which  the  eggs  are  laid  and  hatched,  and  the  young 
larvae  desert  the  parent  scale,  is  about  equal  to  the  preceding  inter- 
vals. This  fourth  period  completes  the  cycle  of  development,  and  its 
close  witnesses  the  death  of  the  female,  following  the  departure  of  her 
progeny. 

During  the  spring  and  early  summer,  in  the  laboratory  at  Washing- 
ton, twenty  days  appears  to  have  been  the  mean  duration  of  each  in- 
terval $  ill  the  open  air  in  Florida  there  is  considerable  acceleration,  due 
to  the  warmer  climate.  This  is  apparent  especially  in  the  later  stages 
of  development,  which  are  greatly  shortened  in  summer.  The  first 
molt  usually  takes  place  within  twenty  days  after  hatching,  but  this 
first  period,  although  more  constant  than  the  following,  varies  with  the 
eeason  or  in  different  species,  from  sixteen  to  twenty -four  days.  The 
whole  cycle,  or  brood  period  in  winter,  may  cover  three  months,  but  in 
summer,  it  is  reduced  to  five  or  six  weeks. 

Nature  of  the  scale  covering. — As  was  first  clearly  pointed  out  by 
Prof.  C.  V.  Riley  (see  Fifth  Missouri  Entomological  Eeport,  p.  80)  the 
scale  of  the  Diaspina3  is  a  shield-like  structure,  covering  the  in- 
sect above,  and  wholly  or  partially  protecting  it  beneath.  It  is  con 
structed,  as  we  have  seen,  in  part  of  tbe  molted  skins  of  the  insect,  but 
mainly  of  a  horny  excretion,  covering  or  surrounding  the  latter,  and  de- 
posited by  the  Ooccid  in  numerous  fine,  overlapping  layers.  The  under 
layer  is  thinner,  and,  although  perhaps  a  separate  piece,  is  firmly  united 
to  the  upper  scale  at  the  edges,  so  that  the  latter  appear  to  be  turned 
under  at  the  sides.  In  the  long  scales  the  ventral  plate  consists  of  a 
flange  along  each  side,  leaving  in  the  middle  an  open  crevice;  but  in 
the  oval  or  circular  scales  it  forms  an  unbroken  shield,  which  entirely 
separates  the  body  of  the  insect  from  contact  with  the  bark. 

The  scale  js  permanently  fastened  upon  the  tree,  and  so  closely  molded 
to  its  surface  that  the  pores  of  the  bark  or  the  stomataof  the  leaf  are 
seen  plainly  stamped  upon  it  when  removed. 

The  materials  of  which  the  scale  is  constructed  are  very  indestructi- 

*  Report  of  Commissioner  of  Agriculture  for  1880,  p.  280. 


THE    LOWG    SCALE    OF    THE    ORANGE.  19 

ble,  and  well  serve  to  protect  the  helpless  organism  which  they  sur- 
round, both  from  the  action  of  the  weather  and  the  attacks  of  exter- 
nal enemies.  The  molted  skins  consist  of  chitine,  a  substance  which 
forms  the  hard  external  parts  of  nearly  all  insects,  and  the  excreted 
portion  of  the  scale  is  composed  of  a  sort  of  hardened  wax,  having  the 
toughness  of  horn. 

The  upper  scale  is  therefore  impervious  to  most  liquids,  and  is  not 
soluble  in  acid  or  alkaline  solutions  strong  enough  to  injure  the  plant. 
It  resists  the  action  of  oils  and  of  bisulphide  of  carbon,  an  almost  uni- 
versal solvent.  Many  insecticides  are  therefore  inoperative,  and  all  in- 
soluble substances,  such  as  sulphur,  etc.,  are  clearly  useless,  as  they  do 
not  reach  the  eggs  or  mature  insects.  The  thinner,  ventral  scale  is  not 
impervious  to  the  more  volatile  oils  or  to  alcoholic  solutions,  some  of 
which  reach  and  kill  the  insect  by  penetration  through  the  bark. 

As  the  scale,  like  the  shell  of  the  snail,  is  formed  by  successive  addi- 
tions, and  keeps  pace  in  its  growth  with  that  of  the  body  of  the  insect 
within,  its  vulnerable  point  is  the  growing  end,  and  there  are  times  dur- 
ing its  formation  when  the  posterior  extremity  of  the  insect  projects 
slightly  beyond  it  and  becomes  exposed  to  the  action  of  penetrating 
liquids.  This  is  particularly  the  case  at  the  critical  periods  when  the 
Coccid  sheds  its  skin.  But  when  the  scale  is  fully  completed  and  tightly 
sealed  at  all  points,  no  insect  is  more  difficult  to  reach  and  to  destroy. 

LONG  SCALE. 

(Mytilaspis  gloverii,  Packard.) 

• 

[Plate  III,  fig.  2;  1Y;  and  Fig.  3.] 

Growth  of  the  Scale. — In  the  Long  Scale  the  increase  in  size  takes  place 
chiefly  in  one  direction,  producing  a  linear  body,  which  may  be  either 
straight  or  curved  in  the  form  of  a  cornucopia.  The  first  molt  or  cast 
skin  of  the  wandering  larva  forms  its  extreme  tip,  but  the  delicate  film 
of  wax  which  at  first  covered  this  skin  disappears,  or  leaves  traces  only 
in  the  form  of  two  minute  projections,  and  its  surface  exhibits  more  or 
less  plainly  marked  indications  of  the  body -joints  of  the  young  louse. 
Beyond,  and  partly  underlying  the  shield-shaped  first  larva  skin,  is  that 
of  the  second  molt,  but  this  skin  is  overlaid  and  imbedded  in  the  sub- 
stance of  the  scale,  so  that  its  oval  outline  is  faintly  visible  beneath 
the  coating  of  horn.  The  scale  increases  in  width  during  the  first  half 
of  its  growth,  after  which  the  width  remains  the  same  and  the  sides  are 
parallel.  ' 

The  plate  which  forms  the  underside  is  firmly  united  to  the  upper  por- 
tion of  the  scale,  and  projects  beyond  it  on  the  sides,  forming  thin 
flanges,  that  greatly  increase  the  tenacity  of  its  hold  upon  the  bark. 
The  ventral  plate  does  not  entirely  cover  the  under  surface,  but  is  di- 
vided in  the  middle,  leaving  a  long,  narrow  slit,  through  which  the  body 
of  the  insect  comes  in  contact  with  the  bark. 


20  INSECTS    AFFECTING    THE    ORANGE. 

The  Scale  of  the  Female  is  brownish,  about  3mm  (ffe  inch)  in  length,  and 
less  than  one-fourth  as  wide;  there  is,  however,  great  variation  in  size, 
and  dwarfed  or  malformed  scales  are  numerous.  When  crowded  the 
scales  are  apt  to  be  warped  and  curved,  although  normally  they  are 
straight. 

The  Scale  of  the  Male  is  much  smaller  than  that  of  the  female,  quite 
uniformly  lmm  (Y§-O-  inch)  in  length,  and  very  seldom  curved. 

The  colors,  varying  shades  of  brown,  are  lighter,  and  incline  to  yel- 
low in  the  males  and  young,  but  become  dark  mahogany-brown  in  the 
older  females.  The  brighter  color  of  the  forming  scales  gives  warning 
of  the  increase  of  the  pest,  and  to  a  practiced  eye  discloses  the  age  and 
progress  of  the  brood,  even  when  scattered  or  mingled  with  the  debris 
of  former  broods. 

In  the  aggregate,  the  scales,  when  densely  clustered,  have  a  reddish 
hue,  which  has  caused  this  species  to  be  known  in  some  localities  as  the 
<<  Bed  Scale." 

Female  Coccid. — The  body  is  an  elongate,  flattened  sack,  rounded  at 
the  extremities  and  divided  into  segments  or  joints.  The  posterior 
segment  is  bordered  with  spines  and  plates  of  microscopic  fineness.  Dur- 
ing the  growth  of  the  insect  this  segment  is  the  widest  portion  of  the 
body,  and  upon  its  surface,  as  upon  a  trowel,  are  laid  the  successive 
additions  to  the  scale.  After  impregnation  it  loses  its  prominence, 
through  the  swelling  of  the  intermediate  joints  of  the  body. 

The  young  and  growing  females  are  translucent,  waxy  white,  with 
the  thin  outer  edge  of  the  last  joint  yellowish  (chitinous).  As  they  grow 
olde"r,  they  are  tinged  with  amethyst,  and  toward  the  end  of  their  lives 
become  dark  purple  in  color. 

The  adult  female  is  1.3mm  (&$  inch)  in  length.  Its  sucking  beak  con- 
siderably exceeds  the  body  in  length.  The  structural  details  are  given 
in  the  Report  of  the  Commissioner  of  Agriculture  for  1880,  page  323. 

Male  Coccid. — The  male  is  a  minute  fly,  T^  inch  in  length.    Its  body  is 


JFlG.  Z.—Mytilaspix  gloverii  (Pack.),  male.     (A  fter  Comstock.) 

pale  pink  in  color,  and  three  or  four  times  as  long  as  wide.    The  differ- 
ent joints  *of  which  it  is  composed  are  very  closely  united,  but  are  indi- 


THE    LONG    SCALE    OF    THE    ORANGE.  21 

cated  upon  the  naked  surface  by  a  variety  of  Hues,  some  of  which  in- 
close shield-shaped  plates.  Toward  the  head  these  plates  are  small  and 
more  or  less. triangular;  upon  the  middle  portion,  to  which  the  \fmgs 
are  attached,  they  are  large  and  with  rounded  sides.  The  abdominal 
extremity  is  divided  into  short,  transverse  joints. 

The  head  is  small,  and  bears  upon  its  apex  a  pair  of  rather  heavy, 
many-jointed  antennae,  equal  to  the  body  in  length,  and  clothed  with 
short  hairs.  The  rnouth-organs  are  wanting,  but  in  their  place  are  seen 
black  dots,  which  are  said  to  be  supplementary  eyes.  The  true  eyes 
are  also  black  in  color,  and  are  visible  on  the  sides  of  the  head. 

The  front  pair  of  legs  is  placed  well  forward,  and  a  wide  interval 
separates  it  from  the  second 'and  third  pairs,  which  underlie  the 
abdomen.  The  wings  are  long,  membranous  paddles,  strengthened  by 
a  vein  with  a  single  branch,  and  supported  by  the  aborted  hind  wings, 
or  balancers,  as  they  are  called.  The  latter  are  minute,  and  terminate 
in  a  hook  which  grapples  a  pocket  in  the  front  wing.  Although  quite 
large,  the  wings  and  also  the  legs  are  weak  and  rather  imperfect  organs 
of  locomotion,  and  the  insect's  powers  of  flight  are  not  good.  The  sex- 
ual organs,  on  the  other  hand,  are  well  developed,  and  consist  exter- 
nally of  a  long,  stout  spine  or  style  at  the  end  of  the  body. 

Eggs. — The  eggs  are  elongate- oval.  The  first  laid  are  white;  those 
laid  later  are  tinged  with  purple.  All  become  purple  before  hatching. 

Young  Coccid. — The  newly-hatched  larva  is  sometimes  white,  but  usu- 
ally more  or  less  tinged  and  mottled  with  purple.  It  is  oval  and  flat- 
tened, and  does  not  exceed  T^Q  of  an  inch  in  length.  The  body  is 
divided  into  a  number  of  unequal  joints ;  the  first  of  these  constitutes 
the  head,  and  bears  a  pair  of  short  antenna,  provided  with  bristles; 
minute  eyes,  widely  separated,  on  each  margin,  and  mouth-organs  be- 
neath united  to  form  a  sucking  beak.  The  body  terminates  in  two 
bristles  of  extreme  fineness,  which  bend  downwards,  and  are  dragged 
after  the  insect  as  it  walks. 

Life-history. — The  development  and  formation  of  the  scale  in  the 
Diaspinse  has  already  been  described.  The  history  of  the  Long  Scale 
presents  few  peculiarities.  The  newly-hatched  larva  wanders  about  for 
a  very  short  time.  As  soon  as  it  has  settled  upon  the  bark  it  begins 
to  emit  along  its  sides  threads  of  wax.  which  in  a  few  days  form  a  white 
film,  and  gradually  cover  the  body,  beginning  from  behind  and  ending 
in  front  in  two  short,  horn-like  projections.  Some  of  the  threads  stand 
out  from  the  rest ;  being  long  and  curly,  they  are  fragile  and  easily 
broken  by  the  wind,  but  in  calm  weather  they  sometimes  accumulate, 
•and  form  cottony  tufts  or  tangles. 

This  first  covering  is  evanescent,  but  traces  of  it  remain  in  the  horn- 
like projections  on  the  sides  of  the  head. 

The  casting  off  of  the  larva  skin,  or  first  molt,  takes  place  eighteen  or 
twenty  days  after  birth,  and  immediately  after  this  the  formation  of  the 
true  scale  is  begun.  The  first  layers  of  horn  are  united  to  the  hinder 


22  INSECTS   AFFECTING   THE    ORANGE. 

end  of  the  larva  skin,  and  partly  underlie  it.  They  are  thin  and  trans- 
parent, but  as  each  successive  layer  adds  to  their  thickness,  they  de- 
velop a  yellow  color,  which  darkens  at  length  to  brown. 

In  the  new  form  assumed  by  the  insect  after  the  molt  the  hinder  end 
is  broadly  dilated,  and  as  this  portion  of  the  body  forms  and  determines 
the  width  of  the  scale,  the  latter  for  awhile  increases  in  width  as  it 
grows  in  length.  After  the  second  molt  in  the  female  the  extremity  of 
the  body  ceases  to  grow  in  width,  and  the  portion  of  the  scale  formed 
after  this  molt  is  linear,  i.  e.,  has  the  sides  parallel. 

The  second  molt  of  the  female  occurs  at  the  age  of  six  or  seven  weeks. 
The  male  molts  and  changes  to  pupa  a  week  or  ten  days  earlier,  and  as 
the  time  required  for  this  transition  period  is  quite  short,  during  the 
time  that  the  females  are  casting  their  skins  many  of  the  males  com- 
plete their  transformations  and  issue  from  their  scales  as  winged  flies. 

After  the  second  molt  the  scale  of  the  female  continues  to  grow,  and 
more  than  doubles  its  length,  but  increases  little  in  width. 

In  nine  or  ten  weeks  from  her  birth  the  female  begins  to  deposit  eggs. 
At  this  time  her  body,  although  greatly  elongated  and  distended  with 
ova,  does  not  entirely  fill  the  scale  ;  a  space  equal  to  about  one-quarter 
of  its  entire  length  is  left  vacant  at  the  upper  or  narrow  end.  The 
female  is  able,  by  means  of  the  serrated  edges  of  her  body,  to  make  a 
slight  forward  and  backward  movement  within  this  vacant  space. 

The  eggs  are  laid  in  two  rows,  and  are  placed  obliquely,  the  eggs  of 
one  row  alternating  and  interlocking  at  the  ends  with  those  of  the  other. 
The  number  of  eggs  laid  by  a  single  female  varies  greatly,  but  rarely 
exceeds  thirty.  The  deposition  of  her  eggs  occupies  the  female  from 
one  to  three  weeks,  according  to  the  season.  The  eggs  hatch  within 
one  week,  unless  retarded  by  cold  weather.  The  first  laid,  those  at  the 
outer  end,  are  the  first  to  hatch,  but  the  young  lice  usually  remain 
several  days  under  the  parent  scale.  The  egg-shells  are  left  in  place  in 
the  scale,  but  their  arrangement  is  somewhat  disturbed  by  the  move- 
ments of  the  latest  hatched  young  in  making  their  escape. 

The  female  after  depositing  all  her  eggs  is  much  shrunken,  and  be- 
comes very  dark  purple  in  color.  The  end  of  her  existence  is  passed  in 
that  portion  of  the  scale  which  she  occupied  at  the  time  of  the  last 
molt. 

Brood  Periods. — There  are  at  least  three  and  sometimes  four  genera- 
tions of  Long  Scale  daring  the  year,  but  the  division  into  separate 
broods  is  not  as  distinct  and  clearly  defined  as  with  many  other  in- 
sects. The  open  winters  in  countries  where  the  Orange  is  grown  per- 
mit continuous  breeding  throughout  the  year,  and  at  all  seasons  scales 
in  every  stage  of  development  may  be  found  upon  the  trees. 

Not  only  does  the  time  required  by  the  insect  for  its  development 
vary  greatly  in  different  seasons,  and  under  varying  conditions,  but 
also  individual  insects  in  each  brood  undergo  their  transformations 
at  unequal  intervals,  some  far  outstripping  the  rest  and  others  lagging 


THE    LONG    SCALE    OF    THE    ORANGE  23 

behind.  This  scattering  in  early  broods  confuses  the  succeeding  ones 
and  renders  it  impossible  to  assign  to  each  an  exact  season  or  in- 
variable duration.  But  although  the  limits  of  each  brood  cannot  be 
exactly  defined,  the  general  progress  in  development  may  be  known  at 
any  time  by  the  condition  of  the  majority  of  the  scales. 

Thus  there  are  times  when  the  number  of  migrating  young  reaches  a 
maximum,  and  the  application  of  remedies  then  proves  particularly 
effective. 

Three  such  periods  occur:  The  first  in  spring,  usually  in  March,  but 
sometimes  extending  into  April;  the  second  in  June  or  July;  the  third 
in  September  or  October.  During  the  winter  months,  if  the  season  is 
a  mild  one,  there  is  a  fourth,  very  irregular  brood  beginning  in  January 
and  continuing  through  this  and  the  following  month.  The  spring  brood 
that  follows  is  greatly  confused.  In  cold  and  rainy  winters  the  hatch- 
ing process  is  retarded,  and  the  appearance  of  the  Iarva3  on  the  return 
of  warm  weather  is  more  nearly  simultaneous  than  in  ordinary  seasons. 

Parasites. — Upon  closely  examining  a  branch  or  leaf  infested  with 
scales  of  Mytilaspis  gloverii,  there  will  always  be  found  a  certain  num- 
ber which  have  through  their  upper  surface  a  small,  round  hole.  The 
scales  thus  perforated  are  invariably  females  which  have  not  quite  com- 
pleted their  growth.  They  are  empty  or  occupied  by  mites  or  other  in- 
truders, and  the  only  trace  of  the  original  inhabitant  which  they  con- 
tain is  its  dry,  distended  skin ;  this  is  also  pierced  with  a  round  hole, 
placed  directly  beneath  the  one  in  the  outer  shell. 

These  are  the  exit  holes  of  Hymenopterous  parasites,  the  most  effect- 
ive enemies  of  the  Scale-insect,  and  which,  after  destroying  the  maker 
of  the  scale,  and  after  completing  their  own  transformations  in  its  room, 
have  eaten  their  way  through  its  skin  and  its  shell,  appearing  finally  as 
minute  four-winged  flies,  both  male  and  female. 

The  female  parasite,  when  seeking  to  deposit  her  eggs,  probes  about 
the  edges  of  the  scale  in  order  to  find,  if  possible,  an  open  crevice  through 
which  to  insert  her  slender  ovipositor.  Failing  in  this  she  bores  directly 
through  the  scale,  using  her  ovipositor  as  a  drill,  and  in  this  way  inserts 
within  the  body  of  the  Coccid  a  single  egg. 

The  footless  grub  that  hatches  from  this  egg  lives  within  the  body  of 
the  Scale-insect  and  gradually  consumes  it.  When  nothing  is  left  but 
the  empty  skin  of  its  host  the  little  parasite,  now  swollen  to  an  almost 
globular  form,  transforms  first  to  a  pupa,  and.  then  to  the  perfect  fly, 
which  at  last  makes  its  appearance  through  a  hole  eaten  in  the  walls 
that  surround  it. 

Several  distinct  species  of  these  minute  parasites  attack  the  Long 
Scale.  They  are  about  yf^  inch  in  length,  with  an  expanse  of  wing 
equal  to  nearly  twice  their  length.  The  head  is  large,  with  large  com- 
pound eyes,  and  three  minute  simple  eyes  (ocelli)  like  jewels  set  upon 
its  vertex.  The  body  is  rather  short  and  thick.  The  wings  are  trans- 
parent and  beautifully  iridescent ;  they  are  strengthened  for  a  portion  of 


24  INSECTS   AFFECTING   THE    ORANGE. 

their  length  by  a  stout  .vein,  placed  very  near  the  margin,  and  having  a 
short  spur  or  branch  at  or  near  the  end  of  the  vein.  The  front  wings 
are  broader  outwards  and  rounded  at  the  tips.  The  hind  wings  are  nar- 
row and  more  pointed  at  the  ends.  The  antennas  are  elbowed,  and 
clubbed  at  the  ends ;  they  arise  from  the  anterior  face  of  the  head,  in 
front  of  the  eyes. 

In  Aphelinus  fuscipennis  Howard1,  the  general  color  is  yellow,  with  a 
black  band  across  the  head  behind  the  eyes,  and  several  dusky  bands 
upon  the  body.  The  wings  are  clouded  with  patches  of  smoky  brown. 
Length,  0.6ram  (TJ5  inch). 

Apliycus  flavus  Howard,  is  uniformly  yellow  in  color,  with  clear 
wings.  Length,  1.2mm,  (yfo-  inch). 

Under  the  name  Aphelinus  aspidioticola,  Mr.  Ashmead  (Orange  In- 
sects, page  7)  describes  another  parasite  of  the  Long  Scale,  which  has 
a  reddish  brown  or  dusky  body,  yellowish  legs,  and  clear  wings.  It  is 
T§-^  inch  in  length.  According  to  Mr.  Howard,  this  insect  is  not  an 
Aphelinus,  but  belongs  to  an  unknown  genus  of  another  family. 

These  parasites  attack  the  female  Long  Scale  insect  about  the  time  of 
her  impregnation,  and  their  egg  is  deposited,  not  simply  beneath  the 
scale,  or,  as  some  writers  have  affirmed,  among  the  eggs  of  the  Coccid, 
but  within  the  body  of  the  Coccid  itself.  The  presence  of  the  parasite 
within  her  body  destroys  the  fecundity  of  the  Scale-insect  and  she 
finally  dies  without  reproducing  her  kind. 

So  effective  are  the  attacks  of  these  internal  enemies,  that  not  less 
than  25  per  cent,  of  the  scales  are  destroyed  by  them,  and  at  times  their 
numbers  increase  to  such  an  extent  that  colonies  of  Long  Scale  are 
reduced  almost  to  extermination. 

Observations  made  at  various  seasons  of  the  year  indicate  a  greater 
abundance  of  the  parasites  in  fall  and  winter,  but  they  are  unfailing 
attendants  upon  every  brood  of  the  Scale-insect.  The  result  of  twenty- 
five  detailed  examinations  in  early  spring  gives  an  average  of  76  per 
cent,  of  the  scales  destroyed  by  Hymenopterous  parasites.  Ten  exam- 
inations during  the  summer  months  give  an  average  of  35  per  cent.,  or 
one-half  that  of  spring.  Fifteen  observations  in  autumn  and  the  be- 
ginning of  winter  give  an  average  of  40  per  cent,  of  scales  parasitized. 

The  activity  of  these  insects  is  not  perceptibly  diminished  by  cool 
weather,  which  on  the  other  hand  greatly  retards  the  development  of 
the  Scale  insect.  It  is  not  therefore  surprising  that  three-quarters  of 
the  winter  brood  perish  from  the  attacks  of  these  enemies. 

Geographical  Distribution.  First  appearance  in  the  United  States. — The 
Long  Scale  is  supposed  to  have  originated  in  China,  and  to  have  spread 
tHence  to  the  orange  groves  of  southern  Europe  and  the  United  States. 
According  to  one  authority*  it  made  its  appearance  in  Florida  in  1838 1 


*  Brown's  "  Trees  of  America,"  cited  by  Glover,  Kept.  Commissioner  Patents  for 
1855,  Agriculture,  p.  117.    See  also  Report  for  1858,  p.  266. 
t  Ashmead  (Orange  Insects,  p.  1)  gives  the  date  1835. 


THE    LONG    SCALE    OF    THE    ORANGE.  25 

at  Mandarin,  on  the  Saint  John's  Eiver,  and  was  first  seen  in  the  grove 
of  Mr.  H.  B.  Robinson,  upon  trees  purchased  in  New  York  from  a  ship 
from  China. 

In  1840  it  was  carried  to  Saint  Augustine  on  trees  obtained  at  Man- 
darin, and  spread  rapidly  through  the  groves  of  that  vicinity.  Fifteen 
years  later  the  same  author  records  the  spread  of  the  pest  throughout 
all  the  groves  then  existing  in  the  State,  and  says:  "Most  of  the  culti- 
vated orange  trees  in  Florida  have  also  been  injured  by  them,  their  tops 
and  branches  having  been  generally  destroyed.  Their  roots  and  stems, 
it  is  true,  remain  alive  and  annually  send  forth  young  shoots,  only  to 
share  the  fate  of  their  predecessors." 

The  disastrous  results  of  this  invasion,  which,  twenty-five  years  ago, 
brought  ruin  to  the  orange  industry,  and  seemed  likely  to  end  in  the 
extermination  of  the  Orange  in  this  country,  were  due  no  doubt  to  the 
almost  complete  absence  of  parasites  at  the  first  advent  of  the  Scale- 
insect,  and  for  some  years  after  it  had  obtained  a  foothold.  Glover, 
writing  in  1857  an  account  of  the  ravages  of  this  Scale-insect  in  Florida, 
notes  the  complete  absence  of  parasites,  although  flies  belonging  to  the 
family  of  the  Chalcididce  were  found  to  do  efficient  service  in  destroying 
Bark-lice  of  other  and  indigenous  species.* 

At  the  present  day,  although  this  Scale-insect  is  everywhere  dissemi- 
nated in  the  groves  of  Florida  and  Louisiana,  and  likewise  infests  the 
wild  orange  trees,  however  remote  from  cultivated  plantations,  the  de- 
structive hordes  are  held  in  check  by  the  effective  attacks  of  parasites 
everywhere  accompanying  the  Bark-lice,  and  increasing  with  their  in- 
crease, so  that  no  general  onslaught  of  the  Long  Scale  at  least  is  likely 
ever  again  to  occur  in  this  country,  and  only  local  irruptions  of  the  pest 
need  be  feared. 

*  Report  of  Commissioner  of  Patents  for  1858,  Agriculture. 


CHAPTER  II. 
DIASPIN^E— Continued. 

PURPLE  SCALE. 

(Mytilaspis  citricola,  Packard.) 
[Plate  III,  Fig.  1,  la,  1&,  lc.] 

Scale  of  Female. — The  scale  of  this  species  is  larger  than  that  of  the 
Long  Scale.  Large  females  exceed  3mm  (-££$  inch)  in  length.  The  form 
is  broadly  trumpet-shaped,  increasing  in  width  behind,  sometimes 
curved,  like  a  cornucopia,  but  never  with  the  sides  parallel.  The  sur- 
face is  smooth  and  even  glossy,  and  the  color  varies  with  age  from  light 
to  dark  red-brown  and  purple.  The  molted  larva  skins  are  very  plainly 
indicated;  they  are  browned  by  the  sun  so  as  to  appear  scorched. 

Scale  of  Male. — The  scale  of  the  male  is  less  than  half  as  long  as  that 
of  the  female  (1.4mm  =  yj^  inch);  it  is  also  more  linear  in  shape,  and 
uniformly  dark  purple  in  color.  The  thin  hinge  is  always  indicated  by 
a  line  of  lighter  color  across  the  upper  surface  of  the  scale,  near  the 
outer  end. 

The  purple  color  of  the  male  scales  gives  the  mass  of  scales  in  the 
aggregate  a  characteristic  hue,  which  readily  distinguishes  this  species 
from  all  others  found  upon  the  Orange. 

Female.  —The  insect  within,  as  well  as  its  outer  covering,  has  a 
broader  and  less  linear  form  than  the  Long  Scale.  The  two  species 
also  differ  in  the  number  and  structure  of  the  microscopic  plates  and 
spines,  with  which  the  margins  of  the  last  two  joints  of  the  body  are 
armed.  The  number  of  excreting  pores  and  spinnerets  is  greater  in  M. 
citricola  than  in  M.  gloverii. 

Mature  females  of  the  Purple  Scale  are  1.3mm  (y^  inch)  in  length, 
and  occupy  less  than  half  the  space  within  their  completed  scales.  The 
color  is  white,  tinged  with  yellow  at  the  extremities. 

Male.—  The  male  and  also  its  pupa  are  pale  amethyst  in  color.  The 
perfect  insect  is  about  lmm  (T^  inch)  in  length,  and,  excepting  in  ite 
somewhat  stouter-  form,  hardly  differs  from  the  male  of  the  preceding 
species. 

Egg. — The  eggs  are  pearly  white,  never  amethystine,  0.2mm  (yA^  inch) 
long,  elongate  oval,  often  somewhat  distorted  in  shape  by  crowding. 
They  are  laid  usually  in  four  rows,  but  the  eggs  at  the  outer  end  are 
26 


THE  PURPLE  SCALE  OF  THE  ORANGE.  27 

irregularly  disposed,  and  sometimes  the  whole  arrangement  is  confused. 
The  number  laid  by  a  single  female  greatly  exceeds  that  of  the  Long 
Scale  j  it  varies  from  twenty-five  to  seventy,  with  a  probable  average 
of  forty-five. 

Young  Larva. — The  newly-hatched  young  is  irregularly  oval  in  shape, 
0.3mm  (rto~o  inch)  in  length,  and  of  a  transparent  white  color,  with  a 
tinge  of  yellow  at  the  extremities.  The  antennae  are  stout,  six-jointed. 
The  eyes  are  minute,  and  of  so  fiery  red  a  color  that  they  resemble 
grains  of  cayenne  pepper.  The  two  bristles  at  the  end  of  the  body  are 
almost  invisible  by  reason  of  their  fineness. 

Life-history. — The  metamorphoses  of  this  species  are  exactly  paral- 
leled by  those  of  the  Long  Scale,  and  are  undergone  in  about  the  same 
periods  of  time.  The  broods  of  one  species  are  sometimes  in  advance  and 
at  other  times  slightly  behind  those  of  the  other. 

Habitat. — Like  the  Long  Scale,  this  species  is  found  upon  the  twigs 
and  branches,  but  has  a  somewhat  stronger  tendency  to  overrun  the 
leaves  and  fruit.  It  is  apt  to  infest  the  Lemon,  Citron,  and  those  varie- 
ties of  Orange  which  have  large  oil  cells  (Tangerine,  etc.).  Although  it 
is  most  at  home  upon  the  Orange  and  its  kind,  this  scale  is  not  exclu- 
sively confined  to  plants  of  this  family,  but  is  probably  a  general  feeder 
upon  plants  of  the  order  Rosacece,  which  includes  nearly  all  of  our  fruit 
trees. 

Origin  and  Spread. — The  Purple  Scale  must  be  a  common  pest  in  most 
.countries  where  the  Orange  is  grown,  for  it  is  very  frequently  seen  upon 
imported  plants  and  upon  foreign  fruit  in  the  northern  markets.  IB 
Florida  it  is  fortunately  not  as  common  as  the  Long  Scale.  It  is,  how- 
ever, more  abundant  in  the  northern  than  in  the  southern  portions  of 
the  orange  belt.  It  is  frequently  associated  with  the  Long  Scale,  and 
orange- growers  do  not  readily  distinguish  the  two  species. 

The  introduction  of  the  species  into  this  country  probably  took  place 
at  an  early  date,  but  no  certain  knowledge  of  its  first  appearance 
exists.  Mr.  Ash  mead  (Orange  Insects,  p.  26)  and  Professor  Comstock 
( Report  Commissioner  of  Agriculture  for  1880,  p.  323)  both  give  Glover  as 
authority  for  the  statement  that  this  scale  was  imported  into  Jackson- 
ville, Fla.,  in  1855,  on  some  lemons  sent  from  Bermuda,  but  in  the 
citation  given  Glover  refers  to  an  entirely  different  scale,  less  than  half 
the  size  of  Hytilaspis  eitricola,  of  a  different  shape  and  habit,  and  which 
from  his  imperfect  description  appears  to  be  the  Chaff  Scale,  Parlatoria 
pergandii  Comstock. 

Parasite*. — The  parasites  of  Mytilaspis  citricola  and  M.  gloverii  are 
identical,  and  the  mode  of  attack  is  in  both  cases  the  same. 

Descriptions  of  several  species  will  be  found  in  the  Keport  of  the 
Commissioner  of  Agriculture  for  1880. 


28  INSECTS    AFFECTING   THE    ORANGE. 

RED  SCALE  OF  FLORIDA. 

( Aspidiotus  Jicus,  Ashmead.) 

[Figs.  4  and  5.] 

The  following  account  of  this  species  is  given  in  the  Report  of  the 
Commissioner  of  Agriculture  for  1880,  page  296 : 

"  Scale  of  Female.  — The  scale  of  the  female  is  circular,  with  the  exuviae 
nearly  central;  the  position  of  the  first  skin  is  indicated  by  a  nipple- 
like  prominence,  which  in  fresh  specimens  is  white,  and  is  the  remains 
of  a  mass  of  cottony  excretion,  beneath  which  the  first  skin  is  shed. 
The  part  of  the  scale  covering  the  second  skin  is  light  reddish  brown  j 
the  remainder  of  the  scale  is  much  darker,  varying  from  a  dark  red- 
dish-brown to  black,  excepting  the  thin  part  of  the  margin,  which  is 
gray.  When  fully  grown  the  scale  measures  2mm  (.08  inch)  in  diameter. 
In  some  specimens  the  part  covering  the  exuviae  is  depressed,  and 
when  the  scale  is  removed  from  the  leaf  and  viewed  under  a  micro- 
scope with  transmitted  light,  the  exuviae,  which  are  bright  yellow, 
show  through  this  part,  causing  it  to  appear  as  described  by  Mr.  Ash- 
mead.  This  scale  is  represented  in  Fig.  5,  natural  size;  Fig.  5&,  en- 
larged. *  *  * 

"Egg. — The  eggs  are  pale  yellow. 

"Scale  of  Male. — The  scale  of  the  male  is  about  one-fourth  as  large  as 
that  of  the  female ;  the  posterior  side  is  prolonged  into  a  thin  flap, 
which  is  gray  in  color ;  in  other  re  spects  the  scale  appears  like  that  of 
the  female.  (Fig.  5b.  enlarged.) 

"Male. — (Fig.  4.)  The  male  is  light  orange-yellow  in  color,  with  the  tho- 
racic band  dark  brown  and  the  eyes  purplish-black.  It  very  closely  re- 
sembles the  males  of  A.  aurantii,  but  differs  from  that  species  in  being 


\*«  ^^ 


Fig.  4.— Aspidiotus fifius  (Ashm.),  male.     (After  Corastock.) 

a  smaller  insect,  with  shorter  antennae,  longer  style,  wider  thoracic  band, 
and  with  the  pockets  of  the  wings  for  the  insertion  of  the  hair  of  the 
poisers  farther  from  the  body. 

"  Development  of  the  Insect  and  formation  of  the  Scale. — The  development 
of  this  insect  from  the  egg  to  the  adult  state  was  followed  through  five 
generations.  I  give,  however,  only  the  substance  of  a  part  of  the  notes 


THE    RED    SCALE    OF    FLORIDA. 


29 


taken  on  a  single  brood — the  second  one  observed — as  that  will  be  suffi- 
cient for  our  purpose.  >xThe  observations  were  made  upon  specimens 
which  were  colonized  on  small  orange  trees  in  pots  in  my  office  in  Wash- 
ington. The  rate  of  the  development  of  the  insects  was  probably  slower 
than  would  have  been  the  case  in  the  open  air  in  Florida. 

u  April  12, 1880,  specimens  of  orange  leaves  infested  by  this  scale  were 
received  from  Mr.  G.  W.  Holmes,  Orlando,  Fla.  At  this  date  males 
were  found  both  in  the  pupa  and  adult  state.  The  females  also  varied 
in  size,  and  some  of  them  were  ovipositing.  Eggs  were  placed  on  an 
orange  tree  for  special  study. 

"April  13,  the  eggs  began  to  hatch.    The  newly-hatched  larva  (Fig. 


S80 


I<ig.  5.—  Aspidiotus  ficus  (Ashui.).  5,  scales  011  leaves  of  orange,  natural  size;  a,  scale  of  female 
enlarged;  b,  scale  of  male,  enlarged ;  c,  young  larva;  d,  e,  and/,  different  stages  in  the  formation  of  the 
scale.  (After  Comstock.) 

oc)  is  broadly  oval  in  outline  and  yellow  in  color.  The  antenna}  are 
five-jointed  ;  the  three  basal  joints  are  very  short  and  nearly  equal  in 
length  ;  the  fourth  and  fifth  joints  are  each  longer  than  the  three  basal 
joints  together.  The  fifth  joint  is  strongly  tuberculated  at  tip  so  as  to 
appear  bifurcated.  The  eyes  are  prominent  and  of  the  same  color  as 
the  body.  The  young  Iarva3  are  quite  active,  but  they  settle  soon  after 
hatching.  Some  settled  the  same  day  that  they  hatched. 

"April  14,  it  was  found  that  the  young  lice,  although  only  twenty -four- 
hours  old,  had  formed  scales  which  completely  concealed  them  from 


30  INSECTS   AFFECTING   THE    ORANGE. 

sight.  These  scales  resembled  in  appearance  the  fruiting  organs  of  cer  - 
tain  minute  fungi.  They  were  white,  circular,  convex,  with  a  slightly 
depressed  ring  round  the  central  portion  (Fig.  5d) ;  their  texture  was 
quite  dense,  and  they  were  not  firmly  attached  to  either  the  insects  or 
the  leaf,  a  slight  touch  being  sufficient  to  remove  them  without  disturb- 
ing the  larvae.  The  larvae  had  not  changed  in  appearance,  and  were 
able  to  move  their  legs  and  antennae. 

"  April  15,  the  lice  had  not  changed  perceptibly.  The  scales  had  be- 
come higher  and  more  rounded. 

"  April  16,  the  lice  had  contracted  considerably, 'being  now  nearly  cir- 
cular, at  least  as  broad  as  long;  in  other  respects  there  was  no  apparent 
change.  The  scales  were  found  to  vary  somewhat  5  those  most  advanced 
having  the  central  portion  covered  with  a  loose  mass  of  curled  white 
threads.  (Fig.  5e.) 

"  April  17,  there  was  apparent  no  further  change  in  the  larva ;  but  the 
mass  of  threads  covering  the  central  part  of  the  scale  was  found  in  some 
specimens  to  have  greatly  increased  in  size,  equaling  in  height  three  or 
four  times  the  width  of  the  scale.  This  mass  is  cottony  in  appearance, 
and  in  those  specimens  where  it  is  largest  is  more  or  less  in  the  form  of 
a  plate  twisted  into  a  close  spiral  (Fig.  5/). 

"  April  19,  not  much  change  was  apparent  in  the  larva,  but  the  mass  of 
cottony  excretion  upon  some  of  the  scales  had  increased  enormously ;  so 
that  in  some  cases  it  extended  in  a  curve  from  the  scale  to  a  point  five 
times  the  width  of  the  scale  above  the  leaf  and  down  to  the  leaf. 

"April  20,  no  important  change  was  observed  either  in  the  Iarva3  or 
scales. 

"  April  21,  it  was  observed  that  the  larvae  had  become  more  or  less 
transparent,  and  marked  with  large  irregular  yellow  spots  near  the 
lateral  margin  of  the  head  and  thorax,  and  with  a  transverse  row  of 
similar  spots  across  the  base  of  the  abdomen ;  the  tip  of  the  abdomen 
is  very  faintly  yellow. 

"April  22,  no  important  change  was  noted. 

"April  23,  it  was  observed  that  the  scales  appeared  faintly  reddish  in 
color  with  the  center  white;  the  reddish  color,  however,  was  due  in  part 
to  the  body  of  the  larva,  which  is  now  orange-red,  showing  through  the 
scale.  It  should  be  noted  that  in  only  a  part  of  the  specimens  did  the 
cottony  mass  become  enlarged  as  represented  in  Fig.  5/.  The  greater 
part  of  the  scales  remained  until  this  date  Of  the  form  shown  in  Fig.  5e, 
and  the  cettony  spirals  have  now  disappeared,  probably  having  been 
blown  away. 

"April  24,  some  of  the  larvae  had  become  deep  orange  in  color. 

"April  26,  most  of  the  scales  had  become  deep  orange  in  color  with  the 
central  part  white ;  some  had  at  tke  center  a  small  nipple  like  protu- 
berance; others  still  preserved  a  short  tuft  of  a  cottony  excretion. 
This  tuft  is  either  removed  by  wind  or  otherwise,  or  it  becomes  com- 


THE   RED   SCALE    OF   FLORIDA.  31 

pact,  melted,  as  it  were,  to  form  the  nipple-like  projection  referred  to 
above. 

"April  28,  the  insects  appeared  as  they  did  two  days  ago;  the  scales 
had  become  very  tough,  and  it  was  with  difficulty  that  they  could  be 
removed  from  the  insect. 

"  April  30,  the  insects  still  remained  apparently  unchanged.  Some  of 
the  scales  were  only  about  one-half  as  large  as  others,  and  still  remained 
perfectly  white ;  these  proved  to  be  male  scales.  All  the  scales  at  this 
date  had  an  elevated  ring  on  the  disk  with  a  central  nipple. 

"May  3,  many  of  the  larvae  began  to  show  that  they  were  about  to 
molt,  the  form  of  the  next  stage  being  visible  through  the  skin  of  the 
insect. 

"May  5,  nearly  all  of  the  larvae  had  molted ;  they  were  now  orange- 
yellow,  with  the  end  of  the  body  colorless.  The  last  abdominal  segment 
now  presents  the  excretory  pores  which  are  represented  in  the  drawing 
of  the  corresponding  segment  of  the  adult  female.  (Fig. 5.)*  The  molted 
skin  adheres  to  the  inside' of  the  little  scale,  and  therefore  cannot  be 
seen  from  the  outside.  The  scales  are  now  pink,  or  rose  colored,  with 
the  center  white. 

"  May  14,  the  insects  had  become  a  somewhat  paler  yellow,  with  the 
anal  segment  slightly  darker.  Most  of  the  scales  were  now  dark  pur- 
ple. On  removing  an  insect  a  very  delicate  round  white  plate  was  ob- 
served adhering  to  the  leaf  where  the  mouth  parts  were  inserted. 

"  May  18,  the  male  scales  were  fully  grown.  At  this  stage  they  were 
dark  reddish  brown  in  color,  with  the  center  white,  and  the  posterior 
side,  which  is  elongated,  gray.  At  this  date  some  of  the  males  had 
transformed  to  pupae;  others  were  still  in  the  larva  state;  these  larvae 
were  covered  with  roundish,  more  or  less  confluent  yellow  spots,  leaving 
only  the  margin  colorless  ;  the  end  of  the  body  was  pale  orange.  The 
newly-transformed  pupae  resembled  in  markings  the  larvae  just  described. 
Xone  of  the  females  had  yet  molted  the  second  time;  their  color  was 
deep  orange. 

"  May  21,  nearly  all  of  the  males  had  changed  to  pupae.  It  was  observed 
that  the  last  larval  skin  is  pushed  backwards  from  under  the  scale,  to 
the  edge  of  which  it  frequently  adheres. 

"  May  24,  none  of  the  male  pupae  had  transformed  to  the  adult  state. 

"May  29,  it  was  found  that  during  the  five  days  previous  more  than 
one-half  of  the  males  had  issued,  and  the  remainder,  though  still  under 
the  scales,  were  in  the  adult  state.  It  was  now  forty-seven  days  from 
the  time  the  larvae  hatched. 

"  June  2,  no  males  could  be  found ;  the  females  were  about  one-half 
grown,  and  were  whitish  with  irregular  yellow  spots. 

"  June  9,  eggs  were  observed  within  the  body  of  a  female. 

"  June  17,  it  was  found  that  one  of  the  females  had  deposited  nine  eggs, 
of  which  six  had  hatched.  This  is  sixty-six  days  from  the  hatching  of 

*  This  figure  reference  is  to  the  original  report  and  not  to  Fig.  5  of  this  report. 


32  INSECTS    AFFECTING   THE    ORANGE. 

the  egg,  and  probably  about  twenty  days  after  impregnation  of  the 
female. 

"The  insects  of  this  brood  continued  to  oviposit  until  July  1. 

"Number  of  generations  per  year. — This  insect,  living  on  orange  trees  in 
a  room  on  the  north  side  of  a  building  in  Washington,  passed  through 
five  generations  in  less  than  one  year ;  the  average  time  occupied  by  a 
single  generation  was  a  little  less  than  seventy  days.  It  is  probable 
that  in  the  open  air  in  Orange  County,  Florida,  there  are  at  least  six 
generations  each  year. 

"Habitat. — Although  I  have  carefully  explored  many  orange  groves  in 
Florida  and  California,  and  have  had  an  extensive  correspondence  with 
orange-growers,  I  have  been  unable  to  find  this  species  in  the  last- 
named  State,  and  have  found  it  only  in  a  single  grove  in  Florida.  This 
is  the  grove  of  Messrs.  Holmes  and  Eobinson,  near  Orlando,  in  Orange 
County.  The  insects  were  first  observed  here  in  the  spring  of  1879  on  a 
sour-orange  tree  which  was  brought  from  Havana,  Cuba,  in  1874.  On 
learning  these  facts  I  sent  specimens  to  a  friend  at  Havana  in  order  to 
ascertain  if  the  species  occurred  there.  He  at  once  returned  me  other 
specimens  with  the  information  that  it  is  a  very  common  pest  in  public 
gardens  of  that  city. 

"  This  species  infests  the  limbs,  leaves,  and  fruit  indiscriminately.  In 
the  grove  of  Messrs.  Holmes  arid  Eobiuson  it  has  spread  slowly.  The 
large  trees  which  are  infested  do  not  seem  to  suffer  much  from  it,  but  the 
young  trees  are  greatly  injured  by  it.  Mr.  Holmes  considers  the  dis- 
figuring of  the  fruit  as  the  worst  feature  of  the  pest.  The  insect  has 
multiplied  to  such  an  extent  upon  the  trees  upon  which  I  colonized  it  in 
my  breeding-room,  that  nearly  all  of  them  have  been  destroyed.  The 
species  is  certainly  one  that  is  greatly  to  be  feared,  and  there  is  no 
doubt  that  it  would  be  a  good  investment  for  the  orange-growers  of 
Florida  to  eradicate  the  pest,  even  if  in  doing  so  it  is  found  necessary 
to  purchase  and  destroy  all  infested  trees.  This  could  be  done  now 
easily,  but  if  delayed  a  few  years  the  species  will  doubtless  become  per- 
manently established." 

Since  the  publication  of  the  above  by  Professor  Corastock,  the  Ked 
Scale  of  Florida  has  made  its  appearance  at  San  Mateo  upon  the  St. 
Johns  Elver.  Its  transportation  was  accomplished  in  1881  or  1882  by 
means  of  infested  fruit  (Lemons),  sent  from  Orlando,  and  packed  for 
shipment  at  San  Mateo.  From  the  packing-house  the  pest  escaped  to 
orange  trees  in  the  vicinity,  and  soon  obtained  a  foothold  in  the  sur- 
rounding groves. 

RED  SCALE  OF  CALIFORNIA. 

(Aspidiotus  aurantiw  Maskell.) 

[Fig.  6.] 

This  very  destructive  pest  of  the  'Jrauge  is  known  as  yet  only  from 
California  j  its  introduction  into  Florida  upon  imported  plants  is  how- 


THE   RED    SCALE    OF    CALIFORNIA. 


33 


ever  greatly  to  be  feared.  The  following  discussion  of  the  species  is 
found  in  the  Report  of  the  Commissioner  of  Agriculture  for  1880,  p.  293: 
''Scaleof  Female.  -  This  scale  resem  bles  that  of  Axp  idiot m  liens  in  shape, 
size,  and  the  presence  of  the  nipple-like  prominence,  which  indicates 
the  position  of  the  first  Jarval  skin  ;  but  it  can  be  readily  distinguished 
from  the  scale  of  that  species  as  follows:  It  is  light  gray,  and  quite 
translucent;  its  apparent  color  depending  on  the  color  of  the  insect  be- 
neath, and  varying  fiom  a  light  greenish  yellow  to  a  bright  reddish 
brown  ;  the  central  third  (that  part  which  covers  the  second  skin)  is  as 
dark,  and  usually  darker  than  the  remainder  of  the  scale;  and  when 
the  female  is  fully  grown  the  peculiar  reniform  body  is  discernible 
through  the  scale,  causing  the  darker  part  of  the  outer  two-thirds  of 
the  scale  to  appear  as  a  broken  ring.  (Fig.  &b.)  *  *  * 


Flo.  C — Anpidiotus  attrantn  Masfcell.    6,  scales  on  leaves  of  orango,  natnral  size;  a,  adult  male, 
much  uular&ed;  b,  scales  of  female,  enlarged;  c,  seale  of  male,  uular^ud.     (Alter  Couistock.) 

"Eyy. — I  have  not  seen  the  eggs  of  this  species,  excepting  those  taken 
from  the  body  of  the  female.  And  as  I  have  repeatedly  found  young 
larvae  under  the  scalts  I  am  led  to  believe  that  the  species  is  vivipar- 
ous. 

u  Scale  of  Male. — The  scale  of  the  male  resembles  that  of  the  female, 
excepting  that  it  is  only  one-fourth  as  large  ;  the  posterior  side  is  pro- 
longed into  a  flap,  which  is  quite  thin;  and  the  part  which  covers  the 
larval  skin  is  often  lighter  than  the  remainder  of  the  scale. 

"Male. — The  male  is  light  yellow,  with  the  thoracic  baud  brown,  and 
6521  o  i 3 


84  INSECTS    AFFECTING   THE    ORANGE. 

the  eyes  purplish  black.  The  outline  drawing,  Fig.  6a,  represents  the 
shape  of  the  various  organs. 

"  Habitat. — I  have  observed  this  species  in  several  groves  at  San  Ga- 
briel and  Los  Angeles,  Cal.  At  the  first- named  place,  where  it  is  very 
abundant,  it  is  said  to  have  first  appeared  on  a  budded  orange  tree  which 
was  purchased  by  Mr.  L.  J.  Kose,  at  one  of  the  hot-houses  in  San  Fran- 
cisco. At  Los  Angeles  it  appears  to  have  spread  from  six  lemon  trees 
which  were  brought  from  Australia  by  Don  Mateo  Keller. 

44  At  first  I  considered  this  an  undescribed  species,  as  I  could  find  no 
description  of  it  either  in  American  or  European  entomological  publica- 
tions. I  therefore  described  it  in  the  Canadian  Entomologist  under  the 
name  of  Aspidiotus  citrL  Afterwards  I  obtained  copies  of  the  papers 
"  On  some  Coccidce  in  New  Zealand,"  by  W.  M.  Mask  ell,  published  in 
the  Transactions  and  Proceedings  of  the  New  Zealand  Institute,  and 
found  that  he  had  described  an  insect  infesting  oranges  and  lemons  im- 
ported into  New  Zealand  from  Sydney  which  was  either  identical  with 
or  very  closely  allied  to  the  red  scale  of  California.  I  at  once  sent  to 
Mr.  Maskell  for  specimens  of  the  species  described  by  him.  These  have 
just  been  received  and  prove  to  be  specifically  identical  with  those  in- 
festing citrus  trees  in  California.  Thus  the  question  as  to  source  from 
which  we  derived  this  pest  is  settled  beyond  a  doubt. 

"  I  have  found  Avpidiotus  aurantii  only  on  citrus  trees.  It  infests  the 
trunk,  limbs,  leaves,  and  fruit.  The  infested  leaves  turn  yellow,  and 
when  badly  infested  they  drop  from  the  tree.  This  species  spreads  quite 
rapidly  ;  and  from  what  I  have  seen  of  it,  1  believe  that  it  is  more  to 
be  feared  than  any  other  scale  insect  infesting  citrus  fruits  in  this 
country.  As  illustrating  the  extent  of  its  ravages  in  Australia,  Dr. 
Bleasdale  told  me  of  a  grove  of  thirty-three  acres  which  nine  years  ago 
rented  for  £1,800  per  year,  and  for  which  three  years  ago  only  £120 
rent  could  be  obtained. 

"  Specimens  of  this  insect  colonized  on  orange  trees  in  the  breeding- 
room  of  the  Department  passed  through  their  entire  existence  in  a  little 
more  than  two  months ;  hence  it  is  probable  that  in  the  open  air  in 
Southern  California  there  are  at  least  five  generations  each  year,  and 
possibly  six.  The  mode  of  the  formation  of  the  scale  in  this  species 
very  closely  resembles  that  of  A.jicus,  described  at  length  in  this  re- 
port. The  ventral  scale,  however,  reaches  a  greater  degree  of  develop- 
ment in  A.  aurantii  than  in  A.  ficus.  At  first  it  consists  of  a  very  del- 
icate film  upon  the  leaf;  when  the  second  molt  occurs  it  is  strengthened 
by  the  ventral  half  of  the  cast  skin,  the  skin  splitting  about  the  margin 
of  the  insect,  the  dorsal  half  adhering  to  the  dorsal  scale  and  the  ventral 
half  to  the  ventral  scale.  Later,  after  the  impregnation  of  the  female, 
the  ventral  scale  becomes  firmly  attached  to  the  dorsal  scale  and  to  the 
insect  5  so  that  it  is  almost  impossible  to  remove  an  adult  female  from 
her  scale." 


tEE    WHITE   SCALE. 


36 


THE  WHITE  SCALE. 

(Aspidiotus  nerii  Bouche".) 

[Fig.  7.] 

Although  this  species  has  not  yet  been  reported  from  orange  groves 
in  Florida,  it  is  known  to  occur  upon  various  plants,  within  the  limits 
of  the  State.  Professor  Comstock,  in  the  Report  of  the  Commissioner  of 
Agriculture  for  1880,  p.  301,  gives  the  following  account  of  its  appear- 
ance and  habits: 

"Scale  of  the  Few  ale  —The  scale  of  the  female  is  flat,  whitish,  or  light 
gray  in  color,  and  with  the  exuviae  central  or  nearly  so  (Fig.  7c).  Exu- 
viae dull  orange  yellow;  the  first  skin  usually  showing  the  segmenta- 
tion distinctly,  the  second  skin  more  or  less  covered  with  secretion,  often 
appearing  only  as  an  orange- colored  circle  surrounding  the  first  skin. 
Ventral  scale  a  mere  film  applied  to  bark  of  plant.  Diameter  of  fully- 
formed  scale,  2mra  (.08  inch).  *  *  * 

"Eggs. — The  eggs  are  very  light  yellow  in  color. 

"Scale  of  Male. — The  scale  of  the  male  is  slightly  elongated,  with  the 
larval  skin  nearly  central;  it  is  snowy  white  with  the  larval  skin  light 
3Tellow;  longest  diameter,  lmtn  (.04  inch)  (Fig.  7  b). 

"Male. — The  adult  male  is  yellow,  mottled  with  reddish  brown,  central 
part  of  thoracic  band  reddish.  Other  characters  represented  in  Fig.  la. 

"Habitat. — This  is  a  very  common  European  species  which  infests 
many  different  plants,  and  it  is  spread  throughout  our.  country  from  the 


FIG.  l.—Aspidlotua  nerii  Boncli6.    7,  scales  on  leaves  of  noacia,  natural  size ;  a,  adult  male,  en- 
larged; b,  scale  ot'mak>,  enlarged;  c,  scalo  of  female,  enlarged.     (After  Comstock.) 

Atlantic  to  the  Pacific,  and  from  the  Great  Lakes  to  the  Gulf  of  Mexico. 
I  have  found  it  more  abundant  on  acacias  in  California  than,  eL&awhere, 


36  INSECTS   AFFECTING   THE   ORANGE. 

and  for  a  time  believed  that  it  Lad  been  introduced  from  Australia  with, 
this  tree.  Many  trees  were  found  the  leaves  of  which  were  completely 
covered  with  the  scales,  appearing  as  if  they  had  been  coated  with 
whitewash.  Leaves  of  magnolia  were  received  from  Mr.  0.  U.  Dwinelle, 
Berkeley,  Gal.,  which  were  infested  to  a  similar  extent.  The  following 
is  a  list  of  the  plants  upon  which  I  have  studied  this  species:  Acacia, 
Magnolia,  oleander,  inn  pic,  Yucca,  plum,  cherry,  currant,  and  Melia 
(Mel  la  azcderadi)  in  California;  oleander  in  Utah;  English  ivy  in  a 
conservatory  at  Ithaca,  N.  Y. ;  ivy  and  u  China  tree"  from  Dr.  II.  S. 
Turner,  Fort  George,  Fla.;  grass  and  clover  growing  in  pots  with  orunge 
trees  upon  which  I  was  rearing  tho  scale  at  this  Department;  lemons 
imported  from  the  Mediterranean  by  a  San  Francisco  dealer;  and 
lemons  forwarded  to  me  by  Mr.  Alex.  Craw  from  the  grove  of  Mr.  Wolf- 
kill,  ut  Los  Angeles,  Cal. 

u  The  scales  upon  magnolia  from  Berkeley,  Cal.,  and  upon  oleander 
from  Salt  Lake  City  appear  somewhat  different  from  those  on  acacia  and 
other  plants.  But  after  a  very  careful  study  of  the  different  forms  from 
each  plant,  I  am  unable  to  point  out  any  character  which  will  distinguish 
those  on  magnolia  and  oleander  from  others. 

a  Specimens  of  infested  lemons  from  Europe  were  forwarded  to  me  at 
Washington  by  the  editor  of  the  Riverside  Press  and  Horticulturist, who 
had  received  them  from  a  correspondent  in  San  Francisco,  who  had 
imported  them  from  the  Mediterranean.  Notwithstanding  the  great 
distance  (once  across  the  Atlantic  and  twice  across  the  continent)  which 
this  fruit  had  been  transported,  the  insects  infesting  it  were  alive  and  in 
a  healthy  condition.  This  illustrates  the  ease  with  which  these  insects 
may  spread  from  one  country  to  another,  and  the  dangers  attending 
the  introduction  of  foreign  fruit  and  nursery  stock. 

u  The  appearance  of  this  pest  upon  citrus  fruits  in  Southern  California 
is  greatly  to  be  regretted,  for  the  species  is  already  so  common  on  other 
plants  that  it  may  be  difficult  to  keep  the  orange  groves  free  from  it. 
The  fact,  however,  that  it  infests  acacia,  oleander,  and  other  plants  to 
such  a  great  extent,  and  has  been  observed  but  few  times  in  this  country 
on  citrus  fruits,  maybe  taken  as  an  indication  that  it  is  not  liable  to 
multiply  to  any  great  extent  upon  oranges  and  lemons. 

"  In  the  specimens  which  I  have  seen  the  leaves  of  the  lemon  were  not 
infested,  but  the  scales  were  very  abundant  on  the  fruit. 

"  The  young  of  this  insect  which  were  found  on  ivy  in  Florida  were 
colonized  on  an  orange  tree  in  the  breeding-room  of  the  Department. 
When  one  day  old  the  larvae  had  settled  and  commenced  excreting  a 
covering;  when  four  days  old  this  covering  was  quite  dense;  on  the 
twentieth  day  some  larvae  molted,  and  on  the  twenty-eighth  day  the 
second  molt. occurred.  It  was  observed  that  this  molt  was  accomplished 
by  a  splitting  of  the  skin  at  the  sides  of  the  body,  so  that  the  dorsal 
half  of  the  skin  became  attached  to  the  scale  and  the  ventral  half  to  the 
leaf.  Soon  ai'ter  this  molt  all  the  specimens  died.  This  was  an  indica- 
tion that  this  species  could  not  mature  upon  the  orange.  But  a  very 


THE  CHAFF  SCALE  OF  THE  ORANGE.  37 

careful  study  of  the  form  from  Florida  lias  failed  to  reveal  any  character 
by  which  it  can  be  separated  from  that  living  on  lemon  in  California. 

"  Although  I  failed  to  ascertain  the  time  occupied  by  a  single  genera- 
tion, the  following  notes  indicate  that  there  are  at  least  two  each  year, 
and  probably  more.  On  the  13th  of  April,  1880,  specimens  of  magnolia 
leaves  were  received  from  Berkeley,  (Jal.,  infested  by  this  insect.  The 
•eggs  were  hatching  from  this  date  till  27th  April.  During  this  time  (22d 
April)  leaves  of  ivy  were  received  from  Florida,  upon  which  were  scales 
and  newly  hatched  young  of  this  species.  On  (he  21st  of  May  other 
Specimens  were  received  from  Florida;  of  these  the  females  were  about 
one  halt  grown,  and  the  males  were  in  the  pupa  state. 

uOu  the  24th  of  August  I  observed  again  at  Los  Angeles,  Cal.,  the 
eggs  of  this  species. 

"During  April  adult  males  emerged  in  my  breeding  cages  from  both  the 
California  (Berkeley)  and  Florida  specimens.  And  during  August  the 
males  were  again  flying  at  Los  Angeles,  Cal, 

"In  conservatories  there  is  apparently  no  regularity  in  the  periods  ot 
this  insect;  for  specimens  of  all  stages,  from  the  egg  to  the  adult,  may 
be  observed  at  the  same  time." 

CHAFF  SCALE. 
(Parlatnria  pergandii  Comstock.) 

[Plate  V,  and  Figs.  8  and  9.] 
Scale  of  Female. — This  is  a  thin,  light  colored 
scale,  less  than  half  as  long  as  either  of  the  Myti- 
laspis  scales.  It  is  more  or  less  circular,  usually 
somewhat  pointed,  and  less  curved  upon  one  side 
than  upon  the  other.  The  first  larval  skin  is  a  little 
darker  in  color  than  the  rest  of  the  scale ;  it  is  dis-  F'°v.  *-—P«riatoria  per- 

ffnha'U   Coins,    a,    sralo    of 

tinct,  and  forms  a  circular  shield,  placed  near  the  1«;.in!l11;-  '•i>^'--<'<i;  b,  scale 

ot  male,   enlarged.     (After 

edge  and  on  the  side,  opposite  the  point.  Beyond  comstuok .) 
and  partly  underneath  the  first  larval  skin  may  be  distinguished  the 
larger  but  less  distinctly  visible  shield  of  the  second  molt.  In  well  de- 
veloped scales  several  faintly  elevated  lines  or  ridges  are  marked  upon 
the  upper  surface,  which  radiate  from  the  point  of  beginning  of  the 
scale,  and  are  partly  obliterated  where  they  are  covered  by  the  molted 
skins.  A  structure  somewhat  similar  to  this  of  the  Chaff  Scale  is  seeu 
in  many  sea  shells,  such  as  the  limpet  and  the  oyster. 

The  female  scale  is  light  straw  color,  1.4mm  to  l.timm  (0  06  inch)  long. 

Scale  of  Male. — The  male  scale  is  slender  and  of  nearly  equal  width 
throughout.  The  material  of  which  it  is  composed  is  very  thin  and 
white  in  color;  the  larva  skin  at  one  end  covers  about  one  third  of  the 
surface,  is  darker  than  the  rest  of  the  scale,  and  has  a  greenish  tinge, 
or  a  dark  green  center.  Length,  lmm  (0.04  inch). 

Female.— The  female  has  the  form  of  a  thickened  disk,  nearly  circular 
in  outline.  The  edges  of  the  last  four  or  five  joints  are  serrate,  with 
minute  tooth-like  lobes  aud  plates.  The  color,  at  first  waxy  white, 


38  INSECTy    AFFECTING    THE    ORA.N8B. 

becomes  dark  purple  at  maturity.    The  serrated  hind  margin  is  thin 
and  tinged  with  yellow. 

The  mature  females  do  not  entirely  fill  their  scales.  When  gravid 
with  eggs,  their  bodies,  although  much  thickened,  are  reduced  in  cir- 
cumference, and  in  laying  they  surround  themselves  with  a  nearly  com- 
plete circle  of  eggs.  Length  of  mature  female  0.6mm  (0.02  inch). 

Er/gs.—The  eggs  are  as  large  or  larger  than  those  of  the  Long  Scale, 
and  resemble  them  in  shape  and  color.  They  are  nearly  ().2mm  (0.008 
inch)  in  length,  and  are  more  or  less  amethystine  in  color. 

Young  Larva.  —  The  migrating  larva  is  very  broadly  oval,  and  mottled 
with  purple.  It  differs  from  the  larva  of  related  species  only  in  minute 
details. 

Male.  (Fig.  9.)—  As  soon  as  it  be- 
gins to  form  its  permanent  scale,  the 
male  insect  becomes  distinguishable 
from  the  female  by  its  more  elongate 
form,  and  it  soon  turns  to  a  dark  pur- 
ple-red color.  The  skin  of  the  second 
molt  is  pushed  toward  the  mouth  or 
thrown  out  of  the  scale.  After  shed- 

dillg  tlllS  skil1  tllG  inale  illS6Ct 


no.  9.-P«rtetorf«  pergnnOti,  male.    (After 

comstock.)  a  pupa  of  dark  red  or  purple  color, 

and  has  the  form  of  the  fly  with  members  folded  or  abbreviated. 

The  perfect  insect  emerges  from  the  thin  outer  end  of  its  scale,  which, 
however,  has  no  hinge  or  flap.  The  fly  is  very  similar  to  those  of  the 
Kcniis  AxpidioiuS)  but  is  shorter  and  stouter,  and  has  larger  eyes  than 
the  species  of  Mylilaspis.  The  color  is  purple,  mottled,  and  somewhat 
p.iler  upon  the  large  shield  of  the  upper  surface.  Length  to  the  tip  of 
the  sryh't  about  equal  to  that  of  its  scale,  O.Gmm  (0.02  inch). 

Life  hfcttory.  —  The  young  Chaff  Scale  repeats  with  slight  variations 
the  history  of  the  species  already  mentioned.  After  wandering  a  few 
hours,  it  chooses  a  fixed  position,  very  often  underneath  a  pile  of  old, 
dead  scales,  and  in  a  few  days  covers  itself  with  a  circular  shield  of 
white  tissue,  so  thin  as  to  be  quite  transparent.  This  covering  disap- 
pears before  tlic-  time  of  the  first  molt.  After  the  molt  the  females  con- 
struct a  circular  and  the  males  a  linear  scale. 

The  number  of  eggs  laid  is  variable.  Professor  Comstock  records  in 
one  instance  twenty-seven  eggs.  The  average  number  is  sixteen. 

Number  of  Gentrations.  —  The  earlier  metamorphoses  take  place  at 
about  the  usual  intervals  of  twenty  days,  but  the  later  periods  vary 
with  the  seasons,  and  are  greatly  accelerated  by  hot  weather. 

The  Chaff  Scale  appears  to  have  one  moie  brood  than  the  Long  Scale. 
There  are  four  summer  generations,  but  these  broods  are  so  greatly 
confused  by  unequal  development  in  the  females  that  the  limits  of  each 
cannot  be  exactly  defined.  The  first  brood  in  spring  and  the  last  brood 


THE    CHAFF    SCALE    OF   THE    ORANGE.  39 

In  fall  may  be  assumed  to  be  approximately  contemporaneous  with  those 
of  the  Long  Scale.  They  occur  in  March  or  April  and  in  September  or 
October.  These  months  are  therefore  the  proper  ones  for  treatment 
with  remedies. 

Habitat. — The  Chaff  Scale  infests  by  preference  the  trunk  and  larger 
branches,  and  to  these  it  generally  confines  itself  until  every  portion  of 
their  surface  is  thickly  coated,  and  the  young  Bark-lice  can  no  longer 
find  places  to  plant  themselves.  It  is  also  frequently  seen  upon  the  fruity 
occupying  the  pit-like  depressions  of  the  rind.  This  habit,  combined 
with  its  light  color,  renders  it  inconspicuous  upon  the  fruit.  Upon  the 
trunks  of  trees,  also,  its  resemblance  to  the  bark  causes  it  to  escape 
notice,  so  that  many  persons  whose  groves  are  suffering  from  the  at- 
tacks of  this  scale  are  unaware  of  its  presence. 

Food-plants  and  Origin. — It  has  been  found  upon  various  plants  grow- 
ing near  infested  orange  trees.  Japonicas  and  similar  thick-leaved 
plants  sometimes  suffer  severely  from  its  attacks.  It  is  not  known  to 
infest  any  native  wild  plants,  and  is  not  found  upon  the  Wild  Orange, 
except  in  the  immediate  vicinity  of  cultivated  plantations.  .  It  cannot, 
therefore,  be  considered  a  native  insect,  nor  is  anything  known  with 
certainty  concerning  its  introduction. 

Professor  Glover,  in  his  report  to  the  Commissioner  of  Patents 
for  the  year  1855,  mentions  the  introduction  in  that  year  of  a  Scale- 
insect,  which  he  says  was  imported  into  Jacksonville,  Fla.,  on  some 
lemons  sent  from  Bermuda.  This  Scale-insect  has  been  stated  to  be 
Mytilaxpis  citricola.  From  the  brief  description  given  by  Glover,  it  is 
not  possible  to  determine  with  certainty  the  species  referred  to,  but  the 
small  size  and  shape  of  the  female  and  the  white  color  of  the  male  scales 
agree  closely  with  the  species  now  under  consideration,  and  render  it 
probable  that  the  Chaff  Scale,  and  not  the  Purple  Scale,  was  the  insect 
in  question. 

Parasites. — In  addition  to  many  external  enemies,  a  single  Hyuae- 
nopterous  parasite  attacks  this  scale,  and  is  a  very  efficient  destroyer  of 
the  species.  It  is  a  larger  insect  than  those  found  in  the  scales  of  My- 
tilaspis,  and  its  larva  does  not  live  within  the  body  of  the  Coccid,  as  is 
usual  with  these  minute  parasites,  but  originates  from  an  egg  deposited 
beneath  the  scale  and  among  the  eggs  of  the  Scale-insect,  which  is  al- 
ways of  adult  size  when  attacked.  The  grub  of  the  parasite  makes 
room  for  itself  as  it  grows  by  eating  first  the  eggs  of  its  host  and  then 
her  body.  Sometimes,  indeed,  the  eggs  alone  of  the  Coccid  appear  to 
suffice  for  its  support  and  the  mother  Bark-louse  is  not  molested. 

The  pupa  of  the  parasite  is  formed  under  the  scale,  and  although 
without  cocoon  or  coverings  of  its  own,  is  surrounded  by  the  dry  skin 
and  egg-shells  of  the  Bark-louse.  x 

The  fly  issues  through  a  round  hole  which  it  eats  in  the  top  of  the 
scale. 


40  INSECTS    AFFECTING   THE    ORANGE. 

The  perfect  insect  is  a  four-winged  fly,  1.2mm  (0.05  inch)  long,  honey- 
yellow  in  color,  and  with  dark  brown  eyes.  The  antennae  have  appar- 
ently six  joints,  but  the  last  three  joints  are  closely  united  into  an 
elongate  club,  and  the  real  number  of  joints  is  therefore  eight.  The 
abdomen  is  rather  broadly  oval,  and  in  the  female  bears  on  the  middle 
of  her  under  side*thc  sharply-pointed  egg-drill. 

The  larva  is  a  yellowish-white,  naked  grub,  so  thick  and  short  as  to 
be  almost  spherical.  It  is  without  visible  members,  even  the  head  being 
withdrawn  out  of  sight  into  the  body.  The  body  is  plainly  ringed,  in- 
dicating the  joints,  and  the  dark  intestinal  contents  are  seen  as  a  red 
or  brown  cloud  through  its  walls.  Length  ().5mm  (0.012  inch). 

The  pupa  is  twice  as  long  as  wide,  flattened,  oval,  and  has  a  tinge  of 
yellow  color.  It  shows  the  form  of  the  perfect  insect  through  the  trans- 
parent envelope.* 

THE  ORANGE  CHIOXASPfS. 
(Chionaspis  citri  Comstock.) 

A  new  Bark-louse  of  the  Orange  has  been  described  by  Professor 
Comstock,  in  the  Second  Entomological  Report  of  Cornell  University, 
as  follows:  u  In  the  Report  of  the  Department  of  Agriculture  for  1880  I 
described  a  species  of  Chionaspis  which  differed  from  all  other  species 
of  that  genus  known  at  that  time  by  the  color  of  the  scale  of  the  female, 
which  is  black.  This  species  was  found  on  Eaony  nus  latifolia  at  Nor- 
folk, Va.  1  stated  in  my  account  of  this  insect  that  it  occurred  also  on 
orange  trees  in  Louisiana  and  Cuba.  A  rc-examiiiatioa  of  the  speci- 
mens on  orange  has  convinced  me  that  they  arc  specifically  distinct 
from  those  on  euonymus.  I  therefore  propose  for  that  form  the  specific 
name  of  citri.  The  species  can  be  recognized  by  the  following  characters : 

"  Scale- of  Female. — The  scale  of  the  fomale  is  of  a  dirty  blackish  brown 
color  with  a  gray  margin  ;  the  exuviae  are  brownish  yellow.  There  is 
a  central  ridge  from  which  ^he  sides  of  the  scale  slope  like  the  roof  of  a 
house.  The  greater  prominence  of  this  ridge,  and  the  more  elongated 
form  of  the  scale  are  the  principal  differences  between  this  scale  am\ 
that  of  the  female  of  Ch.  euonymi.  There  is  no  danger  of  its  being  mis- 
taken for  any  other  known  species. 

"Female. —  *  *  *  This  species  may  readily  be  distinguished  from 
Ch.  euonymi  by  the  following  characters :  There  are  no  groups  of  spin- 
nerets; the  mesal  lobes  are  larger  and  more  distinctly  serrate  than  in 
(Ght  euonymi;  and  in  the  last-named  species  the  plates  are  m  twos,  while 
;  in  Ch.  citri  they  occur  singly." 

According  to  observations  made  by  Mr.  L.  O.  Howard,  the  Orange 
Chionaspis  is  theespecial  pest  of  orange  groves  in  Louisiana.  I  thus  been 
found  by  him  at  Pattersonville,  Saint  Mary's  Parish ;  at  Woodville,  50 

*  This  parasite  is  evidently  au  Aphdinus,  but  ike  only  specimen  in  Mr.  Hubbard's 
collection  is  too  poor  for  specilic  determination.  —C.  ,V.  11. 


THE    ORANGE    CHIONASPIS. 


41 


miles  below  New  Orleans;  on  the  Mississippi  River  above  Algiers,  and 
on  the  east  side  of  the  river  in  the  New  Orleans  cemeteries. 


.  10  —  Chiona*jn'x  eiwymi  Cotnstock.    10,  srnles  on  Euonymus,  natural  size  ;  a,  scale  of  male,  en- 
b,  scalo  of  1'ciualo,  tulai  gcd.     (After 


Fig.  10  represents  Chionaspis  euonymi  Comstock,  to  which  the  above 
species  is  verj*  closely  allied. 


CHAPTER  III. 

• 

DIASPIN^B— Continued. 
RAVAGES  OF  THE  ARMORED  SCALES- 

Bark-lice  omnipresent  in  Orange  Groves. — In  the  foregoing  pages  an  ac- 
count has  been  given  of  all  the  species  of  Diaspinse  known  to  attack 
citrus  plants  in  this  country.  The  appearance,  distinguishing  char- 
acters and  habits  of  each  have  been  set  forth  with  sufficient  clearness, 
it  is  hoped,  to  render  recognizable  by  orange-growers  the  different  mem- 
bers of  this  group  of  insect  pests,  the  most  destructive  and  formidable 
with  which  they  have  to  contend.  It  remains  to  consider  the  nature 
and  extent  of  the  injuries  they  inflict  and  the  conditions  under  which 
the  plant  becomes  liable  to  attack. 

It  may  be  premised  that  in  all  countries  where  the  Orange  is  exten 
sively  cultivated  Scale-insects  exist,  and  not  seldom  make  their  pres 
ence  known  through  the  losses  they  occasion  the  fruit  grower.  From 
time  to  time  there  may  be  sudden  irruptions  of  Scale-insects,  which, 
like  an  epidemic,  are  wide-spread  in  their  effects,  and  overrun  a  great 
extent  of  territory.  Such  an  invasion,  as  has  already  been  shown,  oc- 
curred in  Florida  upon  the  supposed  introduction  of  the  Long  Scale. "  In 
southern  Europe  also,  where  the  Orange  and  the  Lemon  have  been  culti- 
vated for  centuries,  the  occurrences  of  scale  epidemics  have  been  re- 
corded, one  of  which,  in  the  iirst  decade  of  the  present  century,  prevailed 
throughout  the  entire  district  along  the  shores  of  the  Mediterranean, 
from  Italy  to  Spain,  and  spread  consternation  among  the  inhabitants, 
who  were  dependent  upon  the  produce  of  their  lemon  and  orange  groves 
for  support. 

At  the  present  day,  however,  owing  to  a  better  knowledge  of  these 
pests,  the  use  of  cheap  and  effective  insecticides,  and  of  effective  instru- 
ments for  applying  them,  such  wide-spread  devastation  by  Scale-insects 
need  not  bo  feared.  The  omnipresence  of  the  pest,  however,  compels 
the  orange-grower  to  be  ever  upon  the  alert  if  he  would  avoid  loss  of 
growth  in  the  young  or  of  productiveness  in  the  older  trees. 

In  Florida  the  greater  part  of  these  losses  are  caused  by  three  Dias- 
pinous  scales :  Mytilaspis  glovcrii,  the  Long  Scale ;  Mytilaspis  citricola, 
the  Purple  Scale,  and  Parlatoria  pergandii,  the  Chaff  Scale.  These  three 
insects  are  so  universally  distributed  that  it  is  safe  to  say  no  bearing 
orange  tree  exists  in  southern  and  eastern  Florida  upon  which  one  or 
the  other  cannot  be  found. 

42 


RATA0ES    OF    THE    ARMORED   SCALES.  41 

The  Long  Scale  is  the  most  destructive,  while  it  is  the  most  readily  de- 
stroyed. Few  if  any  localities  in  the  State  are  free  from  its  presence. 

The  Purple  Scale,  being  stouter  and  thicker  than  the  Long  Scale,  is 
more  difficult  to  kill.  It  is  not'less  injurious  to  the  trees  which  it  infests, 
but  is  less  widely  distributed. 

The  Chaff  Scale  is  hardly  less  common  than  the  Long  Scale,  and  is  very 
frequently  associated  with  it.  Of  the  three  it  is  decidedly  the  most 
difficult  to  exterminate,  owing,  in  part  at  least,  to  its  habit  of  piling  or 
lapping  one  over  the  other.  Except  upon  very  young  trees  it  seldom 
does  permanent  injury,  and  is  much  less  to  be  feared  than  the  other 
two  species.  Its  thinner  scale  renders  it  liable  to  the  attacks  of  enemies 
to  a  greater  extent  than  the  Mytilaspis  scales,  and  they  sometimes  cause 
its  complete  disappearance  from  a  tree. 

A  fourth  scale  of  this  group,  Aspidiotus,  ficus  Ashtn.  has  been  ^men- 
tioned as  recently  introduced,  and  there  are  still  others  awaiting  im- 
portation from  California  and  elsewhere. 

Afjencibs  ivliick  assist  their  Distribution. — During  the  migratory  age  the 
restless  habit  of  the  young  Bark-lice  impels  them  to  crawl  actively 
about,  turning  aside  for  no  obstacles,  but  mounting  every  object  met 
with  in  their  path.  The  instinct  of  self-protection  being  entirely  want- 
ing in  these  degraded  creatures,  they  make  no  distinction  between  dead 
and  living  objects,  and  crawl  without  hesitation  upon  the  bodies  of 
other  and  larger  insects.  The  latter,  impelled  by  the  annoying  presence 
of  the  intruders,  fly  away,  bearing  with  them  the  scale  Iarva3,  and  thus 
assist  in  distributing  them  upon  surrounding  plants. 

Some  insects,  however,  do  not  notice,  or  at  least  do  not  resent,  the 
liberties  taken  by  the  crawling  lice. 

Thus  the  Lady-bird  beetles  (Coccinellidre)  are  frequently  seen  quietly 
feeding  while  several  young  Bark-lice,  evidently  attracted  by  their 
shining  backs,  are  coursing  in  all  directions  over  their  bodies.  It  can- 
not be  doubted  that  even  these  enemies  of  the  Scale-insect  bear  with 
them  in  their  flights  this  seed  of  the  destroyer  and  scatter  the  pest  from 
tree  to  tree.  Doubtless  very  many  flying  insects,  and  also  birds,  with 
their  sweeping  tail-feathers,  aid  in  disseminating  Scale-insects. 

But  spiders,  more  than  any  other  animals,  must  be  considered  effi- 
cient instruments  in  this  inischiavous  work.  Not  only  do  they  trans- 
port the  lice — and  it  is  an  observed  fact  that  the  movements  of  the  latter 
upon  their  hairy  backs  do  not  incommode  the  spiders — but  they  also 
harbor  them  under  their  webs  in  folded  leaves,  etc.,  where,  safe  from 
the  attacks  of  parasites  and  enemies,  they  increase  and  multiply  inor- 
dinately. 

The  nest  web  of  a  spider  will  most  frequently  be  found  the  starting 
point  from  which  the  lice  swarm  forth  as  from  a  hive  and  cover  the 
surrounding  parts.  Other  webs,  at  a  distance  from  the  infected  one, 
will  be  occupied  in  time,  but  only  as  the  tide  of  scales  reaches  their 
vicinity,  for  it  is  not  the  habit  of  the  migrating  Bark  lieo  to  wander  far 


44  INSECTS   AFFECTING   THE   ORANGE. 

in  search  of  such  lurking  places,  however  readily  they  accept  the  pro- 
tection when  found. 

Theobserved  fact  that  Scale-insects  spread  most  rapidly  .in  the  direction 
of  prevailing  winds  has  often  been  verified,  and  has  led  to  the  belief 
in  direct  transportation  by  the  winds,  as  the  most  important  agency  in 
their  dissemination.  This  popular  theory  is  thus  stated  by  a  writer: 
4-  Now,  in  the  spring  and  fail,  just  when  the  insects  are  hatching  and 
most  numerous,  we  have  our  heaviest-  storms.  *  ,*  *  During 
one  of  these  storms  I  have  often  seen  leaves,  twigs,  and  sometimes 
whole  branches  taken  up  and  carried  whii ling  through  t hi*  air  for  a 
quarter  of  a  mile  or  further.  Ilo\v  easy,  then,  would  it  be  for  these 
microscopical  insects,  but  a  few  atoms  in  weight,  to  becai  ried  lor  miles."* 

The  gentle  southeast  trade-winds  of  Florida  and  the  storms  which 
are  occasional,  and,  fortunately,  somewhat  lare  visitants,  are  very 
different  phenomena.  While  the  influence  of  the  former  is  sometimes 
seen  in  the  more  rapid  spread  of  the  Scale-insects  towards  the  north- 
west it  has  never  been  observed  that  a  sudden  extension  of  the  pest 
has  followed  any  of  the  violent  or  long-continued  wind  storms  on  record. 

That  tempest-borne  branches  and  leaves  might  carry  the  infection 
to  a  distance  cannot  of  course  be  denied,  but  the  dissemination  of  Scale- 
insects,  continues  without  Interruption  at  all  seasons  and  in  all  parts 
of  the  State,  a  process  of  such  constancy  and  regularity,  cannot  be 
attributed  in  any  great  measure  to  the  fitful  agency  of  occasional  storms. 

Nor  can  it  be  by  direct  transportation  that  the  trade-winds  assist  in 
spreading  Scale  insects,  for  winds  of  moderate  force  are  not  competent 
to  dislodge -the  young  lice  from  the  plants.  Of  this  any  one  may  be 
convinced  by  trial  with  a  bellows  or  with  the  breath.  Minute  and  in- 
significant in  weight  though  they  are,  they  cling  with  tenacity  to  the 
bark,  and  the  pressure  of  uir  upon  their  thin  bodies  only  serves  to  press 
them  into  closer  contact  with  the  surface. 

It  is  rather  to  the  indirect  action  of  the  wind,  to  the  influence  which 
it  exerts  upon  the  flight  of  insects  and  other  winged  animals  which 
transport.  Scale  insects,  that  we  must  look  for  an  explanation  of  the  ob- 
served phenomena. 

And  particularly  is  this  influence  of  the  wind  felt  in  the  case  of  spiders, 
most  of  the-species  of  which  are  dependent  upon  the  wind  in  their  mi- 
grations. For,  although  wingless,  they  are  enabled  by  means  of  the 
buoyancy  of  their  web  and  the  power  which  they  possess  of  reeling  it 
out  upon  the  wind  to  bsidgc  long  gaps  from  tree  to  tree,  and  even  to 
copy  the  flight  of  winged  animals. 

The  goss.imer  spider  makes  its  aerial  voyages  by  clinging  to  a  light 
tangle  of  web,  on  which,  as  by  a  parachute,  it  is  borne  to  gieat  distances 
by  the  wind. 

Many  species  have  this  habit  of  the  gossamer.  Some,  however,  use, 
instead  of  a  tangle,  long  lines  of  web  which  are  cast  out  upon  the  wind 
to  a  distance  of  several  hundred  feet,  until  their  buoyancy  becomes 

*  Ashiiieud,  Orau^c  Insects,  page  3. 


RAVAGES    OF   THE   ARMORED    SCALES.  45 

sufficient  to  sustain  tlio  weight  of  Hie  little  aeronaut,  or  until  in  its  sweep 
it  becomes  entangled  in  the  branches  oi'  a  distant  tree  or  shrub,  and 
forms  a  bridge  upon  which  the  spider  readily  crosses. 

The  warm  ascending  currents  of  spring,  the  southeast  trade-winds 
in  Florida,  excite  multitudes  of  spiders  to  set  out  upon  their  travels, 
speeding  them  on  their  way  and  directing  their  course.  At  this  season 
of  the  year,  when  the  migrations  of  insects  are  at  their  height,  and  all 
nature  is  in  restless  activity,  Scale-insects  also  are  most  abundantly  pro- 
ductive, and  the  leaves  and  branches  of  infested  trees  swarm  with  their 
young.  Thus  it  is  that  in  spring  especially  the  spiders,  aided  by  the 
winds,  carry  the  Bark-lice  in  numbers  and  to  great  distance-. 

Conditions  favorable  to  their  Increase. — There  is  good  reason  to  believe 
that  Bark-lice,  like  many  other  destructive  insects,  do  not,  as  a  rule, 
originate  the  disorders  which  follow  their  attacks.  An  enfeebled  con- 
dition  of  the  plant,  from  whatsoever  cause  it  arises,  is  generally  neces- 
sary to  provoke  an  invasion.  Thoroughly  healthy  trees,  even  when  in- 
fected, may  remain  uninjured  for  years.  The  Scale  insects  upon  them 
thrive  only  upon  the  lower  or  inside  branches,  and  are  held  in  check  by 
their  natural  enemies  and  parasites.  An  unfavorable  atmospheric  con- 
dition, such  as  long-continued  drought,  the  impoverishment  of  the  soil, 
neglect  of  cultivation,  and  the  many  obscure  or  utterly  unknown  causes 
which  produce  u  die-back,7'  yellow  and  streaked  foliage,  or  other  indi- 
cations of  vegetable  indigestion,  if  such  it  may  be  called,  all  tend  to 
foster  Scale-insects  and  favor  their  rapid  increase. 

In  explanation  of  these  facts,  it  may  be  conjectured,  although  it  is 
not,  perhaps,  susceptible,  of  proof,  that  peculiar  conditions  of  the  sap 
are  especially  favorable  to  the  development  of  Scale-insects,  and  affect 
the  reproductive  functions,  stimulating  the  females  to  greater  produc- 
tiveness. Observations  show  that  the  number  of  eggs  deposited  varies 
considerably,  and  that  the  maximum  number  is  produced,  not  by  soli- 
tary females  upon  vigorous  p'ants, .but  by  individuals  of  the  advancing 
I. rood  taken  from  portions  of  the  plant  plainly  affected  by  their  attacks. 

Usual  course  of  the  Pest. — If  it  be  true  that  outbursts  of  Scale-insects 
commonly  owe  their  origin  to  some  disturbance  in  the  condition  of  the 
plant,  it  is  no  less  a  l»ict  that  their  ravages  not  only  aggravate  the 
original  trouble,  but  entail  others,  it  may  be,  far  more  s>jrioas  in  their 
consequences.  The  countless  throng  of  Bark-lice  not  only  weaken  the 
plant  by  sapping  and  diverting  its  \italjuices  and  depriving  it  of  nour- 
ishment, but  they  also  strangle  the  parts  which  they  infest  by  coating 
the  surface  and  c'ogging  its  pores  with  their  myriad  bodies.  Their 
long,  hair  like  sucking  beaks  penetrate  and  thread  the  cellular  tissues 
of  the  growing  bark,  breaking  through  and  altering  its  structure  so 
that  the  tender  bark  of  the  twigs  and  younger  shoots  is  destroyed, 
while  the  thicker  bark  of  the  trunk  and  larger  limbs  hardens  and  be- 
comes, as  it  is  popularly  termed,  u  hide-bound."  „ 

In  this  condition  healthy  growth  is  impossible.     If  neglected  and  al 
lowed  to  be  overrun  by  the  pest,  the  growth  of  the  treo  is  checked; 


46  INSECTS   AFFECTING   THE   ORANGE 

the  infested  twigs  and  brandies  die ;  often  the  entire  top  is  lost.  The 
roots  and  trunk,  however,  survive,  and  the  tree  endeavors  to  repair 
the  injury  by  throwing  out  shoots  from  bdow. 

When  the  tree  reaches  tbis  impoverished  condition  matters  usually 
begin  to  mend.  The  Bark-lice  upon  the  dead  or  dying  branches  perish 
by  starvation,  the  parasites  reassert  their  sway,  and  slowly  the  tree  re- 
gains its  health  and  vigor,  but  seldom  its  pristine  beauty. 

The  opinion  is  often  expressed  that  the  tree  will  "  throw  off  the  srales," 
or  that  they  will  "  disappear  in  time  at  the  ends  of  the  branches."  The 
facts  upon  which  this  belief  is  founded  are  simply  that  the  young  lice, 
when  the  branches  become  crowded,  wander  off  and  on  to  new  growth; 
their  course  is,  therefore,  naturally  upward  and  outward.  When  the 
advancing  army  reaches  the  ultimate  branches,  the  insects  crowd  upon 
the  smaller  twigs  and  leaves,  killing  them  rapidly  and  involving  them- 
selves in  the  common  destruction.  The  tide  of  scales  is  then  checked, 
while  the  enemies  thrive  and  multiply,  feeding  upon  the  dead  and  starv- 
ing Coccids.  There  then  occurs  one  of  those  sudden  oscillations  of  the 
balance  which  are  familiar  enough  to  entomologists;  the  unseen  ene- 
mies increase  and  the  scales  visibly  diminish/  The  tree  meantime  has 
rest  and  may  under  favorable  circumstances  recover  its  vigor,  in  which 
case  the  trouble  for  the  time  being  is  over,  and  the  lost  branches  are 
quickly  replaced. 

More  frequently,  however,  the  new  growth,  which  always  pushes  out 
rapidly  in  such  cases,  will,  as  soon  as  it  hardens,  be  overrun  by  the 
crawling  scale-larva3,  newly  hatched  from  eggs  which  were  not  involved 
in  the  destruction  of  the  mother  insects,  and  after  an  interval  a  new 
brood  will  be  found  again  in  possession.  This  process  may  be  repeated 
many  times  in  the  tops  of  full-grown  trees,  and  the  orange-grower  at 
each  ebb  in  the  tide  will  perhaps  flatter  himself  with  the  deluskm  that 
the  scales  have  in  some  mysterious  manner  disappeared  at  the  ends  of 
the  destroyed  branches.  Well-grown  trees  may  submit  again  and  again 
to*  these  vicissitudes.  They  may  even  permanently  recover  without  the 
aid  of  applied  remedies,  but  very  young  orange  trees  do  not  possess 
the  powers  of  resistance  of  adult  trees ;  their  tops  being  small  and 
their  branches  short,  they  are  usually  entirely  overrun  in  a  single  sea- 
son, and,  if  not  attended  to,  sustain  irreparable  injury,  resulting,  in  the 
case  of  budded  trees,  in  the  destruction  of  the  budded  portion. 

Influence  of  Climate. — The  retarding  action  of  cold  weather  upon  the 
development  of  Scale-insects,  and  the  acceleration  produced  by  the 
higher  temperature  of  the  summer  months,  has  already  been  mentioned. 
The  influence  of  a  warm  climate  is  shown  in  the  increased  number  of 
annual  generations.  The  species  of  Diaspin®  found  in  the  Northern 
States  have  all,  or  nearly  all  of  them,  a  single  generation,  occupying  the 
summer  months.  The  same  species  have  in  the  warmer  portions  of  the 
United  States  at  least  two  broods,  and  in  the  extreme  South  those 
species  with  which  orange-growers  have  to  contend  produce  not  less 
than  three  and  some  of  them  more  than  four  generations. 


RAVAGES   OF   THE   ARMORED   SCALES.  47 

The  long-continued  beat  of  summer  acts  as  a  check  upon  the  advance 
southward  of  those  species  which  inhabit  the  North,  and  is  probably  a 
more  important  factor  in  determining  the  geographical  distribution  of 
many  species  than  the  frosts  of  the  northern  winter. 

Indeed  the  notion  that  Scale-insects  are  destroyed  by  frosts  is  entirely 
erroneous.  Their  eggs  withstand  any  ordinary  degree  of  cold,  and  the 
insects  themselves  survive  a  freezing  temperature  that  kills  the  plants 
upon  which  they  feed.  The  winter  climate  of  a  laud  in  which  the  open 
culture  of  the  Orange  is  possible  cannot  be  sufficiently  rigorous  to  kill 
even  the  young  of  Bark-lice.  In  Florida  the  coldest  weather  merely 
serves  to  retard  their  development.* 

Natural  Checks. — The  parasites  of  Bark-lice,  some  of  which  have  al- 
ready been  mentioned,  and  the  numerous  enemies  to  be  considered  here- 
after, are  similarly  affected  by  climatic  conditions.  Their  broods  in- 
crease in  number  as  they  extend  southwards,  and  in  the  main  their 
activity  keeps  pace  with  that  of  their  prey.  Ordinarily,  therefore, 
the  various  checks  upon  their  increase  are  sufficient  to  prevent  the 
spreading  of  Bark-lice  to  an  injurious  extent,  and,  as  we  have  seen,  it 
is  only  at  times  that  they  increase  so  rapidly  as  to  entirely  outstrip  their 
enemies  and  overrun  the  plant. 

*  Mr.  Joseph  Voyle,  in  a  report  made  to  Professor  Riley,  ami  published  in  Bul- 
ledn  No.  4,  United  States  Department  of  Agriculture,  Division  of  Entomology, 
gives  the  results  of  an  elaborate  series  of  experiments  made  by  subjecting  Scale-in- 
sects, with  their  young  and  eggs,  to  the  action  of  low  temperatures  for  varying  lengths 
of  time.  In  these  experiments  the  Coccids  were  placed  in  a  small  tin  cylinder  and 
surrounded  with  a  freezing  mixture  of  ice  and  salt.  The  time  of  exposure  was  never 
less  than  one  nor  more  than  sixteen  hours,  and  the  temperatures  ranged  from  16°  to 
:5G°  F.  Eggs  were  killed  when  the  minimum  fell  below  25°  and  were  not  killed  at 
higher  temperatures;  the  young  Bark-lice  were  killed  in  every  experiment.  It  is  to 
be  remarked,  however,  that  an  average  time  of  nine  days  was  allowed  to  elapse  before 
the  results  obtained  were  considered  iinal.  As  Mr.  Voylo  himself  suggests,  "Some- 
times Iarva3  retain  for  several  days  an  apparently  natural  appearance,  leaving  it 
doubtful  whether  their  final  death  is  the  result  of  the  temperature  or  want  of  food." 

In  regard  to  the  eggs  also  it  is  probable  that  certain  conditions  not  noted  and  not 
taken  into  account  in  these  experiments  vitiated  the  results,  since  they  do  not  cor- 
respond with  what  takes  place  in  the  open  air  during  severe  frosts. 

On  this  point  Mr.  Voylo  himself  gives  evidence  when  he  says:  "During  the  past 
winter,  1832-'«3,  by  some  special  observations,  positive  evidence  was  obtained  that 
often  very  little  damage  was  done  to  scale  insects  by  cold  that  killed  the  tender  orange 
shoots.  On  the  morning  of  December  16,  1882,  the  thermometer  was  reported  at  va- 
rious figures,  from  19°  to  25°  F.  My  own  lowest  reading  was  v!5°.  On  this  morning 
I  cut  orange  branches  incrusted  with  scale  insects,  and  found  young  migratory  larvae 
of  .Uylilaspis  running  about  quite  lively." 

This  discrepancy  is  remarked  by  Mr.  Voyle,  and  the  following  explanation  is  sug- 
gested :  "  There  are  conditions  practically  unattainable  artificially,  where  the  coccids 
arc  protected  from  the  effec's  of  such  temperature  as  under  favorable  conditions 
would  be  fatal  to  them.  The  leaves  of  the  tree,  the  warm  current  rising  from  the 
ground  around  the  trunk  of  the  tree,  and  the  initial  heat  of  the  tree  itself  perform  au 
important  part  in  modifying  temperature  for  these  insects.  In  a  still  atmosphere 
this  might  become  a  perfect  protection  against  a  temperature  much  lower  than  would 
prove  fatal  in  other  conditions." 


'  CHAPTER  IV 

LECANIXJE—  THE  NAKED  Oil  WAXY  SCALES. 

General  Characters  and  L>fc-history. — The  Bark -lice  of  this  subfamily 
make  no  true  scale.  They  are  either  naked  or  possess  waxy  coats  ad- 
hering more  or  less  closely  to  tlic  bodj  of  the  insect,  but  not  fastened 
permanently  to  the  bark.  The  development  from  the  larva  to  the  adult 
female  is  apparently  one  of  simple  growth,  and  no  molts  have  been  ob- 
served. The  change  in  form  takes  place  gradually  and  is  due  to  the 
swelling  of  the  body  as  it  becomes  lilled  with  eggs  or  young,  or  to  the 
accumulation  of  the  covering  of  wax.  Eggs  are  deposited  in  a  cavity 
beneath  the  body  of  the  mother,  or  are  retained  within  her  body  until 
hatched,  in  those  species  which  bring  forth  their  young  living. 

The  young  change  their  position  upon  the  plant  at  will,  and  this 
freedom  of  movement  is  retained  until  near  the  end  of  their  lives.  The 
insects,  however,  become  more  sluggish  as  they  grow  older,  and  at  last, 
in  the  incubating  period,  the  legs  and  other  external  members  of  the 
larva  wither  and  the  body  becomes  adherent  to  the  surface  of  the  plant. 
No  males  have  been  discpvered  in  any  of  the  species  of  the  group  which 
come  within  the  scope  of  this  treatise. 

The  newly-hatched  young  of  the  Lecanina3  closely  resemble  those  of 
the  Diaspina3.  They  are  active,  six-legged  creatures,  with  thin  bodies, 
oval  in  form.  They  feed  in  the  same  manner,  by  plunging  their  sucking 
beaks  into  the  cellular  tissues  of  the  plant,  but  the  beak  never  grows 
very  long,  and  while  active  life  remains  the  insect  has  power  to  remove 
it  and  to  reinsert  it  in  afresh  place. 

Two  genera  of  Lecaninie  fall  within  the  scope  of  this  work. 

In  the  genus  Lecanium  the  insect  makes  no  covering  for  itself  or  its 
eggs,  but  the  skin  becomes  more  or  less  toughened  with  age,  and  finally 
presents  the  appearance  of  a  parchment-like  scale.  The  species  belong- 
ing to  the  genus  Ceroplastcs  excrete  a  thick  coating  of  wax,  which  wraps 
the  body  of  the  insect  above,  but  is  easily  removed  from  its  surface. 
Underneath  the  wax  the  skin  of  the  Coccid  is  thin  and  tender. 

THE  TURTLE-BACK  SCALE— BEOAD  SCALE. 
(Lecanium  hesperidum,  Linn.) 

.     [Fig-  11-] 

Descriptive.— The  full  grown  Coccid  is  3mm  to  4mm  (0.12  to  0.1C  inch) 
long,  broadly  oval,  more  or  less  swollen,  arid  convex  upon  the  disk,  sur- 
rounded by  a  thin,  flat  margin  with  two  shallow  notches  on  each  side 
48 


THE    TURTLE-BACK   SCALE. 


49 


and  one  deeper  indentation  behind.  The  color  changes  with  age  from 
transparent  yellow  in  the  young  to  deepening  shades  of  brown  in  the 
adult. '  Individuals  attacked  by  parasites  turn  black.  Until  it  becomes 
gravid  and  swollen  with  young,  the  insect  is  exceedingly  thin  and  trans- 
parent, the  green  color  of  the  leaf  or  bark  showing  through  the  body  so 
that  the  very  young  Coccid  is  well  nigh  invisible.  The  surface  is  smooth 
and  shining,  with  faint,  scattered  punctures  on  the  disk.  The  six  slender 
legs  are  concealed  beneath  the  dilated  margins  of  the  body.  The  male, 
although  for  liwny  years  diligently  sought,  both  in  this  country  and 
abroad,  still  remains  undiscovered. 

Toinifj  Larva. — The  new-born 
insect  has  the  usual  oval  form  of 
young  Bark-lice.  It  is  yellowish 
in  color,  and  has  a  pair  of  six- 
jointed  ant  enure,  and  two  long 
bristles  at  the  anal  extremity. 

Metamorphoses. — The  metamor- 
phoses which  take  place  in  this 
species  are  very  simple,  and  con- 
sist in  a  llul tening  and  broaden- 
ing of  the  form  of  the  larva,  and 
in  the  gradual  loss  of  external  or- 
gans by  disuse.  The  first  to  dis- 
appear are  the  antennae  and  the 
anal  bristles;  lastly,  but  not  until 
the  body  becomes  swollen  with 
young,  the  legs  become  useless, 
and  are  imbedded  in  the  excre- 
tions, which  iinally  cement  the 
insect  to  the  surface  of  the  plant. 
The  body  of  the  mother  in  this 
last  stage  of  her  existence  be- 
comes a  caskot  filled  with  the 


young  lice.     These  in  due  time 


Fio.  11 .— Lccantum  heupcridvni  (Linn.)  Adult  fe- 
males,  on  Oruuge,  natural  size.  (Afi.tr  Cowstock.} 


swarm  forth  together  and  distri- 
bute themselves  over  the  plant. 

Restricti  >n  to  youny  Growth — The  young  lice  invariably  settle  upon 
the  bark  and  leaves  of  tender  growth.  Even  the  adult  insects  do  nci 
appear  able  to  pierce  with  their  beaks  the  tissues  of  the  plant  when 
hardened  by  age,  and  only  the  gravid  and  incubating  females  are  found 
upon  parts  which  have  completed  a  season's  growth. 

Gregarious  Habits. — There  is  a  tendency  in  the  young  to  kcvp  together, 
and  at  seasons  when  the  Orange  is  in  active  growth,  when  the  p'aut  is 
pushing  out  an  ffbundauce  of  shoots,  the  swarming  larva  do  not  need 
to  wander  far  in  search  of  food.  The.  progeny  of  each  female  then  set- 
tle down  together,  and  extensive  colonies  are  formed.  These  colonies 
G52I  o  i 4 


50  INSECTS   AFFECTING   THE   ORANGE 

never  long  outlast  the  growing  season.  If  not  sooner  exterminated  by 
the  attacks  of  enemies  and.  parasites,  the  hardening  of  the  tissues  of  the 
bark  and  leaves  gradually  puts  an  end  to  their  existence,  and  the -young 
of  later  generations  must  seek  elsewhere  for  their  support. 

Brood  Periods. — Thus,  in  spring  and  early  summer,  when  the  Orange 
renews  its  foliage  and  new  growth  is  abundant,  the  increase  of  this  in- 
sect is  most  rapid,  and  the  number  and  extent  of  its  colonies  often  be- 
come alarming.  The  month  of  June  is  generally  the  time  of  greatest 
activity  in  this  species.  Later  in  the  season  the  colonies  dwindle  and 
become  reduced  to  a  few  gravid  individuals.  The  young  are  obliged  to 
wander  far  in  search  of  bark  sufficiently  tender  to  be  penetrated  by 
their  beaks.  This  can  be  found  only  upon  the  solitary  shoots  and  vig- 
orous leaders,  which  the  tree  in  summer  sends  upwards  from  the  trunk 
or  main  branches  below.  It  is  not  surprising,  therefore,  that  very  many 
of  the  young  lice  hatched  in  summer  perish  from  hunger,  being  unable 
to  find  a  spot  penetrable  by  their  beaks,  or  they  fall  a  prey  to  numerous 
enemies  in  their  wanderings  over  the  plant,  and  in  fall  and  winter,  as 
a  rule,  only  solitary  individuals  are  met  with. 

Excretion  of  Honey. — From  minute  pores  upon  the  sides  of  the  bodies 
of  these  insects  exudes  a  colorless  nectar.  This  liquid  may  also  be 
ejected  by  them  with  considerable  force,  so  that  it  falls  upon  the  leaves 
ttnd  parts  of  the  plant  at  some  distance  away,  and  forms  a  sticky  coat 
ing ;  but  it  is  never  in  sufficient  quantity  to  form  drops,  as  sometimes 
happens  in  the  case  of  other  sucking-bugs  which  produce  honey  dew. 
If  npt  lapped  up  by  other  insects,  the  nectar  attracts  a  black  sugar 
fungus  (Capnodium  citri),  and  the  plant  becomes  coated  with  "smut." 

Attended  by  Ants. — Like  all  sluggish  nectar  producing  insects,  the 
Lecanium  hesperidum  is  attended  by  troops  of  ants,  which  feed  upon 
the  sweet  excretions,  and  not  only  clean  the  surface  of  the  leaves  about 
the  Bark-lice,  but  also  lick  the  insects  themselves,  and  with  caressing 
strokes  of  their  antennse  induce  them  to  give  out  the  liquid  more 
freely.  Ants,  therefore,  are  not  enemies  of  this  Bark-louse;  on  the  con- 
trary they  are  its  friends,  and  afford  it  more  or  less  protection  from  the 
attacks  of  certain  enemies.  The  extent  of  their  services  to  the  Bark- 
lice  has  been  greatly  exaggerated,  however,  and  they  cannot  prevent 
their  destruction  by  internal  parasites. 

As  indicators  of  the  presence  of  this  Bark-louse,  ants  become  useful  to 
the  observing  cultivator,  for  if  a  tree  is  in  the  slightest  degree  infested, 
and  long  before  the  colonies  of  Lecanium  become  destructive  or  even 
noticeable,  the  tell-tale  stream  of  ants  ascending  and  descending  its 
trunk  gives  an  infallible  indication  of  the  impending  evil  and  guides 
the  eye  to  the  secret  lurking  places  of  the  pest. 

PARASITES. — Colonies  of  the  Turtle-back  Scale  are,  however,  seldom 
allowed  to  dwindle  and  dissipate  themselves  solely  by  the  action  of  their 
own  laws  of  growth  and  existence  5  they  are  subject  to  the  attacks  of 
internal  parasites  which  greatly  hasten  their  dissolution.  These  para- 


THE    TURTLE-BACK    SCALE.  51 

sites  are,  as  usual,  minute  Hymenopterous  flies  belonging  to  the  family 
of  the  Chalcididcc.  The  destruction  which  they  work  upon  colonies  of 
the  Bark-louse  is  so  great  that  frequently  it  appears  an  accident  due  to 
oversight  on  the  part  of  the  parasites  if  among  the  throng  an  occeasional 
individual  Coccid  escapes.  Among  scattered  and  solitary  individuals  of 
Lecanium  the  destruction  by  parasites  is  less  complete  and  many  escape. 
If  it  were  to  remain  strictly  gregarious  at  all  seasons  of  the  year  this 
now  common  Bark  louse  would  no  doubt  speedily  become  a  rarity.  The 
following  four  species  of  these  parasites  have  been  observed  to  prey 
upon  Lecanium  liexpcridum : 

Coccophagu*  lecanii  (Fitch). — In  this  species  the  general  color  of  the 
body  is  black,  the  crescent-shaped  shield  on  the  back  between  the 
wings  is  lemon  yellow  in  the  female  and  brown  in  the  male;  eyes  dark- 
red  brown  ;  anteniuB  light  brown,  with  the  tip  of  the  club  darker; 
wings  clear,  with  dark-brown  veins;  thighs  brown,  yellow  at  the  ex- 
tremities, the  remainder  of  the  legs  light  yellow,  with  the  last  joint  of 
the  tarsi  brown.  The  length  varies  from  I1""1  (0.04  inch)  in  the  female  to 
0.5min  (0.0-J  inch)  in  the  male. 

This  parasite  lives  upon  several  species  of  Bark  lice,  and  is  found  in 
all  parts  of  the  United  States.  In  Florida  it  is  the  most  common  para 
site  of  Lecanium  hesperidum,  and  is  seldom  absent  from  its  colonies. 
With  rare  exceptions  a  solitary  specimen  of  Coccophagus  occupies  the 
body  of  each  parasitized  Lecanium.  The  Coccids  are  always  attacked 
before  they  attain  full  growth.  In  dying  they  turn  black  and  adhere 
firmly  to  the  bark.  The  bloated  and  hardened  skin  of  the  Bark-louse 
forms  a  casket  in  which  the  parasite  undergoes  its  transformation  to  a 
pupa  of  dark  color,  and  from  which  it  emerges  in  time  as  a  perfect  tiy 
t  hrough  a  round  hole  eaten  in  the  shell.  If  there  are  any  distinct  broods 
they  coincide  with  those  of  the  Bark-louse,  and  with  the  colonies  of  the 
latter  the  numbers  of  the  parasite  increase  or  diminish. 

Coccophaguscognatm  Howard  (Fig.  12) 
is  a  somewhat  larger  species  than  the 
preceding,  rather  lighter  (dark  brown) 
in  color.  In  the  female  the  shield  upon 
the  back  is  orange-yellow  ;  in  the  male 
the  corresponding  parts  are  tipped  with 
light  yellowish-brown.  The  front  legs 
are  fuscous,  the  middle  and  hind  pairs 
darker;  all  the  tarsi  are  whitish,  with 
the  last  two  joints  dusky.  Length  of 
female  1.2mm  (0.05  inch),  of  male  0.6'p™ 
(0.02  inch).  This  species,  first  noted  Fl°-  i2.-Coccopjo.7«»  oognatut.  (After 

l  Howard  ) 

and  described  by  Mr.  Howard  (Report 

of  Commissioner  of  Agriculture  for  1880,  p.  359),  was  bred  from  Lecan- 
ium  licsperidiim  on  orange  trees  in  the  orange  house  of  the  Department 
of  Agriculture  at  Washington. 


52 


INSECTS   AFFECTING   THE   ORANGE, 


Fio.  13.— Com ys  bicolor.    (After  Howard.) 


The  foregoing  parasites,  belonging  to  the  genus  Coccophagus,  hare 
eight-joiuted  antennae.  In  the  genus  Comys  the  antennae  are  eleven- 
jointed,  the  shield  upon  the  back 
(scutellum)  terminates  in  a  tuft  of 
long,  stiff  hairs,  and  the  fore  wings 
are  clouded  with  brown. 

Comys  Mcolor  Howard  (Fig.  13)  is 
the  largest  parasite  of  Lecanium  lies- 
peridum.  It  has  dark-brown  eyes, 
head  and  face  yellowish  brown,  col- 
lar shining  black,  remainder  of  tho-. 
rax  yellowish-brown,  with  black 
hairs;  abdomen  shining  black.  The 
first  and  second  pairs  of  legs  are 
respectively  dark  and  light  brown, 
with  the  thighs  white  below,  fn scons 
above;  the  hind  legs  dark,  with  silvery  white  tarsi;  length  1.75mm  (007 
inch).  This  parasite  is  found  in  company  witb  Coccophagus  Iccanii. 

Being  larger  it  inhabits  the 
full  grown  scales,  while  the 
Coccophagus  attacks  only  those 
which  are  partly  grown.  The 
Bark-ltee  which  contain  pupae 
of  this  parasite  turn  black  as 
with  the  preceding  species. 

Encyrtus  fluvus  Howard 
(Figs.  14  and  15). — In  this  spe- 
cies the  antennae  are  eleven- 
jointed,  but  the  scutellum  is 
lustrous  and  without  the  tuft 
of  hairs.  The  sexes  are  very 
dissimilar.  Female,  general 
color  ocher  yellow;  eyes  brownish  ;  eyelets  carmine;  antennae  brownish, 
or  yellowish  at  base,  three  intermediate  joints  brilliant  w.hite,  club  at 

the  end  black;  the  lore-wings 
dusky,  cltar  at  base,  with  a  clear 
band  across  the  middle,  and  two 
triangular  clear  spaces  on  the 
outer  third.  Length,  1.2mm  (0.05 
inch).  Male,  color  shining  me- 
tallic green,  with  bronze  tinge  on 
the  back ;  legs  light  yellow,  d usky 
at  tips;  antennae  dusky,  yellow 
at  base,  the  joints  covered  with 
long  hairs.  Length,  0.85mm  (0.03 

Fio.  15.— -Encyrtus flavus,  female.    (After  Howard.)      inch). 

Geographical  Distribution  and  Food  Plants.— Lecanium  hesperidum 


FIG.  l^.— Encyrtus flavus,  male.    (After  Howard.) 


TITE    BLACK    Sl'ALE    OF    CALIFORNIA.  53, 

(Linn.)  is  one  of  the  best  known  and  most  widely  distributed  species  of 
Bark-louse.  For  centuries  it  has  been  transported  from  one  country  to 
another,  until  it  lias  become  thoroughly  cosmopolitan  and  a  common  pest 
in  green  houses  throughout  the  world.  In  mild  climates,  like  those  of 
southern  Europe  and  the  southern  United  States,  it  thrives  in  the  open 
air.  It  is  a  general  feeder,  and  although  found  most  constantly  upon 
plants  of  the  citrus  family,  others  in  great  variety  are  attacked.  Marked 
preference  is  shown  for  plants  with  smooth  bark  and  thick  or  glossy 
leaves;  thus  the  Ivy,  Oleander,  and  Japonica  suffer  equally  with  the 
Orange  from  the  depredations  of  this  Bark-louse. 

THE  BLACK  SCALE  OF  CALIFORNIA. 

(Lccanium  olece  Bernard.) 
[Fig.  16.] 

The  following  account  of  this  scale  is  found  in  the  Report  of  the 
Commissioner  of  Agriculture  for  1880,  p.  336: 

*' Adult  Female.  —Dark  brown,  nearly  black  in  color ;  nearly  hemispheri- 


FIQ.  }6.—Lfcanium  olccz  Bernard.     1C,  cdult  females  on  Olive,  natural  size;  a,  female,  enlarged. 
(AiU-rCumtttock.) 

cal  in  form,  often,  however,  quite  a  little  longer  than  broad:  average 
lengih  from  4:nri  to  5imn ;  average  height  3mm.  Dorsum  with  a  median 
longitudinal  cariua  and  two  transverse  cariuae,  the  latter  dividing  the 


INSECTS    AFFLCTLNG    THE    UilAXGE. 


body  into  three  subequnl portions;  frequently  the  longitudinal  ridge  is 
more  prominent  between  the  transverse  ridges  than  elsewhere,  thus 
forming  with  them  a  raised  surface  of  the  form  of  a  capital  H-  Tlio 
body  is  slightly  margined;  outer  part  of  the  disk  with  many  (18-30) 
small  ridges  which  extend  from  the  margin  half  way  up  to  center  of 
dorsuin.  Viewed  with  the  microscope,  the  ^kiu  is  seen  to  be  filled  with 
oval  or  round  evils  each  with  a  clear  nucleus;  the  average  size  of  the 
cells  being  from  .05mm  to  .00mmin  length,  while  the  nuclei  average  .02mm 
in  diameter.  The  antennae  are  long  and  8  jointed,  the  two  basal  joints 
short;  joint  3  longest,  joints  4  and  o  equal  and  shorter,  joints  G  and  7 
equal  and  still  shorter,  joint  8  with  a  notched  margin  and  almost  as  long 
as  joint  3.  Legs  rather  long  and  stout,  the  tibiae  being  about  one  fifth 
longer  than  the,  tarsi.  The  anal  ring  seems  to  bear  six  long  hairs. 
"  The  Efjcj. — Long  oval  in  shape,  0.4mm  in  length,  yellowish  in  color. 
" Newly-hatoked  Larvce. — There  is  nothing  very  characteristic  about  the 
young  larvae;  they  are  Hat,  and  their  antennae  are  only  G  jointed. 

uThe  black  scale  is  stated  by  Signoret  to  be  properly  in  France  an 
olive  scale,  sometimes,  however,  becoming  so  common  as  to  occur 
on  all 'neighboring  plants  also.  In  California  we  find  it  infesting  the 
greatest  variety  of  plants,  and  becoming  a  very  serious  enemy  to  orange 
and  other  citrus  trees.  I  have  found  it  at  Los  Angeles  on  orange  and 
all  other  citrus  plants,  on  olive,  pear,  apricot,  plum,  pomegranate,  Ore 
gon  ash,  bitter  sweet,  apple,  eucalyptus,  sabal  palm,  California  coffee, 
rose,  cape  jessamine,  Habroth-mus  eleyans  ;  and  elsewhere  upon  an  Aus- 
tralian plant  known  as  Brachaeton,  and  also  upon  a  heath.  It  preferably 
attacks  the  smaller  twigs  of  these  plants,  and  the  young  usually  settle 
upon  the  leaves. 

'•  The  development  of  this  species  is  very  slow ;  and  it  seems  probable 
that  there  is  only  one  brood  in  a  year.  Specimens  observed  by  Mr. 

Alexander  Craw  at  Los  An- 
geles, which  hatched  in  June 
or  July,  began  to  show  the 
characteristic  ridges  only  in 
November.  Mr.  Craw  has 
seen  the  lice,  even  when  quite 
well  grown,  move  from  twigs 
which  had  become  dry  and 
take  up  their  quarters  on  fresh 
ones. 

''Although  carefully  looked 
for,  the  males,  like  those  of  so 
many  other  lecanides,  have 

FIG.  17.— Tomoccra  cctlifornica,  male,    (.liter  Howard.)      uevcr  beCll  f Oil  lid. 

'<  A  dark  brown  bark-louse  has  been  sent  me  from  Florida,  on  live  oak, 
holly,  oleamle:-,  oiange,  and  one  or  two  unknown  plants,  by  Dr.  II.  S. 
Turner,  of  Fort  George,  which  appears  to  be  identical  with  Lecanium 


THE    HEMISPHERICAL    SCALE. 


Pio.18.—  Tomocera  calif  or  nica,  female.  (After 
Howard.) 


olece.    It  is,  however,  by  no  means  as  abundant  or  injurious  in  that 
State  as  in  California. 

"Natural  Enemies. — Enormous  quantities  of  the  eggs  of  the  black 
scales  are  destroyed  by  the  chalcid 
parasite  Tomoiera  californica,  de- 
scribed on  p. [368J  of  this  re- 
port. [Fig.  17,  male;  Fig.  18, 
female.]  Particulars  as  to  the 
work  of  this  parasite  are  given  at 
the  same  place.  Upon  one  occa- 
sion (August  25,  1880),  I  found 
within  the  body  of  a  full-grown 
female  a  lepidopterous  larva, 
which  was  very  similar  in  appear- 
ance to  the'liirvse  of  the  species  of 
Dakruma  described  in  my  last  re- 
port as  destroying  bark-lice.  The  specimen,  however,  was  lost,  and  no 
more  have  been  found  since. 

u  A  number  of  beetles  of  the  genus  Latridius  were  found  under  scales 
which  had  been  punctured  by  the  Tomocera,  but  probably  would  not 
destroy  the  live  insect.  Many  mites  were  found  feeding  upon  the  eggs 
and  young.  The  infested  trees  were  also  swarming  with  the  different 
species  of  lady-bugs  ( Coccinellidce)." 

THE  HEMISPHERICAL  SCALE. 

(Lecanium  hemisphcericum  Targioni.) 
[Fig.  19.] 

Professor  Comstock,  in  the  Report  of  the  Commissioner  of  Agricult- 
ure for  1880,  p.  334,  thus  treats  of  this  Bark-louse : 

"Adult  Female.— Shape  approaching  hemispherical  with  the  edges 
flattened.  Average  length,  3.5mm;  width,  3mm;  height,  2mm.  The  shape 
and  proportions  vary  somewhat  according  as  the  scale  is  formed  upon 
a  leaf  or  a  twig.  Upon  the  rounded  twig  it  loses  something  of  its  hem- 
ispherical form,  becomes  more  elongated,  and  its  flattened  edges  are 
bent  downwards,  clasping  the  twig.  In  such  cases,  of  course,  its  height 
becomes  greater  and  its  width  less.  The  color  varies  from  a  very  light 
brown  when  young  to  a  dark  brown,  occasionally  slightly  tinged  with 
reddish  when  old.  The  oval  cells  of  the  skin  vary  in  length  from  .Olmm 
to  .04mm,  and  each  cell  contains  a  large  granular  nucleus.  The  antenuje 
are  8-jointed  with  joints  1  and  2  short  and  thick;  joint  3  is  the  longest, 
and  the  succeeding  joints  decrease  gradually  in  length  to  joint  8,  which 
is  longer  than  the  preceding.  Occasionally  a  specimen  is  found  in  which 
joint  5  is  longer  than  4,  and  I  have  seen  individuals  in  which  this  was 
the  case  with  one  of  the  anteuua3  while  the  other  was  normal.  The 
legs  are  long  and  rather  slender;  the  bristle  on  the  trochauter  is  long; 
the  articulation  of  the  tarsi  is  very  well  marked.  (This  fact  has  sag- 


INSECTS   AFFECTING   THE    ORANGE. 


gested  to  Signoret  that  the  insects  of  this  series  are  less  fixed  than  their 
congeners.)  The  tarsnl  digi  titles  are,  as  usual,  two  long  and  two  short, 
those  of  the  claws  spreading  widely  at  summit,  and  very  ^tout  at  the 
base.  The  anal-genital  ring  (more  easily  seen  than  in  the  other  species 

we  describe)  is  furnished  with  eight 
long  hairs.  The  anal  plates  are  tri- 
angular with  roum.ed  corners,  and 
are  furnished  with  two  long  hairs 
upon  the  disk,  and  three  much 
shorter  ones  at  the  ti  >. 

"  ThcEgg. — The  egg  is  ellipsoidal  in 
form,  and  0.10mm  in  length.  In  color 
it  is  whitish  with  a  yellowish  tinge, 
and  is  smooth  and  shining. 

" The  neicly-hnichcd Larva. — The  an- 
tennae are  only  7 -jointed,  and  the 
tarso-tibial  articulation  is  hardly 
marked. 

"  This  bark-louse  was  first  noticed 
in  the  orangery  of  the  Department 
upon  the  leaves  and  twigs."  It  was 
also  noticed  upon  various  green- 
house plants,  pisipyrus,  Chryso- 
phyllnm,  sago  palm,  and  Croton  va- 
riegatum.  Shortly  afi  er  being  found 
here  it  was  received  from  corre- 
spondents in  California  as  infesting 
orange  and  oleander.  Dining  my 
visit  to  California  I  found  it  upon  a 
single  orange  tree  in  the  yard  of 
Mr.  Elwood  Cooper,  near  Santa  Barbnra. 

"Actual  observation  shows  the  sumiise  of  Siguoret  as  to  the  locomo- 
tive powers  of  this  insect  to  have  been  correct.  Wo  have  seen  the 
adult  insects  when  removed  Ircin  their  positions  crawl  back  with  ap- 
parent ease." 

THE  WAX  SCALE—  WRITE  SCALE. 

(Ccroplastes  floridensis  Comstock.) 
[Fig.  20.] 

Descriptive. — The  adult  kisect  with  its  covering  is  from  2mm  to  3mm 
(0.08  to  0.12  inch)  in  length;  oval  in  form,  convex  above,  flattened  or 
concave  beneath.  The  upper  surface  presents  a  rounded  central  prom- 
inence, and  on  the  margins  six  or  eight  smaller  prominences  surround- 
ing the  central  one,  and  separated  from  it  by  a  well  marked  depression. 
Near  the  posterior  extremity,  at  the  bottom  of  a  deep  pit,  is  seen  the 
open  end  of  a  fcube  projecting  from  the  body  of  the  insect*  The  excreted 


FIG.  19. — LecaniumhcmiaphcericumTurff.  19, 
adult  females  on  Orange,  nutum!  size;  a,  adult 
female, enlarged.  (Alter  Comstock.) 


THE    WAX   SCALE    OR   \VHITE    SCALE. 


67 


covering  is  a  soft  wax,  very  similar  to  the  white  wax  of  commerce.  The 
color  is  wlirte,  rendered  impure  by  surface  accumulations  of  dust  and 
dirt.  A  faint  tinge  of  pink  i.s  sometimes  given,  to  the  semi-transparent 
wax  by  the  red  color  of  the  insect  beneath. 

When  the  covering  of  wax  is  removed  the  naked  body  of  the  insect 
is  disclosed  to  view.  This  has  the 
form  of  an  almost  globular  sack, 
with  thin  and  delicate  walls,  in- 
closing dark  red  liquid  contents, 
or  eggs  of  similar  color.  The  up- 
per surface  of  the  body  bears  six 
prominent  tubercles,  three  on 
each  side,  and  a  short  anal  tujje, 
the  end  of  which,  as  has  been 
seen,  penetrates  the  covering  of 
wax.  Beneath  the  flattened  ven- 
tral surface  may  be  discovered  the 
disused,  but  not  wholly  discarded, 
legs  and  antenna  of  the  larva. 
The  under  surface  also  usually 
shows  the  marginal  notches,  more 
plainly  seen  in  Lecanium,  and 
which  indicates  the  three  struct- 
ural divisions  of  the  body.  From 
these  notches  radiate  streaks  of 
chalky  white  exudation,  which  at 
a  hasty  glance  have  the  appear- 
ance of  legs,  but  probably  serve 
as  a  cement  attaching  the  scale 
more  firmly  to  the  bark. 

Larva.  —  The     newly-hatched 
louse  has  the  usual  oval,   flat- 
tened form.     Color  pale  ruddy 
brown,  with  the  members  yellowish;   antennae  G jointed,  tipped  with 
long  hairs.    The  caudal  bristles  are  very  long. 

Eggs  0.25mm  long,  elliptical,  having  the  color  of  sherry  wine. 

Life-hi8tory. — The  eggs,  to  the  number  of  seventy-five  or  one  hun- 
dred, are  deposited  under  the  covering  of  the  mother,  and  are  simply 
transferred  from  the  inside  to  the  outside  of  her  body,  which  becomes 
excavated  below,  and  is  more  and  more  depleted  as  the  process  of  lay- 
ing goes  on.  At  last,  entirely  collapsed,  it  forms  a  mere  lining  to  the 
walls  of  the  waxen  casket,  beneath  which  the  eggs  are  brought  to  ma- 
turity and  hatched. 

The  young,  escaping  from  beneath  the  scale,  scatter  in  all  directions 
over  the  tree,  and  soon  attach  themselves,  by  their  beaks,  to  the  sur- 
faces of  the  leaves.  After  they  have  begun  to  feed  and  to  excrete  wax, 


Fio.  20.—  Cer  plant's  floridensis    Comstock. 
adnit  and  ymui^  friii;iK-N  <>i>  ile\",  untsiral  wiz";  a, 
young  iiMifal  ,  r n larked ;  b,  adult  1'ciualc,  enlarged. 
(Alter  Couistock.) 


58  INSECTS   AFFECTING   THE    ORANGE. 

they  are  rarely  seen  to  move  by  day,  but  at  night  they  frequently  change 
their  position.  Finally  they  desert  the  leaves,  and  at  maturity  the 
greater  number  will  be  found  upon  the  bark  of  the  twigs  and  smaller 
branches. 

The-  excretions  of  wax  exude  from  minute  orifices  called  spinnerets, 
placed  in  groups  upon  various  parts  of  the  body,  but  chiefly  upon  the 
margins.  At  first  the  wax  forms  in  ridges,  which  unite  and  form  a 
crown  around  a  central  tuft.  Smaller  tufts  to  the  number  of  a  dozen 
or  fifteen  arise  about  the  central  elevation,  and  the  young  louse,  when 
about  a  week  old,  appears  as  an  oval  white  star  upon  the  leaf.  The  wax 
gradually  spreads  over  the  surface  of  the  insect,  and  for  a  time  forms 
distinct  plates ;  six  of  these,  three  upon  each  side,  are  large  and  dis- 
tinct ;  the  three  remaining  plates  are  small ;  they  are  situate  one  at 
each  end  and  one  in  the  center.  After  the  insect  has  attained  two- 
thirds  its  adult  size,  the  plates  are  found  to  have  coalesced,  and  form 
a  thick,  continuous  sheet  of  wax,  from  which  arise  at  least  as  many 
tufts  as  there  were  plates.  The  tufts,  which  are  merely  exfoliations  of 
wax,  marking  the  spots  where  the  material  is  most  abundantly  given 
off,  slowly  but  constantly  melt  into  the  surrounding  mass.  At  full 
maturity,  when  the  production  of  wax  entirely  ceases,  these  eruptive 
centers  become  obliterated,  or  are  marked  by  a  few  projecting  frag- 
ments which  gather  dust  and  dirt  and  cause  discolorations  and  spots 
which  have  been  variously  described  by  different  authors. 

The  honey  dew  produced  and  given  off  by  these  insects  attracts  ants 
and  other  insects,  and,  as  in  the  case  of  Lecanium,  these  lap  the  nectar 
from  the  bodies  of  the  Ooccids  and  from  surrounding  objects. 

Broods. — The  development  of  this  insect  is  not  very  rapid,  and  ex- 
tends over  three  or  four  months.  The  principal  broods  are  in  spring 
(April  and  May)  and  in  midsummer  (July  and  August).  A  third  brood 
occurs  in  October  or  November. 

Habitat  and  Food  Plants. — This  Bark-louse  is  found  in  all  parts  of  the 
peninsula  of  Florida,  but  is  not  known  to  occur  elsewhere.  Its  prin 
cipal  food  plant  is  the  Gall-berry  (Ilex  glabra),  a  plant  which  grows 
abundantly  in  the  sterile  "  flat  woods  "  and  in  low  ground  about  ponds. 
In  these  waste  places,  often  far  removed  from  cultivated  plantations,  the 
insect  may  be  found  in  such  abundance  that  the  stems  of  the  gall-berry 
bushes  are  loaded  with  them  in  dense  clusters,  while  the  leaves  and  all 
surrounding  objects  are  coated  with  the  black  smut  which  always  ac- 
companies crowded  colonies  of  this  and  other  nectar-yielding  Coccids. 
Such  infested  patches  of  Gall-berry  sometimes  cover  acres  in  extent. 

Although  the  insect  lives  and  thrives  upon  many  other  plants,  and 
particularly  upon  such  fruit  trees  as  the  Quince,  Apple,  and  Pear,  which 
in  Florida  do  not  find  suitable  climatic  conditions,  and  are  not  thrifty, 
yet  in  cultivated  orchards  it  is  seldom  destructive.  Upon  the  Orange 
it  occurs  everywhere  in  numbers  usually  insignificant,  but  at  times  suf- 
ficient to  excite  apprehension.  The  white  color  and  striking  stellate 


THE    BARNACLE    SCALE.  59 

form  of  tho  young,  clotted  over  the  glossy  surfaces  of  the  leaves,  fre- 
quently attract  attention,  but  their  numbers  are  always  so  greatly  re- 
duced during  growth  that  only  three  or  four  per  cent,  reach  tho 
adult  age. 

The  thinning-out  is  not  alone  the  work  of  euemies  and  parasites,  but  is 
also  due  to  the  fact  that  the  lice,  when  they  become  gravid,  cannot  main- 
tain their  hold  upon  the  smooth  surface  of  the  leaves.  They  fall  to  the 
ground  and  perish,  being  in  the  latter  portion  of  their  lives  incapable 
of  free  movement  and,  therefore,  unable  to  reasceud  the  trees.  Tio 
Orange  is  not,  therefore,  adapted  to  this  species  of  Scale-insect,  and  is 
never  subject  to  long-continued  or  very  damaging  attacks  by  it. 

The  occurrence  of  this  Bark-louse  upon  wild  plants,  in  portions  of 
Florida  very  remote  from  cultivation,  seems  to  indicate  that  it  is  indigen- 
our,  and  not  imported  as  supposed  by  Mr.  Ash  mead,  who,  however,con- 
siders  it  identical  with  Ceroplastcs  rusci  (Linn.),  a  common  European 
species.  Professor  Comstock,  who  has  carefully  compared  the  'Jld 
World  species  with  our  own,  remarks  that  C.  floridensis  "presents  sev- 
eral marked  differences ;  the  most  easily  noticeable  being  the  small 
size  of  the  central  plate,  and  its  entire  disappearance  so  early  in  the  life 
of  the  insect." 

Parasites. — A  small  Hymenopterous  fly  has  been  bred  from  Cero- 
plastes  floridensis.  It  is  similar  in  appearance  and  habits  to  Encyrtus 
tlaviis  Howard,  previously  mentioned  as  preying  upon  Lecanium  hes- 
peridum.*  In  his  paper  on  parasites  of  the  Coccidae  (Report  Comin. 
Agric.  for  1880,  p.  3G9),  Mr.  Howard  notices  the  occurrence  of  an  allied 
parasite,  a  species  of  the  genus  Tetrastichus,  which  also  remains  unde- 
scribed.1 

THE  BARNACLE  SCALE. 

(Ceroplastes  cirripediformis  Comstock.) 

[Fig.  21.] 

The  following  account  of  this  somewhat  uncommon  scale  is  given  by 
Professor  Comstock  (Report  Commissioner  of  Agriculture  for  1880, 
p.  333): 

"Adult Female. — Average  length  5mm  ;  width,  4mm ;  height,  4mm.  When 
naked  the  color  is  dark  reddish  brown;  the  shape  sub-globular,  with  a 
strong  spine-like  projection  at  the  anal  end  of  the  body.  The  waxy 
covering  is  dirty  white,  mottled  with  several  shades  of  grayish  or  light 
brown,  and  even  in  the  oldest  specimens  retains  the  division  into  plates, 
although  the  form  is  more  rounded  and  the  dividing  lines  by  no  means 
as  distinct  as- at  an  earlier  age.  There  are  visible  a  large  convex  dorsal 
plate,  and  apparently  six  lateral,  each  with  a  central  nucleus;  the  anal 

*This  may  be  Aphycus  ccroplaitis  Howard,  described  in  Bulletin  5,  Bureau  of  En- 
tomology, as  bred  iroin  Ceroplastes  artemesice  Riley  MSS.,  from  Silver  City,  N.  Mex. 


60 


INSECTS   AFFECTING   THE    ORANGE. 


plate,  however,  is  larger,  and  shows  two  nuclei,  and  is  evidently  two 
plates  joined  together.  Antenna  6  jointed,  and  proportioned  as  with 
C.  Floridcmis.  Less  long;  tibiae  nearly  twice  as  long  as  tarsi  ;  digitizes 
of  the  claw  very  large.  The  other  tarsal  pair  veiy  long  and  slender, 

but  with  a  very  large  button.  The  skin  is 
seen  in  places  to  be  furnished  with  many 
minute,  round,  transparent  cellules,  prob- 
ably spinnerets  (indicated  and  so  called  by 
Signoret  in  his  description  of  C.  Vinsonii), 
and  along  the  border  are  small  groups  of 
the  constricted  arrow-shaped  tubercles  men- 
tioned in  the  last  species;  but  the  bristle- 
shaped  spinnerets  seem  to  be  wanting,  as  in 
C.  Fairmairii  Targ. 

."  The  Eyys.  —  Length,  0.3omm,  rather  slen- 
der, little  more  than  a  third  as  thick  as  long. 
Color  light  rt-ddish  brown,  rather  darker 
than  the  egg  of  C.  Florid  ensis. 

u  Youny  Larva.  —  Very  slender;  dark  brown 
in  color;  legs  and  antenua3  as  with  C.  Flori- 
den  sis. 

"  Growth  of  the  Insect.  —  The  growth  of  the 
insect  and  the  formation  of  the  waxy  cover- 
ing seems  to  be  very  similar  to  that  of  the 
last  species.  Soon  after  the  larva  settles 
the  same  two  dor>al  ridges  of  white  secre- 
tion make  their  appearance,  but  soon  split 
up  into  transverse  bands.  Examined  on 
the  fifth  day  after  hatching,  a  larva  showed 
(Alter  seven  distinct  transverse  bands,  the  ante- 

.      .          .        .          .  . 

nor  one  being  in  the  shape  of  a  horseshoe. 
At  the  same  time  the  lateral  margin  of  the  body  was  observed  to  be 
fringed  with  stiff  spines,  seventeen  to  a  side.  At  nine  days  the  small 
horse  shoe  like  mass  had  extended  so  as  to  nearly  cover  the  thorax,  and 
the  transverse  bauds  had  lengthened  and  widened  until  they  presented 
the  appearance  of  a  nearly  complete  shield  to  the  abdomen,  serrate  at 
the  edges.  Fifteen  lateral  tnfts,  such  as  were  noticed  in  C.  Floridensis, 
and  such  as  Targioni  figures  in  the  larva  of  C.  rusci  (Stud.  Sulle  eoc- 
ciniglie,  Plate  1,  Fig.  G)  had  appeared,  though  still  small. 

"  At  this  stage  of  growth,  as  with  the  last  species,  all  development 
seemed  to  stop,  although  the  specimens  lived  on  for  months,  the  tem- 
perature in  the  breeding-room,  probably  not  being  favorable  to  the  for- 
mation of  the  plates. 

"The  smallest  specimen  in  the  collect  ion  with  theplates  already  formed 
measures  L>mm  long  by  2mm  wide  and  lmm  high.  The,  color  is  light  brown, 
and  the  wax  has  a  sornewhac  translucent  appearance.  The  dorsal  plate 


Comstock.      Adult    fi-mali'H, 

8iz.-;  a,  female,  enlarged. 

Comstock.) 


GENERAL   REMARKS   UPON  THE   LECANIXJE.  61 

is  seven-sided ;  it  is  truncate  anteriorly  and  pointed  posteriorly.  From 
each  angle  radiates  a  suture  to  the  lateral  edge,  thus  forming  seven 
lateral  plates,  of  which  a  single  one  is  above  the  head,  while  above  the 
anus  is  the  suture  between  two.  Through  this  suture  projects  the  anal 
spur.  Each  plate  has  a  dark  brown  patch  in  its  center,  and  in  the  cen- 
ter of  each  brown  patch  is  a  bit  of  the  white  secretion. 

"  Habitat  and  Food  plants. — Found  at  Jacksonville  and  in  Volnsia 
County,  Florida,  on  orange,  quince,  and  on  a  species  of  Eupatorium, 
often  in  company  with  with  C.  Floridensis,  although  it  was  by  no  means 
so  common  a  species." 

GENERAL  REMARKS  UPON  THE  LECANINJE. 

Extent  of  Injuries. — The  Bark-liceof  this  group  arc  less  injurious  to  trees 
and  woody  plants  than  their  hard-shelled  relations,  the  Diaspinre.  Of 
the  five  species  of  Lecanina3  which  Lave  been  known  to  attack  citrus 
plants,  the  widely  distributed  Lecaniuui  hesperidum  (Linn.)  is  most  com- 
mon in  Florida,  and  is  generally  recognized  and  somewhat  feared  by 
orange-growers.  It  is  known  to  occur  also  in  the  orange  districts  of  Cali- 
fornia, where,  however,  it  does  not  appear  to  be  destructive.  The  deci- 
mation which  this  unprotected  scale  suffers  through  the  attacks  of  para- 
sites and  enemies,  and  the  consequent  short  life  of  its  colonies,  effect- 
ively limits  its  destructive  powers.  Very  frequently  the  orange-grower 
will  become  aware  of  its  presence  only  to  iind  it  in  its  decadence  and  the 
life  of  the  colony  virtually  extinguished  through  the  activity  of  his  in- 
visible friends.  This  fortunate  condition  will  be  sufl'ciently  indicated 
by  the  black  color  of  the  scales  which  are  blasted  by  the  presence  of 
parasites. 

Exten  ivc  invasions  of  Lccanium  Jicftperidnm  have  never  been  known 
to  oc uir,  in  this  country  at  least.  The  injuries  which  it  intlicts  in 
orange  groves  arc;  confined  for  the  most  part  to  nnrseiies  or  young 
trees  before  they  have  become  fully  established.  Upon  older  trees  only 
limited  portions,  and  particularly  shoots  in  process  of  hardening,  are 
usually  found  to  be  infested.  Karely  indeed  does  this  hcale  occupy 
the  entire  top  of  a  grown  orange  tree.  Still  more  rarely  is  an  entire 
orchard  overrun  by  it. 

The  species  of  this  group  having  soft  bodies,  which  dry  up  and  shrivel- 
after  death,  become,  loosened  or  washed  by  rains  from  their  attachment 
to  the  bark,  and  soon  disappear  from  trees.  They  do  not,  as  in  the1 
case  of  the  D;aspina3,  remain  and  form  a  permanent  coating  upon  the 
baric,  clogging  its  pores  and  exercising  a  balelul  influence  upon  the 
health  of  the  trea  long  after  life  in  the  insects  themselves  has  become 
extinct. 

The  Black  Scale  of  California,  Lccanium  o/erc  Bernard,  is,  as  its  name 
indicates,  an  olive  scale.  In  California,  however,  it  is  quite  injurious 
to  the  Orange  and  its  kindred,  and  is  said  to  be  sprcadiug  upon,  decidu- 


62  INSECTS    AFFECTING    THE    ORANGE. 

ous  orchard  trees  in  the  more  northern  portions  of  the  State.  •  It  is  not 
distributed  in  Florida,  but  has  certainly  been  introduced  and  is  occa- 
sionally seen  upon  imported  plants,  particularly  upon  the  Olive. 

Lecanium  hemisphcericum  Targioui,  according  to  Professor  Comstock, 
has  been  found  upon  the  Orange  in  California.  It  is  not  known  in 
Florida. 

Of  the  two  species  of  wax  scales,  both  of  which  are  confined  to  Florida, 
Ceroplastes  floridemis  Comstock  is  by  far  the  more  abundant.  C.  cir- 
ripediformis  is  found  in  certain  localities,  but  is  rare  or  unknown  through- 
out a  large  part  of  the  orange  district.  Serious  injuries  rarely,  if  ever, 
result  from  the  attacks  of  the  wax  scales  on  orange  trees,  although  the 
young  of  the  first  named  species  are  frequently  sufficiently  numerous  to 
attract  attention  and  excite  alarm.  They  invariably  disappear,  how- 
ever, or  become  reduced  to  a  few  solitary  individuals,  whose  numbers 
barely  suffice  to  perpetuate  their  race. 

Smut. — The  attacks  of  the  various  species  of  Lecauium  or  Ceroplastes 
are  frequently  accompanied  by  the  appearance  of  the  sugar  fungus,  Cap- 
nodium  cilri  Berk,  and  Des.,  of  which  mention  has  been  made  in  the 
introductory  chapter  of  this  work.  The  soot-like  coating  of  the  fungus 
covers  leaves  and  bark,  and  even  the  Coccids  themselves,  feeding  evi- 
dently upon  the  nectar  which  these  insects  have  the  power  to  eject  to 
a  considerable  distance,  and  not  upon  the  juices  of  the  plant.  In  proof 
of  this  fact  it  may  be  mentioned  that  a  similar  black  coating  appears  at 
times  upon  objects  when  smeared  with  the  nectar  produced  by  flowers, 
and  it  is  always  found  upon  sugar-cane,  where  the  joints  are  not  too 
much  exposed  to  the  light. 

Not  only  does  smut  mask  the  operations  of  Scale-insects,  so  that  it  is 
uot  unfrequently  mistaken  for  the  cause  of  the  ruin  which  they  work, 
but  it  can  hardly  be  doubted  that  it  is  itself  directly  injurious  in  clog- 
ging the  pores  and  stifling  the  vital  action  of  the  growing  parts  of  the 
plant.  A  coating  of  soot,  to  which  this  fungus  bears  so  strong  a  resem- 
blance, would,  it  may  well  be  supposed,  have  an  equally  deleterious 
effect,  particularly  if,  like  the  smut,  it  were  applied  to  the  plant  with  a 
coating  of  some  viscid  liquid. 


CHAPTER  V. 

OOCCI1OG:  THE  MEALY-BUGS. 

General  Characters  and  Habits. — Bark-lice,  belonging  to  the  subfamily 
Cocciua3,  cover  themselves  and  their  eggs  with  masses  of  downy  wax 
of  white  color,  and  hence  they  receive  the  name  Mealy-bugs.  Beneath 
the  flocculent  covering  the  Bark-louse  lies  concealed,  sometimes  nest 
ling  beside  a  mass  of  eggs  so  large  as  to  quite  overshadow  the  insect 
itself,  sometimes  surrounded  by  a  crowd  of  young  lice,  whose  succes- 
sive generations  in  a  short  time  cover  the  surface  of  an  infested  plant 
with  incrustations  of  dirty-white  color  resembling  mildew. 

The  Mealy-bugs  retain  their  legs,  antenna},  and  other  organs  of  the 
larva,  and  to  a  great  extent  their  freedom  of  motion  throughout  their 
lives. 

As  in  the  last  subfamily,  development  in  the  female  is  very  simple, 
and  there  is  but  slight  change  of  form  from  the  larva  to  the  adult. 
The  males  of  this  group  form  a  pupa,  and  develop  into  two  winged 
flies,  like  those  of  the  armored  scales,  and  while  undergoing  these 
changes  they  encase  themselves  in  little  sacks  of  flocculent  wax. 

Compared  with  other  Coccids  occurring  on  the  Orange,  the  Mealy- 
bugs are  of  large  size.  In  destructiveness  they  rival  any  .of  the  pre 
ceding  species.  They  secrete  and  eject  honey-dew,  and  this,  falling 
upon  the  leaves  and  upon  the  insects  themselves,  gives  rise  to  the 
black  smut  fungus  (Capnodium  citri).  The  incrustation  formed  by  the 
mealy  bodies  of  the  insects,  befouled  with  smut,  presents  a  very  un- 
sightly appearance,  and  trees  smitten  with  these  pests  become  con- 
spicuous objects,  visible  at  long  distances. 

Food  Plants. — The  Common  Mealy-bug,  Dactylopius  adonidum  (Linn.), 
is  a  well-known  pest  of  the  garden  and  greenhouse,  attacking  nearly 
all  plants,  even  pines  and  evergreens,  and  undoubtedly  including  the 
Orange  and  its  kind,  at  least  in  the  gardens  of  southern  Europe.  In 
the  United  States,  however,  this  species  has  not  been  known  to  infest 
orange  groves,  but  its  place  is  supplied  by  a  very  closely  related  form, 
which  is  considered  by  Professor  Comstock  a  new  species  of  the  same 
genus,  and  has  been  described  by  him  under  the  name  D.  destructor. 
The  habits  of  this  aid  the  following  species,  Icerya purcliasi  Mask.,  are 
similar,  and,  like  the  common  garden  insect,  they  attack,  with  disas- 
trous results,  almost  all  varieties  of  fruit  and  shade  trees,  as  well  as 
shrubs  and  herbaceous  plants  of  the  most  widely  different  sorts. 

0? 


64  INSECTS   AFFECTING   THE   ORANGE. 

TEE  DESTRUCTIVE  MEALY-BUG. 
(Daciylopius  destructor,  Comstock. 

[Figs.  22  and  23.] 

This  species  has  been  for  several  years  very  destructive  to  orange 
trees  in  groves  and  gardens  in  the  neighborhood  of  Jacksonville,  Fla., 
but  although  this,  or  some  other  species  with  difficulty  distinguished 
from  it,  attacks  the  pineapple,  Banana,  Gtiava,  and  other  tropical  plants, 
no  species  of  Mealy-bug  has  hitherto  been  reported  as  a  pest  in  orange 
groves  in  the  more  southern  portions  of  the  State.* 
Prof.  J.  H.  Comstock  gives  the  following  account  of  this  insect:  t 
"  Adult  Female.— Length,  3.5mmto4inm  ;  width, 2mm.     Color,  dull  brown- 
ish yellow,  somewhat  darker  than  with  D.  longifilis  ;  legs  and  antennae 

concolorous  with  body.  The  lateral  append- 
ages (seventeen  on  each  side)  are  short  and 
inconspicuous  and  are  subequal  in  length. 
Upon  the  surface  of  the  body  the  powdery 
secretion  is  very  slight.  In  spite  of  the  small 
size  of  the  filaments,  the  spinnerets  and  the 
supporting  hairs  are  as  numerous  and  as  prom- 
inent, or  nearly  so*,  as  in  D.  lonijijilis ;  those 
upon  the  anal  lobes  being  especially  long. 
Antenna  8  jointed  :  joint  8  is  the  longest  and 

FIG.  y>.  —  T>actylnpws  destructor 

CmustO'-k;     female,     enlarged.       IS  tWlCC  JIS  loilg  OS  tllC  HCXt  111  length,   lOlllt  3. 
(AfterC'oiiistocli.)  .   „         «*.«-.*  i  -          i 

After  3,  joints  1  and  f,  subequal,  theno  andG, 

joint  4  being  the  shortest.  The  tarsi  are  a  little,  more  than  half  the 
length  of  the  tibiaB  and  thedigitules  are  as  in  the  preceding  species  (D. 
adon'uhu)i);  claws  strung. 

u  Eyj.— Length,  O.i'D"1"1 ;  shape,  rather  long,  ellipsoidal ;  color,  light 
straw  yellow. 

u  Young  Larva. — Rather  brighter  colored  than  the  egg.  Antennae 
6-jointed  with  the  female,  with  the  same  relative  proportions  as  in  the 
preceding  species.  Tarsi  considerably  longer  than  the  tibi«3.  The 
lower  lip  is  large,  conical,  and  reaches  almost  to  the  posterior  coxre. 

"  Male. — Length,  0.87mm  ;  expanse  of  wings.  2.5mm.  Color  light  olive- 
brown,  lighter  than  in  following  species  ( />.  lonyifilix};  legs  coucolorous 
with  body ;  antennaB  reddish ;  eyes  dark  red ;  bands  darker  brown  than 
the  general  color;  anterior  edge  of  mesoscutum  and  posterior  edge  of 
scutellum  darker  brown.  Body,  as  will  be  seen  from  measurements, 
rather  small  and  delicate  compared  with  the  size  of  the  wings;  head 
small,  with  almost  no  hair;  antenna}  10-jointed.  joints  3  and  10  longest 
and  equal;  joints  2,  G,  7,  8,  and  9  nearly  equal  and  considerably  shorter 

*  Local  outbreaks  of  the  Mealy-bu^  aro  froai  time  to  time  reported  in  the  central 
portions  of  the  peninsula.   (See  Appendix  I.) 
t  Report  of  the  Commissioner  of  Agriculture  for  1880,  p.  342. 


THE    DESTRUCTIVE    MEALY    BUG. 


65 


than  3  and  10 ;  joints  3  and  4  subequal  and  a  trifle  shorter  than  the  follow- 
ing-joints. The  lateral  ocelli  are  each  just  laterad  of  the  center  of  the 
eye,  and  not  at  its  posterior  border,  as  in  the  following  species.  (This, 
however,  isa  character  which  will  not  hold  with  specimens  long  mounted.) 


FIG.  23. — Dactylopius  destructor  Comstock,  male.     (After  Comstock.) 

Prothorax  short  ;  legs  sparsely  covered  with  hairs  j  tarsal  digitules  ex- 
tremely delicate,  and  the  button  is  very  difficult  to  distinguish ;  we  have 
been  unable  to  discover  a  trace  of  the  pair  belonging  to  the  claw.  The 
anal  filaments  and  the  supporting  hairs  are  similar  to  those  of  the  fol- 
lowing species. 

"This  species  is  readily  distinguished  from  D.  longifilis  by  the  short- 
ness of  the  lateral  and  anal  filaments  in  the  female.  Indeed,  for  con- 
venience's sake,  we  have  been,  in  the  habit  of  distinguishing  them  as  the 
mealy  bug  with  short  threads  and  the  one  with  long.  The  life-history 
of  this  species  differs  quite  decidedly  from  that  of  D.  longifilis,  in  that 
true  eggs,  which  occupy  quite  a  long  time  in  hatching,  are  deposited. 
The  female  begins  laying  her  eggs  in  a  cottony  mass  at  the  extremity  of 
her  abdomen,  some  time  before  attaining  full  growth,  and  the  egg-mass 
increases  with  her  own  increase,  gradually  "forcing  the  posterior  end  of 
the  body  upwards  until  she  frequently  seems  to  be  almost  standing  on 
her  head.  The  young  Iarva3  soon  after  hatching  spread  in  all  directions 
and  settle — preferably  along  the  mid-rib  on  the  under  side  of  the  leaves, 
or  in  the  forks  of  the  young  twigs,  where  they  form  large  colonies,  closely 
packed  together.  As  mentioned  in  the  description,  they  are  only  slightly 
covered  with  the  white  powder,  and  many  seem  to  be  entirely  bare,  with 
the  exception  of  the  lateral  threads. 
6521  o  i 5 


66  INSECTS    AFFECTING    THE    ORANGE. 

"Habitat. — This  species  is  very  abundant  upon  almost  every  variety 
of  house-plant  in  the  Department  green-houses,  but  especially  so  upon 
the  Arabian  and  Liberian  coffee-plants.  On  these  plants  they  were 
found,  curiously  enough,  in  small  pits  or  glands  on  the  under  side  of 
the  leaf,  along  the  mid-rib.  Almost  every  pit,  of  which  there  is  one  at 
the  origin  of  each  main  vein,  contained  one  or  more  young  mealy  bugs, 
and  the  larger  ones  whole  colonies.  The  name  destructor  is,  however, 
proposed  for  this  insect  from  the  damage  done  by  it  to  orange  trees  in 
Florida,  especially  at  Jacksonville  and  Micanopy,  where  it  is  the  most 
serious  insect  pest  of  the  orange. 

"Natural  enemies. — The  Chalcid  parasite,  Encyrtus  inquisitor  Howard 
[Fig.  24],  described  in  this  report,  was  bred  from  a  specimen  of  this 

mealy  bug  collected  at  Jackson- 
ville, Fla.  A  small  red  bug  was 
observed  by  myself  and  several 
of  our  correspondents  to  prey 
upon  the  mealy  bug.  The  larvae 
of  another  species  have  been 
found,  but  the  mature  form  has 
not  been  obtained.  These  last 
have  the  faculty  of  changing 

-t-     U  \\'  \<=>/v  /I  H  color  quickly  from  red  to  brown. 

"  The  very  curious  larvae  of  a 
lady-bird  beetle,  known  as  Seym- 
nus  bioculatus.  were  found  feed 

FlG.  24.— Ency i tus inquisitor.     (After  Howard.)       -     .  .,  „    ,.  , 

ing  upon  the  eggs  of  the  mealy 

bug  at  Orange  Lake.  These  larvae  mimic  the  Dactylopii  so  closely  that 
they  might  easily  be  taken  for  them.  They  are  covered  by  a  white 
secretion,  and  from  each  segment  exudes  a  white  substance  which  forms 
long  filaments  like  those  of  the  mealy  bug.  Kemoving  the  powder  the 
larvae  are  seen  to  be  yellow  in  color,  with  two  roundish  dusky  spots  on 
the  dorsum  of  each  thoracic  segment.  Each  segment 'of  the  body  is 
furnished  laterally  with  one  long  bristle  and  a  number  of  small  ones.7' 
Two  other  parasites  on  Dactylopius  destructor  have  recently  been  de- 
scribed by  Mr.  Howard  (Bulletin  o,  Bureau  of  Entomology,  U.  S.  Dept. 
Agric.)  as  Leptomastix  dactylopii  and  Oliiloneurus  dactylopii. 

THE   COTTONY  CUSHION  SCALE. 
(Icerya  purchasi,  Maskell.) 

[Fig.  25.] 

This  insect  has  not  yet  been  introduced  into  Florida.  The  following 
excellent  account  of  it  is  from  the  pen  of  Dr.  S.  F.  Chapin,  State  Hor- 
ticultural Officer  of  California :  * 

*  Pacific  Rural  Press,  October  28, 1882. 


THE  COTTONY  CUSHION  SCALE.  67 

u  This  scale  has  been,  it  is  asserted,  known  to  be  on  the  acacia  for  seven 
years  in  San  Jose",  bat  it  is  only  during  the  past  and  present  seasons 
that  it  has  attracted  attention.  Its  great  prolificness  and  its  destruc- 
tive abilities  have  called  widespread  attention  to  it.  This  pest  attacks 
everything  in  the  way  of  tree,  vine  or  shrub;  all  the  evergreens  as 
wc-11  as  deciduous  trees  that  fall  in  its  way  are  attacked,  and  every  orna- 
mental shrub  on  the  lawns  of  some  portion  of  our  cities  will  show  its 
presence.  The  ivy,  even,  is  not  proof  agaras.t  it.  In  San  Eafael,  San 
Muteo,  Santa  Barbara  and  Los  Angeles  it  is  well  established.  While 
in  San  Jose  it  has  not  this  season  caused  so  great  damage  as  last,  yet 
in  the  citrus-growing  regions  it  is  becoming  one  of  the  most  serious 
pests  they  have  to  encounter,  and  it  is  even  stated  that,  should  its 
ravages  not  be  checked,  orange  and  lemon  culture  will  have  to  be  aban- 
doned. 

"  From  the  rapid  destruction  which  follows  the  presence  of  this  scale, 
it  is  well  that  it  should  be  widely  recognized,  and  its  first  invasion 
noticed  and  checked.  In  San  Jose,  in  1881,  it  was  first  noticed  in  May 
as  the  fully  developed  female,  from  which  the  first  brood  of  young  then 
appeared. 

"This  present  season  of  1882  the  first  young  appeared  May  25th,  the 
mother  insect  having  gradually  matured  her  eggs  from  the  opening  of 
spring  until  the  young  were  hatched.  The  egg  of  the  Icerya  is  small, 
pale  or  orange  red,  elongated  and  ovoid.  The  young  just  hatched  out 
are  very  active,  and  are  very  minute,  perhaps  the  twenty-fifth  of  an 
inch  in  length.  The  body  is  pale  redj  the  six  legs  and  two  antennaB  are 
black.  The  anteuna3  are  long  and  club-shaped,  and  have  from  six  to 
nine  joints,  as  they  are  further  matured.  The  antenna  are  covered 
with  long  hairs,  which  bristle  forth  prominently.  The  eyes  are  small 
and  black.  Between  the  pair  of  forelegs  on  the  under  side  of  the  body 
is  to  be  seen  the  beak  or  sucker,  by  which  the  insect  secures  its  nour- 
ishment. 

"  The  females  partly  grown  are  of  a  variety  of  colors,  orange  red  mostly, 
and  spotted  over  with  white  and  green  ;  some  are  nearly  entirely  a 
dirty  white,  and  many  are  a  pea  green.  It  seems  that  the  coloring 
matter  of  the  plant  they  are  upon  colors  them  to  some  extent.  Their 
body  is  ovoid  and  elongated  and  flattened,  the  back  being  ridged  up 
with  several  segments  quite  prominent.  Around  the  rim  of  the  body 
are  a  multitude  of  hairs,  standing  out  prominently.  Around  the  rear 
half  of  the  body  on  its  rim  are  a  row  of  tubercles  or  spinarets,  from 
which  a  white  secretion  issues,  forming  a  cottony  cord,  and  these  placed 
side  by  side  and  the  interspace  filled  up  by  the  same  material  running 
lengthwise  the  body  and  projecting  from  it,  gives  the  whole  a  ribbed, 
satin-like  appearance  whitish  in  color.  Gradually  as  the  insect  matures 
these  projecting  ridges  approach  each  other  at  the  ends,  and  are  joined 
together  and  curved  under  slightly  at  the  point,  while  the  sides  are  at 
the  same  time  curved  under  the  whole  length,  and  the  edges  joined 


68 


INSECTS    AFFECTING   THE    ORANGE. 


together  like  a  flat  ribbon-like  band,  the  whole  forming,  when  complete, 
a  soft  elastic  white  sack,  the  size,  and  somewhat  the  shape  of  a  medium 
sized  white  beau.  The  length,  when  mature,  is  about  three-eighths  of 
an  inch  ;  the  width  one-fifth  of  an  inch. 

"  Inside  the  sack  are  deposited  the  eggs  of  the  female,  among  the  in- 
terstices of  a  mass  of  cotton -like  fiber,  which  under  a  high  magnifying 
power  is  shown  to  be  round,  and  not  more  than  one-sixth  part  the 
thickness  of  pure  cotton  fiber,  with  which  it  was  compared  in  the  same 
field.  This  mass  of  cottony  fiber  is  filled  with  a  great  amount  of  granu- 
lar matter,  for  the  purpose,  it  may  be,  of  affording  sustenance  to  the 
young  insects  within  the  sack.  The  young  hatch  out  in  this  sack,  and 
make  their  way  out  into  the  world  through  a  rent  in  the  soft  and  tender 
underside  of  the  sack. 

"The  female,  after  finding  her  home  and  during  maturity,  does  not 
move,  although  she  does  not  lose  her  legs,  but  clings  tenaciously  with 

her  feet  to  her  support,  leaving  the 
body  tipped  up  in  the  rear  and  the 
cottony  mass  movable  in  any  direction. 
The  male  insect  was  only  found  during 
a  period  of  about  two  weeks  from 
Sept.  25th.  This  was  the  observation 
of  1881,  when  I  found  them  in  great 
numbers.  I  have  failed  to  find  the 
male  insect  this  season.  It  has  a  long 
red  body,  six  legs  and  one  pair  of  very 
long,  dark  and  transparent  wings, 
prominent  eyes  and  antennae  very  long 
and  covered  with  hairs,  arranged  very 
much  as  the  feathers  of  a  peacock. 
(The  antennre  are  16  or  17  jointed.) 

u  The  winged  male  is  easily  seen  and 
easily  caught,  as  it  moves  slowly  about, 
and  is  not  readily  disturbed  so  as  to  fly 
away.  The  female  insect  lives  upon  the  trunk  of  the  tree  and  large 
limbs  and  down  to  the  smallest  twigs,  around  which  it  may  be  seen 
clinging  in  clusters  sufficiently  great  to  completely  hide  the  branch ; 
also  upon  the  leaf,  along  the  stem  and  ribs  of  which  it  is  fixed,  both 
above  and  below,  although  more  abundant  on  the  underside  of  the  leaf. 
u  There  are  three  broods  of  this  insect  in  the  season  ;  the  first  appearing 
in  May,  the  second  in  August  and  the  third  in  October,  or  about  three 
months  apart.  I  havejust  observed,  October  loth,  the  mature  female 
with  eggs  fully  grown  and  with  the  young  hatched  out  and  crawling  in 
the  same  sack.  In  1881  they  rapidly  increased  from  about  the  first  of 
August,  and  were  continually  appearing,  and  still  hatching  out  in  De- 
cember. 

"  Every  female,  it  is  estimated,  produces  from  200  to  500  young.  The 
young  will  mature  and  produce  a  new  brood  in  about  three  months." 


FIG.  25.  —Icerya  purchasi  Maskell.  Females, 
adult  and  young,  on  Orange.  (After  Corn- 
stock.) 


CHAPTER  VI. 

INSECTS  PBEYING  UPON  BABK-LICE. 

[Plate  VI.] 

Numerous  enemies  prey  upon  Bark-lice  in  all  their  stages,  and  always 
greatly  reduce  their  numbers.  Besides  occasional  enemies,  such  as  the 
sucking-bugs  and  other  predatory  insects,  which  are  general  feeders, 
there  are  others  which  live  almost  or  quite  exclusively  upon  the  Coccidse. 
Some  of  these  confine  their  attacks  to  particular  kinds  of  Scale-insects. 
Several  very  common  beetles  of  the  family  Coccinellidce,  the  "  Lady-birds," 
are  useful  destroyers  of  Bark-lice.  One  of  the  smallest  of  this  family, 
Hyperaspidius  coccidivorus,  is  found  to  colonize  upon  the  trunks  of  orange 
trees  thickly  infested  with  Chaff  Scale,  and  entirely  free  them  of  the 
pest.  The  young  of  a  Lace-wing  fly  (Chrysopa)  feeds  upon  the  Bark-lice 
in  all  stages,  and  frequently  makes  its  case  of  scales  torn  from  the  bark 
and  often  still  containing  living  occupants.  The  Orange  Basket- worm 
(Platceceticns  gloveri]  has  the  same  habit,  and  the  caterpillars  of  at  least 
two  moths  are  Bark-louse  eaters.  One  of  these  (an  unknown  Tineid)2 
inhabits  silken  galleries,  which  it  covers  with  half  eaten  fragments  of 
scales,  and  performs  such  efficient  service  that  every  scale  in  its  path 
is  removed  from  the  bark  and  suspended  in  the  investing  web. 

The  most  important  external  enemies  of  the  Scale-insect  are  certain 
mites,  which  are  omnipresent  upon  trees  infested  with  scale,  and  which 
feed  upon  the  eggs  and  young  lice.  They  breed  rapidly  and  lurk  in 
great  numbers  under  old  deserted  scales,  where  their  eggs  are  extremely 
well  protected  from  the  action  of  insecticides.  For  this  reason,  when  an 
effective  application  has  been  made  by  spraying  infested  trees,  the 
trunks  should  not  be  scraped  for  some  time  after,  but  the  dead  scales 
should  be  allowed  to  remain  upon  the  bark  for  several  weeks,  in  order 
that  the  mites  which  they  harbor  may  be  given  time  to  complete  the 
work  of  the  remedy  used.  In  this  they  may  be  confidently  relied  upon 
as  powerful  auxiliaries.  When  large  numbers  of  the  scales  have  been 
killed  by  spraying  with  oils,  &c.,  the  mites  are  often  observed  to  in- 
crease suddenly,  as  they  are  much  less  affected  by  the  application  than 
the  Scale-insects  themselves.  It  seems  probable  that  they  feed  upon 
the  dead  and  dying  Coccids  as  well  as  upon  the  living,  and  the  loosen- 
ing of  the  scales  and  abundance  of  food  at  such  times  stimulates  them 
to  rapid  increase.  They  soon  swarm  in  such  numbers  as  completely  to 
exterminate  the  remnant  of  the  Coccids  left  alive  by  the  wash. 

69 


70  INSECTS   AFFECTING   THE    ORANGE. 

Of  all  its  enemies,  the  most  efficient  destroyers  of  the  Scale  insect  are 
its  hymenopterous  parasites ;  several  species  of  which  have  already  been 
noticed,  each  under  the  head  of  the  particular  Coccid  with  whose  life 
history  it  is  closely  connected.  Fig.  1  on  Plate  VI  represents  the  com- 
mon parasite  (Aphelinus  mytilaspidis)  of  the  Apple  Scale.  These  minute 
four- winged  flies  bore  through  the  scale  and  deposit  within  a  single  egg. 
The  little  grub  hatching  from  this  egg  feeds  upon  and  destroys  the 
occupant  of  the  scale  and  completes  its  own  transformations  in  its 
place.  When  fully  adult  the  parasite  emerges  through  a  round  hole 
eaten  in  the  shell,  leaving  behind  an  empty  domicile  to  serve  as  a 
shelter  for  the  mites. 

•  The  numerous  species  of  these  parasites,  although  not  invariably  con- 
fined in  each  case  to  a  single  species  of  Bark-louse,  have  distinct  meth- 
ods of  attack  from  which  they  do  not  vary.  Thus  the  Long  and  the 
Purple  Scales  are  parasitized  at  about  the  time  of  impregnation  of  the 
females,  or  when  they  are  not  more  than  one-half  their  adult  size,  and 
the  young  Hymenopteron  is  developed  entirely  within  the  body  of  the 
Coccid.  The  skin  of  the  latter  hardens  when  life  is  extinct,  and  doubly 
protects  the  parasite  during  the  latter  part  of  its  larval  and  in  its  pupa 
stage.  The  parasite  of  the  Chaff  Scale  makes  its  attack  at  a  later  stage, 
often  when  the  scale  is  full  of  eggs,  and  its  larva  does  not  enter  the 
body  of  the  Coccid,  but  feeds  upon  it  and  the  eggs  indiscriminately,  oc- 
casionally devouring  the  eggs  alone  and  leaving  the  mother  Coccid  un- 
touched. Its  pupa  is  formed  naked  within  the  scale,  and  has  only  such 
protection  as  this  affords  the  Coccid  and  its  eggs.  In  individual  num 
bers  these  hymenopterous  parasites  abound  to  such  an  extent  that  rarely 
less  than  25  per  cent,  and  often  more  than  75  per  cent,  of  the  scales  are 
attacked  by  them,  and  the  work  of  destruction  accomplished  through 
their  agency  alone  equals  if  it  does  not  excel  that  of  all  other  enemies 
combined.  Doubtless  without  their  aid  the  culture  of  the  Orange  and 
related  trees  would,  in  Florida  at  least,  become  impracticable. 

INSECTS  OF  THE  ORDER  HYMENOPTEBA. 

ANTS. — No  species  of  field-ant,  in  Florida  at  least,  is  in  any  sense 
predatory  upon  Scale-insects.  With  the  hard-shelled  Diaspina3  ants  do 
not  concern  themselves,  except  that  most  of  the  carnivorous  kinds  will 
feed  upon  the  contents  of  a  scale  which  they  chance  to  find  torn  from  the 
bark.  Many  of  the  softer  CoccidaB  are  attended  by  ants  and  to  some 
extent  protected  by  them,  for  the  honey  which  they  produce,  and  upon 
which  the  ants  feed  greedily  without  in  the  slightest  degree  harming  or 
even  disturbing  the  Coccids  themselves. 

The  Chinese,  it  is  said,  have  an  ant  which  is  really  predatory  upon 
Scale-insects,  and  which  they  colonize  in  some  manner  about  their  trees 
for  the  purpose  of  clearing  them  of  these  pests.  If  such  a  species  ex- 
ists, its  importation  to  this  country  would  be  a  great  boon  and  could 
undoubtedly  be  accomplished.  There  is  in  fact  nothing  impracticable 


COLEOPTEROUS    INSECTS    PREYING    UPON    BARK-LICE.  71 

in  the  idea  of  domesticating  ants  and  in  keeping  them  with  their  nests 
in  movable  hives,  as  we  do  bees. 

We  have  in  Florida  a  minute  yellow  ant,  very  common,  and  very 
troublesome  in  houses,  which  might  perhaps  be  employed  in  this  way. 
This  species  seeks  the  shelter  of  buildings  and  hollow  tree-trunks ;  it 
has  not  as  yet  been  found  possible  to  induce  them  to  remain  domiciled 
in  exposed  situations,  and  to  attack  the  Scale-insects  upon  living  trees 
in  the  open  air,-  but  when  branches  covered  with  scale- are  brought  into 
the  house,  they  are  voraciously  attacked,  the  scales  eaten  into  or  torn 
from  the  bark  and  their  contents  devoured.  The  nests  of  this  ant  are 
found  in  very  dry  and  sheltered  situations.  It  is  not  difficult  to  estab- 
lish a  colony  in  a  box  filled  with  shavings,  paper,  or  other  loose  material. 
In  order  to  accomplish  this,  one  or  more  of  the  large  queens  must  be 
obtained  and  confined  with  a  sufficient  number  of  the  workers  to  act 
as  attendants.  If  the  box  is  kept  in  a  suitable  place,  the  ants  will  ac- 
cept their  new  quarters,  and  may  be  allowed  to  roam  at  large  and  for- 
age for  themselves  and  their  young,  but  the  slightest  exposure  to  light 
or  dampness  will  cause  them  to  desert  the  hive  never  to  return.  It  is 
this  dislike  of  exposure  tnat  has  hitnerto  baffled  every  endeavor  to 
colonize  this  ant  upon  orange  trees  and  use  it  as  a  destroyer  of  the  Scale- 
insect.  Further  experiments  with. this  and  other  species  are  necessary 
to  determine  whether  any  of  them  can  be  effectively  employed  against 
Scale-insects. 

INSECTS  OF  THE  ORDEE  COLEOPTERA. 

LADY-BIRDS — Coccinellidce. 

The  beetles  of  this  family  are  among  the  most  efficient  destroyers  of 
Bark-lice  and  also  of  Plant-lice.  Formerly  they  were  supposed  to  feed 
exclusively  upon  small  insects  of  various  kinds.  Although  it  is  now 
known,  through  the  investigations  of  Prof.  S.  A.  Forbes  and  others,  that 
the  spores  of  fungi  and  other  vegetable  matter  constitute  a  large  part 
of  the  food  of  our  common  species,  they  are  not  on  that  account  the  less 
valuable  in  the  orange  grove. 

The  family  contains  numerous  genera  and  species  which  fall  into  two 
divisions ;  the  first,  containing  the  species  of  larger  size,  includes  the 
common  insects,  which  are  popularly  recognized  as  "Lady -birds ";  the 
second  division  embraces  nearly  all  the  smaller  kinds,  many  of  them 
insects  of  minute  size,  but  very  voracious  and  active  destroyers  of  plant- 
eating  insects  and  their  eggs. 

THE  TWICE  -  STABBED  LADY- BIRD  (Chilocorus  Mvulnerus,  Muls.). 
[Fig.  26,  beetle;  Fig.  27,  larva.]— This  species  is  5mm  (-ft-  inch)  long, 
nearly  hemispherical  in  shape,  shining  black,  with  a  red  spot  on  each 
wing-case. 

The  larva  is  rather  broadly  oval,'the  color  bluish-black,  with  the  first 
body -joint  whitish.  The  body  bristles  with  black  spines,  which  are  in 


72 


INSECTS    AFFECTING   THE    ORANGE. 


Fin.  2G.  — Chiloco- 
rus bivulaierus. 
( After  Riley.) 


l''l(}.  27.  —  Chilocorus 
bivitlnerus,  larva. 
(After  Comstor-k.) 


turn  covered  with  spinules  and  give  to  the  insect  a  mossy  appearance. 
The  spines  are  arranged  in  six  longitudinal  rows. 

The  larva,  when  full  grown,  attaches  itself  firmly  by 
the  false  legs  at  the  end  of  the  body,  and  becomes  wedge- 
shaped;  the  skin  of  the  back  splits  and  gapes  open,  part- 
ly disclosing  the  pupa,  which,  however,  remains  within 
the  skin  of  the  larva.  This  mode  of  pupating  is  char- 
acteristic of  the  entire  family. 

The  pupa  is  short  and  thick,  tapering  suddenly  behind, 
in  color  black,  mottled  with  dusky  brown.  The  stout  spines  of  the  larva 
are  replaced  by  patches  of  spiny  hairs. 

The  Twice-stabbed  Lady-bird  is  as  abundant  in  Flor- 
ida as  in  all  parts  of  the  eastern  and  southern  United 
States,  and,  with  its  larva,  is  frequently  seen  upon  the 
orange  trees,  feeding  upon  Scale-insects  and  also  upon 
Aphis.  It  is  rather  fond  of  cool,  damp  situations,  and 
is  most  abundant  in  old  groves,  upon  the  trunks  of 
trees  infested  with  Chaff  Scale  and  fungi.  It  tears  up 
the  scales  and  devours  the  Coccids  and  their  eggs. 
Several  broods  occur  during  the  year.  The  larvae  ap- 
pear to  be  somewhat  gregarious,  and  frequently  when 
they  form  their  pupae  suspend  themselves  in  clusters  to  shreds  of  Span- 
ish moss  or  in  patches  upon  the  bark  when  it  is  coated  with  lichens. 

EXOCHOMUS  CONTRISTATUS  Muls.  (Fig.  28,  beetle ;  Fig.  29,  larva.)— 
This  is  a  much  smaller  species  than  the  preceding.  The  beetle  is  3.3mm 
(0.13  inch)  long.  The  head,  thorax,  and  body  beneath  are  black,  but 
the  wing-cases  are  red,  with  ablack  spot  near  the  tip  of 
each. 

The  larva  has  the  oval  form  and  spiny  appearance  of 
Chilocorus  bivulnerus,  but  is  handsomely  marked  with 
black  and  white.  The  spines  of  the  latter  become  in 
this  species  prominent  spiny  tubercles. 

The  pupa  is  not  provided  with  spiny  hairs,  but  is 
smooth  and  marbled  with  black  and  yellowish  brown,  in  a  manner 
recalling  the  shell  of  the  tortoise. 

In  habits  this  Lady-bird  hardly  differs  from  its  larger  relative.  Chilo- 
corus bivulnerus.    It  however  shows  no  preference 
for  the  shade,  and  is  found  feeding   in  exposed 
situations  upon  the  branches  infested  with  Scale- 
insects,  or  upon  shoots  covered   with  Plant  lice. 
It  is  exclusively  a  southern  species.     In  Florida 
it  occurs  everywhere  upon  the  Oak,  and  frequent- 
ly becomes  abundant  in  the  orange  grove,  where 
it  does  good  service  in  ridding  the  trees  of  in- 
sect pests,  devouring  the  eggs  and  the  young  of  the  larger  kinds,  and 
tearing  up  the  scales  of  Bark-lice  in  order  to  feed  upon  their  contents, 
contents.     It  is  also  an  active  destroyer  of  the  Orange  Aphis. 


FIG.  28.—Exocho- 
mug  contrista 
tus.  (Original.) 


FIG.  IQ.—Exochomus  con- 
tristatus,  larva1  (Orig- 
inal.) 


COLEOPTEROUS    INSECTS    PREYING    UPON    BARK-LICE. 


73 


THE  BLOOD-RED  LADY-BIRD  (Cycloneda  sanguined,  Linn.).    (Fig.  30, 
larva  :  Fig.  .'51,  pupa;  Fig.  32,  adult  beetle,  enlarged  and  natural  size.] — 


FIG.  30.— Cycloneda, 
larva  —  enlarged. 
( After  Comstock.) 


Fit;.  SI.  —  Cycloneda  san- 
guinea,  pupa — enlarged. 
(After  Comstock.) 


FIG.  32. — Cycloneda  sanguined  — 
natural  size  and  enlarged.  (Af- 
ter Comstock.) 


As  its  name  indicates,  the  color  of  this  species  is  orange-red  or  blood- 
red,  varying  somewhat  in  individuals.  The  head  and  thorax  are  black, 
each  with  a  pair  of  yellowish  spots ;  the  thorax  is  also  bordered  with 
yellow.  Length  5mm  (•$>  inch).  The  larva  is  of  a  more  elongate  form 
than  the  preceding  species ;  the  body  not  armed  with  spines,  but  with 
rows  of  small  tubercles  bearing  tufts  of  short  hairs.  The  colors  are 
bluish-black  spotted  with  orange. 

The  pupa  is  orauge  yellow,  clouded  and  spotted  with  dusky  brown  or 
black. 

This  is  a  most  common  and  widely-distributed  species,  extending 
even  to  California,  where,  however,  it  is  said  to  be  less  abundant  than 
in  the  East.  Like  most  of  the  species,  it  is  not  connected  with  any 
particular  plant,  but  is  found  wherever  Plant-lice  occur,  feeding  upon 
their  honey-dew  in  preference  to  Bark-lice  or  other  insects,  but  not  sel- 
dom attacking  the  Orange  Scale-insects  when  the  Aphis  is  not  at  hand. 
It  is  a  sun-loving  species,  and  is  most  active  and  voracious  in  the  hot- 
test weather. 

HIPPODAMIA  CONVERGKENS  Guer.  (Fig.  33,  larva,  pupa,  and  adult ; 
Fig.  34,  beetle,  enlarged.) — This  species  is  also  com 
mon  from  the  Atlantic  to  the  Pacific,  and  every- 
where feeds  voraciously  upon  the  various  species 
of  Aphis  and  Bark-lice.  Its^ving-cases  are  orange, 
red,  with  five  or  six  rather  small  black  spots  on 
each,  but  the  remainder  of  the  body  is  black.  The 
head  has  a  white  crown  and  the  thorax  is  edged 
with  white  and  has  two  converging  dashes  or  short  lines  of  white  upon 
the  disk. 

The  pupa  is  orange-red,  of  the  same  shade  as  the  wing-cases  of  the 
adult,  and  has  upon  its  surface  a  varying  number  of  black  spots.  The 
spots  are  in  some  individuals  entirely  wanting,  but  three  spots  upon 
each  wing-pad  and  at  least  one  pair  upon  the  first  abdominal  joint  are 
very  rarely  absent.  The  surface  of  the  pupa  is  without  spines  or  hairs. 


FIG.  33.—Hippodamia  con- 
vergens.     (After  Riley.) 


74 


INSECTS   AFFECTING   THE    ORANGE. 


The  larva  has  the  same  general  colors  as  the  perfect  beetle,  but  is 
mottled,  the  brighter  red  appearing  as  spots  surrounded  by  dusky 
areas ;  the  prominences  upon  the  back  of  each  body-joint  are  clothed 

with  downy  hairs;  the  single  pair  upon  each 
of  the  first  three  joints  forms  raised  shields 
of  black  color  j  the  head  and  legs  are  dark. 
The  larva  of  this,  as  well  as  that  of  some 
other  species,  is  attacked  by  an  internal  par- 
asite which  causes  its  death  soon  after  it 
has  become  adult.  The  Lady-bird  larva 
attaches  itself  to  the  plant  in  the  manner 
usual  to  it  when  about  to  change  into  pupa; 
the  pupa,  however,  never  appears,  but  the 
body  of  the  larva  becomes  rigid  and  dry,  and 
in  shrinking  sometimes  discloses  the  outlines  of  the  little  oval  cells 
formed  by  the  parasites  within.  The  number  of  parasites  found  in  the 
body  of  a  single  Lady-bird  varies  from  three  to  six,  or  even  eight.  Each 
parasite  finally  issues  through  a  separate  hole,  eaten  in  the  skin  of  its 
host,  and  appears  as  a  little  four- winged  fly  of  black  color  and  with 
banded  wings  (Fig.  35).  It  has  been  described  by  Mr.  L.  O.  Howard 


FIG.  31. — Hippodamia  convergens — 
natural  size  and  enlarged.  (After 
Comstock.) 


FIG.  35.— Homalotylus  obscurus.    (Original.) 

(Bull.  5,  Entom.  Bureau,  United  States  Department  of  Agriculture, 
1885,  p.  22)  under  the  name  of  Homalotylus  obscurus.  Species  of  the 
same  genus  are  known  to  attack  the  larvae  of  Lady-birds  in  Europe. 


COLEOPTEROUS    INSECTS   PREYING    UPON    BARK-LICE.  75 

THE  SCALE-DEVOURING  HYPERASPIDIUS  (Hyperaspidius  coccidivorus 
Ashinead;  Plate  V,  Fig.  2;  «,  larva;  &,  head  of  larva  much  enlarged; 
c,  part  of  side  margin  of  the  head,  showing  antenna  and  ocelli ;  d,  bee- 
tle.)— Although  on  account  of  its  small  size  this  little  beetle  has  been 
generally  overlooked,  it  is'probably  the  most  useful  of  its  family  as  a  de- 
stroyer of  Bark-lice.  It  attacks  principally  the  Chaff  Scale  (Parlatoria 
pergandii)^&i\d  lives  in  colonies  upon  the  trunks  and  branches  of  orange 
trees  infested  with  this  scale.  Both  the  perfect  beetle  and  its  larva 
busy  themselves  without  ceasing  in  emptying  the  scales  of  their  con- 
tents, and  many  instances  have  been  observed.of  trees  ultimately  cleared 
of  Chaff  Scale  through  their  persistent  efforts. 

The  larva  is  1.8mm  (T£«y  inch)  in  length;  body  dark  purple,  covered 
with  minute  pubescence  having  a  silver-gray  reflection  ;  the  head  and 
legs  black. 

The  pupa  has  the  color  of  the  larva,  and  the  form,  in  outline,  of  the 
perfect  beetle. 

The  imago  is  broadly  oval,  shining  black,  with  a  badly-defined  red 
spot  upon  each  wing-case.  Length,  lmm  (yfy  inch). 

The  strength  of  the  little  insect  is  apparently  not  sufficient  to  pene- 
trate the  hard  scales  of  some  of  the  Diaspina3 ;  it  is  not  often  seen  to 
attack  either  the  Lou  g  Scale  (M.  gloverii)  or  the  Purple  Scale  (M.  citricola), 
but  appears  most  frequently  upon  trees  infested  with  Chaff  Scale  (P.per- 
(jandii).  Even  here  it  does  not  seem  able  to  bite  through  the  upper 
shell,  but  inserts  its  thin,  wedge-shaped  head  and  jaws  between  the 
Scale-insect  and  the  bark  and  eats  into  it  from  below.  The  perfect  in- 
sect, and  to  some  extent  the  larva  also,  devour  the  young  of  any  species 
of  Bark-louse,  but  have  not  been  observed  to  attack  Aphis  or  any  other 
insect. 

The  young  hatch  in  spring,  from  eggs  laid  in  patches  among  the 
scales. 

EPITRAGUS  TOMENTOSUS;  family  Tenebrionidw.  (Fig.  30.)— This  is 
about  half  ail  inch  in  length,  regularly  oval  in  form,  and  convex  above. 
The  body  is  dark  brown,  densely  sprinkled  with  ash- 
gray  pubescence.  The  habits  of  the  perfect  insect  are 
similar  to  those  of  the  Lady-birds,  and  it  is  very  com 
monly  found  upon  orange  trees,  engaged  in  feeding  up- 
on Scale-insects  of  all  kinds.  It  tears  the  scale  from 
the  bark  and  devours  the  contents,  and  sometimes  the 
substance  of  the  scales  also.  Its  early  history  is  un- 
known, but  the  larva  probably  lives  upon  the  ground 
among  oak  leaves.  The  beetle  is  also  found  abundantly 
upon  scrubby  oaks,  where  it  feeds  also  upon  Bark-lice. 

Mulching  the  trees  with  oak  leaves  is  very, certain  to 
attract  these  beetles,  and  they  do  good  service  in 
checking  the  increase  of  Scale-insects,  although  they  are  seldom  pres- 
ent in  sufficient  numbers  to  effectually  clean  the  trees. 


76  JNSECTS    AFFECTING    THE    ORANGE. 

PREDATORY  LEPWOPTEEA. 

THE  CocciD-EATiNa  DAKRUMA  (Dakruma  coccidivora  Con  x).  [Plate 
VI,  Fig.  3:  a,  egg;  &,  larva;  c,  pupa;  <Z,  motli;  e,  moth  resting  *»n  a  Bark- 
louse.] — The  predatory  habits  of  this  little  moth  were  first  ma  le  known 
by  Professor  Comstock  (North  American  Entomologist,  I,  p.  25),  who 
found  its  larva  eating  various  species  of  Bark-lice.  It  is  also  v,  ry  com- 
mon in  the  spring  of  the  year  on  orange  trees  infested  by  the«oft  bodied 
Coccids,  Lecanium,  Ceroplastes,  &c.,  and  does  incalculable  service  ii  clear- 
ing them  of  these  pests.  It,  however,  does  not  attack  the  Dia  'pinae 
unless  compelled  by  hunger  to  do  so,  and  seems  to  experience  some  diffi- 
culty in  biting  through  their  hard  scales. 

Several  larvae  live  together  socially  in  silken  galleries,  with  wh  oh 
they  cover  twigs  and  branches  infested  with  Scale-insects.  Undt  v- 
ueath  the  covering  of  web  the  caterpillars  of  Dakrurua  move  back  an  t 
forth,  actively  engaged  in  removing'  the  Bark-lice  from  the  bark  am ' 
suspending  them  in  the  investing  web.  Nothing  could  be  more  thor 
ough  than  their  work.  Branches  iucrusted  with  Lecanium  scales  ar< 
very  quickly  cleared  of  the  lice,  and  the  Dakrurna  larvae  do  not  cease  to 
extend  their  operations  until  every  individual  Ooccid  in  the  colony  has 
been  lifted  from  its  place  and  securely  fastened  in  the  web  above. 

While  constructing  their  galleries  the  caterpillars  stop  occasionally 
to  feed  upon  the  Coccids.  At  such  times  they  seldom  finish  their  repasts, 
but,  like  busy  workmen,  as  they  are,  hastily  snatch  a  bite  or  two  by  way 
of  lunch,  and  suspend  the  half- devoured  fragments  in  their  web.  When 
the  entire  scale  colony  has  been  secured  within  its  net,  the  Dakruma 
larva  rests  from  its  labors  and  feeds  at  leisure  upon  the  Coccids  sus- 
pended in  its  larder.  It  devours  not  only  the  eggs  and  young  and  the 
softer  parts  of  the  Bark-lice,  but  even  to  some  extent  their  harder  skin 
or  scale.  The  result  of  its  operations  upon  Lecanium  and  Ceroplastes 
scales  is  to  utterly  annihilate  the  colonies  of  these  insects  which  they 
attack. 

Larva. — A  rather  slender  caterpillar,  nearly  half  an  inch  in  length, 
very  dark  green,  almost  black  in  color ;  the  body  bears  a  few  long  hairs 
arising  from  pale  brown  spots. 

Pupa. — The  chrysalis  is  formed  within  the  galleries  of  the  larva,  and 
is  loosely  wrapped  in  a  cocoon  of  silk.  It  is  slender,  tapering  to  the 
anal  extremity,  of  varying  shades  of  brown,  darkest  on  the  back  and 
lighter  on  the  belly  and  wing-pads. 

Imago. — A  small,  dark  colored  moth,  one-third  of  an  inch  in  length. 
The  body  is  dark- brown  above  and  gray  beneath ;  the  forewings  are 
light  gray,  with  markings  of  brown  and  black;  the  eyes  are  black  and 
distinctly  faceted. 

Egg. — White,  oval,  the  surface  covered  with  a  network  of  raised 
lines,  the  meshes  forming  irregular  hexagons. 

History. — The  eggs  are  laid  singly  among  the  Coccids;  they  hatch  in 
five  or  six  days  ;  the  caterpillars,  if  food  is  abundant,  attain  their  full 


LEPIDO1  ,fERA    PREDATORY    ON    BARK-LICE.  77 

growth  in  ten  or  twelve  days  5  their  pupa  stage  lasts  about  the  same 
length  of  time,  unless  belated  in  June  or  July,  in  which  case  they  re- 
main in  pupa  until  the  heat  moderates  in  August  or  September.  The 
caterpillars  are  first  seen  in  March,  but  are  not  common  until  April  or 
.May.  The  moths  are  most  abundant  in  June,  but  disappear  in  mid- 
summer and  appear  again  in  the  fall.  There  are  at  least  two,  and  pos- 
sibly three,  broods  in  the  spring  and  early  summer,  and  one  in  the  fall. 
The  pupa}  and  a  few  belated  larv.t  may  be  found  in  winter  at  any  time. 

THE  PALE  DAKRUMA  (D.pallida  Com  stock). — Another  species,  closely 
resembling  the  preceding  and  having  similar  habits,  is  described  by 
Professor  Oomstock  (Eept.  Coinm.  Agric.  for  1879,  p.  243)  from  gall-like 
Coccids  on  Oak.  From  its  similarity  of  habit  this  species  may  be  ex- 
pected to  feed  upon  Orange  Scale-insects,  although  it  has  not  been  actu- 
ally observed  to  do  so.  It  is  known  from  the  first  species  by  its  lighter 
color  in  both  the  adult  and  larval  stages. 

SCALE-EATING  TiNEiD.2  (Fig.  37.) — The  caterpillars  of  a  Tineid  moth 
with  habits  very  similar  to  Dakruma,  are  found  eating  various  Coc- 
cids, and  have  also  been  observed  to  feed 
upon  the  common  Long  and  Chaff  Scales 
on  Orange.  Several  specimens  of  the 
moth  were  bred  in  winter  from  larva? 
inhabiting  tightly-rolled  dead  leaves  in- 
volved in  the  webs  of  a  social  leaf -eating 

Caterpillar     (Anwglis).      The    leaves    thus      FlG-  37- -Scale-eating  Tineid.   (Original.) 

occupied  had  been  infested  by  Scale-insects,  and  the  scales  within  the 
retreat  of  the  larvae  were  all  gnawed  and  partially  devoured. 

In  summer  the  same  species  is  found  forming  silken  galleries  like 
those  of  Dakruma  upon  orange  branches  infested  with  Diaspinous  scales. 

The  following  observations  of  the  habits  were  made  upon  several 
larvti1.  placed  upon  a  twig  of  Orange  covered  with  Long  Scale  (Mytilas. 
pis  gloverii).  The  Iarva3  began  at  once  to  make  a  tangle  of  web  in  a  fork 
of  the  twig,  which  was  afterwards  extended  into  a  gallery  along  the 
branch.  From  time  to  time  a  larva  reached  out  and  tore  a  scale  from 
the  bark.  Sometimes  it  devoured  the  whole  scale,  with  the  contained 
insect;  again  it  turned  the  scale  over  and  ate  the  contents,  eggs  and 
mother  Coccid,  retreating  finally  to  its  gallery  and  taking  with  it  the 
empty  shell,  which  it  fastened  in  its  web.  Occasionally  the  caterpillars 
detached  from  tho  bark  and  fastened  in  their  web  scales  with  their  liv- 
ing contents  untouched.*  From  the  frequent  additions  made  to  it,  the 
retreat  of  the  caterpillars  soon  became  entirely  coated  with  fragments, 
and  could  with  difficulty  be  distinguished  from  the  surrounding  bark. 

*  The  contents  of  these  scales  were,  however,  sooner  or  later  devoured.  The  larvae 
also  frequently  gnawed  into  a  scale  at  one  end  and  pulled  out  and  devoured  the  in- 
sect, leaving  the  empty  scale  still  attached  to  the  bark.  They  also  ate  sparingly  the 
gummy  exudations  of  the  bark. 


78  INSECTS   AFFECTING   TUE    ORANGE. 

These  fragments  consisted  in  great  part  of  half-eaten  scales,  from  which 
the  eggs  and  the  Coccids  had  been  extracted. 

Larva. — The  caterpillars  are  about  one-fourth  inch  long,  dark  purple 
in  color,  with  lines  of  lighter  color  in  fine  blotches  along  the  sides. 

Pupa. — The  chrysalis  is  sometimes  formed  upon  the  branches  within  a 
cocoon  of  silk  densely  covered  with  scales,  and  sometimes  concealed  in 
a  dead,  rolled  leaf,  or  otherwise  protected  under  fragments  lodged  in 
spider-webs,  &c.  It  is  dark  brown  in  color,  and  of  the  usual  form,  with- 
out striking  peculiarities. 

Imago. — The  moth  is  less  than  one-third  inch  in  length,  with  rather 
long  wings  ;  head  and  thorax  are  ashen  gray ;  the  upper  wings  are  lus- 
trous lead  color,  with  silvery  scales  intermixed ;  they  are  marked  each 
with  a  single  distinct  black  spot  near  the  base  and  a  pair  of  faint  dots 
near  the  tip.  The  under  wings  are  silvery  gray,  with  the  membrane 
showing  iridescent  blue  between  the  scales  in  the  middle  of  the  wing ; 
the  antenna  in  one  sex  has  the  third  joint  thickened  and  curiously  ex- 
cised, the  excavation  covered  with  a  tuft  of  long  scales. 

History. — The  Iarva3  of  this  species  have  been  observed  Only  iii  the 
fall  and  winter  months,  and  the  number  of  broods  is  not  known.  It  may 
be  assumed  to  have  three  or  four  broods.  Moths  appeared  in  thirteen  or 
fourteen  days  from  pupa3  formed  late  in  September.  In  December  and 
January  they  remained  twenty  days  in  pupa. 

Two  other  moths  of  this  family  ( Tineidcv]  have  been  noted*  as  feeding 
upon  Coccids  in  Florida,  but  they  were  bred  only  from  gall-like  Bark- 
lice  found  upon  Oak,  and  never  occurring  upon  orange  trees. 

INSECTS  OF  THE  ORDER  HEMIPTEEA. 

THE  SPIDER-LEGGED  SOLDIER-BUG  (Leptocorisa  tipuloides,  Latr. ; 
Plate  VI,  Fig.  4.) — This  is  a  slender,  long-legged  bug.  The  color  of  the 
body  is  orange-yellow,  with  a  rounded  spot  of  black  upon  the  thorax ; 
the  legs,  antenna,  and  tip  of  the  beak  are  black  ;  the  wings  in  the 
adult  have  a  band  of  black  across  the  middle  and  an  oval  spot  of 
black  covering  the  terminal  half;  the  legs  are  covered  with  almost  in- 
visible, short,  stiff  hairs,  which  cause  small  light  objects  to  adhere  to 
them.  The  bodies  of  the  young  especially  are  covered  with  fragments, 
consisting  in  great  part  of  the  pellicles  of  insects  which  have  been 
emptied  of  their  contents  by  the  bug.  Length  of  the  adult,  -f^  inch. 

The  habits  of  this  bug  are  sluggish,  but  it  flies  readily  when  adult. 
It  is  found,  often  in  great  numbers,  upon  the  Orange  and  other  plants 
when  they  are  infested  with  the  common  Lecanium  Scale  (Lecanium  lies- 
perldum.  Linn.).  The  bug  sucks  the  juices  of  these  soft- shelled  Bark- 
lice,  but  has  never  been  observed  to  puncture  the  hard  scales  of  the 
Diaspinse.  Unfortunately  the  Leptocorisa  does  not  discriminate  be- 
tween friends  and  foes,  but  destroys  many  predatory  and  useful  insects. 

*  Rept.  Comm.  Agric.  for  1879,  p.  244. 


HEMIPTEROUS    INSECTS    PREYING   UPON   BARK-LICE.  79 

It  has  been  observed  to  capture  and  suck  the  juices  of  ants  and  of  the 
larvae  of  the  Lace- wing  flies,  and  also  to  empty  of  their  contents  the 
eggs  of  other  insects. 

Eggs. — The  eggs  are  long,  vial-shaped  objects,  brick-red  in  color ; 
they  are  deposited  upright,  in  small  masses,  aglu  tin  a  ted  with  a  viscid, 
frothy  substance,  which  dries  very  slowly  and  remains  sticky  long  after 
the  eggs  have  hatched.  The  eggs  hatch  in  about  one  week  after  they 
are  deposited. 

Life-history. — The  number  of  broods  is  indefinite ;  solitary  individuals 
are  found  at  all  seasons,  but  become  more  numerous  in  spring  and  fall, 
upon  plants  infested  with  Lecanium  Scale,  which  also  breeds  most  rap- 
idly at  these  seasons.  The  young  suck  the  juices  of  plants  for  a  short 
time  after  hatching,  but  afterward  feed  exclusively  upon  insects.  They 
change  their  skins  frequently,  gradually  acquiring  fully-develbped 
wings  and  other  characters  of  the  adult ;  the  process  occupying,  accord- 
ing to  the  season  and  temperature,  from  three  weeks  to  two  months. 
This  species  is  much  more  gregarious  in  its  habits  than  most  predatory 
Soldier-bugs.  Not  only  the  young,  but  also  the  adult  insects  are  fre- 
quently found  in  large  colonies. 

Parasite. — The  only  enemy  known  to  attack  this  bug  is  a  minute 
Proctotrupid  fly,  belonging  to  the  genus  Telenomus?  which  is  bred 
within,  and  destroys  Us  eggs.  The  parasite  is  black,  with  yellow  legs. 
A  single  fly  issues  from  each  egg  of  the  bug,  leaving  a  round  hole  eaten 
in  the  side  of  the  shell. 

Two  small  bugs  (Hemiptera)  prey  upon  the  Mealy-bug  (Dactylopius 
destructor}.  Specimens  of  the  young  bugs  were  sent  to  the  Department 
of  Agriculture,  from  Florida,  on  leaves  of  Orange  infested  with  Mealy- 
bugs, and  were  observed  to  suck  the  eggs  and  young  lice  of  the  Mealy- 
bug. 

In  the  young  of  one  species  the  color  is  deep  red,  with  brown  eyes;  an- 
tennae and  legs  pale  reddish  or  yellowish  white,  with  the  thighs  slightly 
dusky ;  the  antennae  four-jointed,  the  fourth  joint  longest;  the  proboscis 
short,  rather  stout;  from  each  side  of  the  abdomen,  near  the  tip,  projects 
a  pair  of  long  bristles.  Length,  when  adult,  about  3mm  (y1^  inch). 

The  other  species  is  a  smaller  insect  than  the  preceding.  The  young 
bugs  are  coral-red,  the  shanks  and  tips  of  the  legs  white,  the  antennae 
also  parti-colored,  having  the  third  joint  and  tip  of  the  terminal  (fourth) 
joint  white ;  the  proboscis  is  white,  and  reaches  beyond  the  middle  of 
the  body ;  the  body  and  members  are  covered  with  short,  pale  hairs.  The 
adult  is  purple-brown,  with  lighter  eyes,  and  has  parti-colored  legs  and 
antennae;  the  wings  are  ornamented  with  a  large  chocolate  brown  spot 
edged  with  white  or  pale  red,  and  situate  at  the  base  of  the  membranous 
portion,  near  the  tip  of  each  wing- cover;  thebodyand  surface  of  the  wings 
are  thinly  covered  with  silvery  hairs,  giving  a  hoary  appearance  to  the 
insect.  Length  2.2mm  (Tf  $  inch).  The  egg  is  long  and  slender,  vase- 
shaped,  pearly  white,  with  a  tinge  of  pink,  and  has  a  white  rim  ;  it  is 


80  INSECTS    AFFECTING    THE    ORANGE. 

deposited  singly,  lying  upon  its  side,  in  any  situation  where  tbe  female 
may  find  a  lurking  place.4 

This  little  bug  is  one  of  a  number  of  insects  often  associated  with  the 
Orange  Web- worm,  Anceglis  demissalis.  (See  Chapter  X.) 

INSECTS  OF  THE  ORDER  NEUROPTERA. 
LACK -WINGS. 

CHRYSOPA.  (Fig.  38,  adult  fly  and  eggs  of  Chrysopa  ocnlata.) — There 
may  frequently  be  seen,  moving  rapidly  about  upon  the  trunk  and 

branches  of  the  orange  tree,  little  floc- 
culent  masses,  grayish  in  color,  nearly 
hemispherical,  and  of  about  the  size  of 
a  split  pea.  When  one  of  these  mossy 
bunches  is  examined  closely  it  is  found 

to  be  an  insect,  whose  back  is  covered  with  a  nondescript  collection  of 
fragments,  consisting  chiefly  of  the  dried  skins  and  broken  remains  of 
insects.  This  is  the  young  of  a  Ohrysopa,  or  Lace- wing  fly,  and  the  cov- 
ering with  which  its  soft  body  is  protected,  and  which  renders  it  less 
conspicuous  upon  the  bark,  is  formed  from  the  accumulated  remains  of 
the  victims  whose  juices  have  served  the  animal  for  food. 

The  Lace- wing  feeds  to  a  great  extent  upon  Bark-lice,  tearing  loose 
the  scales  from  the  bark,  and  after  devouring  the  soft  contents  adding 
a  portion  of  the  debris  to  the  load  upon  its  back.  Plant  lice  and  many 
other  small  insects  are  also  eaten.  The  activity  and  rapacity  of  the 
larva  is  remarkable ;  it  wanders  restlessly  over  all  parts  of  the  tree  in 
search  of  food,  and  although  insignificant  as  to  numbers  in  comparison 
with  the  swarming  millions  of  its  prey,  it  yet  exercises  an  appreciable 
influence  in  holding  them  in  check. 

Larva. — The  body  of  the  larva,  divested  of  its  extraneous  covering,  is 
somewhat  broadly  oval,  divided  into  joints,  from  the  nicies  of  which  arise 
branching  spines.  These  spines  serve  to  hold  in  place  the  loose,  dry 
materials  which  are  piled  upon  its  back.  The  legs  are  quite  long  and 
slender,  adapted  to  rapid  movements,  and  the  jaws  are  sickle-shaped, 
long  and  keenly  pointed,  projecting  beyond  the  ambuscade  under  which 
the  insect  moves. 

Pupa. — When  prepared  to  pupate,  the  larva  forms  an  almost  globular 
cocoon  by  drawing  together  with  strands  of  silk  the  loose  materials  it 
bears  upon  its  back,  and  constructing  beneath  it  a  spherical  cell  of  thin 
but  strong  parchment,  pure  white  in  color.  Within  this  the  pupa  lies 
curved  like  an  embryo.  The  pupa  has  the  form  of  the  perfect  insect, 
barely  masked  by  a  transparent  envelope,  and  with  the  wings  and  other 
members  contracted  and  closely  applied  to  the  body.  It  gradually 
changes  in  color  from  white  to  pale  green,  and  finally  issues  by  pushing 
outward  a  circular  cap  which  forms  one  end  of  its  cell. 

Imago. — The  perfect  insect  is  a  four-winged  fly,  of  a  delicate  pea-green 
color;  eyes  a  resplendent  copper  bronze.  The  wings  are  large,  closely 
veined,  hyaline  with  a  violet  reflection ;  when  at  rest  they'  meet  in  a 


MITES    WHICH    DESTROY    SCALE-INSECTS.  8i 

ridge  like  the  peak  of  a  roof.  The  antennae  are  black,  paler  outwards. 
Head  porcelain- white;  the  enlarged  first  joint  of  the  antennae,  aud  also 
a  triangular  spot  on  the  head  at  the  base  of  each  antenna  purple  red;  a 
band  of  the  same  color  on  each  side  of  the  thorax. 

Eygs. — The  eggs  are  laid  upon  various  parts  of  the  tree,  often  near  a 
colony  of  Plant  lice,  in  groups  of  five  to  fifteen,  each  supported  on  the 
end  of  an  erect,  bristle  like  stalk,  about  0.4  inch  in  length.  The  object 
of  this  device  is  said  to  be  the  preservation  of  the  egg  from  the  young 
of  its  own  kind,  for  such  is  the  rapacity  of  the  larva  that  those  first 
hatched  would  immediately  devour  the  remaining  eggs  if  they  were  de- 
posited within  reach  upon  the  surface  of  the  plant. 

Life-history. — The  development  of  Chrysopa  is  quite  rapid  in  hot 
weather,  and  is  greatly  retarded  by  cold.  There  are  apparently  but 
two  broods  each  year,  in  spring  and  fall.  Eggs  are  seen  as  late  as  the 
middle  of  July,  but  the  larvae  only  are  abundant  in  midsummer.  In 
winter  both  larvae- and  eggs  are  found,  but  the  perfect  insect  is  not 
common  except  in  early  summer  and  late  in  the  fall.  There  are  said  to 
be  several  species  of  Chrysopa  frequenting  the  Orange,  which,  however, 
are  with  difficulty  distinguished  from  each  other,  and  have  identical 
habits.  One  of  these  has  been  described  as  new  by  Ashmead  under 
the  name  Chrysopa  citri. 

Parasites  (Perilitus  sp.).5 — A  four-winged  parasite  destroys  the  Chry- 
sopa, and  issues  from  its  cocoon.  It  is  of  slender  form,  with  the  abdo- 
men stalked;  color  beneath  light  yellow,  above  black,  with  yellow  mark- 
ings; the  legs  yellow,  the  antennae  dark,  the  face  yellow;  eyes,  ver- 
tex, and  back  of  the  head  black;  the  rings  of  the  hind-body  are  alter- 
nately black  and  yellow.  Length,  3mm  (^  inch). 

HEMEROBIUS. — Several  species  of  this  genus,  which  is  closely  allied 
to  Chrysopa,  exist  upon  orange  trees  and  feed  upon  the  young  of  Bark- 
lice,  and  to  a  still  greater  extent  upon  Plant-lice  (Aphis).  They  have 
nearly  the  same  habits  as  Chrysopa,  but  the  larvae  do  not  protect  them- 
selves with  a  covering  of  fragments.  The  larvae  are  mottled  with  gray, 
brown,  and  dull  red,  and  are  more  slender  than  those  of  the  preceding 
species. 

The  pupa  is  formed  in  a  globular  cocoon  of  white  parchment,  not 
covered  with  fragments. 

The  perfect  insect  is  much  smaller  than  Chrysopa ;  the  wings  are  less 
transparent,  and  are  covered  with  down  of  light-brown  color. 

MITES— A  CA  RINA . 

Next  to  their  internal  parasites,  Mites  constitute  the  most  important 
enemies  of  Scale-insects,  and  exert  a  constant  and  very  powerful  influ 
ence  in  checking  their  increase.  They  are  at  all  times  present  wherever 
Scale-insects  exist,  and  in  numbers  limited  only  by  the  food  supply. 
They  cannot  penetrate  the  hardened  shells  of  mature  Scale -insects,  but 
6521  o  I 6 


82  INSECTS    AFFECTING    THE    ORANGE. 

they  destroy  great  numbers  of  the  young  lice,  as  soon  as  the  latter  have 
fastened  themselves  to  the  bark,  and  while  their  scales  are  still  soft  and 
thin.  They  also  creep  into  the  open  end  of  scales  which  have  begun  to 
hatch,  and  destroy  a  portion  of  the  eggs.  The  scales  vacated  by  para- 
sites, in  which  have  been  left  convenient  open  doorways,  furnish  the 
Mites  with  secure  retreats  and  places  of  deposit  for  their  eggs.  Usually 
the  dry  and  distended  skin  of  the  Coccid  is  left  by  the  parasite,  nearly 
filling  the  scale,  and  with  a  minute  exit  hole. immediately  opposite  that, 
in  the  outer  shell.  Thus  the  Mites  or  their  young  and  eggs  are  provided 
with  a  double  envelope  separated  by  layers  of  confined  air,  and  nearly 
impervious  to  liquids.  It  is,  therefore,  not  astonishing  that  applica- 
tions sufficiently  penetrating  to  kill  Scale-insects  do  not  reach  the  Mites 
and  their  eggs  thus  protected.  In  fact  the  latter  very  frequently  in- 
crease enormously  after  an  effective  application,  because  the  loosening 
of  the  scales  by  the  wash  enables  them  to  penetrate  to  and  feed  upon 
the  dead  or  dying  Bark-lice,  and  the  supply  of  food  is  for  a  time  largely 
increased. 

To  cause  a  marked  increase  in  the  number  of  the  Mites,  it  is  some- 
times sufficient  to  loosen  the  scales  here  and  there  upon  the  trunk  and 
branches  which  are  most  thickly  encrusted  with  them,  by  scraping  the 
bark  with  a  stick  or  knife  blade.  This  gives  the  Mites  an  increased  sup- 
ply of  food,  and  stimulates  them  to  active  breeding.  The  result  is 
often  to  effectively  check  the  progress  of  the  Scale-insects  for  the  time 
being,  although  they  cannot  be  exterminated  in  this  way.  The  method 
is  not  advanced  as  a  practicable  remedy,  and  cannot  be  made  to  replace 
the  proper  application  of  insecticides,  but  from  its  simplicity  it  is  fre- 
quently useful  as  a  means  of  gaining  time,  when  remedies  are  not  at 
hand. 

GLOVER'S  ORANGE  MITE  (Tyroylyphus  f  glorerii  Ashniead).  [Plate 
VI,  Fig.  5.]— This  is  the  commonest  species  found  among  Orange  Scale- 
insects;  it  is  also  the  smallest  species  and  the  most  active  and  rapid  in 
its  movements;  it  is  somewhat  longer  than  broad,  slightly  flattened  ; 
in  color  it  varies  from  pure  white  to  yellowish,  and  often  a  pale  pink  or 
.  flesh-color.  This  color- variation  is  due  to  the  varying  nature  of  its  in 
testiual  contents,  seen  through  the  semi  transparent  body.  Length 
about  O.lmm  ( -roVo-  inch).* 

The  eggs  are  white,  and  are  deposited  either  singly  or  in  small  groups, 
under  a  tangle  of  spider's  web,  among  dead  scales,  &c. ;  lurking  places 
in  which  the  white,  six  legged  young  congregate  and  undergo  their  trans- 
formations. 


*  The  form  iu  most  soft-bodied  Acariuais  very  changeable.,  depending  upon  the  con- 
dition of  the  animal,  whether  full-fed,  or  depleted  by  fasting.  The  figure  of  this 
species  on  Plate  VI  represents  the  shape  commonly  seen.  When  emaciated,  the  sides 
of  the  body  become  deeply  sinuate  or  lobed,  deep  pits  are  formed  upon  the  upper  sur- 
face in  front,  and  several  transverse  folds  iu  the  skin  appear  to  divide  the  abdominal 
portion  into  segments.  In  plethoric  individuals,  the  disteution  of  the  body  into  an 
oval  sack  obliterates  every  trace  of  fold  or  depression  upon  its  surface. 


MITES    WHICH    DESTROY    SCALE-INSECTS  83 

This  species  certainly  feeds  upon  the  eggs  of  Coccids,  and  probably 
also  upon  their  young,  and  sucks  the  juices  of  the  adult  Bark-lice,  when- 
ever it  can  get  at  them. 

THE  HAIRY  ORANGE  MITE.*—  Probably  the  next  in  point  of  abund- 
ance is  a  larger  mite,  dark  red  in  color,  covered  with  pale  hairs,  broadly 
oval  in  form,  and  with  several  irregular  indentations  upon  the  back. 
This  mite  is  als,o  very  rapid  in  its  movements,  and  is  certainly  predatory 
upon  Scale-insects  or  their  eggs. 

The  eggs  are  sherry -brown  in  color,  quite  large  and  globular,  and  aie 
usually  deposited  singly  upon  the  leaf  among  scales,  or  strung  like 
amber  beads  upon  strands  of  spider's  web,  which  harbor  the  mites  and 
their  young.  ' 

The  six-legged  young  are  spindle-shaped,  of  a  lighter,  ruby-red  color, 
the  extremities  pale,  and  have  an  eye-like  prominence  on  each  side  of 
the  anterior  body.  The  length  of  the  adult  is  0.3mm  (T^f-0  inch). 

THE  SPEAR-HEAD  MiTE.7 — Another  not  uncommon  Ked  Mite  seems  to 
be  predatory  upon  Scale-insects.  It  is  rather  larger  than  the  preced- 
ing 5  dull,  opaque  red,  not  hairy ;  the  body  is  distinctly  diamond  or 
spear  shaped,  somewhat  flattened,  with  a  sharp  median  ridge  upon  the 
back,  having  on  each  side  a  longitudinal  depression ;  a  band  of  pale 
brown  is  sometimes  seen  across  the  middle  of  the  back.  Length,  0.35mm 
(i-Jfo  inch). 

This  species  is  sluggish  and  solitary.  The  eggs  are  deep  red,  globu- 
lar, and  are  deposited  singly  among  scales. 

There  are  numerous  species  of  Mites  found  about  and  among  Scale- 
insects,  of  which  a  few  only  appear  to  be  dependent  upon  them  for  their 
subsistence,  or  peculiar  to  the  orange  tree  and  its  kind.  Some  of  these 
mites  are  undoubtedly  merely  scavengers,  living  about,  if  not  upon,  the 
dirt  and  debris  that  collect  where  the  plant  is  fouled  with  Scale-insects, 
but  never  appearing  to  attack  the  insect  itself  in  any  stage.  Possibly 
they  feed  upon  the  excrement  or  excretions  of  other  insects,  or  upon 
molds  that  accompany  such  ejected  mattep. 

The  predatory  Mites  are  usually  active,  running  hither  and  thither 
restlessly,  occasionally  stopping  to  examine  the  sealed  edge  of  a  scale 
or  to  pry  into  a  vacant  and  deserted  shell. 

The  young  of  Mites  frequently  differ  entirely  from  the  adults  in  form 
and  coloration;  they  have,  moreover,  but  three  pairs  of  legs,  while  the 
adults  have  four  pairs.  The  life-history  of  many  species  is  imperfectly 
known. 

THE  SPOTTED  MiTE.8— This  is  a  rather  large,  egg-shaped  or  pear- 
shaped  Mite,  with  a  very  plump,  smooth,  shining,  and  pellucid  body, 
either  white  or  honey -yellow  in  color,  and  provided  with  a  few  very 
long  and  fine  bristle-hairs  ;  the  division  of  the  body  into  two  parts  is 
barely  indicated  by  a  fine  line;  in  adult  specimens  the  bo.dy  behind  is 
more  or  less  clouded  with  red-brown,  forming  sometimes  a  distinct  spot; 
a  large  round  spot  on  each  side,  upon  the  declivities  of  the  hind-body, 


84 


INSECTS    AFFECTING    THE    ORANGE. 


varies  in  color  with  the  age  and  condition  of  the  individual,  from  sulphur- 
yellow  to  brick-red  and  dull  brown.     Length,  0.3Smm  (T^-Q-  inch). 
The  Mite  is  slow  in  movement,  and  gregarious.    White,  elongate  eggs, 
and  the  six-legged  young  are  found  in  groups  of 
three  or  four  to  twenty  upon  scale-infested  orange 
leaves. 

While  this  Mite  may  with  sdtoe  probability  be 
considered  a  scavenger,  feeding  upon  dead  vege- 
table and  animal  matter,  it  is  almost  certain  that 
it  does  also  suck  the  eggs  of  Scale-insects,  with 
which  it  is  very  closely  associated. 

A  species  of  Rhlzoglyphus  (?),9  similar  to  but 
distinct  from  the  preceding,  was  sent  by  Professor 
Comstock  from  Florida.  It  was  found  in  all  stages 
from  egg  to  adult  on  orange  leaves  infested  with 
the  Long  Scale  and  the  Common  Mealy-bug.  Fig. 
FIG.  M.-orange  Mite.  (Origi-  39  represents  the  mite,  after  a  drawing  by  Mr. 
Th.  Pergande;  the  following  are  his  notes  upon  the 
species:  u These  Mites  were  especially  numerous  around  the  Mealy-bugs, 
and  they  were  noticed  to  suck  and  destroy  the  eggs  of  that  insect ;  the 
eggs  of  the  Mite  were  deposited  between  the  egg-masses  of  the  Louse 
and  also  on  the  leaf  itself ;  the  eggs  are  white,  perfectly  oval ;  the  Mites 

are  white,  almost  transparent,  the  full-grown 
ones  slightly  yellow,  with  one  or  sometimes 
three  pale  brownish  spots ;  when  there  is  only 
one  spot  it  is  generally  situated  on  the  pos- 
terior portion  of 
the  abdomen,  but 
when  there  are 
three  spots  they 
are  arranged  as 
shown  in  the  fig- 
ure— the  front  one 
is  largest  and  the 


FIG.  40.— Orange  Mite.     (Original.) 


two  posterior 
spots    are    small 


FIG.  ^l.  —  Tyrofllyphus  mali. 
(After  Kiley.) 


and  rather  mdis-tmct.     The  male  is  shorter 
and  stouter  than  the  female." 

Associated  with  the  foregoing  is  a  Mite 
[Fig.  40]  with  a  more  flattened  form,  concerning  which  the  following 
notes  are  given,  with  the  figure  here  produced:10 

"A  single  specimen  of  a  second  species  of  Mite  was  also  found  on  an 
orange  leaf  sent  by  Professor  Comstock,  from  Sanford,  Fla.  This  Mite 
is  quite  different  from  the  preceding;  it  is  smaller,  more  yellow,  and 
there  are  small  and  very  distinct  eyes  j  the  legs,  especially  the  first  pair, 
are  quite  differently  formed.  It  is  not  as  hairy  and  not  as  slender  as  the 


MITES    WHICH    DESTROY    SCALE-INSECTS. 


85 


other  species.    This  Mite  also  evidently  preys  either  on  the  Mytilaspis 
or  the  Dactylopius." 

A  very  long- bodied  Mite,  without  spots,  is  found  occasionally  in  empty 
Mytilaspis  scales ;  it  has  the  same  habits  as  the  Spotted  Mite.  This 
species  may  be  identical  with  Tyroglyplms  malus  Shinier,  which  preys 
upon  the  Oyster-shell  Bark-louse  of  the  Apple.  The  figures  of  the  lat- 
ter, from  Eiley7s  Fifth  Missouri  Eeport,  are  here  reproduced.  [Fig.  41.] 

THE  ORBICULAR  MITE.— This  is  the  largest  Mite  found  among  Scale- 
insects  ;  it  is  nearly  circular,  or  slightly  oval,  in  outline ;  the  body  is 
thick  and  somewhat  flattened,  covered  with  a  pol- 
ished, horny  shell  of  brown  color,  surmounted  by 
a  few  fine  bristles.    The  shell  or  carapace  is  turned 
under  at  the  sides  and  ends,  so  that  the  short, 
stout  legs  are  concealed  beneath  it  as  the  animal 
walks,  and  only  the  tip  of  the  head  and  beak  pro- 
ject beyond  the   front  margin.      Length,  about 
0.4mm  (T^  inch). 

This  is  an  active,  wandering  Mite,  undoubtedly 
predatory  upon  Scale-insects,  but  found  also  suck- 
ing the  eggs  of  many  other  insects.  Its  eggs  are 
laid,  and  transformations  undergone,  under  loose  bark  and  in  crevices, 
where  the  early  forms  are  mingled  with  those  of  numerous  other  Mites, 
from  which  they  have  not  been  clearly  distinguished.* 

A  variety  of  other  Mites  are  found  from  time  to  time  wandering  over 
scale-infested  leaves  and  branches,  but  the  forms  above  indicated  are 
believed  to  include  those  most  closely  connected  with  orange  pests. 


FIG.  42. — Nothrus  ovivorus. 
(After  Packard). 


*  This  may  be  the  Nolhrus  ovivorus  of  Packard,  Fig.  42,  which  is  found  sucking  the 
eggs  of  the  Canker-worm. 


CHAPTER  VII. 

MEANS  OF  DEFENSE   AGAINST   SCALE-INSECTS— REME- 
DIES. 

INTRODUCTION  OF  SCALE-INSECTS  ON  IMPORTED  PLANTS. 

In  the  wide  range  of  insect  life  few  forms  possess  a  greater  vitality 
than  is  found  among  the  Bark-lice,  and  none  are  more  readily  trans- 
ported upon  plants  from  place  to  place,  and  from  one  country  to  an- 
other. Whenever  orange  plants  are  imported  from  infested  districts, 
Scale-insects  will  be  brought  with  them,  and  their  introduction  and 
spread  in  regions  where  they  were  before  unknown  are  inevitable. 

Even  the  soft  and  unprotected  Coccina3  sustain  without  injury  an  as- 
tonishing amount  of  rough  handling,  and  exist  for  long  periods  of  time 
without  food  or  moisture. 

During  the  winter  of  1882->83  living  specimens  of  the  Common  Mealy- 
bug (Dactylopius  adonidum,  Linn.)  were  sent  to  the  writer,  through  the 
mails,  from  Italy  and  also  from  Morocco,  inclosed  with  a  few  orange 
leaves  in  common  letter  envelopes.  Although  the  orange  leaves  were 
entirely  dry,  and  some  of  the  insects  were  crushed  between  their  sur- 
faces, many,  even  of  the  adults,  were  found  to  be  uninjured,  and  young 
lice  had  even  been  produced  in  transit. 

The  scale-covered  Diaspina3,  it  may  well  be  supposed,  are  even  better 
able  to  sustain  long  voyages  than  their  soft-bodied  relatives,  and  their 
eggs  are  not  affected  by  long-continued  drought,  nor  by  sudden  changes 
of  temperature. 

It  can  hardly  be  doubted  that  all  the  common  Bark-lice  found  upon 
the  Orange  in  Europe  have  been  many  times  imported  into  Florida  upon- 
living  plants.  In  this  way,  in  the  year  1835,  it  is  supposed,  the  com- 
mon Long  Scale  (Mytilaspis  gloverii]  was  introduced,  first  at  Jackson- 
ville, and  subsequently  at  Saint  Augustine,  from  whence  it  spread  de- 
vastation over  all  the  groves  then  in  the  State. 

In  1855,  according  to  Glover,  a  new  scale,  probably  the  Chaff  Scale 
(Parlatoria  pergandii),  was  introduced  into  Florida  on  some  lemons  sent 
from  Bermuda.  More  recently  a  new  and  very  destructive  scale  has 
made  its  appearance  at  Orlando,  in  Orange  County,  Florida,  and  is 
slowly  but  surely  spreading  to  other  parts  of  the  State.  This  is  the 
Eed  Scale  of  Florida  (Aspidiotus  [Ghrysomplialus]  ficus  Ash  mead).  It 
was  first  observed  in  a  grove  near  Orlando,  in  the  spring  of  1879,  upon 
a  sour-orange  tree  brought  from  Havana,  Cuba,  in  1874.  Professor 
86 


REMEDIES    AGAINST    SCALE-INSECTS.  87 

Comstock  received  specimens  from  Havana,  and  learned  that  it  was  a 
very  common  pest  in  the  public  gardens  of  that  city. 

In  California,  owing  to  the  very  direct  communication  with  China 
and  Japan,  and  frequent  importations  of  plants  from  these  countries, 
many  destructive  species  of  Bark-lice  have  been  introduced  upon  fruit 
and  shade  trees.  Some  of  these  are  the  most  serious  pests  of  their  kind ; 
many  have  a  wide  range  of  food-plants,  including  also  the  Orange,  and 
one  at  least,  the  Ked  Scale  of  California,  is  peculiar  to  citrus  plants. 
It  was  introduced  into  California  from  Australia.  Professor  Corn- 
stock  believes  this  to  be  the  most  destructive  species  known  to  in- 
fest citrus  plants  in  this  country.  Its  introduction  into  Florida,  to- 
gether with  others  now  ravaging  the  groves  of  California,  is  greatly  to 
be  feared,  and  is  probably  only  a  question  of  time,  as  the  interchange 
of  plants  between  these  two  States  increases  annually. 

Not  only  plants  of  the  citrus  family,  but  many  other  trees  and  shrubs, 
and  notably  the  Olive,  may  cause  the  introduction  of  Scale- insects, 
some  of  which  have,  besides  the  Orange  and  its  kind,  a  great  variety 
of  food-plants. 

It  would  be  well  for  the  horticultural  interests  of  Florida  if  some 
system  of  inspection  of  imported  fruit-trees  could  be  adopted  and  vigor- 
ously enforced  by  the  State.  This  would,  no  doubt,  be  difficult  of 
accomplishment,  and,  perhaps,  impracticable.  Individual  importers 
should,  however,  be  made  fully  aware  of  the  danger  which  exists  of  in- 
troducing other  destroyers  more  serious  than  those  already  at  hand, 
and  should  be  on  their  guard.  •  Living  plants  received  from  foreign 
countries  ought  to  be  carefully  cleaned  upon  their  arrival,  and  all  in- 
sects found  upon  them  destroyed. 

It  is  not  easy  to  estimate  the  extent  of  the  damage  that  would  be 
occasioned  should  any  of  the  Aspidiotus  scales  now  ravaging  the  groves 
and  orchards  of  California  be  permitted  to  obtain  a  permanent  foothold 
in  Florida. 

PRECAUTIONARY  MEASURES. 

Infection  from  nursery  Stock. — What  has  been  said  as  to  the  danger  of 
introducing  exotic  Scale-insects  by  importations  from  abroad  will  apply 
as  well  to  the  spreading  of  domestic  species  by  the  exchange  and  sale  of 
nursery  stock. 

It  must  be  acknowledged  that  many  of  the  leading  nurserymen  are 
fully  alive  to  the  necessity  of  establishing  and  maintaining  a  reputation 
for  painstaking  care,  and  rarely  send  out  infested  plants.  Others  exer- 
cise less  care  and  frequently  scatter  insect  pests  by  means  of  the  befouled 
plants  they  distribute. 

Close  planting  in  the  nursery  is  a  most  frequent  cause  ot  the  appear- 
ance of  Scale  insects  in  destructive  numbers.  Young  orange  trees  are 
planted  a  few  inches  apart  in  rows,  and  are  often  left  for  years  in  close 
ranks,  with  their  branches  interlocking,  and  affording  easy  passage  for 


88  INSECTS    AFFECTING   THE    ORANGE. 

the  migrating  young  of  Bark-lice,  so  that  if  they  effect  a  lodgment  upon 
any  plant,  the  entire  row,  and  even  the  whole  nursery,  is  quickly  over- 
run by  them. 

The  crowding  of  the  plants  prevents  free  and  vigorous  growth  ;  they 
are  stunted,  and  for  want  of  nourishment,  as  well  as  lack  of  light  and 
air,  they  are  thrown  into  a  condition  in  which  they  are  particularly  liable 
to  the  attack  of  Scale  insect.  In  common  parlance,  "they  breed  scale." 

In  the  existing  almost  universal  distribution  of  the  pest,  those  nurser- 
ies only  can  be  kept  from  becoming  foul  in  which  a  reasonable  amount 
of  space  is  allowed  to  each  plant  for  its  growth  and  cultivation.  At 
least  18  inches  should  intervene  between  the  plants,  and  the  rows  should 
be  not  less  than  3  feet  apart.  Experience  teaches  that  it  is  easier  to 
keep  clean  and  uninfested  a  large,  well-ordered  nursery  than  it  is  to 
remove  the  Scale-insect  from  a  single  orange  tree  of  moderate  size  when 
once  the  pest  has  become  fully  established. 

No  part  of  the  grove  is  so  liable  to  suffer  neglect  as  the  nursery,  and 
it  is  unfortunately  a  very  common  practice  to  allow  seedling'  plants  to 
grow  up  without  attention  in  neglected  corners,  and  frequently  to  become 
so  foul  with  scale  as  to  become  a  source  of  infection  to  the  groves  and 
nurseries  in  the  vicinity. 

To  this  neglect,  undoubtedly,  is  due  the  fact  that  the  advance  of  insect 
pests  has  fully  kept  pace  with  that  of  the  orange  industry  in  the  recently 
occupied  districts,  both  in  Florida  and  California. 

Protection  afforded  by  Hedges  and  Forest  Trees. — It  is  a  serious  evil,  and 
one  as  yet  hardly  appreciated,  that  in  Florida,  in  removing  the  forest 
to  make  way  for  the  advancing  orange  groves,  every  tree  is  generally 
sacrificed.  Not  even  in  the  lanes  and  roadways  has  the  ax  spared  an 
occasional  pine  to  serve  as  a  wind-break  against  the  sweep  of  storms. 
In  many  districts,  once  well  clothed  with  timber,  the  naked  laud  for  many 
miles  now  lies  exposed  to  the  destructive  force  of  gales,  which,  by  whip- 
ping and  thoruiug  the  fruit,  will,  when  the  groves  begin  to  bear,  occasion 
severe  losses. 

The  pines  of  the  original  forest,  from  their  great  height,  serve  to  break 
the  force  of  upper  currents,  and  a  single  giant  tree  extends  its  protecting 
influence  over  a  wide  area.  If  cut,  the  loss  is  well-nigh  irreparable ;  many 
generations  must  elapse  before  its  place  can  be  satisfactorily  supplied 
by  the  lower  and  more  spreading  oaks  and  pines  of  second  growth.  But 
a  discussion  of  this  subject,  though  of  sufficient  importance  to  horticul- 
turists, would  be  out  of  place  in  the  present  treatise,  were  it  not  for  the 
great  value  of  wind-breaks  as  an  aid  in  isolating  and  preventing  the 
spread  6f  Scale-insects  and  other  pests  of  fruit-trees. 

From  the  time  of  their  first  appearance  it  has  been  remarked  that 
Scale  insects  spread  most  rapidly  in  the  direction  of  prevailing  winds. 
This  phenomenon  is  now  known  to  be  due  to  the  influence  of  the  wind 
in  guiding  the  flight  of  other  insects  which  transport  the  minute,  crawl- 
ing young  of  Bark-lice  upon  their  bodies. 


REMEDIES    AGAINST    SCALE-INSECTS.  &9 

The  feet  and.  tail-feathers  of  birds  are  also  invaded  by  the  crawling 
lice,  which  are  thus  borne  with  tUem  in  their  flights  to  be  scattered  over 
new  plantations. 

The  leaves  and  branches  of  shrubs  and  trees  standing  to  the  windward 
of  a  grove  protect  it  by  receiving  these  pest-laden  visitors,  and  detain- 
ing them  long  enough  to  relieve  them  of  the  scale-larvae  they  bear  upon 
their  bodies. 

It  is,  therefore,  a  great  protection  to  leave  narrow  belts  of  timber  be- 
tween adjoining  groves,  allowing  the  undergrowth  to  spring  up  and  form 
a  natural  screen,  or  else  to  replace  this  with  cultivated  plants.  Fences 
may  usefully  be  replaced  by  thorny  hedges,  which  will  aid  in  maintain- 
ing an  effective  quarantine  against  invasions  of  Scale-insect  and  other 
minute  pests. 

To  be  of  value  the  screen  or  hedge  should,  of  course,  be  composed  of 
such  plants  as  are  not  themselves  subject  to  the  attacks  of  orange  insects ; 
otherwise  it  may  first  become  infested  and  afterward  prove  a  source  of 
danger,  in  place  of  a  safeguard.  For  example,  the  Oleander  is  not  desir- 
able in  the  neighborhood  of  orange  trees,  because  of  its  liability  to  the 
attacks  of  certain  soft  Scale-insects  (Lecanium.)  On  the  other  hand, 
pines,  cedars,  and  other  coniferous  plants,  having  very  few  insect  ene- 
mies in  common  with  other  plants,  are  absolutely  safe,  and  are  also 
admirably  adapted  to  form  wind-breaks. 

CLEANLINESS. 

Beneficial  action  of  Light. — It  is  with  plants  as  with  animals,  a  rule  to 
be  borne  in  mind  that  foulness  breeds  vermin.  The  growing  bark  as 
well  as  the  leaves  has  its  pores  and  its  respiratory  functions,  for  the 
proper  performance  of  which  it  needs  exposure  to  light  and  air.  From 
the  lack  of  these  conditions  for  healthful  growth,  the  inside  branches 
of  orange  trees  dwindle  and  lose  vitality,  becoming  breeders  of  Scale- 
insects,  which  thrive  best  when  the  plant  has  lost  its  vigor. 

Pruning  and  opening  Tops  to  Light  and  Air. — Upon  trees  of  consider- 
able size  and  which  have  formed  dense  heads,  Bark-lice  usually  make  a 
start  upon  the  devitalized  inside  branches,  and  from  thence  they  may 
spread  over  a  portion  or  the  whole  of  the  tops. 

It  may  be  doubted  if  any  bearing  orange  tree  entirely  free  from  scale 
can  be  found  in  Florida.  Somewhere  under  the  canopy  of  leaves  there 
will  always  be  a  twig  or  stifled  branch  upon  which  the  enemy  lurks  in 
concealment,  latent,  but  ever  present,  and  waiting  for  favorable  condi- 
tions to  swarm  forth  in  destructive  numbers  and  possess  the  tree.  The 
careful  cultivator  needs  not  to  be  warned  of  this  source  of  danger,  and 
will  not  allow  dead  and  dying  branches  to  remain  and  accumulate  until 
they  become  a  menace  to  the  health  of  the  tree  and  breeders  of  insect 
pests.  He  will  frequently  examine  his  bearing  trees,  and  at  least  once 
each  year  remove  the  unfruitful  and  devitalized  inside  growth  from  their 
tops, 


90  INSECTS   AFFECTING   THE    ORANGE. 

Clearing  off  Webs. — Young  trees,  while-they  require  less  pruning  than 
the  old,  will  well  repay  the  time  and  care  that  may  be  expended  in 
keeping  them  free  from  entangling  moss  and  from  the  webs  of  insects. 
These  not  only  befoul  and  injure  the  trees,  but  directly  foster  Scale- 
insects  by  sheltering  and  protecting  them  from  the  attacks  of  many 
very  active  enemies  and  parasites.  The  webs  and  lairs  of  spiders  in 
particular  may  be  regarded  with  suspicion,  and  will  very  frequently  be 
found  to  harbor  the  foe  when  it  can  be  found  nowhere  else. 

Scrubbing  the  Trunks. — Accumulations  of  Scale-insect,  living  or  dead^ 
as  well  as  of  lichens  and  other  fungi,  upon  their  trunks  affect  most  in- 
juriously the  health  of  trees,  and  their  removal  from  the  bark  always 
causes  a  marked  improvement  in  condition.  The  incrustations  upon 
orange  trees  formed  by  Chaff  Scale  are  particularly  hurtful.  This  spe- 
cies continues  to  accumulate  for  many  generations,  piling  its  scales  over 
each  other  as  long  as  it  is  possible  for  the  young  to  find  a  crevice  through 
which  to  insert  their  sucking  beaks.  There  results  a  dense  crust, 
which  remains  for  years,  and  becomes  still  further  consolidated  and 
converted  into  a  tough,  fibrous  coating  by  the  threads  of  the  peculiar 
fungus,  which,  as  has  already  been  mentioned,  feeds  upon  the  debris  of 
this  Bark-louse. 

To  partially  cleanse  the  trunks  of  orange  trees,  without  entirely  de- 
stroying the  life  that  always  remains  in  scale-crusts,  no  matter  of  how 
long  standing,  is  to  expose  the  plant  to  fresh  incursions  of  Scale-insects 
by  clearing  away  the  obstructions  to  their  spread.  Therefore  it  is  im- 
portant not  only  that  the  clearing  should  not  be  neglected,  but  that, 
when  undertaken,  the  work  should  be  thorougly  done. 

For  scrubbing  the-trunks  properly  a  brush  stiff  enough  to  remove  the 
scales  is>required,  and  to  insure  the  destruction  of  any  insects  or  .eggs 
that  may  escape,  hidden  in  unseen  crevices,  it  should  be  dipped  in 
cleansing  liquids,  such  as  the  dilute  kerosene  and  soap  emulsions  recom- 
mended in  the  following  pages  for  spraying  the  trees,  or  very  strong 
solutions  of  lye  may  be  used,  and  will  be  more  effectual  in  destroying 
fungi  than  the  kerosene  washes.  Solutions  of  whale-oil  soaps  are  very 
commonly  employed  and  with  good  effect ;  but  if  the  solutions  are  thick 
and  strong,  as  indeed  they  need  to  be  in  order  to  kill  the  insects,  the 
trunks  should  be  rubbed  down  before  they  dry  with  clear  water,  to  re- 
move the  film  of  soap,  for  this,  if  allowed  to  remain,  has  a  tendency  to 
harden  the  bark  by  clogging  its  pores. 

Palmetto  Brushes. —  A.  better  implement  than  the  common  domestic 
scrubbing  brush,  usually  employed  in  cleaning  tree-trunks,  may  be 
made  in  a  few  mome'rits  out  of  a  bit  of  saw-palmetto  root  (root-stalk)  by 
pounding  the  ends  until  the  fibers  separate  and  form  a  brush.  For  the 
removal  of  scales  and  dead  bark  nothing  better  than  this  rude  brush 
can  be  devised.  In  Florida  the  material  is  always  at  hand  and  costs 
nothing.  In  use  the  palmetto  brush  wears  away  slowly,  but  never 
wears  out  so  long  as  any  portion  of  it  remains. 


REMEDIES   AGAINST   SCALE-INSECTS  91 

POPULAR   METHODS   AND   REMEDIES. 

Cutting  back  infested  Trees. — The  utter  inadequacy  of  nearly  all  the 
washes  hitherto  used  has  led  many  fruit-growers  to  despair  of  obtain- 
ing permanent  benefit  from  the  application  of  remedies,  and  a  common 
practice  has  been  to  cut  back  badly  infested  trees,  leaving  only  the 
main  trunks,  or  in  the  case  of  well-grown  trees,  a  portion  of  the  main 
branches,  and  to  scrub  thoroughly  every  part  of  these  with  solutions  of 
soap  or  lye,  using  a  stiff  brush,  and  as  far  as  possible  removing  every 
scale.  This,  however,  involves  great  care  and  considerable  labor,  and 
the  complete  extermination  of  the  pest  -is  rarely  accomplished  in  this 
way.  The  loss  of  branches  is  indeed  replaced  with  extraordinary  rapid-, 
ity,  but  the  Scale-insects  reappear  as  if  by  magic,  and  in  one  or  two 
years  become  as  bad  as  before. 

Fumigating. — Various  plans  have  been  proposed  for  destroying  Scale- 
insects  with  pungent  vapors  of  various  kinds.  The  difficulties  in  the 
way  of  applying  vapors  to  trees  growing  in  the  open  air  are  very  great, 
and  appear  to  have  been  overlooked  by  the  advocates  of  this  method. 
Tobacco  smoke  has  been  very  frequently  tried  in  inclosed  green-houses, 
but  although  it  will  destroy  Plant-lice  (Aphis),  it  is  found  to  have  no 
effect  upon  Scale-insects,  which  are  far  too  well  protected  by  their  tightly 
scaled  scales  to  be  reached  by  vapors,  except  those  of  a  corrosive  na- 
ture. 

Sulphur  has  been  recommended,  evidently  on  theoretical  grounds 
only,  as  its  fumes  are  not  less  destructive  to  vegetable  than  to  animal 
life.  The  chloiophyl  of  the  leaves  and  plants  is  bleached  and  the  life 
of  a  plant  destroyed  by  a  short  exposure  to  any  gas  containing  sulphur. 
Actual  trial  of  fumigation  upon  the  Orange  was  made  by  covering  a 
young  and  vigorous  plant  with  a  barrel  and  exposing  it  for  ten  minutes 
to  the  fumes  produced  by  burning  one  ounce  weight  of  sulphur.  The 
leaves  were  completely  bleached  and  tbe  plant  killed.  The  Scale-insects 
upon  it  (Long  Scale)  were  uninjured  by  the  sulphur  vapor,  and  survived 
until  the  bark  became  entirely  dead  and  dry,  perishing  finally  from 
want  of  food  and  moisture. 

Applications  to  the  Roots. — No  results  of  any  value  have  been  attained 
by  attempts  to  kill  Scale-insects  through  the  juices  of  the  plant  by 
making  applications  to  the  soil  with  the  expectation  that  they  will  be 
taken  up  by  the  roots.  Many  nostrums  are  advertised  and  sold  as 
insecticides,  which  it  is  claimed  act  in  this  way.  There  are  also  in  the 
market  not  a  few  combined  fertilizers  and  insect-exterminators,  so- 
called,  to  which  is  assigned  a  double  action,  beneficial  in-  tbe  ca.se  of  the 
plant,  but  deadly  to  the  insect  life  which  it  supports.  These  claims  are 
based  upon  the  assumed  power  of  the  plant  to  appropriate  and  mingle 
with  its  juices  unchanged  the  substances  which  have  insecticide  prop- 
erties— an  assumption  wholly  at  variance  with  the  known  laws  of  vege- 
table physiology.  In  fact  an  insecticide,  if  it  could  be  introduced  into 


92  INSECTS   AFFECTING   THE    ORANGE. 

the  circulation  through  the  roots  of  the  plant,  would  be  far  more  likely 
to  injure  the  plant  itself  than  the  Bark-lice  upon  it. 

Inoculating  with  Poisons. — For  the  same  reason  it  has  been  found  im- 
possible to  reach  and  destroy  insect  pests  by  inoculating  the  bark  or 
wood  of  the  trunk  or  branches. 

The  attempt  has  usually  been  made  by  boring  into  the  trunk  of  the 
tree,  introducing  the  article  to  be  tested,  and  tightly  closing  the  hole 
with  a  plug.  Numerous  experiments  of  this  sort  are  recorded.  Of  the 
long  list  of  substances  which  have  been  thus  tried,  and  which  includes 
many  mineral  and  vegetable  poisons,  as  well  as  sulphur  and  other  sub- 
stances possessing  insecticide  properties,  none  have  proved  effective. 

Popular  Fallacies. — There  is  a  widespread  and  apparently  well-founded 
opinion  that  vigorous  trees  are  in  little  danger  from  attacks  of  Scale- 
insects,  but  if  from  any  cause  a  tree  becomes  enfeebled,  its  investment 
is  only  a  question  of  time.  Many  persons  therefore  reject  the  aid  of 
insecticides,  and  when  a  tree  becomes  infested,  rely  upon  a  liberal  use 
of  fertilizers  to  restore  its  lost  vitality  and  force  it  into  vigorous  growth, 
believing  that  in  this  way  it  will  rid  itself  of  the  pest.  It  cannot  be  de- 
nied that  this  course  of  treatment  is  often  successful,  at  least  for  a  time, 
but  the  Scale-insect  is  never  entirely  eradicated,  and  its  return  at  some 
future  time  may  be  expected.  Indeed,  overstimulation  by  means  of 
fertilizers  is  apt  to  defeat  its  object,  and  reaction  follows  in  unfavorable 
seasons. 

In  fighting  Scale  with  fertilizers,  therefore,  success  may  be  said  to 
depend  upon  conditions  unknown  or  beyond  our  control.  When  these 
are  favorable,  the  system  may  be  found  to  work  well;  otherwise  failure 
is  inevitable,  and  by  adhering  to  it  valuable  time  will  be  lost,  and  the 
pest  will  perhaps  be  allowed  to  spread  until  it  can  with  difficulty  be 
controlled. 

'    EFFECTIVE  REMEDIES. 

Kerosene. — This  is  without  doubt  the  most  effective  insecticide  for  use 
against  Scale-insects,  and  it  is  almost  the  only  substance  known  which 
will  with  certainty  kill  their  eggs  without  at  the  same  time  destroying 
the  plant.  The  difficulty  of  diluting  it,  and  the  danger  to  the  plant  of 
applying  it  undiluted,  have  long  prevented  its  extensive  use.  Easy 
methods  of  emulsifying  the  oil  and  rendering  it  miscible  with  water  are 
now  known,  and  have  recently  been  set  forth  by  Professor  Eiley  in  his 
official  reports. 

Milk  and  Kerosene  Emulsions. — The  method  of- emulsify  ing  kerosene 
with  milk,  as  given  in  a  preliminary  report  on  Scale-insects  in  the  Ee- 
port  of  the  Commissioner  for  the  years  1881  and  1882,  remains  the 
best  and  simplest,  where  milk  can  be  easily  and  cheaply  obtained. 
The  milk  should  first  ba  heated  nearly  to  the  boiling  point,  and  then 
mixed  with  kerosene  in  the  proportions  one  part  of  milk  to  two  parts 


REMEDIES    AGAINST    SCALE-INSECTS. 


93 


of  keroseue.  The  mixture  requires  to  be  very  violently  churned  for  a 
period,  varying  with  the  temperature,  from  five  or  ten  minutes  to  half 
an  hour.  If  the  mixture  is  quite  hot  the  emulsion  is  very  easily  and 
quickly  formed.  It  is  quite  thin  while  warm,  but  thickens  on  cooling. 
If  cold,  the  process  is  delayed,  but  after  continued  agitation  the  emul- 
sion forms  suddenly,  as  in  butter  making,  and  becomes  at  once  an  ivory- 
white  glistening  paste,  or  jelly. 

To  form  a  perfectly  stable  emulsion  more  violent  agitation  is  re- 
quired than  can  be  effected  by  hand  stirring,  or  by  dashing  in  an  ordi- 
nary churn.  The  particles  of  oil  and  milk  are  more  readily  driven 
into  union  by  passing  the  mixture  through  the  spray-nozzle  of  a  force- 
pump. 

The  aquapult  pump  (Fig.  43),  which  is  also  one  of  the  most  effective  in- 
struments for  spraying  trees,  may 
be  satisfactorily  used  for  this  pur- 
pose. The  pump  is  inserted  in  a 
pail  or  tub  containing  the  mix- 
ture, and  this  is  pumped  back 
into  the  same  receptacle  through 
the  flexible  hose  and  spray-nozzle 
until  the  emulsion  is  formed. 
From  3  to  5  gallons  of  emulsion 
may  be  churned  at  one  time  by 
means  of  the  ordinary  hand  form 
of  this  pump.  For  larger  quan- 
tities a  larger  pump  or  some  form 
of  druggist's  churn  will  be  re- 
quired. 

The  emulsion,  if  well  made,  is 
permanent,  provided  it  is  not  ex- 
posed to  the  air,  which  causes  in 
time  a  partial  separation  of  the 
oil.  The  union  of  the  ingredi- 
ents is  purely  mechanical,  and 


FIG.  43.— The  aquapult. 


the  presence  of  the  kerosene  does 
not  prevent  the  fermentation  of 
the  milk,  which  will  become  sour  and  curdle  without,  however,  separat- 
ing from  the  oil. 

For  fresh  milk  may  be  substituted  an  equivalent  of  condensed  milk 
and  water,  or  of  sour  milk.  If  sour  milk  is  used  no  subsequent  curd- 
ling of  the  emulsion  takes  place,  and  it  is  therefore  preferable  to  sweet 
milk. 

The  milk  emulsions  may  be  diluted  in  water  to  any  extent,  and  if 
cold  require  to  be  thinned  at  first  with  a  small  quantity  of  water. 
One  part  of  emulsion  to  nine  or  ten  parts  of  water  will  be  found  to 
make  an  effective  wash. 


94  INSECTS   AFFECTING   THE    ORANGE. 

Soap  and  Kerosene  Emulsions. — The  difficulty  of  obtaining  fresh  milk 
in  Florida,  and  the  cost  of  condensed  milk,  have  made  a  cheaper  substi- 
tute desirable.  This  is  found  in  a  solution  of  soap,  which  forms  with 
kerosene  an  equally  good  emulsion.  The  quantity  of  soap  used  in  so- 
lution need  not  exceed  one-quarter  of  a  pound  to,  one  gallon  of  water, 
but  stronger  soap  solutions  are  required  to  form  a  permanent  emulsion. 
The  percentage  of  kerosene  may  also  be  varied  greatly.  But  emulsions 
containing  over  80  per  cent,  of  the  oil  have  too  light  a  specific  gravity 
and  are  not  readily  held  in  suspension  in  water.  On  the  other  hand,  in 
the  process  of  ernulsifi cation,  kerosene  loses  a  portion  of  its  value  as  an 
insecticide,  and  emulsions  containing  less  than  30  per  cent,  of  the  oil, 
although  they  do  not  at  all,  or  only  very  slowly,  rise  to  the  surface  when 
diluted  with  considerable  quantities  of  water,  are  nevertheless  too  much 
weakened  for  effective  use  against  Scale-insects. 

The  following  formula  is  considered  the  best  for  general  use.  It 
gives  a  wash  of  sufficient  strength  to  kill  the  eggs  of  those  species  of 
Scale-insect  which  are  commonly  found  in  Florida,  although  in  dealing 
with  some  of  the  Aspidiotus  scales  a  somewhat  stronger  emulsion  may 
be  required. 

FORMULA : 

Kerosene 2  gallons=67  per  cent. 

Common  soap  or  whale-oil  soap  .  J  pound  )      ,>Q  ^ 

/  :=oo  uei  cent/. 
Water 1  gallon  ) 

Heat  the  solution  of  soap  and  add  it  boiling  hot  to  the  kerosene. 
Churn  the  mixture  by  means  of  a  force-pump  and  spray-nozzle  for  five 
or  ten  minutes.  The  emulsion,  if  perfect,  forms  a  cream,  which  thick- 
ens on  cooling,  and  should  adhere  without  oiliness  to  the  surface  of 
glass.  Dilute  before  using,  1  part  of  the  emulsion  with  9  parts  of  cold 
water.  The  above  formula  gives  3  gallons  of  emulsion  and  makes  when 
diluted  30  gallons  of  wash. 

Necessary  precautions  in  the  use  of  Kerosene. — A  reckless  use  of  any 
penetrating  oil  upon  plants  cannot  fail  to  prove  detrimental.  Kero- 
sene is,  however,  much  less  injurious  than  the  lighter  oils,  naphtha, 
benzine,  &c.,  with  which,  in  a  crude  state,  it  is  associated.  The  refined 
oil,  such  as  is  commonly  used  for  illuminating  purposes,  is  safer,  and 
should  always  be  used  in  preference  to  the  lower  grades,  which  contain 
a  large  admixture  of  other  oils  exceedingly  deadly  to  vegetation. 

Effect  of  Kerosene  upon  the  Orange. — Although  the  action  of  kerosene 
proves  more  injurious  to  some  plants  than  to  others,  a  healthy  orange 
tree  is  but  slightly  affected  by  it,  and  will  even  support  without  serious 
injury  applications  of  the  undiluted  oil  if  judiciously  made,  i.  <?.,  applied 
in  fine  spray  and  avoiding  exposure  of  the  plant  to  hot  sunshine  or  to 
frost  before  the  oil  has  evaporated.  Unhealthy  trees  and  trees  suf- 
fering from  the  attacks  of  Scale-insects  receive  a  shock  more  or  less 


REMEDIES    AGAINST    S.CALE-INSECTS.  J  5 

severe,  according  as  their  vitality  is  more  or  less  impaired.  Young, 
tender  shoots,  budding  leaves  and  blossoms,  are  not  much  affected  by 
kerosene,  and  may  even  be  dipped  in  the  pure  oil  with  impunity. 

The  heat  of  the  sun  increases  to  an  injurious  extent  the  action  of 
kerosene,  and  applications  of  very  strong  solutions  or  undiluted  kero- 
sene, if  used  at  all,  should  be  made  on  cloudy  days  or  at  evening. 

Milk  or  soap  emulsions  containing  60  or  70  per  cent,  of  oil  and  diluted 
with  water  ten  times  are  more  nearly  harmless  to  the  Orange  than  any 
other  insecticide  capable  of  killing  the  Scale-insect.  Nevertheless  the 
plant  receives  a  shock,  imperceptible  when  the  tree  is  in  good  condition, 
but  sufficiently  severe  when  it  is  infested  and  injured  by  Scale  to  cause 
the  loss  of  the  old,  devitalized  leaves.  Complete  defoliation  and  the 
death  of  moribund  twigs  and  branches  may  be  expected  to  occur  in  ex- 
treme cases.  The  shock  is  invariably  followed  by  a  reaction,  and  in  ten 
to  fifteen  days  new  growth  appears.  This  growth  is  healthy  and  nat- 
ural, and  if  the  application  h^s  been  sufficiently  thorough  to  destroy 
the  Scale-insect,  results  in  permanent  benefit. 

Enough  has  been  said  to  show  that  kero'serie  is  a  powerful  remedy, 
perfectly  effective  and  safe  if  used  in  moderation,  but  hurtful  in  strong 
doses 5  that  its  use  undiluted  is  attended  with  danger,  is  entirely  un- 
necessary, and  cannot  be  recommended.  In  Appendix  II  will  be  found 
an  examination  of  results  obtained  in  experimental  applications  of  kero- 
sene, together  with  other  insecticides,  arranged  in  tabular  form  for  con- 
venience of  comparison. 

The  most  favorable  season  for  applying  kerosene  washes  is  undoubt- 
edly early  spring  or  as  soon  as  all  danger  of  frost  is  past.  The  shed- 
ding of  the  last  year's  leaves,  which  takes  place  naturally  after  the 
orange  tree  has  renewed  its  foliage  in  spring,  is  often  accelerated  by 
the  action  of  the  oil,  which  is  thus  made  to  appear  very  severe.  But  the 
loss  of  old  and  devitalized  leaves  is  of  slight  consequence,  and  in  the 
case  of  badly  infested  trees  is  a  positive  advantage,  as  the  leaves  in  fall- 
ing carry  with  them  the  scales  most  difficult  to  reach  with  insecticides. 

Whale-oil  Soap. — This  has  long  been  considered  one  of  the  best  insecti- 
cides known.,  and  is  extensively  used  as  a  remedy  for  Bark-lice.  Ex- 
periments show  that  very  strong  solutions  kill  the  Coccids  but  have 
little  or  no  effect  upon  their  eggs.  Solutions  of  one  pound  of  the  soap 
to  three  gallons  of  water  failed  to  kill  the  adult  Bark-lice  or  their  eggs, 
and  did  not  destroy  all  the  young.  The  strongest  solution  used,  one 
pound  of  the  soap  to  one  gallon  of  water,  killed  all  the  Coccids  and  few 
or  none  of  the  eggs. 

This  solution  solidifies  on  cooling,  and  must,  therefore,  be  applied 
hot.  The  effect  upon  the  trees  is  about  equal  to  that  of  effective  kero- 
sene emulsions 5  badly  infested  trees  are  somewhat  defoliated,  but  new 
growth  and  vigorous  trees  are  not  appreciably  affected.  As  the  eggs 
are  not  killed,  several  applications  at  intervals  of  four  to  six  weeks  will 
be  required  to  clear  a  tree  of  scale.  (See  Appendix  II,  table  2.) 


96  INSECTS    AFFECTING    THE    ORANGE. 

Whale-oil  soap  is  sold  in  Eastern  Florida  at  10  to  12  cents  per  pound. 
The  cost  of  an  effective  wash  is  therefore  much  greater  than  emulsions 
of  kerosene.  For  scrubbing  and  cleansing  the  trunks  of  orange  trees 
this  soap  may  be  recommended.  A  solution  of  1  pound  to  4  gallons 
will  probably  be  sufficiently  strong  for  this  purpose. 

Potash  and  Soda  Lye. — These  substances  have  been  recommended  as 
remedies  for  Scale-insect  in  California.  According  to  reports  promul- 
gated by  the  State  Horticultural  Commission,  solutions  as  strong  as  1J 
pounds  to  the  gallon  of  water  are  deemed  necessary  to  exterminate  the 
pest,  and  are  said  to  have  been  used  with  good  results  upon  Peach, 
Pear,  and  other  deciduous  fruit-trees.  Although  these  caustic  solu- 
tions burn  and  partially  destroy  the  bark,  it  is  said  to  be  soon  restored, 
and  no  loss  of  fruit  results  if  applied  in  winter  while  the  trees  are  dor- 
mant. 

Experiments  made  in  Florida  upon  the  Orange  with  caustic  soda  and 
potash  lyes  show  that  solutions  of  1  pound  to  2,  2J,  and  3  gallons 
were  of  little  or  no  practical  benefit  as  regards  the  extermination  of 
Scale-insects,  while  the  effect  upon  the  trees  was  more  severe  than  with 
applications  of  pure  kerosene.  Unlike  kerosene,  lye  is  injurious  to  the 
tender  portions  of  the  plant,  an<J  new  growth  is  destroyed  at  once  by 
strong  solutions.  Solutions  of  1  pound  to  the  gallon  severely  cauterize 
the  leaves  and  tender  bark,  and  kill  back  the  smaller  branches,  but  fail 
to  destroy  all  the  Bark-lice,  and  have  hardly  an  appreciable  effect  upon 
their  eggs.  (See  Appendix  II,  table  3.) 

Concentrated  potash  is  somewhat  stronger  than  soda  lye,  but  the  re- 
sults attained  with  it  are  also  unsatisfactory.  In  the  strongest  appli- 
cations, made  with  a  solution  of  two  pounds  of  potash  to  one  gallon  of 
water,  the  trees  were  burned  as  by  fire,  the  leaves  were  charred  with- 
out falling  from  the  branches,  all  the  growth  under  two  years  old  was 
destroyed,  and  the  main  trunks  alone  remained  alive.  The  Scale-insects 
perished  with  the  cauterized  bark  and  foliage ;  nevertheless,  a  very 
large  percentage  of  their  eggs  escaped  destruction,  and  continued  to 
hatch.  A  few  days  later  the  young  were  seen  in  abundance,  crawling 
over  the  blackened  trunk  and  branches.  It  is  probable  that  they  all 
perished,  however,  through  inability  to  penetrate  the  cicatrized  bark 
with  their  sucking  beaks.  The  trees  thus  treated  survived,  indeed,  but 
in  a  mutilated  condition  and  with  an  entire  loss  of  symmetry  in  their 
tops. 

It  would  appear  from  careful  experiments  and  observations  with  both 
soda  and  potash  lyes,  that  these  substances  are  inferior  to  kerosene  in 
killing  power  as  regards  Scale-insects,  and  far  more  injurious  to  the 
tree  when  used*  in  solutions  strong  enough  to  be  effective  as  insecti- 
cides. Weaker  solutions  are,  however,  extremely  useful  in  cleansing 
the  trunks  of  orange  trees  with  the  scrubbing  brush.  For  this  purpose 
they  are  superior  to  solutions  of  soap,  and  have  an  advantage  over  di- 


BEMED1ES   AGAINST    SCALE-INSECTS.  97 

lute  kerosene  emulsions,  in  that  they  destroy  the  spores  of  lichens  and 
fungi,  which  kerosene  does  not. 

Crude  Carbolic  Acid  or  Oil  of  Creosote. — The  crude  oil,  dissolved  in 
strong  alkalies  or  solutions  of  soap,  forms  a  very  effective  remedy  for 
Scale-insect.  It  may  also  be  emulsified  with  milk  in  the  same  manner 
as  kerosene.  The  undiluted  oil  is,  however,  exceedingly  injurious  to 
vegetation,  and  destroys  the  bark  of  Orange  and  other  trees.  It  is,  in 
fact,  a  more  dangerous  substance  than  kerosene,  and  requires  to  be  used 
with  great  caution.  Solutions,  emulsions,  and  soaps  containing  it  should 
be  very  carefully  mixed,  in  order  that  no  globules  of  free  oil  may  be 
allowed  to  come  in  contact  with  the  bark  of  the  tree. 

Its  action  upon  the  Scale-insect  is  even  more  powerful  than  kerosene, 
but  it  does  not  destroy  as  large  a  percentage  of  the  eggs.  The  effect 
upon  the  Coccids  is  not  immediate,  as  in  the  case  of  other  insecticides, 
and  for  three  or  four  days  after  an  application  very  few  of  the  insects 
die.  At  the  end  of  a  week,  however,  the  Bark-lice  are  found  to  be 
affected  and  continue  to  perish  in  increasing  numbers  for  a  week  longer. 
Even  after  the  lapse  of  three  weeks  the  destructive  action  of  the  oil  is 
still  appreciable.  These  facts  lead  one  to  suspect  that  the  insects  are 
killed,  in  part  at  least,  by  the  poisoning  of  the  sap  upon  which  they  feed. 

The  visible  effect  upon  the  plant  appears  to  confirm  this  view.  Leaves 
upon  infested  trees  begin  to  drop  after  four  or  five  days,  and  the  defolia- 
tion reaches  a  maximum  during  the  second  week.  As  is  the  case  with 
kerosene,  the  effect  upon  the  tree  depends  upon  its  condition  at  the 
time  of  application ;  but  carbolic  acid  is  more  severe  in  its  action,  and 
there  is  greater  loss  of  leaves  and  infested  branches.  With  care,  how- 
ever, an  application  may  be  made  sufficiently  strong  to  exterminate  the 
scale  without  serious  injury  to  the  plant,  and,  as  new  or  vigorous  growth 
is  very  slightly  affected,  recovery  is  rapid. 

The  following  solution  of  crude  carbolic  acid  will  be  found  nearly  if 
not  quite  as  effective  as  a  G4  per  cent,  kerosene  emulsion,  and  may  be 
applied  without  danger  to  orange  trees.  Dilute  the  carbolic  acid  with 
twice  its  volume  of  soap  solution  (2  ounces  common  soap  to  I  pint  hot 
water).  Mix  thoroughly  until  all  the  oil  is  dissolved.  Add,  before 
using,  to  one  part  of  the  above  solution  twenty  parts  water,  and  apply 
in  as  fine  spray  as  possible. 

The  most  effective  method  of  using  oil  of  creosote  is  to  saponify  it 
with  heavy  oils  and  potash.  In  this  way  a  solid  soap  containing  about 
12  per  cent.,  by  volume,  of  the  oil  may  be  obtained.  The  process  of 
making  the  soap  is,  however,  exceedingly  tedious  and  difficult,  and  un- 
less proper  appliances  be  used  the  resulting  product  is  imperfect  and 
even  dangerous  to  use,  as  it  contains  a  large  amount  of  free  creosote. 
Manufacturers  of  carbolic  soap  could  undoubtedly  supply  a  better  article 
and  at  a  less  cost  than  the  consumer  could  make  for  himself. 

(For  detailed  experiments  see  Appendix  II,  Table  4.) 
6521  o  I 7 


98  INSECTS    AFFECTING    THE    ORANGE. 

SULPHURATED  LIME.* — A  combination  of  lime  and  sulphur,  made 
by  boiling  the  sublimate  (flowers)  of  sulphur  in  milk  of  lime,  is  some- 
times recommended  as  a  u  cure-all"  for  application  to  orange  trees. 
The  preparation  contains  a  mixture  of  sulphides  and  sulphates  of  lime, 
together  with  varying  quantities  of  the  uucoinbiued  ingredients.  By 
continued  boiling  the  action  of  the  sulphur  is  rendered  more  complete, 
and  if  an  excess  of  lime  is  present  the  mixture  becomes  highly  caustic, 
eating  the  skin  from  the  hands  and  destroying  the  tender  leaves  and 
bark  of  plants.  Its  preparation  is  rendered  unpleasant  and  even  dan- 
gerous because  of  the  sulphurous  fumes  that  are  given  off. 

One  part  sublimated  sulphur,  two  parts  lime,  and  ten  parts  water, 
boiled  together  half  to  three  quarters  of  an  hour  give  the  best  results. 
After  standing  a  short  time  the  uncombined  lime  settles  to  the  bottom, 
leaving  a  clear  yellowish  liquid,  which,  according  to  the  United  States 
Dispensatory,  is  "an  impure  aqueous  solution  of  sulphide  of  calcium, 
necessarily  containing  hyposulphite  of  calcium." 

Under  varying  conditions  higher  combinations  are  formed,  and  the 
chemical  reactions  are  exceedingly  complicated.11  A  large  percentage 
of  the  yellowish -green  mass  consists  of  insoluble  and  inert  sulphides, 
but  with  these  are  mingled  other  compounds  of  lime  and  sulphur,  which 
give  off  sulphureted  hydrogen  gas  (hydro- sulphuric  acid),  and  are  grad- 
ually altered  by  exposure  to  the  air.  When,  therefore,  the  mixture  is 
allowed  to  stand  in  open  barrels,  the  sulphur  compounds  part  with  their 
active  gases,  and  at  length  only  the  caustic  action  of  the  lime  remains. 

Use  in  the  Orange  Grove. — As  an  insecticide  sulphurated  lime  has 
nearly  the  same  value  as  potash  or  soda  lye,  and  in  like  manner,  by  its 
caustic  action,  it  kills  the  Bark -lice,  but  does  not  destroy  their  eggs, 
unless  it  is  applied  strong  enough  to  injure  the  bark. 

Its  action  upon  the  plant  resembles  very  closely  that  of  potash  and 
other  caustics,  which  are  more  injurious  to  the  young  growth  than  to 
the  older  and  less  vital  parts  of  the  tree. 

The  imperfect  mixture  formed  by  adding  sulphur  to  lime  in  the  act  of 
slaking  is  deficient  in  strength,  and  has  little  value  as  an  insecticide. 

Sulphurated  lime  may  prove  useful  to  orange-growers  as  a  destroyer 
of  fungi,  and  it  is  advocated  as  a  remedy  for  foot- rot  or  other  diseases 
of  a  similar  nature.  But  these  claims,  it  is  proper  to  state,  have  not  as 
yet  been  substantiated  by  sufficient  evidence. 


*  The  term  " sulphurated  lime"  is  here  used  as  a  convenience,  and  is  made  to  include 
the  .various  compounds  formed  by  the  action  of  hot  water  on  lime  and  sulphur.  In 
strictness,  the  monosulphide  (Ca  S.)  is  not  formed  by  the  wet  process  here  given.  It 
is  thus  described : 

"Sulphurated  Lime  is  a  grayish- white,  or  yellowish- white,  powder,  gradually 
altered  by  exposure  to  air,  exhaling  a  faint  odor  of  hydrosulphuric  acid,  having  an 
offensive,  alkaline  taste,  and  an  alkaline  reaction.  Very  slightly  soluble  in  water 
and  insoluble  in  alcohol.  On  dissolving  Sulphurated  Lime  with  the  aid  of  acetic- 
acid,  hydrosulphuric  acid  is  abundantly  given  off,  and  a  white  precipitate  (Sulphate 
of  Calcium)  is  thrown  down."  (United  States  Dispensatory,  1883,  page  3*26.) 


REMEDIES    AGAINST    SCALE-INSECTS.  99 

If  used  in  sufficient  strength  to  kill  Scale-insects,  the  hands  and  arms 
must  be  protected  from  the  liquid  by  rubber  gloves,  and  care  must  also 
be  had  to  avoid  inhaling  the  poisonous  gases  exhaled. 

In  its  active  state  the  preparation  is  a  depilatory,  and  by  applying  it 
as  a  paste  the  hair  upon  any  part  of  the  body  may  be  reduced  to  gela- 
tine and  removed. 

Bisulphide  of  Carbon. — The  few  trials  made  of  this  substance  have  not 
given  very  satisfactory  results,  and  additional  experiments  are  needed 
to  determine  whether  it  can  be  safely  and  economically  used  as  a  remedy 
for  Scale-insects.  Although  a  powerful  insecticide,  the  extreme  severity 
of  its  action  upon  the  trees  and  the  cost  of  the  materials  detract  greatly 
from  its  value.  It  is  an  exceedingly  volatile  and  explosive  liquid,  which 
must  be  kept  in  tightly-sealed  glass  bottles,  and  the  fumes  cannot  be 
inhaled  by  man  or  other  animals  without  danger.  The  bisulphide  may 
be  emulsified  with  oils  and  milk  or  soap,  but  not  more  than  three  or 
four  fluidouuces  should  be  contained  in  each  gallon  of  the  diluted  wash. 

Appendix  II,  table  5,  gives  the  result  of  some  experiments  with  bi- 
sulphide of  Carbon. 

Sulphuric  Acid. — A  single  experiment  with  sulphuric  acid,  4  fluid- 
ounces  .in  6  quarts  of  water,  applied  with  a  brush  as  far  as  possible  to 
all  parts  of  a  young  tree,  killed  nearly  all  the  Scale-insects,  and  very 
nearly  killed  the  tree.  The  bark  was  blackened  but  not  destroyed,  and 
nearly  all  the  leaves  dropped.  The  tree,  however,  slowly  recovered. 

Sulphate  of  Iron. — This  substance  is  exceedingly  injurious  to  vegeta- 
tion, but  is,  nevertheless,  a  very  common  ingredient  of  patent  and  pro- 
prietary remedies.  Its  presence  can  be  detected  by  the  inky-black  or 
brown  stains  which  it  forms  in  the  substance  of  the  leaves  and  the  rind 
of  the  fruit. 

It  does  not  affect  the  Scale-insect  except  by  destroying  the  vegetable 
tissues  from  which  it  gets  its  subsistence. 

Ammonia. — With  this  in  a  pure  state-no  experiments  have  been  made, 
but  to  its  presence  in  fermenting  urine  is  probably  due  the  insecticide 
properties  of  the  latter.  Applications  of  urine  have  often  been  recom- 
mended as  a  remed3r  lor  scale,  and  are  certainly  not  without  value>  but 
if  allowed  to  stand  and  ferment,  and  especially  if  soot  or  other  absorb- 
ents of  the  ammonia  are  mixed  with  it,  it  becomes  highly  injurious  to 
vegetation,  and  if  applied  at  all  should  be  greatly  diluted.  A  mixture 
of  soot  and  fermented  urine  applied  undiluted  to  a  small  orange  tree 
effectually  cleared  it  of  scales,  but  very  nearly  killed  the  tree. 

Silicate  of  Soda. — This  is  a  thick  viscid  liquid,  sometimes  sold  as  a 
solid.  It  is  readily  soluble  in  water.  When  sprayed  upon  orange  trees 
it  soon  dries  and  forms  a  coating  of  gum  which  partially  peels  off,  car- 
rying with  it  many  of  the  old  dead  scales  and  some  living  ones.  When 
applied  in  sufficient  strength  it  kills  most  of  the  Coccids,  but  does  not 
destroy  the  eggs.  It  injures  the  plant  more  than  kerosene,  with  which 
it  cannot  be  compared  in  efficiency  or  cheapness.  The  preparation  is 


100  INSECTS   AFFECTING   THE   ORANGE. 

inert  and  harmless  to  man,  and  acts  mechanically  by  covering  and  stifling 
the  Bark-lice  or  by  removing  them  bodily  from  the  tree.  (See  Appen- 
dix II,  table  G.) 

Very  many  substances  used  separately,  or  in  various  combinations, 
are  recommended  as  remedies  for  Scale-insect.  Among  the  number  the 
following  have  been  examined  with  more  or  less  care  and  found  to  be 
of  doubtful  or  of  no  value :  sal-soda,  muriate  of  potash,  salt,  lime,  soot, 
and  ashes. 

Many  otherwise  valueless  washes  and  applications  have  been  ren- 
dered partially  effective  by  the  addition  of  a  small  quantity  of  free  kero- 
nene.  The  result  in  all  such  cases  has  been  a  very  unequal  distribution 
of  the  oil,  some  portions  of  the  tree  receiving  a  dangerous  dose  and 
other  portions  none  at  all.  It  seems  hardly  necessary  to  point  out  the 
uselessness  of  such  half-way  measures  in  combatting  a  pest  which  the 
most  perfect  remedy  is  powerless  to  eradicate  unless  applied  with  thor- 
oughness and  care. 

THE  APPLICATION   OF  INSECTICIDES. 

Fineness  and  Force  of  Spray. — In  dealing  with  an  enemy  so  thor- 
oughly protected  as  are  many  of  the  Bark-lice,  liquid  insecticides  should 
be  applied  in  as  fine  a  spray  as  possible,  or  at  least  in  moderately  fine 
spray,  driven  with  considerable  force,  in  order  to  increase  to  the  ut- 
most their  penetrating  power.  The  aim  should  also  be  to  reach  and 
thoroughly  wet  every  portion  of  an  infested  tree,  so  that  no  individual 
Scale-insect  shall  escape  the  action  of  the  liquid.  This  result  is  not  at- 
tainable by  the  old  method  of  sending  a  jet  from  a  distance  into  the  tops 
of  the  trees.  An  ordinary  garden  syringe  is  practically  useless.  There 
is  needed  a  force  pump  and  a  nozzle  giving  a  finely  atomized  spray. 
This  nozzle  should  be  attached  to  a  sufficient  length  of  flexible  hose  to 
allow  it  to  be  introduced  into  the  top  of  the  tree.  The  orifice  of  the 
nozzle  should  be  directed  at  a  right  angle  to  the  hose,  and  not  in  line 
with  it.  The  jet  of  spray  may  thus  by  a  turn  of  the  wrist  be  directed 
upward  or  downward,  and  brought  into  contact  with  all  parts  of  the 
foliage  and  branches,  from  beneath  as  well  as  from  the  upper  side. 

The  Cyclone  Nozzle.  (Fig.  44:  1,  profile 5  2,  plan;  3,  section). — A  nozzle 
which  answers  the  above  conditions  and  is  easily  attached  to  any  force- 
pump  by  means  of  a  rubber  tube  is  described  in  the  report  of  the  En- 
tomologist (Report  of  the  Commissioner  of  Agriculture  for  18S1-\S2,  p. 
1  (J2).  It  consists  of  a  shallow,  circular,  metal  chamber  soldered  to  a  short 
piece  of  metal  tubing  as  an  inlet.  The  inlet  passage  penetrates  the  wall 
of  the  chamber  tangentially,  admitting  the  fluid  eccentrically,  and  caus- 
ing it  to  rotate  rapidly  in  the  chamber.  The  outlet  consists  of  a  very 
small  hole  drilled  in  the  exact  center  of  one  face  of  the  chamber.  The 
orifice  should  not  be  larger  than  will  admit  the  shaft  of  an  ordinary  pin. 
Through  this  outlet  the  fluid  is  driven  perpendicularly  to  the  plane  of 


REMEDIES    AGAINST   SCALE-INSECTS. 


101 


Fio.  44.— Cyclone  or  eddy-chamber 
nozzle.    (After  Barnard.) 


rotation  In  the  chamber.  Its  whirling  motion  disperses  it  broadly  from 
the  orifice,  and  produces  a  very  fine  spray,  which  may  be  converted 
into  a  cloud  of  mist  by  increasing  the  pressure 
in  the  pump.  The  perforated  face  of  the  noz- 
zle-chamber is  removable  for  convenience  in 
clearing  the  orifice  when  it  clogs.  The  diam- 
eter of  the  chamber  inside  need  not  exceed 
one-half  inch  and  its  depth  one-quarter  inch. 
A  nozzle  of  these  dimensions  attached  to  the 
aquapult  pump  covers  one  and  a  half  square 
yards  of  surface  at  a  distance  of  4  or  5  feet 
from  the  orifice.  The  amount  of  dispersion 
depends  somewhat  upon  the  thickness  of  the 
perforated  face  of  the  chamber.  The  diam 
eter  of  the  cone  of  spray  may  be  increased  by 
countersinking  the  exit  hole  and  making  its 
edges  thin. 

Three-eighths-inch  guin  tubing  is  sufficient- 
ly large  to  supply  one  or  a  gang  of  several 
nozzles.  The  tubing  must  be  strengthened 
with  one  ply  of  cloth. 

In  use,  the  end  of  the  hose  is  supported  by  being  fastened  to  a  light 
rod  of  wood,  which  forms  a  handle,  by  means  of  which  the  nozzle  may 
be  applied  to  all  parts  of  the  tree.  For  full- sized  trees  a  rod  long 
enough  to  reach  nearly  to  their  tops  must  be  used.  For  this  purpose  a 
convenient  device  may  be  made  by  passing  the  small  rubber  hose 
through  a  hollow  bamboo  rod  of  the  required  length.  A  three-six- 
teenth brass  tube  inserted  in  a  bamboo  rod  has  also  been  used. 

Plate  VII  exhibits  a  complete  outfit  for  treating  orange  groves  with 
liquid  insecticides,  from  a  photograph  taken  during  actual  service  in  the 
field.  This  consists  of  a  common  pendulum  pump  inserted  in  a  barrel 
and  mounted  upon  a  cart.  The  liquid  is  delivered  through  two  lines  of 
hose,  each  ending  in  a  cyclone  nozzle.  The  arrangement  here  shown 
permits  the  spraying  of  two  rows  of  young  trees  at  once,  and  thus  effects 
a  considerable  saving  in  time.  In  the  same  plate  is  shown  an  aquapult 
pump  fitted  with  a  cyclone  nozzle  and  a  single  length  (12  feet)  of  three- 
eighths-inch  hose.  The  pump  is  inserted  in  a  pail,  ready  for  use  as  a 
portable  apparatus  for  one,  or  preferably  for  two  men. 

Several  Applications  necessary. — Unless  exceptional  care  is  exercised 
some  portions  of  the  bark  or  leaves  will  escape  thorough  wetting  and 
isolated  scales  will  be  left  alive.  The  eggs  also  to  some  extent  will 
escape  destruction  and  may  hatch  in  sufficient  numbers  to  restock  the 
plant.  As  a  rule,  therefore,  two,  or  even  more,  applications  will  be  nec- 
essary. A  second  application  should  not  follow  too  closely  on  the  first. 
Sufficient  time  should  be  given  for  the  hatching  of  all  the  eggs  which 
may  have  been  left  alive.  On  the  other  hand,  if  delayed  too  long,  a 


102  INSECTS    AFFECTING   THE    ORANGE. 

brood  interval  will  have  elapsed  and  fresh  eggs  will  be  deposited.  Suc- 
cessive applications  should,  therefore,  be  made  at  intervals  of  not  less 
than  three  and  not  exceeding  six  weeks. 

Proper  Seasons  for  applying  Remedies. — If  kerosene  emulsions  are  used 
trees  may  be  treated  for  Scale  at  any  time  during  the  growing  season. 
Strong  solutions  of  lye,  whale-oil  soap,  and  other  applications  which 
are  injurious  to  tender  growth  do  least  harm  to  the  trees  when  dormant. 
The  brood  periods  of  Scale-insects  are  quite  irregular,  and  breeding  is 
more  or  less  continuous  throughout  the  year.  As  a  rule,  however,  in 
Florida  new  broods  begin  in  March,  June,  and  September,  and  in  these 
months,  or  the  month  succeeding  each,  the  application  of  insecticides 
gives  the  greatest  advantage.  The  period  immediately  preceding  the 
appearance  of  each  brood  is  that  in  which  the  majority  of  scales  are 
filled  with  eggs,  upon  which  many  insecticides  have  little  or  no  effect. 
The  months  of  February,  May,  and  August,  and  the  winter  months 
from  November  to  January,  are,  therefore,  seasons  in  which  the  applica- 
tion of  remedies  is  likely  to  prove  least  effective. 

To  apply  washes  in  winter  is  somewhat  hazardous,  and  exposes  the 
trees  to  risk  of  serious  injury,  by  causing  them  to  put  forth  new  growth 
at  a  time  when  there  is  danger  from  frost.  For  in  Florida  the  Orange  is 
never  quite  dormant  even  in  the  coldest  winter,  and  the  reaction  that 
follows  an  application  is  liable  to  start  the  buds  unless  the  weather  re- 
mains uniformly  cool. 

When  the  air  is  charged  with  moisture,  and  the  nights  are  cold,  with 
heavy  dews  or  frost,  the  evaporation,  even  of  volatile  oils,  is  checked, 
and  they  remain  too  long  in  contact  with  the  plant.  Applications  made 
under  such  atmospheric  conditions  sometimes  prove  very  severe,  and 
cause  the  tree  to  shed  all  its  leaves,  or  even  kill  the  branches. 


P--ART    II. 


MISCELLANEOUS  INSECTS  AFFECTING  THE  ORANGE. 


103 


CHAPTER  VIII. 
BUST  OF  THE  ORANGE. 

NATURE   OF  RUST. 

Discoloration  of  the  Fruit — The  brownish  discoloration  of  the  rind 
of  oranges,  familiarly  known  under  the  name  of  "rust,"  has,  since  the 
production  of  this  fruit  became  an  important  industry  in  Florida,  given 
great  concern  to  the  producers,  and  occasions  annually  serious  loss  by 
affecting  injuriously  the  salableuess  of  the  fruit.  In  appearance  the 
rust  varies  from  a  light  or  dark  brown  stain  beneath  the  cuticle  to  a 
rough  incrustation  resembling  an  exudation  of  resinous  gum  upon  the 
surface.  In  the  former  case  the  golden  color  of  the  ripe  orange  is  more 
or  less  obscured,  and  in  the  latter  entirely  destroyed  by  the  discol- 
oration. When  entirely  coated  with  rust  the  surface  becomes  finely 
chapped  and  roughened,  giving  to  the  unripe  fruit  a  likeness  to  russet 
apples. 

The  season  during  which  rust  makes  its  appearance  includes  nearly 
the  entire  period  of  growth  of  the  fruit,  beginning  in  early  summer, 
when  the  fruit  has  attained  less  than  one-third  its  full  size,  and  contin- 
uing late  into  autumn.  Its  most  rapid  increase  is,  however,  in  August 
and  September,  as  the  orange  approaches  maturity.  Rarely  is  there 
any  real  increase  after  the  rind  begins  to  ripen,  although  the  discolor- 
ation usually  attracts  attention  just  at  this  time,  and  frequently  occa- 
sions unnecessary  alarm.  On  the  contrary,  there  is  always  a  percep 
tible  brightening  as  the  fruit  attains  its  full  color,  and  oranges  slightly 
affected,  or  affected  very  early  in  the  season,  when  fully  ripe  show  but 
little  trace  of  rust. 

J*  Rust  a  Fungus,  or  an  exudation  of  Gum? — The  term  "rust"  is  very 
indefinitely  applied  to  a  great  variety  of  plant  diseases,  some  of  which 
are  clearly  due  to  the  presence  of  fungi,  and  others  are  considered  path- 
ological conditions  of  the  plant,  attributable  to,  for  the  most  part,  un- 
known or  conjectural  conditions  of  soil  or  climate. 

A  good  example  of  the  first  class  is  found  in  the  common  and  very 
destructive  rust  of  the  Fig.  Any  one  who  will  take  the  trouble  to  ex- 
amine with  a  good  glass  the  brown  discoloration  upon  the  surface  of 
the  leaves  may  easily  detect  the  sacks,  or  asci,  of  the  fungus,  filled  to 
bursting  with  the  spores,  or  pouring  them  out  upon  the  surface. 

Nothing  of  this  kind  is  seen  upon  the  leaves  or  rusted  fruit  of  the 
Orange.  A  microscopic  examination  of  the  fruit-rind  reveals  no  forms 

lOt 


106  INSECTS    AFFECTING   THE    ORANGE. 

of  fungus,  but  shows  the  oil-cells  to  be  more  or  less  completely  emptied 
of  their  contents,  and  the  outer  layers,  the  epithelial  cells,  clogged  with 
brownish  resin,  or  entirely  broken  up  and  divided  by  fissures,  which 
permit  evaporation  of  the  fluids  from  the  underlying  cells.  The  rind  of 
rusted  fruit,  therefore,  shrinks  and  toughens,  and  loses  by  evaporation 
or  oxidation  the  greater  part  of  its  essential  oil. 

THE   ORIGIN   OF  RUST. 

Reasons  for  considering  it  the  Work  of  a  Mite. — If  we  examine  critically 
with  a  hand  lens  of  considerable  magnifying  power  the  surface  of  a 
rusted  orange,  we  will  find  here  and  there  in  the  depressions,  groups  of 
'minute  white  filaments  adhering  closely  to  the  rind.  Carefully  trans- 
ferring one  of  these  filaments  to  the  stage  of  a  compound  microscope, 
and  applying  a  power  of  several  hundred  diameters,  the  character  of 
the  object  is  clearly  shown.  It  is  the  cast  skin  of  an  insect. 

If  the  examination  chance  to  be  made  in  winter,  when  the  fruit  is' 
ripe,  the  number  of  these  exuviae  will  not  be  strikingly  great.  But  if 
made  in  autumn  or  late  summer,  the  surface  of  every  orange  showing- 
rust  will  be  found  thickly  sprinkled  with  them,  and  we  shall  be  forced 
to  conclude  that  we  have  before  us  the  relics  of  a  numerous  colony, 
which  at  some  former  period  infested  the  fruit. 

Extending  the  examination  to  fruit  that  as  yet  shows  no  indication 
of  rust,  we  will,  if  the  season  is  not  too  far  advanced,  obtain  abundant • 
confirmation  of  this  conclusion,  and  find  these  colonies  in  the  full  tide 
of  their  existence.  The  former  occupants  of  the  cast  skins  prove  to  be 
elongate  Mites,  of  honey-yellow  color,  too  minute  to  be  seeu  as  indi- 
viduals with  the  unassisted  eye,  but  visible  in  the  aggregate  as  a  fine 
golden  dust  upon  the  surface  of  the  fruit. 

The  Mite  on  the  Leaves. — Having  tracked  the  Mite  by  means  of  its  tell- 
tale exuviae,  and  detected  it  at  work  upon  the  fruit,  if  we  turn  our  at- 
tention to  the  leaves  it  needs  no  prolonged  search  to  discover  it  here 
also,  and  in  even  greater  abundance.  In  fact,  it  is  evidently  upon  the 
leaves  that  the  Mites  exist  and  propagate  throughout  the  year  j  for  not 
only  are  they  found  upon  fruiting  trees,  but  upon  plants  of  all  ages,  in 
the  nursery  as  well  as  in  the  grove. 

Nothing  resembling  the  rust  of  the  fruit  follows  their  attacks  upon 
the  leaves.  Each  puncture  of  the  Mites  gives  rise  to  a  minute  pimple 
or  elevation,  until  the  surface  of  the  leaf  becomes  finely  corrugated, 
loses  its  gloss,  and  assumes  a  corroded  and  dusty  appearance. 

This  tarnished  appearance  of  the  foliage  is  very  characteristic,  and 
remains,  a  permanent  indication  of  their  depredations,  after  the  Mites 
themselves  have  disappeared. 

First  appearance  of  Mites  on  the  Fruit. — From  the  time  when  the 
cellular  structure  of  the  rind  has  completely  developed,  and  the  oil-cells 
have  begun  to  fill,  until  the  fruit  is  far  advanced  in  the  process  of 
ripening;  in  other  words,  from  early  spring  until  late  in  autumn,  it  is 


RUST    OF    THE    ORANGE.  107 

liable  to  attacks  of  the  Mites,  but  it  is  in  the  intermediate  period  of  its 
growth  that  the  fruit  offers  conditions  most  favorable  to  their  increase. 

Attacks  of  the  Mite  always  fottawed  ~by  Rust.— The  evidence  that  rust 
follows  as  a  sequence  upon  the  depredations  of  this  Mite  is  circumstan- 
tial rather  than  direct,  but  it  is  also  cumulative.  Oranges  marked  and 
kept  under  observation,  but  allowed  to  remain  upon  the  tree,  have  in 
all  cases  rusted  after  being  overrun  by  the  Mites.  Those  upon  which 
no  Mites  made  their  appearance  remained  bright  to  maturity. 

A  very  large  number  of  observations  show  a  close  connection  between 
the  occurrence  of  Mites  upon  the  foliage  and  rust  on  the  fruit,  so  that  it 
may  be  stated  as  a  rule,  when  the  foliage  of  a  tree  retains  its  gloss,  the 
fruit  also  will  be  bright,  and,  conversely,  when  the  condition  of  the 
leaves  indicates  the  presence  of  Mites  in  great  numbers,  the  fruit  will 
be  discolored. 

This  is  found  to  be  true,  not  only  of  the  entire  tree,  but  of  restricted 
portions.  Thus  the  upper,  the  lower  branches,  or  one  side  of  an  orange 
tree  may  produce  rusty  fruit  while  that  on  the  other  parts  of  the  tree 
remains  bright.  In  such  cases  there  will  always  be  a  marked  difference 
in  the  condition  of  the  foliage  upon  the  two  portions,  and  the  leaves 
surrounding  the  affected  fruit  will  indicate  more  or  less  clearly  the 
work  of  the  Mites. 

Other  and  perhaps  more  conclusive  reasons  for  considering  the  Mite 
responsible  for  rust  will  be  better  understood  when  the  habits  of  the 
Mite  itself  have  been  considered. 

Interval  between  the  Disappearance  of  the  Mites  and  the  Appearance  of 
liust. — As  has  been  already  indicated,  the  Mites  do  not  permanently 
infest. either  the  surface  of  the  leaf  or  the  rind  of  the  fruit,  but  wander 
off  to  fresh  feeding  ground  when,  through  their  combined  attacks,  all 
the  accessible  oil-cells  have  been  emptied  of  their  contents,  or  the  tissues 
have  been  too  much  hardened  by  advancing  maturity  to  be  easily  pene- 
trated by  their  beaks. 

The  effects  of  their  punctures  upon  the  cellular  structure  of  the  plant, 
however,  continue  after  their  departure,  and  upon  the  fruit,  rust  de: 
velops  with  a  varying  interval,  depending  possibly  upon  the  relative 
humidity  of  the  air.  Usually  the  discoloration  is  very  apparent  after 
the  lapse  of  a  week,  and  the  rind  continues  to  harden  indefinitely,  or  as 
long  as  it  is  exposed  to  the  air. 

THE  RUST-MITE. 

(Typhlodromus  oleivorus  Ashm.) 

Description. — The  so-called  Bust  Insect  (Fig.  45,  a  b)  is  a  four-legged 
Mite,  honey-yellow  in  color,  and  about  three  times  as  long  as  broad. 
The  body  is  cylindrical,  widest  near  the  anterior  extremity,  and  tapers 
behind,  terminating  in  two  small  lobes,  which  assist  the  animal  in  crawl- 
ing and  enable  it  to  cling  firmly  to  the  surface  upon  which  it  rests. 
The  front  is  prolonged  in  a  conical  protuberance,  which  appears  to  be 


108 


INSECTS    AFFECTING   THE    ORANGE. 


composed  of  two  closely- applied  lobes.  The  upper  surface  at  its  widest 
part  is  marked  on  each  side  with  shallow  depressions,  which  are  faintly 
prolonged  on  the  sides  and  reach  nearly  to  the  terminal  lobes.  The 
abdomen  consists  of  about,  thirty  segments.  The  beak,  a  short,  curved 
tube,  is  usually  retracted  between  the  organs  of  the  mouth.  The  latter 

form  a  truncated  cone,  concealed  from 
above  by  the  projection  of  the  front, 
and  difficult  to  resolve  into  its  compo- 
nent parts.  Under  high  powers  it  can 
be  seen  to  consist  of  at  least  two  thick 
lobes,  which  in  the  living  Mite  have  a 
reciprocal  forward  and  back  movement. 
The  two  pairs  of  legs  are  placed  close 
together,  at  or  very  near  the  anterior 
extremity,  and  project  forwards.  They 
are  four-jointed,  and  terminate  in  a 
curved  spine,  with  opposing  bristles. 
(Fig.  45,  c.)  The  intermediate  joints 
bear  one  or  two  very  long,  curved  bris- 
tles. Several  fine  bristle-hairs,  arising 
from  the  under  surface  of  the  body, 
curve  upwards  at  the  sides,  and  two 
very  long  bristles  at  the  caudal  extrem- 
ity, curving  downwards,  are  trailed 
after  the  Mite  as  it  crawls. 
The  length  of  the  adult  Mite  is  0.14rnra  (y^  inch).  The  young  do  not 
differ  essentially  in  structure  from  the  adults,  but  are  thick  and.  short, 
almost  cordiform,  and  the  legs  are  very  short. 

The  eggs,  which  are  deposited  singly  or  in  little  clusters  upon  the 
surface  of  the  leaves,  are  spherical,  transparent,  with  a  yellow  tinge. 
Their  diameter  is  more  than  half  that  of  the  mother  at  its  widest  part, 
aud  they  probably  increase  in  size  by  the  absorption  of  moisture  after 
they  are  laid ;  otherwise  the  body  of  the  Mite  could  not  contain  more 
than  three  or  four  fully- developed  ova.  The  embryo  is  curved  within 
the  egg,  its  head  slightly  overlapping  the  tail.  (Fig.  45,  d.) 

Life-history. — In  hot  weather  the  eggs  hatch  in  four  or  five  days,  but 
in  winter  their  development  is  more  or  less  retarded  by  cold,  although 
it  is  not  entirely  arrested  even  by  frost,  and  the  duration  of  the  egg 
period  seldom  exceeds  two  weeks. 

The  young  are  bright,  translucent  yellow  in  color.  Within  a  week 
or  ten  days  they  undergo  a  metamorphosis  or  molt,  during  which  the 
animal  remains  dormant  for  about  forty-eight  hours.  With  its  legs, 
which  are  placed  close  together,  and  stretched  out  in  line  with  the, 
body,  and  with  its  two-lobed  anal  proleg,  it  clings  closely  to  the  surface 
of  the  leaf.  The  form  becomes  more  elongate  and  spindle-shaped.  The 
body  of  the  transforming  Mite  separates  from  the  old  skin,  which  be- 


Fio.  45.— The  Orange  Rust-mite:  a,  dorsal 
view ;  ft,  lateral  view — enlarged,  the  dot 
in  circle  indicating  natural  size;  c,  leg; 
d,  egg,  with  embryo  just  about  to  hatch- 
more  enlarged.  ( After  Hubbard.) 


RUST   OF   THE    ORANGE.  109 

coines  pellucid  and  empty  at  the  extremities,  and  finally  splits  longi- 
tudinally, releasing  the  renovated  Mite.  The  rejected  pellicle  is  left 
tirmly  adhering  to  the  surface  on  which  it  rests,  but  is  in  time  removed 
by  the  action  of  the  weather,  and  much  sooner  from  the  leaves  than 
from  the  rind  of  fruit. 

The  adult  Mite  is  slightly  darker  than  the  young  in  color,  and  be- 
comes more  opaque  as  it  grows  older.  No  sexual  differences  have  been 
distinguished,  nor  has  the  act  of  coupling  been  observed. 

Owing  to  the  difficulty  of  confining  the  Mites  without  interfering  with 
the  conditions  necessary  to  their  existence,  it  has  not  been  possible  to 
determine  the  duration  of  their  lives.  It  is,  however,  safe  to  conclude 
that  they  live  several  weeks  after  reaching  the  adult  stage.  The  num- 
ber of  eggs  deposited  is  also  uncertain,  but  it  is  probably  not  abnormal, 
and  the  enormous  populousness  of  their  colonies  must  be  attributed  to 
rapid  development,  and  comparative  immunity  from  enemies  and  para- 
sites, rather  than  to  excessive  fecundity. 

Food. — This  evidently  consists  of  the  essential  oil  which  abounds  in 
all  succulent  parts  of  the  Orange  and  its  congeners,  and  which  the  Mites 
obtain  by  penetrating  with  their  sucking  beaks  the  cells  that  lie  im- 
mediately beneath  the  epidermis.  That  they  do  not  feed  upon  the  chlo- 
rophyl  is  shown  by  the  color  of  their  intestinal  contents,  which  has  no 
tinge  of  green,  but  a  clear  yellow,  unmistakably  indicating  the  source 
from  which  it  came. 

Wandering  Habits.—-  While  engaged  in  feeding,  the  mites  remain  qui- 
escent for  a  length  of  time  varying  from  a  few  minutes  to  half  an  hour. 
They  then  move  on  a  short  distance  and  again  become  motionless.  If 
disturbed  they  have  a  habit  of  erecting  themselves  upon  the  leaf,  cling- 
ing to  its  surface  only  by  the  anal  proleg. 

When  dissatisfied  with  their  surroundings,  or  when  food  becomes 
scarce,  they  wander  restlessly  about,  and  undoubtedly  travel  to  consid- 
erable distances.  Their  rate  of  progress  on  a  smooth  surface  is  quite 
rapid,  and  amounts  to  10  or  12  feet  per  hour.  It  is  therefore  not  sur- 
prising to  find  them  changing-  their  position  frequently  5  disappearing 
suddenly  from  one  portion  of  a  tree  and  appearing  as  suddenly  in  great 
numbers  upon  another  and  distant  part  of  the  same  tree. 

It  is  not  to  be  understood  that  the  Mites  show  any  concert  of  action 
in  moving  their  colonies,  or  that  they  are  in  any  other  sense  gregarious 
than  that  they  are  usually  found  very  thickly  scattered  over  those  parts 
of  an  infested  plant  which  offer  favorable  conditions  for  their  support. 
Thus  the  new  growth  of  many  orange  trees  becomes  occupied  or  infested 
by  them  as  rapidly  as  the  leaves  fully  mature,  and  the  number  upon  a 
single  leaf  may  be  estimated  by  many  thousands. 

Numerical  Abundance. — The  following  examination,  made  in  January, 
will  give  an  idea  of  the  extent  of  the  brood  during  the  coldest  part  of 
the  Florida  winter. 

From  a  large  number  of  leaves  of  late  autumn  growth  one  was  »e- 


110  INSECTS    AFFECTING   THE    ORANGE. 

lected  which  showed  an  even  distribution  of  Mites  upon  its  surface. 
An  area  of  one  square  inch  was  accurately  marked  out  with  a  needle, 
and  subdivided  into  sixteen  equal  squares.  The  number  of  Mites  and 
their  eggs  upon  four  of  the  small  squares,  taken  at  random,  was  counted, 
and  found  to  aggregate  1,142.*  This  gives  for  the  square  inch  under 
observation  4,568  mites.  The  leaf  was  then  cut  into  squares  and  tri- 
angles, and  was  found  to  cover  15  square  inches  upon  a  sheet  of  paper. 

On  the  supposition  that  the  experimental  square  inch  gives  a  fair 
average,  the  number  of  Mites  upon  the  upper  surface  of  this  leaf  was 
68,520.  Certain  portions,  not  exceeding  one-quarter  of  the  whole,  were, 
however,  more  or  less  thinly  populated.  Deducting,  therefore,  27  per 
cent,  from  the  above,  we  have  50,020  Mites,  the  approximate  popula- 
tion of  the  upper  surface.  The  under  side  of  the  leaf  was  less  thickly 
infested,  but  the  number  of  Mites  maybe  estimated  as  one-half  that  of 
the  upper  face,  or  25,000.  Thus  the  number  of  Mites  and  their  eggs, 
upon  a  single  leaf,  is  found  to  reach  even  in  midwinter  the  enormous 
sum  of  .75,000. 

In  early  summer,  when  the  breeding  is  active,  these  estimates  will  be 
greatly  exceeded.  At  times  ail  orange  tree  may  be  so  completely  in- 
fested with  the  Mites,  that  of  its  thousands  of  leaves  very  few  can  be 
found  free  from  their  presence.  If,  then,  we  attempt  to  calculate  the 
number  that  may  exist  contemporaneously  upon  a  bearing  tree,  we  find 
it  represented  not  by  millions  but  by  billions,  and  the  figures  obtained 
convey  no  definite  impressions  to  the  mind. 

Preference  shown  for  half  Shade. — An  examination  made  on  a  bright, 
sunny  day  shows  that,  while  the  Mites  cannot  long  endure  the  direct 
light  and  heat  of  the  sun,  they  also  avoid  dark  shade.  At  midday  they 
are  more  abundant  upon  the  under  side  of  exposed  leaves,  and  although 
they  at  all  times  show  a  marked  preference  for  light,  they  desert  those 
parts  of  leaf  or  fruit  upon  which  it  falls  brightest.  On  a  leaf  partially 
exposed  to  the  sun  the  Mites  congregate  near  one  edge  in  the  morning, 
and  in  the  afternoon  cross  to  the  opposite  side  of  the  same  surface,  fol- 
lowing the  shifting  shade,  which,  by  reason  of  its  curvature,  the  edges 
of  the  leaf  throw  upon  one  side  or  the  other.t 

Rings  of  Rust  on  Fruit. — On  the  fruit,  this  preference  of  the  Mites  for 
half  shade  causes  a  phenomenon  which  will  be  recognized  as  verycom- 

*The  number  of  eggs  exceeded  that  of  the  Mites,  a  phenomenon  not  often  observed, 
and  which  may  be  attributed  to  unusually  cold  and  unfavorable  weather  at  the  time 
of  the  examination  and  for  several  weeks  previous. 

tThe  conditions  most  favorable  to  their  increase  are  afforded  by  luxuriant  foliage 
when  thoroughly  penetrated  by  light,  but  dense  shade  effectually  bars  their  progress. 
Vigorous  young  trees  on  which  the  foliage  is  illuminated  from  beneath  by  radiation 
from  the  surrounding  soil  are  especially  subject  to  attack,  the  succulence  of  their 
leaves  serving  only  to  increase  enormously  the  numbers  of  the  invading  host.  The 
same  luxuriance  in  older  trees,  whose  branches  interlock  in  the  grove  and  shade  the 
ground,  acts  unfavorably  upon  the  productiveness  of  the  Mites  and  checks  their  in- 
crease. These  are  facts  of  importance,  as  will  be  seen  when  we  come  to  consider  the 
means  of  combating  the  pest. 


RUST    OF    THE  ORANGE.  Ill 

inon  on  rusty  oranges.  This  is  the  occurrence  of  rust  in  a  well-defined 
ring,  obliquely  encircling  the  orange  as  the  ecliptic  does  the  earth.  The 
rust  ring  is  seen  most  plainly  on  fruit  from  the  upper  portion  and  south 
side  of  a  tree  when  it  stands  with  others  in  a  grove,  and  will  be  found 
to  mark  the  band  of  half  shade  between  the  portion  of  the  orange  most 
directly  exposed  to  the  sun's  rays  and  that  in  densest  shadow.  The 
surface  covered  by  this  penumbra  band  is  precisely  that  upon  which 
the  mites  gather  most  thickly  in  the  middle  of  the  day.  Here  their 
attack  upon  the  rind  will  be  most  severe  and  its  after  effects  most 
noticeable.  (Plate  VIII.) 

There  is  also  observable  in  rusted  fruit  a  marked  difference  in  the 
amount  of  discoloration  upon  the  opposite  sides.  Even  where  no 
plainly  marked  ring  is  visible,  the  side  of  the  fruit  which  upon  the 
tree  was  turned  towards  the  sun  frequently  presents  a  bright  spot, 
and  the  opposite  side  an  area  of  lighter  bronze,  with  less  sharply  de- 
nned boundaries. 

These  facts,  taken  in  connection  with  the  observed  habits  of  the  Mites, 
may  be  regarded  as  the  strongest  evidence  showing  a  connection  be- 
tween rust  and  their  attacks  upon  the  fruit. 

Influence  of  Weather. — It  has  been  already  observed  that  the  hatching 
of  the  eggs,  although  retarded,  does  not  cease  in  cold  weather,  and  that 
the  breeding  continues  throughout  the  year.  Frost,  which  is  sometimes 
severe  enough  to  kill  the  adult  Mites,  does  no  injury  to  the  eggs,  and 
the  severity  of  a  winter  has  little,  if  any,  effect  upon  their  prevalence 
during  the  following  summer.  In  droughts,  however,  there  is  some 
evidence  that  many  of  the  eggs  dry  up  and  are  exterminated.  The 
extremely  dry  seasons  of  1881  and  1882  were  followed  in  the  winter  of 
1882-'83  by  the  brightest  crop  of  fruit  that  had  been  known  for  several 
years. 

Agencies  which  assist  in  the  Distribution  of  Mites. — The  activity  of  the 
Mites  and  their  readiness  to  climb  upon  anything  they  meet  in  their 
path  renders  it  evident  that  any  living  creature  which  passes  from  one 
tree  to  another  is  competent  to  transport  the  Mites  with  it.  The  tail- 
feathers  of  birds  must  sweep  thousands  from  the  surfaces  of  the  leaves, 
and  spread  them  from  tree  to  tree  or  from  grove  to  grove. 

So  readily  do  they  relinquish  their  hold  when  brought  into  contact 
with  a  moving  body,  that  the  point  of  a  needle  swept  across  the  surface 
of  an  infested  leaf  will  usually  be  found  to  have  several  Mites  adhering 
to  it. 

The  same  agencies  which  assist  in  the  spread  of  Scale-insects  un- 
doubtedly serve  to  scatter  the  Mites.  Not  only  do  they  climb  readily 
along  the  webs  of  spiders,  but  they  may  frequently  be  seen  upon  the 
bodies  of  the  spiders  themselves,  which  do  not  seem  to  be  at  all  dis- 
turbed by  the  restless  movements  of  their  little  attendants. 

The  wandering  habit  of  spiders  is  well  known.  Their  method  of 
bridging  great  distances  by  casting  out  hundreds  of  feet  of  silken  line, 


112  INSECTS   AFFECTING   THE   ORANGE. 

to  be  wafted  by  the  winds  and  caught  in  distant  trees,  has  often  been 
noted.  There  is  little  doubt  that  of  all  other  modes  of  dissemination, 
both  of  Scale-insect  and  Eust-mite,  that  of  transportation  by  spiders  is 
the  most  impprtaut,  the  most  constant,  and  regular.  The  spiders  bear 
with  them  upon  their  hairy  bodies  the  young  Bark-lice  and  the  adult 
Mites,  conveying  them  in  their  own  migrations  to  distant  points,  and 
colonizing  them  under  their  protecting  web  whenever  they  chance  to 
select  the  leaves  of  a  citrus  plant  as  their  resting  place. 

And  here  is  found  the  solution  of  that  puzzling  influence  of  the  wind 
so  often  remarked  in  the  case  of  Scale-insects,  and  which  has  led  many 
to  believe  that  they  are  disseminated  directly  by  this  agency,  and  there- 
fore spread  most  rapidly  in  the  direction  of  the  prevailing  currents. 

Spiders  of  the  web-making  kinds  are  necessarily  dependent  upon  the 
wind  in  making  long  voyages.  The  warm  southeasterly  winds  of  spring 
excite  in  them  the  migratory  instinct,  and  at  a  time  when  the  orange 
trees  are  swarming  with  the  quickened  life  of  Scale  and  Mite  from  a 
thousand  projecting  points  of  branch  or  leaf,  the  spiders  are  sending 
out  their  lines  of  rapid  transit,  and  are  bearing  with  them  "on  the  wings 
of  the  wind"  the  seeds  of  mischief  to  the  orange- grower. 

RAVAGES  OF  THE  EUST-MITE. 

The  Mite  known  only  upon  Plants  of  the  Citrus  Family. — The  Eust-mite 
attacks  indiscriminately  the  various  species  of  Citrus  in  common  culti- 
vation, but  has  not  been  observed  to  feed  upon  plants  of  any  other  ge- 
nus. It  is  found  upon  the  Lime,  Lemon,  Citron,  Shaddock,  Bigarde,  and 
Tangerine,  and  none  of  the  varieties  of  the  Orange  are  known  to  be  in 
any  degree  exempt. 

Upon  the  leaves  and  fruit  of  all  these  species  of  Citrus  the  effects  of 
its  attack  are  essentially  the  same,  although  the  rust  is  most  noticeable 
on  the  Sweet  and  Bitter  Orange. 

Effect  of  Attacks  upon  the  Foliage. — Like  certain  internal  animal  para- 
sites which  feed  only  upon  the  fat  of  their  hosts,  and  do  not  touch  its 
vital  organs,  the  Mite  does  not  destroy  the  vital  functions  of  the  leaf. 
The  chlorophyl  is  untouched,  and  the  plant  is  robbed  of  a  portion  only 
of  its  essential  oil.  The  leaves  never  drop,  no  matter  how  severely  at- 
tacked, but  there  is  loss  of  vitality,  and  the  growth  of  the  plant  is 
checked.  This  is  especially  noticed  in  young  trees,  which  are  frequently 
overrun  by  the  pest  in  early  summer,  and  during  the  remainder  of  the 
year  make  little  progress. 

The  foliage  of  affected  trees  wears  a  dry,  dusty  appearance,  and  loses 
color.  The  leaves  are  without  gloss,  and  become  slightly  warped,  as  in 
droughts. 

Rusted  Fruit. — If  severely  attacked  by  rust  before  it  has  completed 
its  growth,  the  orange  does  not  attain  its  full  size.  Yery  rusty  fruit  is 
always  small.  Its  quality  is,  however,  improved  rather  than  deterio- 
rated. The  toughened  rind  preserves  it  from  inj  ury  and  decay ,  prevents 


RUST  OF  THE  ORANGE REMEDIES.  113 

evaporation  from  within,  and  carries  the  ripening  process  to  a  higher 
point. 

Busty  oranges  can  be  shipped  without  loss  to  great  distances.  They 
keep  longer,  both  on  and  off  the  tree,  and  when  they  reach  the  north- 
ern markets  are  superior  to  the  bright  fruit  in  flavor.  Consumers  not 
being  aware  of  this  fact,  however,  prefer  the  latter,  and  the  reduced 
price  of  the  bronzed  fruit  more  than  offsets  to  the  producer  its  superior 
keeping  and  shipping  qualities 

Introduction  and  Spread  of  the  Mite. — Of  the  origin  of  the  Rust-mite, 
whether  native  or  introduced,  we  as  yet  know  nothing.  As  far  as  has 
been  observed,  it  is  not  found  upon  the  wild  orange  trees  in  Florida, 
although  it  attacks  them  indiscriminately  with  others  of  the  citrus 
family  when  transplanted  to  open  ground,  and  it  may  exist  upon  them 
in  small  numbers  in  their  native  swamps. 

It  is  said  that  a  few  years  ago  rust  was  entirely  unknown;  but  the 
orange  industry  in  this  State  is  of  such  recent  growth  that  attention  has 
not  long  been  directed  to  this  matter.  When  but  little  fruit  was  pro- 
duced, occasional  discoloration s  of  the  rind  would  naturally  pass  un- 
noticed. 

Periods  of  Increase. — As  is  the  case  with  most  invasions  of  insects,  the 
pest,  although  increasing  rapidly  for  a  time,  is  likely  to  reach  a  maxi- 
mum in  a  few  years  and  afterward  decline.  This  has  been  the  expe- 
rience in  former  years  with  Scale-insect,  and  is  attributable  to  compar- 
ative immunity  from  enemies  and  parasites  at  the  outset.  As  the 
number  of  their  enemies  increases,  that  of  the  destroyers  diminishes, 
until  in  time  a  state  of  equilibrium  is  reached,  which  is  disturbed  only 
temporarily  by  the  changing  conditions  of  climate,  or  other  and  obscure 
causes. 

It  seems  probable  that  the  Bust-mite  has  reached  or  is  already  past 
the  period  of  maximum  destructiveness,  and  that  succeeding  years  will 
witness  its  subsidence.  The  Mite  has  at  present  few  enemies,  and  of 
these  the  most  important  are  unfortunately  not  abundant.  They  give 
promise,  however,  of  greater  efficiency  in  future,  as  they  belong  to 
families  many  of  whose  members  are  as  prolific  as  the  Bust-mite  itself. 

Geographical  Distribution. — Bust  appears  to  be  known  upon  the  Orange 
only  in  Florida.  Within  the  limits  of  the  State,  however,  its  presence 
is  universal.  Xo  section,  whatever  claims  may  be  made  to  the  contrary, 
is  exempt. 

REMEDIES. 

Influence  of  Soil  and  Methods  of  Cultivation. — The  effect  upon  the 
prevalence  of  rust  of  various  systems  of  cultivation  and  of  applications 
to  the  soil,  for  the  purpose  of  changing  its  nature  or  supplying  assumed 
deficiencies  in  its  composition,  has  been  the  subject  of  endless  discus- 
sion, and  of  experiments  affording  negative  or  conflicting  results,  which 
cannot  profitably  be  reviewed  here. 
6521  o 


114  INSECTS    AFFECTING    THE    ORANGE. 

Suffice  it  to  say,  no  method  of  combating  rust  by  the  indirect  action 
through  the  plant  -of  chemical  substances  applied  to  the  soil  has  been 
proven  effective.  By  forcing  with  fertilizers  or  high  cultivation,  no  im- 
provement is  effected  in  the  color  of  the  fruit.  This  depends,  not  upon 
the  condition  of  the  tree,  but  rather  upon  the  number  of  the  Mites,  which 
is,  in  fact,  increased  by  an  abundant  supply  of  new  growth  and  a  con- 
stant succession  of  fresh  and  vigorous  leaves. 

It  seems,  however,  to  be  an  established  fact  that  the  fruit  is  less  liable 
to  rust  upon  low  than  upon  high  lands.  Groves  planted  upon  moist, 
rich  hammock  or  clay  soils  produce,  as  a  rule,  brighter  fruit  than  those 
upon  high,  sandy  pine  lands. 

This  result  is  commonly  attributed  to  the  abundance  of  moisture  in 
low  ground ;  but  it  may  be  more  directly  due  to  the  denser  shade  af- 
forded by  a  more  vigorous  foliage  and  reduced  radiation  from  a  darker 
soil.  In  the  native  wild  groves,  which  are  always  densely  shaded  by 
forest,  neither  rust  nor  Mites  are  found,  and  the  same  immunity  is  en 
joyed  by  cultivated  trees  planted  in  similar  situations. 

Preventive  Measures. — Any  means  which  will  enable  us  to  produce  on 
the  light,  sandy  soil  of  the  uplands  those  conditions  of  shade  which 
appear  natural  and  grateful  to  the  Orange,  and  which  we  have  seen  are 
unfavorable  to  the  increase  of  the  Eust-mite,  should,  if  the  foregoing 
account  is  correct,  give  immunity  from  Bust.  In  point  of  fact,  there  is 
strong  evidence  to  warrant  the  belief  that  with  intelligent  management 
almost  any  grove  may  in  a  few  years  be  made  to  produce  bright  fruit, 
by  reducing  the  radiation  and  darkening  the  soil,  (1)  with  mulch,  or, 
still  better,  with  a  liberal  coating  of  muck,  (2)  by  encouraging  the 
branches  to  grow  low  and  spreading,  and  especially  avoiding  the  vicious 
practice  of  trimming  young  trees  too  -high. 

Other,  ways  of  shading  the  ground  and  promoting  vigorous  leafy 
growth  will  occur  to  every  orange-grower. 

Those  who  advocate  forest  culture  for  the  Orange  may  justly  claim  for 
it  the  advantage  of  affording  comparative  immunity  from  rust ;  but  a 
discussion  of  the  merits  and  demerits  of  this  and  other  systems  of  cul- 
tivation must  be  left  to  the  horticulturist. 

It  may,  however,  be  proper  to  suggest  that  where  isolation  is  prac- 
ticable much  can  be  accomplished  toward  the  exclusion  of  such  pests  as 
the  Eust-mite  and  the  Scale-insect  by  properly  arranged  natural  screens. 
Narrow  belts  of  original  forest,  with  its  undergrowth,  may  be  left,  at 
least  on  the  southeast  side  of  the  grove  or  on  high  land ;  the  tall  pines 
may  be  supplemented  by  hedge-rows  of  the  native  Holly,  the  Jujube,  or 
other  evergreen  shrubs,  which  thrive  upon  uplands  in  the  South. 

Such  wind  breaks  not  only  protect  the  bearing  trees  and  fruit  from 
the  whipping  action  of  southeasterly  gales,  but  afford  the  best  and  only 
hindrance  to  the  spread  of  Mites  and  Bark-lice,  prohibiting  their  direct 
importation  upon  spiders  and  other  insects,  through  whose  aid  they  are 
disseminated. 


RUST  OF  THE  ORANGE REMEDIES.  115 

Application  of  Insecticides. — As  the  Bust-mite  lives  exposed  upon  tbe 
surface  of  the  plant,  neither  inhabiting  a  gall  nor  making  any  protec- 
tive covering  for  itself  or  young,  it  is  not  a  difficult  matter  to  reach  it 
with  insecticides  thoroughly  applied.  The  adult  Mites  are  very  deli- 
cate, and  readily  succumb  to  applications  of  moderate  strength,  but  the 
eggs  possess  much  greater  vitality,  and  require  for  their  destruction 
solutions  of  great  penetrating  power.  The  immature  Mites,  while  un- 
dergoing their  transformations,  are  also  difficult  to  kill,  and  appear  to 
be  specially  protected  by  the  old  skin,  within  which  their  changes  take 
place. 

These  three  stages,  the  adult,  the  molting  young,  and  the  egg,  exist 
simultaneously  at  all  seasons  of  the  year.  The  development  of  the  Mite 
has  been  shown  to  be  very  rapid.  The  eggs  hatch  in  four  or  five  days, 
the  time  extending  rarely,  in  winter,  to  two  weeks.  Molting  takes 
place  in  seven  to  ten  days,  and  lasts  two  days.  Eggs  are  probably  laid 
in  a  few  days  after  the  molt. 

In  applying  remedies,  it  follows  from  these  data  that  if  the  Mites 
alone  are  killed,  and  their  eggs  left  alive,  young  Mites  reappear  imme- 
diately, adults  are  found  in  ten  or  twelve  days,  and  fresh  eggs  are  de- 
posited within  two  weeks.  If  the  molting  Mites  are  also  left  alive, 
very  little  good  can  be  accomplished,  as  a  fresh  crop  of  adult  Mites  and 
eggs  will  be  produced  in  two  or  three  days. 

In  combating  Bust- mite  the  difficulty  in  killing  the  eggs  compels  us 
to  adopt  one  of  two  alternatives.  We  must  either  use  powerful  insecti- 
cides, in  solutions  even  stronger  than  are  required  for  Scale-insects,  or 
else  make  several  applications,  at  short  intervals,  of  washes  competent 
to  kill  the  Mites  only.  In  this  way  the  trees  may  be  freed  of  Mites,  by 
killing  the  young  as  they  hatch,  and  not  allowing  any  to  reach  the 
adult  stage  and  produce  a  fresh  crop  of  eggs. 

The  following  substances  have  been  tried  and  their  effects  noted  upon 
the  Mites  and  their  eggs : 

Whale  oil  soap. — The  action  of  this  substance  upon  the  Mites  is  pecul- 
iar. A  trace  of  it  in  solution  causes  them  to  relinquish  at  once  their 
.hold  upon  the  leaf.  All  other  liquids  that  have  been  tried,  even  if  they 
kill  the  Mites,  increase  the  tenacity  with  which  they  cling  to  its  sur- 
face. All  the  free  *  mites  are  at  once  removed  from  leaves  dipped  in  a 
solution  of  1  pound  to  100  gallons  of  water.  Stronger  solutions  are, 
however,  required  to  kill  them  or  their  eggs  and  the  dormant  (molting) 
young. 

The  following  experiments  made  in  the  laboratory  upon  infested 
leaves,  show  the  action  of  solutions  of  various  strength.  In  order  to 
retain  the  Mites  upon  the  leaves,  the  liquids  were  beaten  into  foam, 
which  was  spread  evenly  upon  both  surfaces,  care  being  taken  to  wet 
every  part  of  the  leaf. 

(1.)  Solution:  1  pound  to  100  gallons.    Free  Mites  washed  from  the 


*  This  term  includes  adults  aud  young  not  dormant,  or  undergoing  transformation. 


116  INSECTS   AFFECTING   THE    ORANGE, 

leaf  with  spray  and  collected  upon  blotting  paper,  began  to  crawl  away 
as  soon  as  dry,  and  showed  no  injury  the  following  day.  Eggs  and 
molting  young  remained  upon  the  leaf  and  were  not  aflected. 

(2.)  Solution :  1  pound  to  50  gallons.  Applied  in  foam.  Free  Mites 
in  great  part  killed.  Molting  young  and  eggs  not  killed. 

(3.)  Solution  :  1  pound  to  32  gallons.  Adult  Mites  all  killed.  Molt- 
ing young  in  part  killed.  Eggs  not  killed. 

(4.)  Solution :  1  pound  to  1C  gallons.  Adult  Mites  all  killed  and  shriv- 
eled, iii  two  or  three  hours.  Molting  Mites,  about  80  per  cent,  killed. 
Eggs,  a  large  percentage  killed. 

(5.)  Solution:  1  pound  to  5  gallons.  Adult  Mites  all  killed.  Molting 
Mites  apparently  all  dead  in  two  days.  Eggs  evidently  affected,  not 
all  killed,  but  many  collapsed  by  the  second  day. 

(6.)  Solution :  1  pound  to  1  gallon.  (This  solution  is  nearly  solid  when 
cold.)  Mites  all  killed.  On  the  second  day  all  the  eggs  appeared  col- 
lapsed and  dead. 

The  whale-oil  soap  usually  supplied  by  dealers  is  inferior  to  that  used 
in  the  above  experiments.  As  an  effective  remedy  for  Bust-mite  a  solu- 
tion of  1  pound  to  5  gallons  of  water  may  be  recommended:  It  should 
be  applied  in  early  spring,  before  the  new  growth  begins.  Two  or  three 
applications  will  be  required,  which  should  be  made  at  intervals  of  one 
week.  The  cost  of  the  wash,  at  the  ordinary  retail  price  for  the  soap 
(10  cents  per  pound),  is  2  cents  per  gallon. 

Very  weak  solutions  may  be  made  effective  if  used  at  frequent  short 
intervals,  but  the  labor  and  expense  of  making  the  numerous  applica- 
tions required  will  be  very  great. 

A  solution  of  1  pound  to  5  gallons  will  not  injure  the  trees,  but  may 
cause  the  blossoms  to  drop.  No  directions  can  be  given  as  to  the 
greatest  strength  of  solution  that  can  be  used  upon  blooming  trees  with- 
out loss  of  fruit,  as  this  depends  largely  upon  the  condition  of  the  tree. 
Solutions  of  1  pound  to  10  gallons  can  probably  be  safely  used,  in  most 
cases,  and  will  be  effective  if  several  applications  are  made  at  intervals 
of  a  few  days. 

Sulphur. — The  Mites,  both  adult  and  young,  are  very  sensitive  to  sul- 
phur, and  are  readily  killed  by  it  in  any  form  in  which  it  can  be  made 
to  act  upon  them.  The  eggs,  however,  are  not  readily  affected,  and 
even  survive  an  exposure  to  the  fumes,  which  will  kill  the  plant.  Fu- 
migation cannot  be  resorted  to  without  extreme  danger  to  the  life  and 
heal ih  of  the  tree.  The  finely  powdered  (sublimed)  flowers  of  sulphur 
does  not  affect  the  plant.  It  adheres  more  readily  than  might  be  sup- 
posed to  the  smooth  surface^  of  the  leaves,  and,  especially  when  they 
are  roughened  by  the  Mites,  it  is  not  entirely  tvashed  away  by  heavy 
rains.  Although  it  does  not  kill  the  eggs,  it  effectually  exterminates 
the  i'ree  Mites,  which  are  sure  to  come  in  contact  with  it  in  their  wan- 
derings, and  if  it  can  be  made  to  remain  upon  the  plant,  the  young  as 
they  hatch  are  also  destroyed. 


RUST  OF  THE  ORANGE REMEDIES.  117 

Flowers  of  sulphur  must  therefore  be  regarded  as  one  of  the  cheapest 
and  most  effective  remedies  for  Rust-mite,  and  it  may  be  used  to  great 
advantage  in  connection  with  whale  oil  soap  or  other  insecticides.  It 
may  be  suspended  in  water  and  applied  in  spray.  With  proper  appli 
ances  the  dry  powder  may  be  sifted  or  blown  upon  the  foliage  when 
wet  with  dew  or  rain.  A  little  wheat  flour  added  to  the  powder  would 
increase  its  adhesiveness. 

The  pharmaceutical  preparation  known  as  milk  of  sulphur  (precipi- 
tated), although  a  much  more  finely  divided  powder,  proves  milder  in 
its  effect  upon  the  Mites,  and  its  cost  will  prevent  its  extensive  use. 

EXPERIMENTS. 

(1.)  A  small  seedling  Orange  infested  with  Rust-mite  was  covered 
with  a  nail-keg  and  fumigated  for  ten  minutes  by  burning  one  ounce  of 
sulphur  under  the  keg.  All  the  Mites  were  destroyed,  but  the  eggs 
remained  alive  ten  days,  and  finally  dried  up  with  the  leaves  of  the 
plant,  which  was  entirely  killed. 

(2.)  Flowers  of  sulphur  dusted  over  infested  leaves  through  a  loosely 
woven  cloth.  Free  Mites  all  dead  in  twenty-four  hours.  Molting 
young  all  dead  in  three  or  four  days.  Eggs  not  killed  in  nine  days, 
but  young  Mites  killed  soon  after  hatching. 

(3.)  Experiment  No.  2  repeated  in  the  open  air,  and  leaves  allowed 
to  remain  on  the  tree.  Heavy  rains  on  the  second  day  did  not  remove 
all  the  sulphur.  Results  the  same  as  in  No.  2.  Mites  all  killed.  Eggs 
not  killed. 

(4.)  Milk  of  sulphur  dusted  upon  the  leaves  through  muslin.  Effect 
less  powerful  than  in  Nos.  2  and  3,  but  Mites  in  the  end  all  killed. 
Eggs  not  killed. 

(5.)  Milk  of  sulphur;  two  ounces,  by  measure,  of  the  powder  suspended 
in  one  gallon "  of  water.  Leaves  dipped  in  the  liquid,  when  dry  were 
lightly  coated  with  grains  of  sulphur.  Adult  Mites  dead  on  the  second 
day.  Some  molting  Mites  and  numerous  eggs  alive  on  the  second  day. 

(6.)  Leaf  with  Mites  confined  in  a  tight  box  with  another  leaf  on  which 
sulphur  had  been  dusted.  Ko  effect  after  twenty-four  hours.  On  the 
third  day,  however,  only  one  adult  Mite  appeared  to  be  alive.  In  six 
days  all  the  Mites  were  plainly  killed.  Eggs  not  killed. 

This  experiment  was  repeated  with  sulphur  scattered  in  the  bottom 
of  the  box,  and  precautions  taken  to  prevent  its  contact  with  the  Mites. 
Results  precisely  the  same  as  before. 

Note. — By  confinement  in  very  tight  metal  boxes,  Mites  may  be  kept 
alive  between  one  and  two  weeks,  or  until  the  leaves  dry  up  or  mold. 
The  destruction  of  the  Mites  in  this  experiment  was  therefore  due  en- 
tirely to  the  slow  volatilization  of  the  sulphur. 

(7.)  Sulphuretted  hydrogen.  Leaves  dipped  in  water  strongly  im- 
pregnated with  the  gas.  In  twenty-four  hours  all  adult  Mites  were 
dead  or  dying.  In  thirty-six  hours  all  free  Mites  were  dead.  In  the 


1  1  8  INSECTS    AFFECTING    THE    ORANGE. 

same  time  40  to  50  per  cent,  of  the  molting  Mites  died.     On  the  third 
day  many  molting  Mites  remained  alive.    Eggs  not  killed. 

The  above  solution  of  sulphuretted  hydrogen  (sulphur  water)  was  pre- 
pared by  passing  through  two  gallons  of  water,  the  gas  given  off  by 
three  ounces  of  sulphuret  of  iron,  treated  with  dilute  sulphuric  acid.* 

The  remarkable  results  obtained  with  sulphur  in  these  experiments, 
and  especially  the  effect  of  the  gas  in  solution  upon  the  adult  Mites,  sug- 
gests the  use  of  water  from  the  sulphur  springs  which  abound  in  various 
parts  of  Florida.  Although  it  cannot  be  supposed  that  these  natural 
waters  contain  a  sufficiently  high  percentage  of  the  mineral  to  render 
them  powerful  insecticides,  their  value  cannot  be  determined  without 
trial.  Persistent  applications  may  suffice  to  ultimately  exterminate  the 
Bust- mite  or  cause  its  disappearance  from  the  trees.  In  view  of  its  pos- 
sible importance  as  a  remedy,  those  who  have  access  to  natural  springs 
or  who  now  use  flowing  wells  of  sulphur  water  for  the  purpose  of  irriga- 
tion, should  thoroughly  test  it  by  making  repeated  applications  at  short 
intervals. 

Kerosene. — Emulsions  containing  66  per  cent,  of  kerosene  oil,  and 
diluted  with  water  ten  times,  as  in  applications  for  Scale-insects,  do  not 
kill  the  eggs  of  the  Rust-mite.  The  same  emulsions,  diluted  one  to 
twenty,  kill  nearly  all  the  mites,  but  do  not  kill  the  eggs.  With  dila- 
tions of  one  to  forty,  many  adults  escape  destruction.  En  all  the  ex 
periments  made  with  kerosene  upon  Scale-insects  the  trees  were  not 
cleared  of  Rust-mites.  They  usually  reappeared  in  numbers,  within 
five  or  six  days,  owing  to  the  hatching  of  the  eggs.  As  a  remedy  for 
Rust-mite,  therefore,  kerosene  is  not  as  effective  as  either  whale-oil  soap 
or  sulphur. 

In  making  applications  for  Scale-insect  it  is  advisable  to  render  the 
wash  effective  against  Rust-mite  also,  and  this  can  be  in  a  measure  ac- 
complished by  adding  sulphur. 

Experience  has  shown  whale-oil  soap  to  be  superior  to  condensed  milk 
in  forming  emulsions,  and  much  cheaper.  Emulsions  made  with  soap 
do  not  thicken  or  ferment,  as  when  milk  is  used. 

The  formula  given  in  the  preceding  chapter  (see  ante,  page  94)  gives 
the  best  results. 

The  emulsion  should  be  diluted  with  water  ten  times,  or  in  the  propor- 
tions 1  to  9,  and  applied  in  fine  spray. 

In  cases  where  an  application  is  needed  for  both  Scale-insect  and  Rust- 
mite  the  above  wash,  with  two  or  three  ounces  of  sulphur  added  to  each 
gallon  of  the  mixture,  forms  the  most  effective  combination  that  can  at 
present  be  devised.  It  is  best  applied  in  early  spring,  but  should  never 
be  used  in  midwinter  or  when  there  is  danger  from  frost. 

Carbolic  Acid.— Several  experiments  with  crude  Carbolic  acid,  saponi- 
fied with  lard  oil  and  lye,  or  dissolved  in  strongly  alkaline  solutions, 

*A  solution  of  sulphuretted  hydrogen  may  be  very  simply  prepared  by  boiling  sul- 
phur in  lime-water.  (See  Sulphurated  Lime,  ante,  p.  98.) 


RUST  OF  THE  ORANGE REMEDIES.      .      119 

gave  about  the  same  results  as  66  per  cent,  kerosene  emulsions.  The 
Mites  were  readily  killed,  but  their  eggs  for  the  most  part  survived. 

Carbolic  acid  is  highly  poisonous  to  plants,  and  must  be  used  in 
small  doses.  Three  or  four  fluid  ounces  of  crude  acid  dissolved  in  one 
gallon  of  strong  soap  solution  make  as  strong  a  wash  as  it  is  safe  to 
apply.  Although  even  cheaper  than  kerosene,  it  is  not  a  more  effective 
remedy,  and,  owing  to  the  greater  danger  attending  its  use,  it  cannot 
be  recommended  in  preference  to  the  latter. 

A  strong  carbolic  or  creosote  soap  can  be  purchased  at  a  reasonable 
price,  and  will  prove  very  useful  to  orange-growers,  as  it  is  not  only  a 
powerful  insecticide,  but  also  a  remedy  for  "  die-back,"  and  possibly  also 
for  "  foot-rot,"  or  any  disease  of  the  plant  of  fungoid  origin. 

Potash. — Very  strong  lye  is  required  to  kill  the  Mites,  and  their  eggs 
are  not  destroyed  except  by  solutions  sufficiently  caustic  to  burn  the 
leaves  and  bark. 

The  different  commercial  brands  of  concentrated  lye  and  caustic  pot- 
ash vary  greatly  in  purity  and  strength.  The  potash  used  in  the  fol- 
lowing experiments  was  a  superior  article,  put  up  in  1-pound  balls, 
coated  with  rosin : 

(1.)  Solution  :  4  pounds  (48  ounces)  potash  to  1  gallon  water.  Leaves 
dipped  in  this  solution  were  badly  burned,  and,  together  with  them,  the 
Mites  and  eggs  were  entirely  destroyed. 

(2.)  Solution  :  2  pounds  (24  ounces)  potash  to  1  gallon  water.  Leaves 
charred.  Mites  and  eggs  destroyed. 

(3.)  Solution  :  1  pound  (12  ounces)  potash  to  1  gallon  water.  Mites 
nearly  all  killed.  A  single  living  adult  seen.  Molting  Mites  and  eggs 
not  all  killed.  Leaves  devitalized,  but  not  charred. 

(4.)  Solution:  8 ounces  potash  to  1  gallon.  Adult  Mites  nearly  all 
killed.  One  half-grown  Mite  seen  crawling  about  among  crystals  of 
potash.  Molting  Mites  and  eggs  not  killed. 

(5.)  Solution :  6  ounces  potash  to  1  gallon.  Adult  Mites  killed.  Sev- 
eral recently  molted  Mites  seen  crawling  on  second  day.  Molting  Mites 
not  killed.  Eggs  uninjured. 

(6.)  Solution :  4  ounces  potash  to  1  gallon.  Many  adult  Mites  killed ; 
some  alive.  Numerous  young  Mites  alive  on  second  day.  Molting 
mites  and  eggs  uninjured. 

(7.)  Solution :  3  ounces  potash  to  1  gallon.    Same  results  as  No.  6. 

Solutions  of  1  pound  to  the  gallon  have  been  used  upon  orange  trees, 
and  although  all  the  leaves  and  portions  of  the  bark  were  destroyed, 
they  recovered  rapidly  from  the  effects  of  the  application.  Such  heroic 
treatment  for  insect  pests  is,  however,  unnecessary  and  unadvisable. 

Pyrethrum. — Applied  in  fine  powder,  this  insecticide  visibly  affected 
the  adult  Mites  and  caused  them  to  erect  themselves  frequently  upon 
their  anal  prolegs.  The  free  Mites  left  the  leaves  in  a  few  hours,  but  it 
is  doubtful  if  many  of  them  were  killed.  The  molting  Mites  and  eggs 
remained  uninjured.  Continued  exposure  to  contact  with  the  strong 


120  INSECTS    AFFECTING    THE    ORANGE. 

powder  disables  and  finally  kills  the  Mites,  but  they  are  not  as  violently 
affected  as  many  of  the  higher  insects,  and  recover  from  slight  applica- 
tions. 

Lime. — Not  the  slightest  effect  was  obtained  with  applications  of  lime, 
as  the  following  experiments  will  show : 

(1.)  Freshly  air-slaked  stone-lime  dusted  thickly  over  infested  leaves. 
Mites  continued  feeding  and  propagating  under  the  coating  of  lime- 
powder,  and  did  not  abandon  the  leaves  during  eight  days  in  which 
they  were  kept  under  observation. 

(2.)  Slaked  lime,  1  pint  measure  suspended  in  1  quart  water,  and 
allowed  to  partly  settle.  Leaves  dipped  in  the  turbid  liquid.  No  in- 
jurious eifect  upon  the  Mites  or  their  eggs.  Adult  Mites  were  rendered 
restless  by  fine  particles  of  lime  adhering  to  them,  and  all  left  the  leaves 
within  two  days,  but  were  not  killed. 

(3.)  Same  solution  as  No.  2,  clarified  by  standing  several  days.  Leaves 
dipped  in  the  clear  lime-water.  No  effect  whatever  during  eight  days' 
observation. 

Ashes. — Finely-sifted  hard-wood  ashes  dusted  upon  the  leaves  pro- 
duced no  effect  whatever  upon  the  Mites,  and  did  not  seem  to  discom- 
mode them  in  the  least. 

The  above  experiments  were  made  in  December,  during  continued 
cold  weather,  which  retarded  the  development  of  the  Mites  and  inter- 
fered somewhat  with  observations  as  to  hatching  of  the  eggs  under 
treatment. 

CAUTION. 

There  is  danger  in  applying  penetrating  liquids  to  orange  trees  dur 
ing  the  winter.  First,  because  any.  shock  to  a  dormant  tree  is  apt  to 
start  the  buds  and  induce  new  growth  at  a  time  when  there  is  danger 
of  frost.  Secondly,  a  succession  of  cold  nights  and  cloudy  days,  such 
as  frequently  occurs  in  severe  winters,  following  immediately  after  an 
application,  will  increase  to  an  injurious  extent  its  effect  upon  the  plant, 
by  preventing  evaporation  of  the  liquids  used,  and  allowing  them  to 
remain  too  long  in  contact  with  the  leaves  and  bark.  Serious  loss 
is  liable  to  follow  a  disregard  of  this  warning. 


CHAPTER  IX. 

INSECTS    AFFECTING    THE    BOOT.    CROWN,  TRUNK,   AND 

BEANCHES. 

INSECTS  AFFECTING  THE  ROOT  AND  CROWN. 

TAP-BOOT  BORERS. 

A  grub  or  "Sawyer"  is  sometimes  found  boring  into  the  tap-root  of 
the  Orange.  No  specimens  have  been  examined,  but  from  the  descrip- 
tions given  by  competent  observers,  it  can  only  be  -the  larva  of  some 
lougicorn  beetle  of  moderately  large  size. 

Mr.  William  H.  Ashmead,  in  the  Florida  Agriculturist,  February  1GT 
1881,  mentions  and  gives  a  figure  of  a  larva,  which  is  possibly  that  of 
Ohion  cinctus  (Drury),  found  boring  in  the  tap-root  of  a  Bitter-sweet 
orange  tree.  It  was  only  discovered  upon  taking  up  the  tree  in  order 
to  transplant  it,  and  may  therefore  be  presumed  to  have  done  little 
damage. 

A  larva  which  appeals  to  belong  to  this  species  has  also  been  sent  in 
Orange  roots  to  the  Department  of  Agriculture  from  Florida. 

Other  borers  of  this  numerous  and  destructive  family  are  likely  to 
occur  in  the  trunk  and  branches,  as  well  as  in  the  roots  below  the  sur- 
face of  the  ground.  It  is  difficult,  without  a  previous  knowledge  of 
their  habits,  to  suggest  a  remedy  for  these  subterranean  borers,- but 
should  they  at  any  time  become  troublesome  they  may  be  removed  by 
uncovering  the  roots  and  destroying  the  borer  in  its  gallery  with  a 
pointed  wire. 

WHITE  ANTS  OR  "WOOD-LICE." 

Habits. — Termites  or  white  ants  are  small,  soft  bodied  insects  resem. 
bling  ants  and  living  in  numerous  colonies.  They  shun  the  light  and 
travel  to  great  distances  through  galleries  constructed  beneath  the  sur- 
face of  the  ground.  They  feed  for  the  most  part  upon  dead  wood  and 
decaying  vegetable  matter,  but  sometimes  attack  living  plants,  espec- 
ially those  parts  which  lie  below  the  surface  of  the  ground.  A  certain 
amount  of  moisture  is  necessary  to  their  existence,  and  very  dry  wood 

is  usually  free  from  their  attacks. 

121 


122  INSECTS    AFFECTING   THE    ORANGE. 

TEBMES  FLAVIPES  Kollar. 
[Fig.  46.] 

This  species  is  common  from  Maine  to  Texas,  and  is  especially  abun- 
dant in  the  South,  where  it  invariably  attacks  wood  buried  in  or  lying 
upon  the  ground. 

Each  colony  consists  of  numerous  workers,  among  which  are  several 
distinct  forms,  and  a  few  males  and  females.  The  females  never  leave 
the  home  nest,  but,  like  the  queen  of  the  honey  bee,  devote  themselves 
to  producing  eggs,  which  are  hatched  and  cared  for  by  the  workers. 

The  central  nests,  in  which  are  hived  the  queens  and  eggs,  are  rarely 
discovered,  but  generally  exist  in  deeply -buried  roots  or  in  the  hearts  of 
stumps  and  logs  of  the  largest  size. 

The  workers  extend  their  operations  to  immense  distances,  and,  in 
search  of  food,  excavate  slender  subterranean  galleries,  hundreds  and 
even  thousands  of  feet  in  length.  It  is,  therefore,  practically  impossi- 


FIG.  46.—  Termes  flavipes :  a,  larva;  &,  winged  male ;  c,  worker;  d,  soldier;  e,  large  female ; /,  nymphe 

(From  the  Am.  Ent.,  Vol.  II.) 

ble  to  trace  these  galleries  to  their  source,  and  by  finding  and  destroy- 
ing the  brood  nest  to  break  up  a  colony. 

Twice  each  year,  in  spring  and  fall,  multitudes  of  winged  males  and 
females  are  produced,  which  swarm  forth  during  the  cooler  parts  of  the 
day  or  after  rains,  and  fill  the  air  with  their  fluttering  forms.  Most  of 
these  fall  a  prey  to  birds,  reptiles,  insects,  and  other  predatory  animals, 
but  many  escape,  and,  after  coupling,  lose  their  wings,  and  in  pairs  seek 
suitable  places  in  which  to  found  new  colonies. 

Injuries  to  Orange. — Owing  to  their  subterranean  habits  and  avoid- 
ance of  light,  Termites  are  very  insidious  foes.  Their  vast  numbers  en- 
able them  to  very  quickly  accomplish  the  work  of  destruction,  so  that 
often  the  finding  a  tree  in  dying  condition  is  the  first  intimation  which 
the  orange-grower  receives  of  their  presence.  Upon  removing  the  earth 


WHITE    ANTS    INJURING    THE    OEANGE.  123 

about  the  collar  and  root,  the  bark  is  found  eaten  away  and  the  tree 
perhaps  completely  girdled. 

The  growing  wood  of  plants  is  not  the  natural  food  of  Termites,  and 
is  only  attacked  by  them  under  exceptional  circumstances.  Thus  in 
orange  groves  they  may  be  impelled  to  escape  from  the  heated  soil  by 
excavating  galleries  iuto  the  root  bark  of  the  trees,  the  moisture  and 
coolness  of  which  are  grateful  to  them.  It  is  to  be  remarked  that  they 
at  first  confine  their  galleries  to  the  soft  outer  layers,  and  only  subse- 
quently penetrate  and  feed  upon  the  heart  wood  as  the  tree  dies  in  con- 
sequence of  their  injuries. 

Recently  transplanted  trees  whose  roots  have  suffered  mutilation, 
young  groves  set  out  on  new  land,  and  frees  planted  too  deep  or  which 
have  too  much  earth  heaped  about  the  crown,  are  exposed  to  danger 
from  Termites,  but  old  and  well-established  trees  are  little  liable  to  their 
attacks,  unless  from  disease  or  other  injuries  dead  and  unhealthy  wood 
is  present  to  invite  their  entrance. 

Their  Work  easily  distinguished  from  that  of  other  Insects. — The  galleries 
of  Termites  are  seldom  circular,  but  most  frequently  present  a  series  of 
broad  and  shallow  chambers,  often  overlying  one  another  and  connected 
by  short  passages.  The  walls  of  the  galleries  are  always  lined  with  a 
a  layer  of  comminuted  wood,  which  gives  them  a  mottled  appearance, 
very  characteristic,  and  distinct  from  those  of  ants  or  other  boring  in- 
sects, and  renders  them  easily  recognizable  in  the  absence  of  the  Ter 
mites  themselves.  These  latter  are  usually  present,  however,  as  they 
seldom  leave  a  piece  of  wood  in  which  they  have  effected  a  lodgment 
until  every  portion  of  its  solid  interior  has  been  eaten  away  and  re- 
duced to  powder,  unless,  indeed,  the  material  becomes  too  dry  for  their 
further  existence.  Their  entrance  galleries"  are  always  beneath  the  sur- 
face of  the  ground  or  under  cover  of  other  material,  for  they  never  ex- 
pose themselves  to  light. 

In  living  orange  trees,  as  has  been  said,  their  first  attack  is  made  at 
the  base  of  the  trunk,  just  beneath  the  surface  of  the  ground.  Not 
unfrequently  this  is  betrayed,  before  extensive  damage  has  been  done, 
by  a  slight  exudation  of  sap  from  the  wounded  bark,  which  moistens 
and  cakes  the  ground  at  the  surface. 

SOURCES  OF  DANGER— PRECAUTIONS.— -Stumps  and  buried  Roots  of 
forest  Trees. — So  abundant  are  Termites  in  the  South  that  no  buried 
fragments  of  wood  long  escape  their  visits.  The  hardest  live  oak,  and 
the  most  resinous  pine  yield  in  time  to  these  scavengers.  The  decaying 
stumps  and  roots  of  forest  trees,  therefore,  form  an  element  of  danger 
to  orange  groves  planted  on  newly  cleared  land,  that  cannot  well  be 
avoided 5  but  the  risk  may  be  reduced  to  a  minimum  by  removing  the 
stumps,  particularly  those  of  oak  and  other  hard  woods,  which  stand 
nearer  than  five  or  six  feet  to  any  orange  trees,  and  by  care  in  removing 
chips  and  severed  roots  from  contact  with  or  too  close  proximity  to  the 
young  trees. 


124  INSECTS    AFFECTING    THE    ORANGE. 

On  mulching  and  the  use  of  decaying  Wood  as  a  Fertilizer  in  the  Orange 
Grove. — A  mulch  of  muck,  leaves,  gras§,  pine-straw,  succulent  vegetable 
matter,  and  even  well-rotted  and  disintegrated  wood  from  old  brush 
piles,  does  not  in  itself  attract  Termites,  and  its  use  is  not  attended  with 
any  danger,  provided  it  is  not  piled  against  the  trunk  of  the  tree,  the 
crown  of  which  should  in  all  cases  be  left  exposed  to  the  air.  It  is  well 
to  maintain  an  open  space  immediately  about  the  tree,  and  the  mulch- 
ing should  not  be  allowed  to  approach  nearer  than  six  or  eight  inches 
to  the  trunk  on  any  side. 

The  practice  of  bringing  brush,  logs,  and  chips  of  wood  into  the 
orange  grove,  and  either  burying  or  allowing  them  to  rot  upon  the 
ground,  is  hazardous,  and  will  surely  attract  and  colonize  Termites, 
which,  under  any  circumstances,  must  be  considered  dangerous  and 
undesirable  neighbors  for  orange  trees.  If  disintegrated  wood  is  used 
at  all  as  a  fertilizer,  all  solid  fragments  should  be  carefully  excluded. 

Deep  planting.— This  is  a  most  frequent  cause  of  trouble,  and  should 
be  obviated  by  raising  the  trees  too  deeply  set.  In  cultivating,  also,  the 
tendency  of  the  earth  to  heap  about  the  trees  should  be  corrected  by 
turning  the  furrows  toward  the  centers  between  the  rows,  or  by  drawing 
back  the  earth  with  the  hoe. 

REMEDIES. — Exposure  to  Light  and  Air. — As  Termites  require  for  their 
existence  darkness  and  moisture,  on  discovering  their  attacks  the  first 
step  should  be  to  remove  the  earth  about  the  affected  parts,  and  uncover 
the  crown  and  root  to  a  depth  of  several  inches,  at  the  same  time  re- 
moving with  the  knife,  as  far  as  possible,  all  the  dead  wood  and  bark, 
and  exposing  their  galleries  to  the  drying  action  of  the  air.  In  cases 
of  slight  attack  this  will  generally  suffice  to  drive  them  away. 

Hot  Water. — If  the  galleries  extend  too  deeply  into  the  wood  to  be 
readily  uncovered  with  the  knife,  or  if  a  numerous  colony  is  found  to 
have  established  itself  at  a  considerable  depth  beneath  the  surface,  a 
liberal  application  of  hot  water  will  usually  reach  and  destroy  them 
without  injury  to  the  tree. 

Pyrethrum. — Termites  are  exceedingly  sensitive  to  the  action  of  this 
insecticide,  and  are  invariably  killed  by  contact  with  the  powder.  It 
may  be  used  to  great  advantage  whenever  it  can  be  brought  into  con- 
tact with  the  insects.  Pyrethrum  loses  its  properties  rapidly  on  expos- 
ure to  the  air,  and  although  it  retains  its  power  for  a  longer  time  when 
covered  with  earth,  it  remains  effective  for  a  few  days  only,  and  cannot 
be  relied  upon  to  permanently  protect  the  plant  from  the  attack  of  this 
or  other  insects. 

Penetrating  Liquids. — Kerosene  in  emulsion  is  very  effective,  and  may 
be  safely  used  in  moderate  quantities ;  but  all  penetrating  oils  should 
be  applied  with  great  caution  to  the  roots  of  plants.  . 

Bisulphide  of  carbon  is  most  useful  for  destroying  colonies  remote 
from  the  trees,  but  is  far  too  dangerous  a  substance  to  use  upon  or  near 
the  roots.  The  central  nest,  when  its  position  is  known,  may  be  broken 


THE    COMMON    ORANGE    SAWYER.  125 

up  and  the  queens  destroyed  by  pouring  a  few  ounces  of  the  liquid  into 
the  galleries,  or  into  a  hole  made  by  a  stake  driven  as  close  to  the  nest 
as  possible.  The  hole  should  then  be  closed  with  earth  to  insure  perco- 
lation of  the  vapor  through  the  soil. 

Ashes,  Lime,  and  Sulphur  are  without  effect  in  protecting  orange  trees 
from  the  attacks  of  Termites.  In  the  cases  where  these  substances  have 
seemed  effective  in  driving  them  away  the  result  has  been  accomplished 
simply  by  the  disturbance  to  their  mines  and  exposure  to  the  drying 
action  of  the  air. 

Ingrafting  Scions. — Trees  completely  girded  by  Termites  may  be  saved, 
it'  taken  in  time,  by  inarching  scions  between  the  root  below  and  the 
stock  above,  thus  ivstablishing  the  connection  between  the  two.  The 
tree  will  in  time  restore  the  eroded  bark,  and  the  scions  may  be  allowed 
to  remain  or  may  be  afterwards  cut  out. 

Supplementary  stocks  may  also  be  planted  close  to  the  injured  tree, 
and  grafted  in  above  the  girdled  portion,  to  sustain  the  life  of  the  trunk 
and  enable  it  to  restore  the  severed  connection.  A  poultice  of  mud  and 
cow  dung,  applied  to  the  injured  part,  will  protect  it  and  materially  as- 
sist the  formation  of  new  wood  and  bark. 

CALOTERMES   CASTANEUS. 

A  second  species  of  Termite,  somewhat  larger  than  Termesflavipes.,  but 
otherwise  closely  resembling  it,  has  been  found  in  decaying  branches 
and  stumps  of  orange;  but  as  far  as  its  habits  have  been  observed  it  is 
a  tree-inhabiting  species,  seldom  forming  very  large  colonies,  and  not 
likely  to  do  injury  to  growing  plants,  as  it  prefers  very  dry  wood,  and  is 
most  frequently  found  in  dead  branches  from  the  tops  of  forest  trees. 
Should  it  prove  injurious  to  the  orange  it  will  probably  require  the  same 
treatment  as  the  related  species. 


INSECTS  AFFECTING  THE  TRUNK  AND  BRANCHES. 

COLEOPTERO  US  BOR ERS.     l  ( SA  WYERS." 
THE   COMMON  ORANGE  SAWYER. 

(Elaphidion  inerme  Newman.) 
[Fig.  47.] 

The  larvae  of  this  beetle  are  cylindrical,  whitish,  fleshy  grubs  or 
sawyers,  with  rudimentary  legs,  which  cannot  be  of  much  assistance  to 
the  animal  in  moving  about,  and  a  pair  of  strong  short  jaws.  As  with 
most  borers  of  this  family,  the  head  is  small  and  can  be  withdrawn  en- 
tirely into  the  body.  The  first  body-joint  is  somewhat  enlarged,  and 


126 


INSECTS    AFFECTING    THE    ORANGE. 


covered  above  with  minute  horny  asperities,  which  are  pressed  against 
the  walls  of  the  burrow,  and  serve  to  hold  the  body  firmly  in  place  while 
the  jaws  are  forced  into  the  wood.  The  full-grown  larva  is  about  one 
inch  in  length. 

The  pupa  is  formed  in  the  gallery,  in  a  rude  cell  made  by  pushing 
aside  the  chips  with  which  the  larva  stops  up  all  the  approaches  to  its 
burrow. 

The  perfect  insect  has  a  long,  cylindrical  body  with  rather  roughly 
pitted  surface  j  the  color  is  dark  brown,  dusted  densely  beneath,  but 


FIG.  47,—Elaphidion  inerme.     (Original.) 

irregularly  above,  with  fine  ash-gray  hairs  ;  the  antennae  are  not  longer 
than  the  body.  The  length  varies  from  llmm  to  15mm  (-*fo  to^-  inch) ; 
the  males  are  smaller  than  the  females. 

Fig.  48  illustrates,  in  all  its  stages,  Elapliidion  parallelum  Newm.,  a 
closely  allied  species,  which  lives  in  northern  fruit-trees,  and  has  habits 

similar  to  the  Orange  Sawyer.  In  the 
figure,  a  represents  the  larva 5  6,  the 
pupa  in  its  ^ell ;  c,  the  perfect  insect ; 
dj  the  head;  e,f,  and  #,  the  mouth  parts; 
and  7i,  the  antenna  of  the  larva,  enlarged; 
i  and^'  show  details  of  the  antennaB  and 
tip  of  the  wing-cases,  respectively,  in 
the  imago ;  fc,  the  end  of  the  twig  which 
contains  the  borer. 

The  Iarva3  of  this  beetle  are  more  prop- 
erly scavengers  or  pruners,  feeding  by 
preference  upon  dead  branches,  not  only 
of  Orange,  but  also  of  Hickory  and  other  hard-wood  trees,  and  confin- 
ing themselves  to  the  dry  and  lifeless  wood,  unless  compelled  by  hunger 
to  enter  the  living  portions  of  the  plant. 


FIG.  4S.—Elaphidion  parallelum  Newm. : 
a,  larva;  6,  chrysalis  in  twig;  c,  adult 
beetle ;  d,  e,  /,  <j,  h,  head  and  mouth  parts 
of  the  larva ;  i,  part  of  antenna ;  and  j, 
end  of  wing  case  of  the  adult;  k,  end  of 
twig,  cut  off.  (After  Eiley.) 


THE  COMMON  ORANGE  SAWYER.  127 

The  injuries  caused  by  them  result  from  careless  pruning,  and,  espe- 
cially in  the  case  of  budded  nursery  trees,  from  leaving  untrimmed  the 
dead  end  of  the  stock  above  the  insertion  of  the  bud.  These  dead 
stubs  attract  the  mother  beetle,  and  she  deposits  one  or  two  eggs  in 
each. 

The  grubs  that  hatch  confine  themselves  to  the  dead  ends  until  they 
are  completely  hollowed  out  and  reduced  to  mere  shells,  filled  with  saw- 
dust. But  if  the  supply  of  dead  wood  fails,  they  are  forced  to  descend 
into  the  living  stock  below,  and  thus  weaken  the  bud  if  they  do  not  kill 
it  outright,  undermining  the  tissues  which  support  it. 

Protection  afforded  the  Tree  by  its  Gum. — Very  frequently  tfhe  larva  in 
penetrating  the  living  tissues  causes  its  own  death  by  suffocation  from 
the  flow  of  gum,  which  rises  in  the  gallery,  filling  it  to  the  top.  This  is 
particularly  apt  to  occur  in  the  case  of  Lemon,  Citron,  and  others  of  the 
citrus  family,  which  produce  an  abundance  of  gum.  When  in  vigorous 
condition  the  trunk  of  the  Orange  is  perfectly  protected  by  its  gum  from 
the  attacks  of  boring  Coleoptera,  and  it  is  only  endangered  when,  from 
loss  of  vitality,  such  as  follows  transplanting  or  disturbance  from  dis- 
ease, attacks  of  Scale-insects,  &c.,  the  circulation  of  sap  and  the  flow  of 
gum  are  decreased. 

Necessary  Precautions.— It  follows  from  what  has  been  said  that  dead 
limbs,  especially  the  dead  ends  of  budded  stocks,  should  be  carefully 
trimmed  off,  back  to  and  even  with  the  healthy  wood.  Trees  trans- 
planted during  an  unfavorable  season,  and  which  do  not  get  a  good  or 
early  start,  are  apt  to  die  back  and  present  dead  ends,  which  attract 
borers.  Such  trees  need  to  be  closely  watched  and  kept  pruned  until 
their  vigor  is  restored. 

When  trees  of  large  size  are  cut  off  and  budded,  the  entrance  of  bor 
ers  in  the  ends  of  the  stump  or  large  branches  should  be  prevented  by 
protecting  them  with  a  coating  of  shellac  or  grafting-wax.  It  is  also 
well  to  allow  a  few  suckers  to  grow  for  a  time  on  the  side  opposite  the 
bud,  in  order  to  preserve  a  healthy  flow  of  sap  on  this  side  and  encour- 
age the  more  rapid  formation  of  wood  and  bark  over  the  exposed  heart 
wood. 

It  is  in  consequence  of  the  sluggish  flow  of  sap  and  drier  condition 
of  the  wood  on  the  side  opposite  the  growing  shoot  or  bud  that  this  side 
of  a  budded  trunk  is  particularly  exposed  to  the  attacks  of  borers ;  and 
most  of  their  damage  is  done  by  undermining  and  killing  the  bark,  with 
long  galleries  running  down  one  side  of  the  tree. 

Means  of  destroying  the  Borers. — Should  the  borer  be  found  to  have 
penetrated  the  wood  beyond  the  reach  of  the  knife,  no  simpler  method 
of  destroying  it  can  be  suggested  than  the  old  one  of  following  it  to  the 
bottom  of  its  retreat  with  a  piece  of  annealed  wire  sharpened  at  the  end. 
If  the  wire  is  also  slightly  hooked  at  the  end,  the  sawyer  may  generally 
be  pulled  out  and  removed  bodily. 


128 


INSECTS    AFFECTING    THE    ORANGE. 


FIG 


—Oncideres 


cingulatus.  (After 
Kiley.) 


THE   TWIG  GIRDLER. 

(Oncideres  cingulatus,  Say). 
[Figs.  49  and  50.] 

This  beetle  is  injurious  to  fruit  and  timber  trees  in  all  parts  of  the 
southern  and  eastern  United   States.     The  female  has  the  singular 
habifc-of  cutting  off  twigs  and  branches  not  exceeding  three-fourths  of 
an  inch  in  diameter  in  which  she  had  previously  depos 
ited  a  number  of  eggs.    Fig.  49  shows  the  insect  in  the 
act  of  cutting  a  twig.    In  the  South  the  Persimmon  suf- 
fers most  severely,  but  Oak,  Hickory,  Cherry,  in  fact,  all 
hard-wood  timber  and  fruit-trees,  are  attacked,  and 
even  climbers  and  ligneous  shrubs  like  the  Eose  are  not 
exempt. 

Coextensive  depredations  upon  the  Orange  have  hith- 
erto been  reported,  but  in  most  groves  an  occasional 
branch  is  amputated.  The  loss  is  seldom  noticed  ex- 
cept in  young  trees,  which  it  is  sometimes  provoking  to 
find  deprived  of  their  leaders  of  the  previous  season's 
growth.  The  cutting  is  so  cleverly  done  as  to  pass  for 
a  malicious  use  of  the  pruning  shears,  and  few  persons 
would  suspect  it  to  be  the  work  of  an  insect. 
The  beetle  is  about  16mm  (/0^0-  inch)  long,  rather  stout  and  cylindrical, 
dark  chocolate-brown  in  color,  speckled  with  lighter  brown,  and  lightly 
covered  with  short,  gray  pubescence,  resembling  a  coat  of  bluish  dust 
or  pruina,  denser  beneath  and  upon  head  and  thorax,  and  forming  a 
broad  transverse  band  upon  the  wing-cases.  The  antennae  of  the  female 
about  equal  the  body  in  length,  and  are  somewhat  longer  in  the  male. 
There  is  but  one  brood  each  year.  The  eggs  are  laid  in  September  and 
October,  and  are  deposited  singly  beneath  the  bark,  usually  close  to  a 
bud.  [Fig.  49,  b;  e,  egg,  natural  size.]  After  placing  an  egg  under  each 
bud  for  a  distance  of  two  or  three  feet,  the  female  cuts  off  the  branch 
containing  them  by  gnawing  around  it  a  deep,  narrow  groove,  .so  nearly 
severing  it  from  the  tree  that  it  falls  by  its  own  weight,  or  is  broken 

off  by  the  wind  and  falls  to  the  ground, 
where  it  obtains  the  moisture  necessary  to 
the  development  of  the  young.    The  eggs 
hatch  into  white,  fleshy  Iarva3  of  the  form 
common  to  wood-boring  beetles,  and  known 
in  the  South  as  "Sawyers."    (Fig.  50,  a.) 
The  larvaB  remain  nearly  a  year  feeding  upon 
the  wood  of  the  fallen  branch,  which  they 
riddle  with  their  galleries,  and  in  the  latter 
part  of  summer  form  within  the  wood  oval  cells,  in  which  they  trans- 
form to  pupa.    .(Fig.  50,  b.) 
The  perfect  beetles  appear  again  in  September.     They  are  very  shy, 


FIG.  50.  —  Oncideres  cingulatus.    a 
larva ;  b,  pupa.    (After  Kiley.) 


INJURIES    CAUSED    BY    ANTS. 


129 


and  remain  perfectly  motionless  when  disturbed.  Their  mixed  colora- 
tion of  neutral  gray  and  brown  is  also  admirably  adapted  for  conceal- 
ment upon  all  kinds  of  bark,  and  they  are  therefore  not  easily  detected 
at  their  work. 

Remedies. — The  simplest  means  of  destroying  this  pest  is  to  gather  up 
and  burn  during  the  winter  the  fallen  branches  which  have  been  cut  by 
them,  and  which  contain  their  eggs  or  lamp.  Where  persimmon  bushes 
are  abundant  this  will  prove  a  work  of  some  labor,  but  will  be  abso- 
lutely necessary  if  the  Japan  persimmon  is  cultivated  for  profit. 

The  G-inller  is  not  likely  to  prove  a  very  serious  pest  to  the  Orange, 
but  should  it  ever  become  such  some  advantage  may  be  gained  by  trap- 
ping the  perfect  beetles  as  soon  as  they  begin  to  appear  in  the  fall. 
Tliis  can  be  done  by  means  of  sirup  daubed  upon  trees  and  fences. 
The  sugared  spots  must  be  visited  at  night  with  a  lantern,  and  the 
beetles,  which  will  be  found  attracted  to  these  spots,  can  be  detected 
and  destroyed.  The  sirup  may  be  mixed  with  a  little  beer,  wine,  or 
alcohol  to  render  it  intoxicating,  so  that  the  beetles  found  feeding  upon 
it  will  not  be  disturbed  by  the  light  of  the  lantern  and  try  to  escape. 

INJURIES  CAUSED  BY  ANTS. 
SOLENOPSIS  XYLONI  McCook. 

[Fig.  51.J 


FIG.  51. — Solenopsis  xyloni:  a.  ant  from  above;  6,  same,  side  view;  c,  same,  view  of  head;  dt  queen, 

side  view.     (After  McCook. ) 

The  well-known  carnivorous  habits  of  this  ant — it  is  one  of  the  com- 
monest and  most  effective  destroyers  of  the  Cotton  Worm — would  lead 
us  to  reject  any  but  the  most  positive  and  direct  evidence  that  it  fed 
upon  living  plants.  There  is,  unfortunately,  no  room  to  doubt  that  it 
does  frequently  and  seriously  injure  the  Orange  by  gnawing  away  the 
6521  o  I 9 


130  INSECTS    AFFECTING   THE    ORANGE. 

bark,  and  causing  an  exudation  of  gum  which,  seems,  at  certain  seasons 
of  the  year,  to  become  one  of  its  principal  sources  of  food-supply. 

In  obtaining  this  the  ant  is  led  by  its  instinct  to  make  incisions  at  the 
base  of  the  largest  and  most  vigorous  leaders  at  a  time  when,  having 
nearly  or  completely  attained  their  full  growth,  the  young  shoots  are  in 
process  of  hardening  and  ripening  their  wood,  and  the  flow  of  elaborated 
sap  to  these  parts  is  greatest,  giving  in  consequence  the  most  copious 
exudation  of  gum  from  a  wound, 

The  ants  make  their  attacks  in  force,  and  either  girdle  and  kill  the 
shoots  or  cut  so  deeply  into  their  bases  that  they  bend  over  or  break 
off  by  their  own  weight.  Sometimes,  but  rarely,  the  ants  attack 
the  old  bark  of  the  trunk  and  larger  branches  and  gnaw  holes  in  it, 
eating  away  the  cambium  layer  without  waiting  for  gum  to  exude. 
When  the  flow  is  very  copious  the  ants  bring  sand  and  mix  with  the 
gum.  This  enables  them  to  tunnel  into  it,  and  while  some  individuals 
are  continuing  the  excavation  in  the  bark  beneath,  others  are  penetrat- 
ing the  gum  thus  hardened  and  removing  it  piecemeal  to  their  nests. 

Habits  of  the  Ant. — Solenopsis  xyloni  is  a  mahogany-brown  ant  of  me- 
dium size.  It  is  very  pugnacious  and  stings  sharply.  It  lives  in  large 
colonies,  making  its  nest  in  the  earth,  and  after  rains  throwing  up  irreg- 
ular heaps  of  finely-granular  earth.  These  heaps  swarm  with  ants, 
among  which  are  seen  occasional  individuals  (workers  major)  with 
enormously  enlarged  heads.  It  is  exceedingly  fond  of  the  nectar  of 
plants  and  the  honey-dew  secreted  by  insects,  and  is  a  constant  attend- 
ant upon  Plant-lice  and  Lecanium  Scales  on  the  Orange.  During  the 
greater  part  of  the  year  it  is  attracted  by  them  alone,  and  its  visits  to 
the  trees  are  harmless,  but  in  October  and  November,  when  these  in- 
sects are  scarce,  the  ant  turns  its  attention  to  the  gum  of  the  tree  itself. 
During  these  months  the  summer  growth  is  hardening  and  the  bark  is 
full  of  elaborated  sap,  containing  a  large  amount  of  saccharine  matter. 
It  is  probably  in  this  condition  only  that  the  ants  find  it  palatable  and 
accept  it  in  lieu  of  their  ordinary  food. 

Destroying  Colonies. — When  not  too  near  the  tree,  bisulphide  of  carbon 
may  be  used  in  breaking  up  colonies  of  this  ant  in  the  same  manner 
as  recommended  for  those  of  Termites.  Pyrethrum  powder,  to  the  ac- 
tion of  which  they  are  very  susceptible,  stirred  into  the  soil  about  and 
within  their  nest  kills  great  numbers  of  the  ants  and  frequently  causes 
the  survivors  to  abandon  the  premises.  Naphthaline,  in  the  form  of  a 
crystalline  powder,  used  in  the  same  way  is  equally  effective  in  break- 
ing up  colonies.  After  frosty  nights  in  winter,  when  the  sun  shines 
warm  on  the  following  morning,  the  ants  come  out  of  the  ground  and 
gather  in  clusters  under  fallen  leaves  or  other  objects  affording  them 
protection  from  the  wind  with  exposure  to  the  warmth  of  the  sun.  At 
such  times  an  excellent  opportunity  is  afforded  to  destroy  the  entire 
colony  by  raking  over  the  ground  about  the  nests,  at  the  same  time 
spraying  the  disturbed  ants  with  kerosene  or  dusting  them  with  pyreth- 
rum. 


INJURIES    CAUSED    BY    ANTS.  131 

Means  of  preventing  the  Ants  from  ascending  the  Trees. — When  they  have 
begun  to  attack  a  tree  it  is  with  extreme  difficulty  that  they  can  be  per- 
manently driven  off.  Pyrethrum  dusted  over  those  upon  the  tree,  and 
scattered  over  the  ground  about  its  base,  kills  all  the  ants  with  which 
it  comes  in  contact,  and  affords  temporary  relief,  but  its  effect  is  not 
lasting,  and  it  does  not  always  prevent  their  return.  Coating  the  raw 
spots  witl?  shellac  and  protecting  the  trunk  with  a  band  of  tar  and  other 
viscid  substances  cannot  be  permanently  relied  upon  to  keep  them  off. 

Sir  John  Lubbock,  in  his  work  on  Ants,  Bees,  and  Wasps,  speaks  of 
isolating  nests  of  ants  "  by  fur,  with  the  hair  pointing  downwards," 
but  we  are  not  told  what  kind  of  fur  was  used.  A  broad  band  of  fur 
tied  around  the  trunk  of  the  tree,  and  with  the  hair  pointing  downwards, 
is  effectual  in  preventing  their  ascent.  The  skin  of  the  rabbit  has  been 
used  with  success,  but  probably  that  of  any  fur-bearing  animal  would 
answer. 

Fur  does  not  form  a  barrier  absolutely  impassable  to  ants,  and  they 
will  frequently  clamber  through  a  very  narrow  band,  but  they  expe- 
rience great  difficulty  in  making  their  way  against  the  hairs,  and  almost 
invariably  become  confused  and  turn  back,  if  the  distance  exceeds  1  or 
2  inches. 

Still  more  simple  and  almost  as  effective  is  a  barrier  of  chalk.  This 
is  applied  by  rubbing  a  lump  of  dry  chalk  over  the  bark  to  form  a  band 
at  least  8  inches  wide,  and  completely  encircling  the  trunk.  In  at- 
tempting to  cross  such  a  band  the  ants  nearly  always  slip  and  fall  to 
the  ground.  The  fine  interstices  of  the  bark  are  filled  with  loose  grains 
of  chalk,  in  which  their  claws  find  a  very  treacherous  support.  While 
fresh  and  dry  the  chalk  band  is  well  nigh  impassable  to  ants  of  the  size 
and  weight  of  the  Solenopsis,  but  dews  at  night,  or  rains,  and  the  moist- 
ure of  the  atmosphere  in  a  short  time  change  the  character  of  the  sur- 
face by  causing  the  grains  of  chalk  to  cohere  with  sufficient  firmness  to 
support  the  weight  of  the  insect  and  they  then  cross  it  in  safety.  The 
device  cannot,  therefore,  be  regarded  as  a  permanent  one  and  requires 
frequent  renewal,  but  it  may  be  resorted  to  temporarily  when  a  piece  of 
fur  is  not  at  hand. 

Very  soft,  fine  clay,  fuller's-earth,  or  talc  may  be  substituted  forchalk^ 
but  in  all  cases  must  be  applied  by  rnbbing  on  from  a  dry  lump.  Good 
results  cannot  be  obtained  by  using  any  of  these  substances  in  powder, 
dry,  or  as  a  whitewash  applied  with  a  brush. 


CHAPTER  X. 
AFFECTING  THE  TWIGS  AND  LEAVES. 

INSECTS  OF  THE  ORDER  HYMENOPTERA. 

LEAF-EATING  ANT. 

(Monomorium  carbonarium  Sm.) 

A  small  black  ant  eats  holes  in  the  leaves  of  orange  trees  when  they 
are  very  young  and  tender,  but  seldom  does  any  damage  beyond  de- 
stroying a  leaf  or  two,  which  in  most  cases  the  plant  can  very  well 
spare.  Should  this  ant,  however,  become  destructive,  it  may  be  com 
batted  in  the  same  way  as  the  Solenopsis  mentioned  in  the  preceding 
chapter.  A  band  of  far  around  the  trunk  of  the  tree  will  prevent  their 
ascending. 

INSECTS  OF  THE  ORDER  COLEOPTERA. 

BEAOHYS  OVATA  (Web.). 

This  small  beetle,  belonging  to  the  family  Buprestidse,  is  frequently 
met  with  upon  the  leaves,  in  which  it  occasionally  eats  small  holes. 
The  beetle  is  5mm  (&  inch)  long  and  nearly  the  same  in  width.  The 
body  is  flattened,  or  very  slightly  convex,  and  shield-shaped.  The 
color  is  a  mixture,  finely  mottled,  of  dark  and  light  bronze.  When  dis- 
turbed, the  legs  are  drawn  into  grooves  in  the  underside  of  the  body 
and  the  beetle  falls  to  the  ground,  where  it  bears  a  remarkably  close 
resemblance  to  the  seeds  of  some  of  the  common  wild  vetches.  The  beetle 
has  not  hitherto  been  known  to  do  appreciable  damage  to  plants  of  the 
citrus  family.  Its  natural  food  is  the  Oak,  upon  which  its  strangely-flat- 
tened larvae  live  as  leaf -miners,  excavating  galleries  in  the  narrow  space 
between  the  upper  and  lower  surfaces  of  the  leaves,  and  feeding  upon 
the  parenchyma. 

132 


THE  ORANGE  LEAF-NOTCHER. 
ODONTOTA  RUBRA  (Web.) 


133 


FIG.  52.  —  Noto- 
lomus  basalig. 
(Original.) 


A  beetle  of  the  leaf-eating  family  Chrysomelidae  is  occasionally  found 
eating  the  leaves  of  Orange,  but  never  to  an  injurious  extent.  Like  the 
preceding,  its  larva  is  a  leaf- miner,  and  is  found  on  various  plants, 
but  not  upon  the  Orange. 

NOTOLOMUS  BASALIS  Leconte. 

[Fig.  52.] 

A  weevil  or  snout-beetle  (family  Curculionidce)  of  small 
size  and  light  straw  color,  frequently  found  upon  the 
trees,  usually  hiding  in  dead  leaves  or  tangles  of  spider- 
web.  It  has  been  seen  to  eat  the  leaves  and  tender  bark, 
but  it  nibbles  rather  than  feeds  upon  the  Orange,  and 
cannot  be  convicted  of  doing  serious  harm.  When  the  Orange  is  in 
bloom  the  beetle  is  quite  common  upon  the  flowers,  and  it  feeds  upon 
the  pollen  and  nectar  without  injury  to  the  plant.  The  early  stages 
are  not  known,  but  it  is  suspected  of  a  connection  with  the  Saw-pal- 
nietto,  upon  the  bloom  of  which  the  beetle  is  always  found  in  abund- 
ance. 

THE   ORANGE   LEAF-NOTCHER. 

(Artipus  floridanm  Horn.) 
[Fig.  53.] 

This  is  a  snout-beetle  of  bluish-white  color,  stout,  cylindrical  form, 
6mm  (J  inch)  in  length.    It  is  said  to  eat  jagged  notches  in  the  edges  of 
orange  leaves  (see  Report  of  Commis- 
sioner of  Agriculture  for  1879,  p.  207), 
and  was  also  found  by  Ashmead  on  the 
Florida  Keys  feeding  upon  the  Lime 
and  other  plants.     (Orange  Insects,  p. 
62.)    The  beetle  is  confined  to  the  penin- 
sula of  Florida,  and  is  rare  except  in  the 
extreme  southern  portions  of  the  State. 


PACHN^EUS  OPALUS,  Olivier. 


FIG.  53.  —  Artipus  fioridanus,  and  orange 
leaf  with  edges  gnawed  by  the  beetle. 
(AfterComstock.) 


A  weevil  similar  in  form  and  color 
to  the  preceding,  but  one-half  larger. 
Ashmead,  in  his  Orange  Insects,  p.  61, 
says :  "  This  weevil  was  caught  by  me 
in  great  quantities  in  South  Florida  on  the  Keys,  feeding  on  the  leaves 
of  the  lime-tree  (Citrus).  I  also  found  it  eating  the  leaves  of  Baccharis 
halimifolia  and  Borrichia  frutescens,  which  I  think  are  its  natural  food 
plants."  It  is  certainly  very  rare  on  the  mainland,  and  does  not  occur 


134  INSECTS    AFFECTING   THE    ORANGE. 

in  the  northern  part  of  the  State.  Both  this  and  the  preceding  species 
may  be  removed,  as  suggested  by  Mr.  Ashmead,  by  shaking  them  from 
the  trees  into  cloths  spread  to  receive  them.  They  fold  up  their  legs 
and  simulate  death,  when  disturbed.  The  early  stages  of  both  species 
remain  unknown. 


INSECTS  OF  THE  ORDER  ORTHOPTERA. 

THE  ANGULAR-WINGED  KATYDID. 

(Microcentrum  relinerve'BiiTm.) 
(Plate  IX.) 

This  large,  green  grasshopper,  common  in  all  parts  of  the  United 
States,  has  been  exhaustively  studied  by  Professor  Eiley,  and  its  full 
history  detailed  in  his  sixth  Missouri  report.  It  has  been  several  times 
noticed  in  reports  of  the  Department,  and  is  quite  fully  treated  in  the 
report  for  1880.  The  eggs— large  oval  objects,  flattened  like  flax-seed 
and  dark  gray  in  color,  are  placed  overlapping  each  other  in  a  row  along 
the  edge  of  an  orange  leaf,  or  are  deposited  in  two  parallel  rows  along  a 
twig.  There  are  two  broods  each  year.  Eggs  laid  in  December  hatch 
in  January  or  February.  The  young  complete  their  growth  in  eight  or 
nine  weeks.  The  eggs  of  the  second  brood  begin  to  appear  in  May,  and 
are.  continually  .being  deposited  during  the  summer.  Young  of  the  sec- 
ond brood  are  first  seen  in  July. 

Throughout  their  lives,  the  Katydids  feed  upon  the  Orange.  The 
young  confine  themselves  to  the  tender  foliage,  but  the  adults  often 
gnaw  the  bark  of  growing  shoots  and  leaders,  and  thus  inflict  very 
serious  injuries.  Occasionally  a  tree  is  almost  defoliated  by  Katydids, 
and  this,  of  course,  happens  most  frequently  in  the  case  of  young  trees ; 
but,  owing  to  the  luxuriance  of  its  foliage  and  the  rapidity  with  which 
the  orange-tree  renews  its  lost  leaves,  the  damage  done  by  these  insects 
is  rarely  sufficient  to  repay  the  cost  of  fighting  them.  Young  groves 
should,  however,  be  protected  from  their  attacks,  and  early  in  the  winter 
the  trees  should  be  examined  and  the  leaves  with  eggs  upon  them  re- 
moved. The  young  may  very  readily  be  killed  by  dusting  the  foliage 
with  pyrethrum  powder. 

EGG-PARASITE  OF  THE  KATYDID. — (Eupelmus  [Antigaster]  miraMlis, 
Walsh.)— (Plate  IX,  Fig.  2,  female 5  Fig.  2a,  male.)— The  eggs  of  the 
Katydid  are  very  frequently  found  with  a  small,  round  hole  cut  through 
the  side.  This  is  the  exit-hole  of  the  parasite  which  is  hatched  and 
bred  within  the  egg  of  the  Katydid,  feeds  upon  its  contents,  and  in  due 
course  issues  forth,  a  four- winged  fly,  The  larva,  like  that  of  most 
Hymenopterous  parasites,  is  a  transparent,  white,  footless  grub;  the 
pupa  of  the  female  is  flattened,  and  is  very  curiously  packed  in  its  nar- 
row quarters,  so  that  it  exactly  fills  the  space  within  the  egg-shell.  To 


THH    LUBBER    GRASSHOPPER. 


135 


accomplish  this,  the  abdomen  and  legs  are  folded  back  over  the  body, 
and  it  is  remarkable  that  the  perfect  insect  retains  through  life  the  power 
of  thus  rolling  itself  up  into  a  ball.  In  the  imago  stage  the  two  sexes 
are  very  dissimilar.  The  female  has  clouded  wings,  the  body  shows 
metallic  reflections  of  purple,  green,  and  cop  per- bronze,  and  the  abdo- 
men is  black,  with  the  first  joint  white.  The  male  is  smaller  than  the 
lernale,  has  clear  wings,  and  is  uniformly  bright  metallic  green  in  color. 
It  has  not  the  power  of  rolling  itself  like  the  female. 

THE  LUBBER  GRASSHOPPER. 

(Romalea  microptera  Serv.) 
(Fig.  54.) 


FIG.  54.— The  Lubber  Grasshopper.     (Alter  Glover.) 

This  huge  locust  has  nomadic  habits,  and  wanders  about  in  search  of 
food,  attacking  almost  all  succulent  plants.  It  sometimes  does  damage 
to  orange  trees  by  feeding  upon  the  leaders  and  tender  shoots,  and  is 
at  times  sufficiently  abundant  to  become  a  serious  pest.  The  eggs  are 
laid  in  the  ground  and  hatch  in  March  or  April.  The  young  are  black, 
with  bright  yellow  markings.  For  several  weeks  after  leaving  the 
ground  they  are  gregarious,  each  brood  in  its  wanderings  keeping  to- 
gether and  gathering  at  night  in  a  cluster  upon  some  low  herbaceous 
plant.  This  habit,  with  their  conspicuous  coloration,  renders  it  an  easy 
matter  to  find  and  destroy  them  at  first.  Later  in  the  summer  they 
separate  and  become  scattered,  and  the  separate  individuals  must  then 
be  sought  for  and  destroyed. 

During  its  growth  the  jnsect  several  times  changes  its  skin.  After 
the  final  molt,  which  takes  place  in  July  or  August,  its  appearance  is 
entirely  changed.  The  colors  of  the  young  are  reversed  in  the  adult; 
yellow  becomes  the  predominant  color,  and  the  body  is  marked  with 
spots  and  lines  of  black.  The  wings  are  tinged  with  pink;  they  are 
too  short  and  rudimentary  for  flight.  The  adult  insect  is  nearly  3 


136  INSECTS    AFFECTING    THE    ORANGE. 

inches  long,  exclusive  of  its  members;  it  is  very  heavy,  clumsy,  and 
slow  in  its  movements. 

There  is  but  a  single  brood;  after  depositing  its  eggs,  in  September 
and  October,  the  insect  disappears  and  is  not  seen  again  until  the  young 
come  out  of  the  ground  in  the  following  spring. 

Absence  of  enemies. — The  Lubber  Grasshopper  has  no  known  enemies. 
Predaceous  animals  cannot  be  induced  to  feed  upon  it,  and  doubtless 
its  juices  have  an  acrid  and  disagreeable  flavor.  Its  sluggish  habits, 
taken  in  connection  with  its  conspicuous  coloration,  show  that  it  has 
little  need  of  concealment,  and  that  it  does  not  fear  attacks  of  enemies. 
The  eggs  are  probably  preyed  upon  by  some  species  of  Bee-fly  (Bomby- 
liidcc),  but  if  such  an  enemy  exists  it  remains  as  yet  undiscovered. 

Remedy. — So  large  and  conspicuous  an  insect  is  not  likely  ever  to 
prove  an  alarming  pest,  and  hardly  requires  elaborate  directions  for  its 
management.  If  care  is  taken  to  destroy  the  young  broods  by  tramp- 
ling upon  them  when  they  appear  in  early  summer,  and  before  they 
have  scattered,  there  will  be  an  end  to  anxiety  from  this  source  for  the 
season,  and  with  a  little  pains  taken  at  the  proper  time  for  two  or  three 
successive  seasons  a  farm  may  be  entirely  rid  of  these  'hoppers,  even  if 
previously  much  infested  by  them. 

OTHER  LOCUSTS  (Acridiidce). 

The  various  species  of  Acrid iidse,  grasshoppers,  as  they  are  com- 
monly called,  nibble  the  leaves  of  orange  trees,  but  do  serious  injury 
only  where  weeds  are  allowed  to  grow  up  around  the  trees.  From  their 
size  and  voracity  the  species  of  the  genus  Acridium,  of  which  three  are 
found  in  Florida,  are  most  injurious.  They  are  large  insects,  2  or  2J 
inches  long,  and  are  very  active,  jumping  and  flying  to  great  distances. 

In  Acridium  obscurum  Burin,  the  general  color  is  olive  green,  with 
fuscous  dots  and  a  yellow  stripe  from  the  head  to  the  tip  of  the  closed 
wings.  The  wing-covers  are  chocolate  brown. 

Acridium  americanum  Scud.  (Fig.  55)  is  very  similar,  but  the  general 


Fio.  55. — Acridium  americanum.     (After  Biley.) 

color  is  reddish-brown  and  the  wing-covers  are   marked  with   large 
brownish  spots. 
Acridium  alataceum  Harr.  is  dull  brownish-yellow  in  color,  and  the 


THE    ORANGE   DOG.  137 

wing-covers  are  marked  with  small  spots.  Like  the  Katydid,  these 
larger  grasshoppers  occasion  loss  of  growth,  and  stunt  the  plant  by 
eating  back  the  succulent  ends  of  the  shoots,  as  well  as  by  consuming 
the  leaves.  With  clean  culture,  and  keeping  the  grove  free  from  weeds 
and  succulent  plants,  very  little  trouble  will  be  experienced  from  the 
ravages  of  locusts,  which  are  only  attracted  in  numbers  by  dense  masses 
of  vegetation. 

INSECTS  OF  THE  ORDER  LEPIDOPTERA. 

THE   ORANGE  DOG. 

(Papilio  cresphontes  Cramer.) 
[Plate  X  and  Plate  XI,  Figs.  1  and  2.] 

The  most  important  enemy  to  the  Orange  among  this  group  of  insects 
is  a  caterpillar  2J  inches  long,  of  a  dark  brown  color,  with  large  blotches 
and  markings  of  cream  color.  (Plate  X,  Fig.  &.)  The  anterior  part  of 
the  body  is  enlarged,  and  when  at  rest  and  not  feeding  the  head  is  drawn 
in  and  turned  under.  The  swollen  extremity  then  presents  a  hideous, 
mask-like  face,  or  dolphin  head,  of  which  the  upper  portion  of  the  true 
head  forms  the  snout,  and  two  velvet-black  spots  in  deep  depressions 
on  each  side  do  duty  as  eyes.  When  irritated,  the  larva  shoots  forth 
from  a  fold  just  back  of  the  head  two  long,  fleshy,  orange-colored  ten- 
tacles, resembling  a  pair  of  horns.  (Plate  X,  Figs,  c  and  d.)  These 
are  scent-organs,  emitting  a  penetrating  odor,  disagreeable  alike  to  man 
and  beast. 

When  full-grown,  the  larva  retires  to  the  vertical  trunk  or  to  some 
large  branch  of  the  tree,  weaves  a  mat  of  strong  thread  to  which  it 
fastens  itself  by  its  terminal  hooks,  and  with  its  head  directed  upwards 
slings  itself  at  an  angle  to  the  trunk  by  means  of  a  silken  band  passed 
around  its  body  and  fastened  at  the  ends  to  the  bark.  Within  this  loop 
it  changes  to  chrysalis  by  casting  its  larval  skin.  The  chrysalis  (Plate 
X,  Fig.  e)  is  a  remarkable  example  of  protective  mimicry ;  the  mixture 
of  grey  and  b  .own  colors,  together  with  irregularities  of  form,  such  as 
projecting  points  upon  the  breast  and  at  the  upper  end,  give  it  a  very 
close  resemblance  to  a  dead,  lichen-covered  twig. 

From  this  somber-colored  case  issues  in  time  a  large  and  gaily-col- 
ored butterfly,  with  wings  above  velvet-black,  crossed  by  a  double 
series  of  large  yellow  spots,  and  beneath  yellow  with  black  veins  (Plate 
X,  Fig.  a).  The  under  wings  end  in  tails,  and  are  adorned  above  with 
a  pair  of  eye-like  spots  of  red  edged  with  black  and  surmounted  by  a 
thin  crescent  of  blue.  Upon  the  under  side  these  spots  are  repeated, 
with  the  addition  of  a  second  pair  of  red  blotches  and  a  complete  row  of 
pale  blue  crescent-shaped  spots. 

This  showy  butterfly  is  one  of  the  commonest  insects  in  the  South, 
and  is  seen  everywhere  flitting  about  in  the  orange  groves. 


138  INSECTS   AFFECTING   THE   ORANGE. 

Life-history. — The  eggs  are  spherical,  smooth  and  pearly  in  luster, 
with  a  dull  red  or  reddish-yellow  tinge,  and  are  deposited  singly,  inva- 
riably upon  the  youngest  and  most  tender  shoots,  usually  upon  the  tips 
of  the  budding  leaves  (Plate  XI,  Fig.  1).  The  butterflies  appear  with 
the  opening  of  spring  from  chrysalids  formed  in  November  and  Decem- 
ber. The  first  eggs  are  deposited  early  in  February,  or  as  soon  as  the 
new  growth  appears  upon  the  orange  trees.  The  eggs  hatch  in  ten  or 
twelve  days.  The  caterpillar  completes  its  growth  in  about  thirty  days, 
and  remains  in  pupa  from  ten  to  fifteen  days.  About  two  months  is 
thus  occupied  by  a  single  brood,  and  there  are  four  full  broods  during 
the  season  beginning  with  February  and  ending  with  October.  The 
breeding  is,  however,  continuous  during  the  summer,  and  eggs  are  laid 
whenever  new  growth  appears  upon  the  orange  trees. 

The  ovaries  contain  over  five  hundred  eggs,  the  laying  of  which  occu- 
pies the  female  many  days  j  she  scatters  them  over  a  wide  area,  seldom 
depositing  more  than  four  or  five  upon  a  single  plant.  The  young 
caterpillars  feed  at  first  only  upon  the  tenderest  leaves,  but  when  well 
grown  demolish  both  leaves  and  shoots  which  have  not  hardened  into 
wood. 

On  account  of  its  large  size  and  voracity,  the  Orange  Dog  does  great 
damage,  particularly  to  young  trees,  which  are  sometimes  completely 
defoliated.  It  has  other  food  plants  besides  the  Orange;  among  the 
number  the  species  of  Prickly  Ash  (Zanihoxylum)  are  mentioned  by 
several  authors.  It  is  found  commonly  in  the  swamps  of  Florida,  feed- 
ing upon  the  Tupelo  (Nyssa  aquatica,  L.)  and  upon  the  Eed  Bay  (Persea 
carolinensiSj  Nees).  It  seems,  however,  to  prefer  the  Orange  and  its 
relatives  to  all  other  plants. 

Defensive  measures. — Hand-picking  is  not  a  very  difficult  task  in  the 
case  of  so  large  an  insect,  and  must  in  most  cases  be  relied  upon  to 
keep  young  trees  free  from  Orange  Dogs.  As  the  eggs  are  quite  large, 
and  conspicuously  placed.at  the  tips  of  the  growing  stalks  and  budding 
leaves,  it  is  a  simple  matter  to  find  and  pinch  them  between  the  fingers. 
A  very  little  practice  will  enable  the  orange  grower  to  go  rapidly 
through  his  young  grove  and  destroy  by  hand  nearly  every  egg.  If 
this  method  is  systematically  pursued,  the  result  will  well  repay  the 
trouble.  Two  rules  should  be  borne  in  mind,  and  will  greatly  facilitate 
the  work.  (1.)  Only  those  trees  which  are  pushing  out  tender  sprouts 
need  be  examined  for  eggs  and  young  larvae.*  (2.)  In  nearly  all  cases 
the  eggs  are  laid  upon  sprouts  at  the  top  of  the  young  tree  and  not 
upon  those  low  down  and  near  the  ground. 

*  While  this  rule  in  regard  to  the  disposition  of  the  egg  can  be  predicated  with 
great  confidence  for  the  orange  district  of  Florida,  it  is  but  just  to  observe  that  it 
may  not  hold  good  for  Louisiana  and  other  more  northern  localities.  Mr.  L.  O.  How- 
ard has  in  fact  found  the  eggs  of  Papilio  crespliontes  upon  the  older  leaves,  and  on  the 
twigs  of  orange  trees,  growing  in  public  parks  in  the  city  of  Savannah,  Ga.  The 
observation  was  made  about  the  middle  of  August. 


THE  ORANGE  DOG.  139 

A  great  deal  can  be  accomplished  towards  reducing  the  numbers  of 
the  Orange  Dog,  by  destroying  the  butterflies  j  the  most  effective  imple- 
ment for  this  purpose  is  a  light  fowling-piece,  loaded  with  dust  shot 
or  coarse  salt.  It  may  seem  somewhat  ridiculous  to  advocate  the  shoot- 
ing of  butterflies,  but  an  insect  which  has  a  spread  of  wiog  of  four  or 
five  inches  affords  a  by  no  means  despicable  object  for  target  practice. 
A  more  certain  method  for  those  not  skilled  at  shooting  on  the  wing  is 
to  attract  the  butterflies  iroin  a  distance  by  planting  in  some  conven- 
ient place  a  bed  of  flowering  plants.  It  is  a  common  sight  to  see  a 
dozen  or  more  individuals  of  this  butterfly  hovering  over  a  garden  bed 
of  Phlox  or  Zsenias,  within  easy  range  of  the  drowsy  orange- grower, 
as  he  takes  his  midday  siesta  upon  the  veranda.  What  a  loss  of  oppor- 
tunity it  is  to  allow  these  foes  to  escape  and  continue  their  havoc  in  the 
orange  grove. 

PARASITES. — A  Tachwa  fly,  with  a  hairy  body,  and  somewhat  larger 
than  a  common  house-fly,  which  it  superficially  resembles,  attacks  the 
caterpillars  when  partly  grown,  and  deposits  upon  each  several  elon- 
gate, oval,  white  eggs ;  these  hatch  maggots,  which  penetrate  the  skin 
of  their  host  and  feed  upon  its  body-contents,  eventually  killing  the 
worm.  The  tachinized  caterpillar  usually  attempts  to  pupate,  but 
strength  fails,  and  it  dies  suspended  in  its  silken  loop.  The  parasitic 
maggots  eat  their  way  out  and  drop  to  the  ground,  in  which  they  form 
oval  puparia.  They  emerge  as  flies  in  twelve  or  fifteen  days,  or,  if  the 
season  is  far  advanced,  remain  in  the  ground  during  the  two  or  three 
months  of  winter,  and  issue  with  the  return  of  warm  weather  in  Feb- 
ruary. From  four  to  eight  flies  are  bred  from  a  single  Orange  Dog. 

Chalcis  robuata  Cresson.  (Fig.  56.) — From  the  chrysalis  of  Papilio 
cresphomes  there  sometimes  issues,  instead  of  the  butterfly,  a  four- 


FIG.  56.— Chalcis  robusta.     (Original.) 

winged  fly.  This  parasite  is  a  large  and  handsome  member  of  a  family, 
the  Chalcididae,  composed  for  the  most  part  of  minute  forms.  It  is 
8.4mm  (-^Q-  inch)  long  ;  in  color  black,  with  golden-yellow  legs.  The  pos- 
terior thighs  are  swollen,  and  adorned  with  an  oblique  band  of  black 


140  INSECTS   AFFECTING   THE    ORANGE. 

across  the  middle.  The  wings  are  smoky.  The  head  and  thorax  are 
very  coarsely  punctured,  and  clothed  with  short,  golden  hairs.  The 
fly  in  quitting  its  host  makes  a  large,  round  hole  in  he  side  of  the 
chrysalis.  All  the  specimens  obtained  emerged  in  June  or  July  from 
pup*  of  the  second  brood.  There  can  be  no  doubt  that  this  parasite 
would  in  case  of  undue  multiplication  of  the  Orange  Dog  become  an 
efficient  check  upon  its  increase.  At  present,  however,  it  is  somewhat 
rare. 

SLUG  CATEEPILLARS— STINGING  CATERPILLARS. 

Several  species  of  Bombycida3,  called  "slug  caterpillars,"  because  of 
their  apparent  want  of  legs,  and  their  gliding,  snail-like  movements,  are 
occasionally  found  doing  damage  to  orange  trees  by  feeding  upon  the 
leaves.  The  hairy  species-are  known  as  " stinging  caterpillars,"  being 
provided  with  nettling  hairs.  They  are  all  of  rather  large  size,  an  inch 
or  more  in  length,  and  have  sluggish  habits.  They  construct  stout  and 
very  tough  cocoons,  attached  to  the  bark  of  the  tree,  and  they  know 
how  to  conceal  them  with  great  art.  The  perfect  insects  are  moths, 
with  rather  thick,  heavy  bodies,  covered  with  long,  downy  hairs,  and 
flying  only  at  night.  The  four  species  which  are  known  to  feed  upon 
the  Orange  are  Lagoa  opercularis  Sm.  &  Abb.,  Empretia  stimulea  Clem., 
Phobetron  pithecinm  Sm.  &  Abb.,  and  Limacodes  scapha  Harr. 

LAGOA  OPERCULARIS   Sm.  &  Abb. 

[Figs.  57,  58,  59.J 

The  caterpillars  of  this  moth  are  covered  with  long,  silky  hair,  under- 
neath which  are  concealed  shorter,  stiff  hairs,  exceedingly  sharp  at  the 
points,  and  powerfully  nettling  when  they  pen- 
etrate the  flesh.  Upon  some  persons  the  invis- 
ible wounds  made  by  these  hairs  produce  swell- 
ings, and  an  amount  of  irritation  equivalent  to 
a  sting;  the  larvre  are,  in  consequence,  popular- 
ly  supposed  to  be  very  poisonous.  When  young 
the  caterpillars  are  white  and  resemble  a  flock 
of  cotton  wool.  They  undergo  six  molts,  at  one  of  the  last  of  which 
they  become  darker,  the  color  varying  in  individuals,  from  red-brown  to 
light  clay-color.  When  full-grown  the  larva  presents  the  singular  ap- 
pearance of  a  lock  of  hair  possessing  sluggish  life  and  a  gliding,  snail- 
like  motion.  It  is  1£  inches  long,  bluntly  rounded  in  front  and  dimin- 
ishing rapidly  to  a  point  behind.  The  hair  rises  in  a  sharp  ridge  upon 
the  back,  and  forms  several  tufts  of  rust-red  color. 

The  cocoon  (Fig.  58)  is  placed  in  a  crotch  of  the  tree  or  upon  a  branch 
of  considerable  size;  it  is  20mm  (-ft-  inch)  long,  oval,  convex,  flattened 
on  the  side  next  the  tree,  and  fastened  very  firmly  to  the  bark.  The 
upper  end  is  abruptly  truncate,  and  fitted  with  a  hinged  trap-door, 


SLUG  CATERPILLARS  ON  ORANGE. 


141 


FIG.  58.—Lagoaojjercularis,  co- 
coon.    (Original.) 


FIG.  59,—Lagoa  opercularis,  moth, 
inal.) 


(Orig- 


which  is  readily  pushed  open  from  within  by  the  escaping  moth,  but 
does  not  yield  to  pressure  from  without,  and  is  so  accurately  fitted  that 
no  tell-tale  crack  can  be  discerned.  Upon  the 
back  of  the  cocoon  is  an  elevation  formed  by  the 
meeting  of  several  folds  and  ridges,  forming  a 
marvelously  exact  imitation  of  a  winter  bud. 
The  ends  of  a  lock  of  hair  from  the  body  of  the 
caterpillar  counterfeit  the  down  which  in  nature  protects  the  dormant 
bud.  The  substance  of  which  the  cocoon  is  made  is  a  tough  parchment, 
composed  of  agglutinated  silk,  in  which  is.  felted  the  long,  hairy  cover- 
ing of  the  larva.  Its  color  is  a  neutral  brown,  closely  approximating  to 
that  of  the  bark  upon  which  it  is  placed.  The  entire  arrangement  is  a 
most  successful  representation  of  the  stump  of  a  small  branch  broken 
off  near  its  junction  with  the  main  stem, 
and  upon  which  is  plainly  shown  the 
swelling  of  a  bud. 

The  perfect  insect  (Fig.  59)  is  a  moth 
with  a  very  wooly  body,  pale  yellow, 
tinged  with  brown.  The  fore  wings 
are  umber-brown  at  the  base,  fading  to 
pale  yellow  outwardly;  the  surface  is 
marked  with  fine  wavy  lines  of  silver 
gray,  and  the  fore  margins  are  nearly  black.  The  legs  are  yellow,  with 
dusky  feet.  The  wings  of  the  male  moth  spread  about  one  inch ;  those 
of  the  female  an  inch  and  a  half. 

Life-history. — The  larva  is  a  very  general  feeder,  and  although  the 
Oak  appears  to  be  its  principal  food  plant,  it  is  occasionally  injurious  to 
the  Orange.  It  never  injures  the  bark  or  tender  shoots,  but  subsists  gnly 
upon  the  mature  leaves. 

There  are  two  broods,  one  in  early  summer  and  the  other  in  the  fall. 
The  Iarva3  of  the  second  brood  form  their  cocoons  in  November  or  De- 
cember, and  in  them  pass  the  winter,  not  changing  to  pupa  until  the 
following  March  or  April,  or  about  two  weeks  before  the  moths  appear. 

Parasites. — The  same  parasites  have  been  bred  from  Lagoa  as  from 
the  Orange  Dog.  Tachiua  flies  issued  in  June  from  a  cocoon  found  on 
Orange  in  March.  The  hymeuopterous  parasite  Chalcis  robusta  issued 
September  15  from  a  cocoon  collected  August  27. 

THE  SADDLE-BACK  CATERPILLAR. 

(Empretia  stimulea  Clemens.) 

• 

[Figs.  60  and  61,  and  Plate  XI,  Fig.  3.] 

The  caterpillar  of  this  species,  also  a  general  feeder,  is  short  and 
thick,  and  very  strangely  marked  with  a  large,  quadrate  patch  of  green, 
in  the  center  of  which  is  an  oval  spot  of  purple,  so  that  the  animal 


142 


INSECTS   AFFECTING   THE    ORANGE. 


appears  to  have  thrown  across  its  back  a  green  cloth  surmounted  by 
a  purple  saddle.    The  fringing  hairs  along  the  sides  of  the  larva  have 
irritating  properties  like  the  concealed  nettling  hairs  of  Lagoa. 
The  cocoons  are  short,  oval,  almost  globular,  flattened  against  the 

branch  to  which  they  are   at- 
tached,  and   are  of   the  same 
tough,  parchment-like  material 
and  brown  color  as  in  Lagoa. 
They  are  usually  placed  in  con- 
cealment, often  against  the  main 
trunk  of  the  tree,  at  or  near  the 
surface  of  the  ground.    The  lar- 
va before  pupating  cuts  a  circu- 
lar flap  at  the  end,  making  an 
opening  nearly  equal  to  the  en- 
tire   diameter   of   the    cocoon, 
through  which  the  moth  makes 
its  escape  by  pushing  open  the  door  from  within. 
The  moth  has  a  wooly  body  and  legs  of  rich  maroon  color,  with  the 
^  base  of  the  abdomen  and  the  under  wings  of 
lighter  brown.    The  scales  of  the  fore-wing  lie 
flat  and  have  a  silken  sheen  upon  the  prominent 
veins  and  margin,  while  in  the  depressions  be- 
tween the  veins  they  stand  erect,  as  in  velvet, 
giving  an  embossed  appearance  to  the  wing. 
The  upper  surface  of  the  fore-wing  bears  sev- 
eral dots  of  pale  yellow,  each  consisting  of  a  few  opalescent  scales. 
The  dots  are  arranged  in  two  pairs,  one  at  the  base  and  the  other  at 
the  apex  of  the  wing,  with  a  single  minute  fleck  placed  half-way  be- 
tween the  pairs. 
Parasite. — The  larva  is  destroyed  by  a  Microgaster. 


FIG.  QQ.—Empretia  stimulea:  a,  moth  (Original);  6, 
larva  (after  Riley). 


FIG.  61.  —  Empretia  stimulea^ 
cocoon.    (Original.) 


THE  HAG-MOTH   CATERPILLAR. 

(Phobetron  pithecium.  Smith  and  Abbot.) 
[Figs.  62  and  63.] 

This  insect  receives  its  name  from  the  curious  hairy  appendages  which 
cover  the  back  and  project  from  the  sides  of  the  larva,  and  have  a  back- 
ward twist,  like  locks  of  dishevelled  hair.  These  are,  in  fact,  fleshy 
hooks,  covered  with  feathery,  brown  hairs,  among  which  are  longer, 
black,  stinging  hairs.  The  larva  is  15mm  (f-Q  inch)  long  and  has  an  oval 
body,  over  which,  however,  the  flattened  and  closely  applied  appendages 
form  a  nearly  square  shield.  The  cocoon  (Fig.  63)  is  almost  spherical,  like,, 
that  of  the  Saddle-back  caterpillar,  and  is  defended  by  the  hairy  ap- 
pendages which  the  larva  in  some  way  contrives  to  leave  upon  the  out- 


SLUG    CATERPILLARS    ON    ORANGE. 


143 


FIG.  62.— Phobctron  pi- 
thccium,  larva,  (af- 
ter lliley  ) 


side.  These  tufts  give  to  the  bullet- shaped  cocoon  a  very  nondescript 
appearance,  and  the  stinging  hairs  afford  a  very  perfect  protection 
against  birds  and  other  insectivorous  animals. 

Unlike  the  preceding  species,  the  Hag-moth  larvse  do  not  seek  to  hide 
away  their  cocoons,  but  attach  them  to  leaves  and  twigs  fully  exposed 
to  view,  with,  however,  such  artful  management  as  to 
surroundings  and  harmonizing  colors  that  they  are  of 
all  the  group  the  most  difficult  to  discover.  A  device 
to  which  this  insect  frequently  resorts  exhibits  the 
extreme  of  instinctive  sagacity.  If  the  caterpillar 
cannot  find  at  hand  a  suitable  place  in  which  to  weave 
its  cocoon  it  frequently  makes  for  itself  more  satisfac- 
tory surroundings  by  killing  the  leaves,  upon  which, 
after  they  have  become  dry  and  brown  in  color,  it 
places  its  cocoon. 

Several  of  these  caterpillars  unite  together,  and  selecting  a  long  and 
vigorous  immature  shoot  or  leader  of  the  orange  tree,  they  kill  it  by 
cutting  into  its  base  until  it  wilts  and  bends  over. 

The  leaves  of  a  young  shoot,  in  drying,  turn  a  light  tan-color,  which 
harmonizes  most  perfectly  with  the  hairy  locks  of  the  caterpillar  cov- 
ering the  cocoon.     The  latter  is,  consequently,  not  easily 
detected,  even  when  placed  upon  the  exposed  and  up 
turned  surface  of  the  leaf. 

The  moth  has  body  and  legs  of  purple-brown,  with 
ochreous  patches  on  the  back  and  a  light  yellow  tuft  on 
the  middle  pair  of  legs.    The  abdomen  is  sable,  ending 
in  a  tuft  of  ochreous  scales.     The  fore-wings  have  the 
colors  of  the  thorax  finely  mingled,  as  in  graining.     The  hind-wings  are 
sable,  bordered  with  ochreous  in  the  female.     The  fore  wings  of  the  male 
are  long  and  narrow,  the  hind-wings  short  and  very  triangular.     Both 
pairs  are,  in  this  sex,  partly  transparent. 

^The  spread  of  wing  varies  in  this  moth  from  20  to  24mm  (-$,-  inch  to 
-ft%  inch). 

THE   SKIFF-CATERPILLAR. 

(Limacodes  scapha  Harris.) 
[Figs.  64  and  65.1 

The  generic  name  Limacodes,  signifying  slug-like,  is  very  appropri- 
ately given  to  this  naked  and  slow-moving  caterpillar,  which  is  thus 
described  by  Harris :  "  Body  thick,  and  its  outline  nearly  diamond- 
shaped  ;  the  back  is  a  little  hollowed  and  the  middle  of  each  side  rises 
to  an  obtuse  angle ;  it  is  of  green  color  with  the  elevated  edges  brown 
The  boat-like  form  of  this  caterpillar  induced  me  to  name  it  Limacodes 
scapha,  the  skiff  Limacodes,"  (Ins,  Inj.  to  Yegetation,  p.  419.) 


FIG.  63.  —  Phobe- 
tron  pithcciinn, 
cocoon.  (Oiigi- 
nal.) 


144  INSECTS    AFFECTING    THE    ORANGE. 

The  larva  (Fig.  64)  lives  upon  Hickory,  Oak,  &c.,  but  has  been  re. 
ported  as  feeding  also  upon  orange  leaves.  It  forms  a  tough,  rounded- 
oval  cocoon.  The  moth  (Fig.  65)  is  cinnamon-brown;  upon  each  fore- 


FIG.  64. — Limacodes  scapha,  larva.  FIG.  65. — Limacodes  scapha,  moth. 

(Re-drawn  from  Harris.)  (After  Packard.) 

wing  is  a  large  tan -colored  spot  with  a  border  of  silver.     It  has  a  spread 
of  wing,  in  the  female,  of  30mm  (1.2  inches). 

The  life-histories  of  the  four  species  of  slug-caterpillars  are  similar, 
and  that  given  above  for  the  first  species  may  be  assumed  to  apply  to 
each  of  the  others.  The  same  parasites  are  probably  common  to  them 
all. 

BAG-WORMS. 

[Plate  XII.] 

Worms  living  in  cases  made  of  sticks  or  leaves,  and  which  they  carry 
about  with  them  from  place  to  place,  and  enlarge  with  their  growth. 
Pupa3  formed  within  the  the  case  of  the  larva.  Males  issuing  as  small 
moths,  not  differing  greatly  from  others  of  the  same  family.  Females 
remaining  wingless,  degraded  forms,  to  the  end  of  their  existence,  when 
they  leave  the  protecting  sack,  in  order  to  make  room  for  their  eggs, 
and  die. 

THE   COMMON   BAG-WORM  OR  BASKET-'WORM. 

(Oiketicus  abbotii  Grote.) 

The  baskets  of  this  species  are  very  large,  those  of  the  female  over 
two  inches  long ;  the  sack  of  the  male  is,  however,  only  one- third  as  long 
as  that  of  the  female.  , 

The  caterpillar  is  dirty  brown  in  color.  The  first  three  joints,  which 
bear  the  legs,  and  are  protruded  from  the  case  when  the  animal  moves 
about,  are  protected  by  horny  shields,  and  together  with  the  head  are 
mottled  and  streaked  with  light  and  dark  brown.  When  tyoung  the 
case  is  carried  erect  upon  the  upturned  end  of  the  body,  but  as  the  worm 
grows  larger  and  the  basket  becomes  heavy  with  the  weight  of  sticks 
and  fragments  of  which  it  is  composed,  it  is  allowed  to  hang  down. 

The  Bag- worm  is  an  omnivorous  and  most  voracious  feeder ;  nothing 
vegetable  appears  to  come  amiss  to  it,  and  it  sometimes  is  common 
enough  upon  orange  trees  to  do  serious  damage,  especially  as  it  does 
not  confine  itself  to  the  leaves,  but  also  gnaws  the  tender  bark  of  the 
shoots  and  cuts  off  bits  of  the  twigs  with  which  to  form  its  basket.  The 


BAG-WORMS    ON    ORANGE.  145 

basket  is  differently  constructed  to  suit  its  surroundings;  on  oak  it  is 
usually  formed  of  bits  of  rounded  twigs,  placed  crosswise  alter  the  fash 
ion  of  a  log  cabin  ;  on  trees  with  dense  foliage  like  the  Orange  it  is  oftener 
fashioned  with  leaf  material.  In  all  cases  it  is  thickly  lined  and  firmly 
bound  together  with  strong,  grayish-white  silk,  and  is  too  tough  to  be 
torn  asunder  with  the  fingers.  Before  the  larva  becomes  a  pupa  the 
bag  is  suspended  by  a  band  of  silk  to  a  twig  or  branch. 

The  winged  male  escapes  from  the  sack  leaving  the  pupa  shell  pro- 
truding. It  is  a  rather  thick-bodied  moth  of  dark  brown  color.  The 
abdomen  is  very  long,  slender,  and  tapering  to  the  point,  which  is 
armed  with  a  pair  of  shell  like  claspers,  and  these  conceal  the  point  of 
the  intromittent  male  organ.  These  parts  are  very  elastic  and  extensile, 
and  enable  the  male  to  reach  deeply  into  the  sack  of  the  female,  in  the 
act  of  coupling.  The  fore-wings  of  the  male  are  rather  long  and  nar- 
row; they  are  slightly  paler  than  the  body,  and  are  marked  with  a 
short  oblique  line,  devoid  of  feathers,  and  situated  just  beyond  the 
middle  of  the  wing.  The  hind  wings  are  short  and  angular. 

The  female  is  without  wings  or  legs,  and  is,  in  fact,  hardly  more  than 
a  living  egg-sack.  When  fully  mature  the  pupa  splits  at  the  anterior 
end,  and  the  body  of  the  female  protrudes.  Without  entirely  leaving 
the  pupa  shell,  but  dragging  it  after  her,  she  works  her  way  to  the 
mouth  of  the  basket,  where  she  awaits  the  visit  of  the  male,  having  her 
head  at  the  outlet. 

In  what  precise  manner  the  act  of  fertilization  takes  place  is  not  well 
understood,*  but  as  soon  as  it  is  accomplished,  the  female  pushes  her- 
self backwards  to  the  farther  end  of  the  basket,  and,  her  hinder  ex- 
tremity being  still  within  the  pupa  shell,  she  proceeds  to  fill  it  nearly 
full  of  pearly,  cream-colored  eggs,  packed  in  silk.  The  vacant  space  at 
the  end  is  then  filled  with  a  tangle  of  floss  silk,  mingled  with  feather 
scales,  which  the  mother  plucks  from  her  own  body.  When  finally 
her  body  is  entirely  withdrawn  from  the  pupa  shell  the  lips  of  the 
f  shaped  slit  at  the  end  snap  together,  entirely  closing  the  exit. 

The  female  continues  to  work  her  way  slowly  outward,  weaving  as 
she  goes  a  tangle  of  silk,  mingled  with  scales  stripped  from  her  own 
body.  Having  filled  the  entire  space  within  the  basket,  and  lest  she 
should  imperil  the  safety  of  her  young  by  remaining  in  the  case  to  die, 
the  mother  completes  the  sacrifice  by  dropping  from  its  mouth.  Her 
exhausted  body,  shorn  of  its  downy  covering,  falls  to  the  ground,  where, 
naked  and  defenceless,  it  becomes  a  ready  prey  to  ants  and  other 
prowlers. 

How  wonderful  an  example  is  here  shown  of  the  power  of  the  mater- 
nal instinct,  which  can  thus  overpower  the  instinct  of  self-preservation 
in  an  unreasoning  insect,  and  compel  her  to  yield  to  her  offspring, 
unborn  and  unseen,  a  secure  retreat,  which  otherwise  in  life  she  never 
leaves,  and  from  which  she  could  not  be  torn  except  piecemeal. 

The  eggs  of  the  Bag- worm  hatch  in  September.    The  young  larvae 

*  See  Appendix  III. 
6521  01 10 


146  INSECTS    AFFECTING   THE    ORANGE. 

(PI.  XII,  Fig.  2,  a)  push  or  eat  ttu-ir  way  out  of  the  pupa  shell  of  the 
mother,  and  emerge  from  the  mouth  of  the  basket.  They  almost  imme- 
diately begin  to  form  their  cases,  which  they  make  of  any  material  soft 
enough  to  be  rasped  by  their  jaws.  A  bit  of  cork,  for  example,  is  ex 
actly  suited  to  their  wants.  The  process  of  forming  the  basket  is  curi- 
ous, and,  observed  under  a  lens,  is  as  follows  :  The  larva  cuts  off  with 
its  jaws  a  fragment  of  cork,  of  a  size  and  shape  determined  by  the  cavi- 
ty of  the  mouth  5  each  fragment  is,  in  fact,  a  mouthful,  which  the  larva 
ejects  and  places  between  its  front  legs,  adding  one  to  another  to  form 
a  pile,  which  from  time  to  time  it  fastens  loosely  with  web.  (Plate 
XII,  Fig.  2,  b.)  Pieces  are  added  at  the  sides  until  the  pile  becomes 
a  transverse  tangle  about  as  long  as  the  body  and  placed  at  right  an- 
gles to  it.  Each  end  of  the  pile  is  fastened  loosely  to  the  surface  on 
which  it  rests,  and  several  strands  of  silk  are  laid  along  it  from  end  to 
end.  Then,  standing  with  its  body  astride  of  the  tangle,  the  larva 
bends  down  its  head,  tind  dives  under  the  mass,  turning  a  complete 
somersault,  so  that  when  its  head  and  fore  part  of  the  body  appear 
on  the  other  side,  the  insect  lies  on  its  back,  bound  down  by  the  fillet 
of  silk  and  bits  of  cork,  which  still  remain  fastened  to  the  surface  at 
the  ends.  (Plate  XII,  Fig.  2,  c.)  With  a  quick  movement  the  larva 
twists  around  and  stands  again  upon  its  feet,  having  its  neck,' as  it 
were,  under  a  yoke.  (Plate  XII,  Fig.  2,  d.)  It  then  makes  of  theyoke  a 
complete  collar  by  adding  bits  of  cork  to  each  end  until  the  circle  is 
complete.  Eow  after  row  of  fragments  is  added  to  this,  until  the  collar 
becomes  a  ho'.low  cylinder  within  which  the  body  of  the  little  workman 
gradually  disappears.  (Plate  XII,  Fig.  2,  e.)  Each  fragment  as  it  is 
ejected  from  the  mouth  is  fastened  by  one  end  to  the  edge  of  the  baud, 
and  secured  with  a  few  rapid  passes  of  the  silk-producing  mouth-organs. 
From  time  to  time  the  larva  cuts  the  anchoring  threads,  shifts  its 
work,  and  fastens  it  down  again.  Like  a  skillful  artisan  it  works  rap- 
idly, not  stopping  to  finish  the  work  as  it  goes,  but  only  occasionally 
strengthening  it  with  a  few  strands  of  silk  on  the  inside,  until  the  cylin- 
der is  long  enough  to  entirely  cover  its  body.  One  end  is  then  closed 
up  and  the  inside  well  coated  and, finished  with  a  tough  lining  of  silk; 
the  case  meantime  standing  upright  and  fastened  by  one  end.  (Plate 
XII,  Fig.  2,/.)  When  fully  completed  the  larva  cuts  loose  the  anchor- 
ing cables,  and  marches  off,  with  the  case  borne  aloft  like  a  cap,  on  the 
upturned  end  of  its  body.  This  case  of  the  young  larva  is  constantly 
enlarged,  until  it  becomes  the  basket  of  the  adult. 

The  Bag-worm  appears  to  be  single-brooded,  and  the  winter  is  passed 
by  the  young  larvae  in  their  cases.  Pnpa3  are  formed  late  in  summer. 
The  males  emerge,  the  females  deposit  their  eggs  and  perish,  and  the 
young  hatch  during  the  month  of  September.  Hand  picking  must  be 
relied  upon  to  rid  the  trees  of  Bag- worms  whenever  this  becomes  neces- 
sary. 

Parasites. — The  Bag-worm  is  attacked  by  an  Icbneumonid,  Hemitelea 


BAG- WORMS    ON    ORANGE.  147 

fhyridopterigis  Biley.  (Plate  XII,  Fig.  3.>  The  females  (6)  are  dull  red, 
with  banded  wings,  and  are  rather  more  than  one-third  of  an  inch  (9mm) 
long.  The  males  (a)  are  slender,  with  black,  shining  bodies  and  clear 
wings 5  they  are  somewhat  smaller  than  the  females  (8mm),  A  number 
of  the  parasites  inhabit  a  single  case  of  the  Bag-worm,  which  they 
partly  fill  with  a  consolidated  mass  of  their  own  dark-brown,  parch, 
rnent-like  pupa  cases.  (Fig.  3,  c.).  The  parasites  cut  their  way  out 
through  the  thick  sides  of  the  Bag-worm  follicle,  each  individual  appa- 
rently making  an  exit-hole  of  its  own. 

Another  Ichneumouid,  Pimpla  conquisitor  (Say)  (Plate  XII,  Fig.  4),  will 
undoubtedly  prove  to  be  parasitic  upon  this  Bag-worm,  as  it  has  been 
bred  from  other,  closely  related  species,  and  is  a  very  common  enemy  of 
many  large  caterpillars  in  the  south.  It  has  a  rather  slender  body  of. 
black,  banded  with  white,  and  clear  wings.  It  is  about  0.4  inch  long. 
It  is  a  solitary  parasite,  the  female  depositing  but  a  single  egg  in  each 
worm  which  she  stings. 

A  third  and  much  smaller  parasite,  Microgaster  sp.,  issues  late  in  Sep- 
tember from  the  young  larva  cases  of  Oiketicus,  in  which  it  spins  a  snow- 
white  silken  cocoon  of  its  own.  The  parasitic  fly  is  red-brown  in  color, 
with  dark  antennas  and  ovipositor.  It  measures  3mm  (0.12  inch)  in  length, 
exclusive  of  appendages. 

NORTHERN  BAG- WORM. 

(Thyridopteryx  epliemerceformis.  Ha  worth.) 
[Plate  XII,  Fig.  1.)] 

This  Bag-worm  bears  a  very  close  resemblance  to  Oiketicus,  and  ap- 
pears to  replace  it  in  the  North,  where  it  is  particularly  injurious  to 
Cedars.  It  is  not  certainly  known  to  occur  in  Florida,  but  may  be  found 
in  the  northern  part  of  the  orange  belt.  Its  case  is  formed  in  the  same 
way  and  its  life-history  is  probably  similar  to  that  of  Oiketicus.  The 
pupa  of  Oiketicus  is,  however,  chestnut-brown,  while  that  of  Thyridop- 
teryx is  dark  mahogany  in  color.  The  baskets  of  both  species  vary  in 
construction,  and  are  not  readily  distinguished  the  one  from  the  other. 
The  male  of  Thyridopteryx  is  black,  with  transparent  wings. 

PARASITES. —  Besides  the  Ichneumonid,  Hemiteles  thyridopterigis 
Eiley,  which  was  first  known  as  a  parasite  of  this  Northern  Bag-worm, 
and  has  been  noticed  above,  several  other  related  parasites  are  men- 
tioned by  authors  as  preying  upon  Thyridopteryx. 

Pimpla  inquisitor  (Say)  (Plate  XII,  Fig.  5)  is  mentioned  by  Mr.  Glover 
as  destructive  to  this  Bag- worm.  It  has  a  black  body,  with  parti-col- 
ored legs  ;  the  face  is  white  in  the  male.  Length  about  one-tenth  inch. 

The  Yellow -banded  Ichneumon  (Pimpla  conquisitor ',  Say)  (Plate  XII,  Fig. 
4). — This  is  also  a  common  parasite  of  the. Cotton  Worm  and  other  large 
moths.  It  closely  resembles  the  preceding,  but  the  joints  of  the  abdo- 
men are  ringed  with  white.  It  is  mentioned  by  Lintner  as  one  of  the 


148  INSECTS    AFFECTING    THE    ORANGE. 

parasites  of  the  Northern  Bag- worm.*     The  species  varies  in  length 
from  about  one-quarter  of  an  inch  to  over  half  an  inch. 

In  Harris's  Entomological  Correspondence,  p.  242,  we  find  the  follow- 
ing: "The  parasite  of  the  drop- worm  is  Ichneumon  concitator  Say,  a 
very  common  and  somewhat  variable  species,  which  attacks  all  sorts 
of  Iarva3.  It  is  one  of  the  most  common  parasites  of  Clisiocampa  amer- 
icana."  No  mention  of  this  species  can  be  found  elsewhere  than  in 
Harris's  writings,  and  the  presumption  is  that  a  confusion  has  been 
made  between  names  of  similar  sound,  and  that  either  Pimpla  conquis- 
itor  or  Cryptus  inquisitor  was  intended. 

THE   CYLINDRICAL  BAG-WORM. 

(Psyche  sp.) 

The  cases  of  a  Bag- worm  supposed  to  belong  to  the  genus  Psyche  are 
sometimes  seen  upon  orange  trees ;  they  are  not  spindle-shaped,  as  in 
the  preceding  species,  but  cylindrical,  and  the  fragments  composing  the 
outside  are  laid  on  longitudinally.  The  fragments  usually  consist  of 
bits  of  straw  or  dead  pine-needles,  some  of  which  are  very 
long  and  project  beyond  or  out  from  the  sides  of  the  case. 
The  basket  of  the  female  is  about  38mm  (1J  inches) ;  that  of 
the  male  251""1  (1  inch)  in  length,  exclusive  of  projecting 
points.  The  female  is  wingless;  its  pupa-case  is  of  a  light 
chestnut-brown,  and  is  15mm  (-f-6  inch)  long. 

Fig.  66  represents  the  basket  of  the  male  of  Psyche  con- 
fedcrata,  with  the  pupa-shell  protruding.  (Reproduced 
from  Trans.  Arner.  Ent.  Soc.,  vol.  II,  Plate  III,  Fig.  67.) 

The  male  remains  unknown  5  it  is  a  winged  moth,  which 
probably  resembles  Psyche  confederata  G.  and  E.,  but  is  larger  and  pos- 
sibly lighter  in  color.f 

The  life-history  of  this  Bag- worm  is  undoubtedly  similar  to,  if  not  iden- 
tical with  that  of  Oiketicus  and  Thyridopteryx. 

THE   ORANGE   BASKET-WORM. 

(Platceceiicus  gloverii  Packard.) 
[Fig.  67.] 

A  much  smaller  species  than  the  preceding  was  first  mentioned  by 
Mr.  Glover,  who  gave  an  account  of  its  habits  in  the  Patent  Office 


*  First  Annual  Report  of  the  Injurious  and  Other  Insects  of  the  State  of  New  York, 
by  J.  A.  Lintner,  page  84. 

tThe  male  of  Psyche  confederata  G.  and  R.,  is  "  entirely  deep,  smoky  black.  Anten- 
nae plumose.  Wings  ample,  closely  scaled,  rounded  and  full.  *  *  *  Expanse, 
19mm :  Length  of  body,  7mm."  The  specimens  described  by  Grote  and  Robinson 
(Trans.  Am.  Eut.  Soc.,  vol.  II,  p.  191)  were  sent  from  Texas.  Plate  III,  fig.  67,  gives 
a  representation  of  the  basket  of  this  species.  Similar  cases,  which  may  possibly 
belong  to  this  species,  have  been  seen  upon  the  Orange  in  Florida. 


BAG-WORMS    ON   ORANGE. 


149 


Agricultural  Eeport  for  1858.  Its.  basket  is  spindle-shaped,  that  of 
the  female  18ram  (^  inch),  and  that  of  the  male  13mm  (J  inch)  long.  It  is 
covered  with  finely  chopped  bits  of  dry  leaf,  bark, 
moss  and  other  scraps,  supplemented  not  unfre- 
quently  with  the  scales  of  Bark-lice.  As  an  addi- 
tional protection,  several  small  orange  thorns  are 
often  fastened  to  the  outside  of  the  case,  with  their 
sharp  tips  projecting  backwards  and  outwards. 
The  pupa  case  is  dark  mahogany-brown,  and  the 
sutures  between  the  joints  are  opaque,  black,  form- 
ing on  the  female  pupa  three,  and  on  the  male  pupa 
four,  very  distinct  rings.  The  male  is  a  small,  dark- 
brown  moth,  measuring  16mm  (-^A-  inch)  across  the  FIG.  w—piat<xceticus 

gloverii.  ( After  Glover. ) 

extended  wings.    The  female,  as  in  the  preceding 

Bag-worms,  is  wingless,  and  undergoes  a  development  similar  to  that 

of  Oiketicus. 

UNNAMED  BAGr-WORM. 

[Fig.  68.] 

A  species  of  Bag- worm  smaller  than  any  of  the  preceding  exists  upon 
Orange,  and  is  not  uncommon.  Its  cases  are  long,  slender,  and  cylin- 
drical, and  covered  with  fragments  of  bark,  straw,  &c. ;  many  of  these 
are  linear,  and  have  projecting  ends.  The  female  case  (Fig.  68a)  is 


FIG.  68.— Unknown  Bag-worm  on  Orange:  a,  case  of  female;  b,  pupa  of  female;  c,  pupa  of  male;  d 
end  of  male  pupa,  enlarged.     (Original.) 


15mm  (-!%  inch),  and  that  of  the  male  12mm  (-^f0-  inch)  long.  The  pupa 
of  the  female  (Fig.  G8,  6)  measures  Simu  (-f0\  inch)  in  length.  The  male 
pupa  (Fig.  G8,  c  ;  d,  end  of  pupa  enlarged)  is  very  minute,  being  only  half 
the  size  of  the  i'emale.  Both  are  slender,  bluntly-rounded  at  the  ends, 
and  of  a  light  chestnut  color. 

This  small  species  is  allied  to  Psyche  confederata,  by  the  slender  form 
and  light  color  of  its  pupa,  as  well  as  by  the  construction  and  cylindri- 
cal shape  of  its  case.  In  Platoeceticus,  on  the  other  hand,  the  fusiform 
shape  and  dark  color  of  the  case  and  pupa,  indicate  a  closer  relation- 
ship to  Oiketicus.* 

*  The  species  of  Bag-worms  are  more  numerous  than  has  been  supposed,  and  sev- 
eral undescribed  species  are  confused  in  collections  with  the  few  species  hitherto 
described. 


150 


INSECTS   AFFECTING   THE    ORANGE. 


LEAF-EATEES  WITHOUT  CASES. 
ARTACE  PUNCTISTRIGA  Walker. 

The  following  account  of  this  insect  appears  in  the  report  of  the 
Commissioner  of  Agriculture  for  1880,  p.  252  : 

"  There  is  occasionally  to  be  found  upon  the  orange  a  fusiform  white 
silken  cocoon,  an  inch  and  a  half  in  length.  From  this  cocoon  there, 
issues  in  spriug  a  thick-bodied  woolly  white  moth,  the  female  measuring 
an  inch  and  three-quarters,  and  the  male  an  inch  and  one-quarter  across 
the  wings.  Each  fore  wing  has  five  transverse  rows  of  small  black 
dots.  We  have  riot  seen  the  caterpillar  which  spins  this  cocoon,  but 
from  an  examination  of  the  cast-off  skin  to  be  found  at  the  end  of  the 
pupa,  and  from  other  facts,  we  may  readily  state  it  to  be  a  rather  thick 
larva,  about  an  inch  and  a  half  in  length,  and  covered  with  long  mixed 
black  and  whitish  hairs,  giving  it  a  grayish  effect.-  These  cocoons  are 
not  confined  to  orange,  but  are  also  found  upon  the  grass  at  the  foot  of 
the  tree,  and  one  specimen  received  was  evidently  found  upon  cherry, 
as  pieces  of  the  bark  still  adhered.  The  species  seems  to  be  compara- 
tively rare,  but,  as  we  have  said  before  of  other  species,  it  is  liable  at 
any  time  to  increase  and  become  injurious;  therefore  the  sooner  it  is 
treated  of  the  better.  As  one  of  the  causes  of  its  rarity  we  may  mention 
the  existence  of  a  large  ichneumonid  parasite,  which  we  have  not  been 
able  to  breed,  owing  to  the  fact  that  it  in  its  turn  is  parasitized  by  a 
chalcid,  of  which  we  have  bred  thirty-six  specimens  from  a  single  co- 
coon, all  having  made  their  exit,  as  usual,  from  a  single  hole.  It  is  pos- 
sible that  this  chalcid  may  also  be  a  primary  parasite.  The  specimens 

were  referred  to  Mr.  Howard  for  study,  and 
decided  to  be  a  new  species  of  the  genus 
Encyrtus  of  Dalman."  It  was  described  (loo. 
cit.)  as  Encyrtus  artacece  n.  sp. 

THE  GRASS -WORM. 

(Laphygma  frugiperda,  Sm.  &  Abb.) 
[Figs.  69  and  70.) 

Patches  of  the  eggs  of  this  common  moth 
are  very  commonly  found  on  orange  leaves. 
But  although  the  young  caterpillars  eat  the 
leaves  to  some  extent,  they  soon  find  their 
way  to  some  other  and  more  succulent  food- 
plant.  Full-grown,  caterpillars  are  scarcely 
ever  seen  upon  the  Orange,  although  they 

can  be  bred  upon  it  in  confinement. 
The  eggs  are  dull  white,  with  a  pearly  luster.     The  clusters  contain  a 

variable  number  of  eggs,  and  are  covered  with  mouse  colored  down  from 

the  body  of  the  mother. 


FIG.  69.— Laphygma 
a,  larva,  natural  size ; 
c,  middle  joint  from  above;  cf, 
do.from  side,  enlarged.  (After 
Riley.) 


LEAF-ROLLERS    ON    OKANGE. 


151 


FIG.  70.  —  Laphygma  friiflipercla: 
a,  moth,  normal  form  ;  b,  wings 
of  variety  fusca,-  c,  do.  of  variety 
obscura  —  natuial  size.  (After 
Riley.) 


The  caterpillars  grow  to  the  length  of  an  inch  and~a  half.    They  are 
very  variable  in  color,  the  young  being  dark,  sometimes  nearly  black, 
and  the  adults  of  lighter  color,  varying  from  brown  to   pale  green, 
with  fine  mottlings  of  other  colors.     Several 
broad  stripes  of  dark  and  light  brown,  run- 
ning from  head  to  tail,  render  this  caterpil- 
lar conspicuous  and  easily  recognized. 

The  moth  belongs  to  the  numerous  group 
of  Owlet  Moths,  called  in  the  South  "Candle 
Flies."  It  has  narrow  front  wings  of  gray 
and  brown,  finely  intermingled  ;  and  the  semi- 
transparent  hind  wings  of  dull  white,  with 
smoky  margins.  Spread  of  wings  about  one 
and  a  quarter  inches. 

The  pupa  is  polished,  mahogany-brown, 
and  is  formed  in  a  simple,  unlined  cell  be- 
neath the  surface  of  the  ground.  The  trans- 
formations of  this  insect  are  completed  in 
one  month.  There  are  several  broods,  but 
the  worms  are  most  numerous  in  August,  and  the  moths  in  September. 

Orange  groves  which  are  kept  clean  will  not  be  liable  to  injury  from 
the  Grass -worm,  which  feeds  naturally  upon  grass  and  succulent  herbs. 
Young  groves  are  sometimes  attacked  when  they  are  allowed  to  become 
foul  and  only  cultivated  at  long  intervals.  The  amount  of  damage  done 
by  this  caterpillar  is  small,  but  it  may,  under  special  conditions,  become 
a  serious  pest.  Clean  culture  will  in  such  cases  prove  an  all-suflicient 
remedy. 

LEAF-ROLLERS. 

Slender,  almost  naked,  worms,  of  small  size,  and  usually  yellowish- 
green  in  color,  which  roll  up  leaves,  or  bind  together  tender  bud-leaves, 
to  form  a  protecting  tube,  within  which  they  lurk  and  feed,  and  in  time 
transform  to  pupae. 

Before  the  moth  issues,  the  pupa  is  pushed  partly  out  of  the  tubular 
shield  of  leaves.  Fig.  71  shows  the  pupa  of  Platynota  rostrana  pro- 
truding from  the  side  of  a  folded  orange  leaf. 

The  adults  are  rather  small  moths,  with  pointed  heads,  and  oblong, 
somewhat  heavy  fore  wings,  which,  when  folded,  form  a  roof-like  ridge 
over  the  body. 

The  eggs  are  laid  upon  the  surfaces  of  leaves,  in  elongate,  oval 
patches  of  transparent  yellowish-green  color.  In  these  patches  each 
egg  forms  an  excessively  thin  overlapping  scale,  and  the  whole  mass  of 
fifty  to  eighty  eggs  is  thus  firmly  knit  together,  and  can  be  removed 
from  the  leaf  without  separating.  The  thinness  and  cellular  structure 
of  the  egg-cluster  give  it  a  resemblance  to  certain  low  forms  of  vegeta- 
ble life,  and  it  might  readily  be  mistaken  for  a  mold  or  a  lichen. 


152  INSECTS  AFFECTING  THE  ORANGE. 

THE  CORK-COLORED  ORANGE  TORTRICID. 

(Platynota  rostrana,  Walker.) 
[Fig.  71.J 

The  tubular  webs  of  this  species  are  very  common  and  quite  destruc- 
tive to  small  seedling  and  nursery  plants,  as  the  worm  is  apt  to  select 
the  tender  budding  leaves  at  the  top  of  the  plant,  and  by  killing  these 
check  further  growth.    Both  this  and  the  other  Tortricid  leaf-rollers  do 
occasional  damage  to  the  fruit  by  puncturing  the  rind 
beneath  the  shelter  of  a  leaf,  which  they  fasten  with  web 
to  its  surface. 

The  larva  is  translucent,  dull  yellowish-green  above, 
paler  on  the  sides  and  beneath.  The  head  is  brown,  and 
the  next  joint  bears  a  polished  shield  of  the  same  color, 
edged  with  white.  A  dark  stripe  extends  along  the  back, 
and  a  stripe  of  pale  brown  along  each  side.  The  body 
of  the  larva  is  naked,  except  that  each  joint  bears  a  few 
long,  fine  hairs,  each  arising  from  a  dot  of  glistening 
white.  These  hairs  are  sensitive  organs  of  touch.  The 

FIG.  71.—  Platynota 

rostrana.-  pupa    length  of  the  caterpillar  is  18ram  d2^  inch). 

shell  protruding 

from  folded  leaf.  The  pupa  is  of  slender  form  and  chestnut-brown  color. 
It  has  six  pairs  of  terminal  hooks,  with  which  it  clings 
to  its  tubular  web. 

The  male  moths  are  much  darker  than  the  females,  the  upper  wings 
cinnamon  in  color,  with  oblique  bands  of  umber,  and  their  surface's 
much  roughened  with  elevated  tufts  and  ridges  of  coarse  scales.  The 
females  are  larger  and  the  upper  wings  much  lighter  in  color,  the  red 
being  mingled  with  silver-gray.  In  this  sex  the  tufts  of  scales  are  very 
minute,  and  the  oblique  bands  are  reduced  to  fine,  elevated  lines. 
Length  of  the  male,  with  wings  folded,  10mm  (-fa  inch);  of  the  female, 
12mm(-nfo-mch). 

The  eggs  of  each  batch  hatch  simultaneously,  the  last  caterpillar 
quitting  its  egg  shell  a  few  minutes  after  the  first.  The  young  cater- 
pillars immediately  scatter  over  the  plant,  but  hide  in  crevices  at  first, 
and  do  not  begin  rolling  the  leaves  until  they  are  three  or  four  days 
old.  They  shed  tneir  skins  five  times  during  the  eighteen  or  twenty 
days  of  their  existence  as  larvae.  They  remain  eight  or  ten  days  in 
pupa.  Allowing  eight  or  ten  days  for  the  laying  and  hatching  of  the 
eggs,  a  period  which  is  not  certainly  known,  a  single  generation  oc- 
cupies less  than  six  weeks.  There  are  apparently  four  or  five  broods 
during  the  eight  warm  months,  and  an  additional  brood  in  mild  winters, 
but  the  caterpillars  may  be  found  at  all  seasons  of  the  year,  and  there 
is  in  fact  very  little  evidence  of  a  separation  into  distinct  broods. 

Hand-pickiug  is  the  only  remedy  that  can  be  relied  upon,  and  by  this 


LEAF-ROLLERS    ON    ORANGE. 


lf)3 


cZ 

FIG.   72. — Trichogramma    minuta. 
Riley.) 


(After 


method  young  trees   can    without  difficulty  be  kept  free  from  their 
attacks. 

PARASITES. — Trichogramma  pretiosa  Eiley. — This  minute  Chalcid 
fly,  well  known  as  the  parasite  which  renders  effective  aid  by  destroying 
the  eggs  of  the  Cotton  Worm,  also  infests  the  egg  clusters  of  the  Orange 
Leaf-roller.  The  mother  parasite  deposits  a  single  egg  in  each  cell  like 
egg  of  the  Tortrix,  and  within  this  nar- 
row cell  the  young  parasite  finds  food 
and  domicile  until  it  has  completed  all 
its  changes.  Then  it  eats  its  way  out, 
making  a  ragged  hole  in  the  shell,  and 
emerges  as  a  perfect  four- winged  fly  like 
its  parent.  The  fly  is  0.3mm  (-^  inch) 
long,  clear  yellow  in  color,  with  ruby 
eyes  and  iridescent,  hyaline  wings, 
which  are  delicately  fringed  with  hairs. 
It  has  been  bred  from  the  Tortrix  eggs  in  March  and  also  in  September. 
Fig.  72  represents  Trichogramma  minuta,  a  closely-allied  species,  which 
differs  from  Triclwgramma  pretiosa  only  in  color  and  the  form  of  the 
small  joints  of  the  antenna. 

MiotropisplatynotceHowsir'Ct.12 — A  slender  hymenopterous  fly  has  been 
bred  from  the  larva  of  the  Orange  Leaf-roller.  It  is  honey-yellow 5 
head  lemon-yellow,  with  dark  eyes  and  antennae.  The  head  is  much 
wider  than  long,  and  bears  above  three  dark-colored,  simple  eyelets 
(ocelli).  The  wings  are  hyaline.  Three  or  four  maggots  of  the  parasite 
are  found  living  within  a  single  caterpillar  of  the  Tortrix,  which  is  at 
last  almost  completely  devoured  by  them.  The  parasites  form  naked 
pupae,  loosely  disposed  within  the  tubular  web  of  the  destroyed  Leaf- 
roller,  and  in  about  nine  days  change  to  adult  flies  by  casting  the  thin, 
transparent  skin  of  the  pupa.  The  flies  were  obtained  in  September. 

Polysphincta  albipes  Oresson. — Cocoons  of  slightly  yellowish,  coarse 
silk,  loosely  spun,  were  found  by  Professor  Comstockon  an  orange  leaf, 
at  Rock  Ledge,  Fla.  The  flies  issued  in  February.  They  have  been 
described  by  Mr.  Cresson  in  the  Keport  of  the  Commissioner  for  1879, 
p.  208.  The  body  is  dull  red,  smooth  and  polished  5  head  black,  with 
white  mandibles;  wings  hyaline,  and  legs  white.  Length  7mra  (f£-0 
inch).  This  insect  is  somewhat  doubtfully  considered  a  parasite  of  Tor- 
trix rostrana. 

Goniozus  n.  sp. ; 13  family  Proctotrupidce. — A  minute  parasite  is  bred 
from  the  caterpillar  of  the  Leaf-roller.  It  has  a  shining,  black  body, 
with  yellow  legs  and  antennae,  and  hyaline  wings,  with  a  dark-brown 
stigmal  spot.  Length  2.5mm  (^  inch).  Four  or  five  of  the  parasites 
are  found  in  a  single  caterpillar.  They  spin  oval  cocoons  of  whitish 
silk  within  the  tubular  web  of  the  Tortrix.  The  parasites  issued  Octo- 
ber 1. 


154  INSECTS   AFFECTING   THE   ORANGE. 

THE   SULPHUR-COLORED   TORTRICID. 

(Dichelia  [  Tortrix]  snlphureana,  Clem.) 

The  caterpillars  of  this  widely-distributed  Leaf-roller  are  very  general 
feeders.  In  the  northern  States  they  are  frequently  injurious  to  Clover; 
in  the  South  the  long  list  of  their  food-plants  includes  Cotton,  Straw- 
berry, Grape,  and  Orange;  upon  the  latter  they  are  somewhat  rarely 
found,  and  it  is  probable  that  tlie  thick  leaves  of  the  citrus  family  are- 
not  well  adapted  to  the  needs  of  this  species.  The  caterpillar  bears  a 
close  general  resemblance  to  that  of  Platynota  rostrana,  but  is  somewhat 
smaller,  and  the  head  and  thorax  are  pale  yellow.  The  pupa  is  dark 
mahogany  brown,  almost  black.  The  moth  is  sulphur  yellow  above; 
the  upper  wings  are  marked  with  red-brown,  or  purple-brown.  The 
markings  vary  greatly  in  different  individuals,  forming  a  double  letter 
Y  or  an  X  upon  the  folded  wings,  but  are  sometimes  reduced  to  a  series 
of  dots,  representing  only  the  terminal  and  intersecting  points  of  these 
letters.  The  under  wings  are  varying  shades  between  yellow  and  brown. 
Length  from  the  tip  of  the  beak  to  the  extremity  of  the  folded  wings,  11""" 
( j4^  inch).  The  life-history  and  habits  of  this  species  in  Florida  are  prob- 
ably the  same  as  Platynota  rostrana.  In  the  Eeport  of  the  Commissioner 
of  Agriculture  for  1880  will  be  found  an  account  of  both  species.  T. 
sulphureana  is  there  said  to  have  three  generations  in  a  year  in  the  lat- 
itude of  the  District  of  Columbia,  and  probably  only  one  in  middle  and 
northern  Maine. 

LARGER  LEAF-ROLLER. 

(Tortrixl)14 

This  is  a  somewhat  larger  insect  than  Platynota  rostrana,  from  which, 
however,  the  larva  differs  only  in  minute  details.  The  pupa  also  is  sim- 
ilar to  that  of  P.  rostrana.  The  moth  is  rust-red,  with  three  oblique 
bands  of  maroon-red  upon  the  upper  wings,  and  their  anterior  (outer) 
edge  is  sinuate. 

The  habits  of  this  species  are  precisely  the  same  as  the  foregoing,  but 
the  larva  being  larger  is  more  destructive,  and  often  half  cuts  off  small 
twigs  of  tender  growth,  the  leaves  of  which  it  folds  and  binds  together 
longitudinally,  and  feeds  without  preference  upon  the  wilted  leaves 
within  its  retreat,  or  upon  the  fresh  leaves  of  surrounding  branches. 

WEB-MAKERS. 
THE   ORANGE-LEAF  NOTHRIS. 

(Nothris  citrifoliella  Chambers.) 

The  caterpillars  of  a  minute  moth  have  been  reported  from  the  ex- 
treme southern  portion  of  the  orange  district,  as  doing  injury  in  the 
groves.  The  following  account  of  it  is  found  in  the  Annual  Report  of 
the  Commissioner  of  Agriculture  for  1879,  p.  205: 

"  Specimens  of  this  insect  were  last  summer  received  from.  Brevard 


WEB-MAKERS    ON    ORANGE  155 

County,  Florida.  We  do  not  know  enough  of  its  habits  at  present  to 
do  more  than  describe  it  and  its  methods  of  work. 

"According  to  Mr.  H..S.  Williams,  of  Koek  Ledge,  the  larvae  have 
been  very  injurious  to  the  orange  trees  in  his  vicinity.  They  infest  the 
young  leaves  of  the  new  growth.  These  they  web  together  by  a  deli- 
cate white  silken  web,  and  feed  upon  the  bud,  entirely  stopping  the 
growth  of  the  shoot.  If  disturbed,  the  worm  drops  by  a  thread.  It  is 
very  active,  and  when  removed  from  its  web  runs  quite  quickly. 

"The  full  grown  larva  measures  about  12mm  (J  inch)  in  length.  It  is 
yellowish  in  color,  with  the  head  and  first  thoracic  segment  black  and 
somewhat  polished.  The  posterior  margin  of  the  black  thorax  is  pale- 
yellow.  The  anal  plate  and  legs  are  polished  yellow,  with  the  scattered 
hairs  upon  the  former  blackish ;  all  other  hairs  are  yellow.  The  first 
pair  of  legs  is  black  and  the  rest  yellow. 

"  When  ready  to  pupate,  the  larva  rolls  a  leaf  around  itself  and  spins 
a  delicate  silken  cocoon,  in  which  it  transforms  to  a  rather  stout,  dark- 
brown  chrysalis.  There  is  nothing  so  characteristic  about  the  chrysalis 
as  to  merit  description.  The  moths  emerged  from  August  25  to  Sep- 
tember 5."* 

THE   ORANGE   WEB-WORM. 

(Anceglis  demissalis  Led.) 
[Plate  XIII,  Fig.  1,  la,  16.] 

The  caterpillars  of  this  interesting  little  moth  are  not  uncommon  upon 
orange  trees,  but  so  remarkably  well  protected  are  they  by  their  form, 
color,  and  surroundings,  that  the  skill  of  the  collector  will  be  taxed  to 
the  utmost  in  discovering  them. 

They  surround  themselves  with  a  tangle  of  web,  involving  several 
twigs  and  small  branches,  together  with  their  leaves.  (Plate  XIII,  Fig. 
1.)  Caterpillars  of  different  ages  will  be  found  in  each  web,  which  they 
occupy  in  joint  proprietorship  with  a  small  spider.  Between  this  spi- 
der and  the  AnaBglis  there  exists  the  most  perfect  harmony.  In  fact,  so 
close  is  the  association  of  these  allies,  that  the  Web  worm  is  never  seen 
except  in  company  with  the  spider,  and  the  webs  of  the  latter  are  sel- 
dom without  the  presence  of  the  caterpillars. 

It  must  not  be  supposed,  however,  that  the  Web-worm  is  a  mere  pen- 
sioner  upon  the  bounty  of  the  spider.  Both  are  web-makers  j  the  spi- 
der toils  by  day,  its  companion  is  active  at  night.  During  the  day  time 
the  caterpillars  remain  suspended  here  and  there  in  the  web,  and  feign 
death.  Their' slender  bodies,  slung  in  all  sorts  of  positions,  are  rigidly 
extended,  and  the  head  is  bent  sharply  upwards  at  the  neck,  as  if  in 
rigor  mortis.  No  amount  of  disturbance  can  induce  the  insect  to  betray 


*  The  original  description  of  the  moth  will  be  found  in  Prof.  Comstock's  Report 
(Report  of  Commissioner  of  Agriculture  for  1879,  p.  205). 


156  INSECTS   AFFECTING   THE    ORANGE. 

itself  by  a  movement,  and  it  will  even  suffer  itself  to  be  crushed  with- 
out exhibiting  any  signs  of  life. 

The  color  of  the  caterpillar — a  cinnamon-brown — and  its  flattened, 
wrinkled  form  give  it  an  extraordinary  resemblance  to  a  shriveled  bit 
of  twig  or  leaf.  The  deception  is  rendered  perfect  by  the  presence  in 
the  web,  whether  by  accident  or  design,  of  dry  fragments  arid  petioles 
of  orange  leaves  which  have  fallen  from  the  surrounding  branches. 

In  these  web-tangles  not  only  the  spider  lives  sociably  with  others  of 
its  kind,  hanging  their  egg-sacks  in  the  net,  and  raising  their  young, 
sometimes  in  numerous  colonies,  but  two  other  insects  unite  in  the  re- 
markable confederation,  and  form  for  mutual  protection  a  sort  of  ento- 
mological happy  family.  These  are  a  small  tree  Cockroach  and  a  coral- 
red  bug  (Hemipteron),  both  of  which  breed  and  lurk  in  the  tangles, 
passing  with  facility  over  and  between  the  meshes  of  the  net,  and  evi- 
dently feel  perfectly  at  home  there.  The  bug  is,  however,  known  to 
be  a  predatory  species,  and  feeds  upon  the  eggs  and  young  of  the 
Mealy-bug  (see  Chapter  VI). 

The  caterpillar  of  Anasglis  (Plate  XIII,  Fig.  1,  a)  is  long,  slender,  and 
somewhat  flattened,  in  color  rusty  or  cinnamon-brown,  with  a  faint 
tinge  of  green ;  beneath,  dull  green.  The  body  is  finely  wrinkled  and 
speckled  with  minute  white  dots  and  with  a  row  of  bristles  on  each 
side,  having  a  large  white  dot  at  the  base  of  each.  The  second  joint 
and  last  joint  of  the  body  paler.  Head  mahogany-brown.  Length,  19 
to  20mm  (•&•  inch). 

Pupa  clear  brown,  finely  and  densely  speckled  with  darker  brown, 
the  intermediate  shades  producing  a  dark  mahogany  color;  the  breath- 
ing pores  on  the  sides  are  prominent  and  jet-black  in  color.  Terminal 
point  (cremaster)  red-brown,  furnished  with  six  or  eight  rather  long 
hooklets.  It  is  usually  suspended,  like  the  larva,  in  a  more  or  less  hori- 
zontal position  in  the  thicker  parts  of  the  web ;  sometimes  naked,  but 
generally  with  a  light,  loose  tangle  of  web  and  bits  of  excrement  gath- 
ered about  it.  The  length  is  less  than  half  that  of  the  larva. 

The  imago  is  a  dainty  little  moth,  with  silver-gray  wings,  marked  with 
a  broad  band  and  several  wavy  lines  of  purple- black,  and  with  parti- 
colored legs.  It  has  the  triangular  form  characteristic  of  the  PyralidaB 
sometimes  called  Deltoides,  from  the  outline  assumed  by  the  wings  when 
at  rest,  which  is  that  of  the  Greek  A.  The  eyes  are  large,  prominent, 
and  black.  The  rather  heavy  antennas  curving  backwards,  and  the 
pointed  maxillaa  directed  upwards  like  horns,  instead  of  forward  in  line 
with  the  head,  give  an  air  of  alertness  to  the  insect. 

The  egg  is  laid  singly  upon  a  strand  of  the  web,  either  of  the  larva  or 
the  spider  with  which  it  is  associated.  It  is  spheroidal,  pearly,  yellow- 
ish white,  and  adorned  with  a  microscopic  pattern,  consisting  of  elevated 
points,  from  each  of  which  five  pairs  of  raised  lines  radiate  to  the  five 
surrounding  points. 


HEMIPTEROUS    INSECTS    ON    ORANGE.  157 

Broods. — As  in  the  case  of  the  Leaf-rollers  (Tor  trie  idee),  there*  are 
many  broods  during  the  year.  The  moths  have  been  bred  in  February, 
March,  April,  June,  July,  September,  and  October,  and  caterpillars  of 
all  ages  are  found  at  any  time  during  the  summer.  In  December  and 
January,  however,  only  the  pupa  is  obtainable. 

Remedies. — The  extent  of  direct  injury  done  to  the  Orange  by  these 
Web-worms  is  slight.  It  is,  however,  desirable  to  remove  them  from 
the  trees,  as  the  tangles  of  web  harbor  Scale-insects,  and  by  protecting 
them  from  enemies  foster  their  increase.  In  many  cases  Scale-insects 
will  be  found  to  have  made  their  appearance;  brought  there,  in  all 
probability,  by  the  spiders.  It  is  therefore  a  wise  plan  to  cut  away 
the  infested  portion,  usually  comprising  only  a  small  inside  branch.  If 
this  cannot  be  done  without  too  much  mutilation — as,  for  example,  on 
young  plants — after  removing  the  web  from  the  branches  they  should 
be  sprayed  with  one  of  the  washes  recommended  in  the  treatment  of 
Scale-insects. 

INSECTS  OF  THE  ORDER  HEMIPTERA. 
THE   ORANGE  APHIS. 

(Siphonophora  citrifolii  Ashmead.) 
[Plate  XIII,  Fig.  3  a,  &,  c,  and  d.] 

The  history  of  the  common  Plant-louse  of  the  greenhouse  and  gar- 
den has  often  been  written  and,  briefly  stated,  is  as  follows :  In  the 
autumn  eggs  are  deposited  singly  in  sheltered  places;  from  these  hatch 
in  the  spring  only  wingless  females,  which  do  not  lay  eggs,  but  are  vi- 
viparous and  produce  young  without  the  appearance  of  males.  During 
the  summer  one  generation  follows  another  with  an  astonishing  rate 
of  increase;  each  brood  consisting  solely  of  wingless  agamic  females. 
Finally,  the  last  brood  in  the  fall  consists  of  winged  males  and  females, 
by  whom  the  winter  eggs  are  produced  and  the  perpetuation  of  the  spe- 
cies secured  in  the  ordinary  manner. 

The  Aphis  of  the  Orange  (Plate  XIII;  a,  wingless  female;  6,  winged 
females)  is  a  dark  green  Plant-louse,  from  1.5  to  2mm  (yf  0-  to  -4-§-0-  inch) 
in  length,  and  hardly  distinguishable  in  a  popular  description  from 
some  of  the  species  common  everywhere  in  greenhouses  and  gardens. 
It  has  parti-colored  legs  and  garnet-red  eyes.  The  hue  of  the  body 
varies  with  age,  from  light  yellowish-green  or  rusty  green  in  the  very 
young,  to  dark  green  in  the  adults.  The  winged  individuals  are  of  so 
dark  a  green  as  to  have  been  described  as  black,  and  the  young  of  this 
form  are  distinguishable  at  an  early  age  from  those  destined  to  remain 
wingless,  both  by  their  darker  color  and  more  prominent  tubercles 
upon  the  upper  surface  of  the  body.  Two  pairs  of  these  prominences 
gradually  develop  into  wing-pads,  and  after  the  final  molt  become  well- 
formed  and  transparent  wings. 


158  INSECTS   AFFECTING   THE    ORANGE. 

Tne  development  of  this  sou them  Aphis  differs  from  that  of  its  north 
ern  congeners,  in' that  the  winged  and  the  wingless  individuals  occur 
together  at  all  seasons,  and  both  forms  produce  their  young  living.  The 
males  remain  undiscovered,  and  it  is  entirely  possible  that  they  rarely 
make  their  appearance,  perhaps  only  at  intervals  of  several  years.  In 
the  warm  climate  of  Florida  the  cold  is  never  sufficiently  severe  to 
kill  winged  females,  and  the  Orange  not  being  deciduous  a  supply  of 
food  is  nearly  always  at  hand.  A  winter  egg  is  not,  therefore,  a  neces- 
sity, as  in  the  North,  and  it  may  be  that  none  are  deposited  in  ordi- 
nary seasons.  The  late  fall  broods  consist  in  great  part  of  the  winged 
females,  while  in  spring,  and  especially  in  midsummer,  the  wingless  form 
predominates. 

In  the  act  of  birth,  the  hinder  end  of  the  young  Aphis  appears  first. 
The  young  is  slowly  protruded  from  the  body  of  the  mother,  until  only 
the  tip  of  the  head  remains  unexpelled.  During  the  process  aud  for 
a  few  minutes  after,  all  motion  outwards  ceases,  the  larva  remains  im- 
movable and  with  its  members  rigidly  applied  to  its  body.  Soon  it  dis- 
engages first  one  leg,  and  then  another,  until  all  are  Widely  extended. 
The  antennas  are  then  raised  and  brought  forward.  This  movement 
severs  the  contact  with  the  mother,  and  the  new-born  young  drops  upon 
its  feet,  in  the  full  possession  of  its  faculties  (which  it  makes  no  delay 
in  putting  to  the  test).  Within  ten  minutes  from  the  time  when  its  ex- 
pulsion from  the  mother  began,  it  is  quietly  feeding  by  h^r  side,  its 
sucking  beak  inserted  in  the  tender  tissues  of  the  leaf,  and  its  body 
rapidly  becoming  distended  with  the  juices  of  the  plant.  In  less  than  a 
week  after  its  birth,  the  plant-louse  has  become  adult,  and  begins  in  its 
turn  to  produce  young. 

Destructive  powers. — The  Orange  Aphis  attacks  the  tender  new  growth ; 
it  checks  the  growth  of  young  shoots,  and  curls  the  tender  leaves. 
With  such  a  direct  and  rapid  method  of  reproduction,  and  with  a  winged 
form  of  female  ever  present  to  spread  the  pest,  it  will  be  seen  that  this 
insect  presents  a  truly  formidable  aspect  as  a  destroyer.  Were  it  not 
held  in  check  by  numerous  enemies  and  parasites,  it  would  soon  ruin 
the  trees  by  destroying  the  new  growth,  and  render  the  culture  of  the 
orange  for  profit  an  impossibility. 

The  work  of  enemies. — Such,  however,  is  the  activity  of  its  enemies 
that  not  a  single  individual  Aphis  escapes  destruction,  or  is  allowed  to 
exert  to  the  full  its  reproductive  powers.  Colonies  rarely  attain  great 
size,  and,  in  fact,  are  frequently  exterminated  in  their  very  beginning, 
and  before  any  appreciable  injury  has  been  done. 

The  parasite. — The  principal  agent  in  accomplishing  this  result  is  a 
parasite,  whose  larva,  feeding  internally  upon  the  Plant-louse,  finally 
kills  it.  In  dying  the  body  of  the  Aphis  becomes  distended  to  the 
utmost,  assumes  a  globular  shape,  and  turns  to  a  dingy  yellow  color. 
In  drying  it  adheres  firmly  to  the  plant.  (Plate  XIII,  Fig.  3,  c.} 

Within  the  body-cavity  of  its  victim,  the  space  within  which  it  nearly 


HEMIPTEROUS    INSECTS    ON    ORANGE. 

fills,  the  larva  of  the  parasite,  a  little,  white,  footless  grub,  lies  concealed, 
curled  up,  with  its  head  touching  its  tail.  In  a  few  days  it  becomes  a 
pupa,  and  six  or  seven  days  later  it  emerges  through  a  large  hole  eaten 
in  the  dry  shell  of  the  Aphis,  as  'a  slender,  black,  wasp-like  fly.  with 
yellow  legs.  This  fly  is,  of  course,  very  minute,  being  r£-0-  inch  in  length . 
It  is  Trioxys  testaceipes  Cresson.*  (Plate  XIII,  Fig.  4.) 

Its  work  can  always  be  seen  where  the  Orange  Aphis  has  been  colo- 
nized for  a  week  or  more,  in  the  numerous  bloated  remains  of  the  Aphis, 
some  of  which  may  still  contain  the  parasite,  and  others  exhibit  the 
round  hole  through  which  it  has  made  its  exit.  (Plate  Xllf,  Fig.  3,  c 
and  fl.) 

Although  only  a  single  fly  is  bred  from  each  individual  of  the  plant- 
louse,  the  numbers  of  the  parasite  increase  more  rapidly  than  those  of 
its  victim,  and  as  every  Aphis  is  in  time  parasitized,  no  colony  long  es- 
capes extermination.  Were  it  not  for  the  facility  with  which  new  colo- 
nies can  be  started  at  a  distance,  through  the  flight  of  the  winged  females, 
this  species  of  Aphis  and  some  others  which  are  similarly  attacked 
would  suffer  complete  extinction  in  a  single  season. t 

Other  enemies'. — Numerous  other  enemies  combine  to  thin  the  numbers 
of  Plant-lice.  Those  which  have  fallen  under  observation  as  destroying 
the  Orange  Aphis  are  discussed  in  the  chapter  on  Predatory  Insects. 
Among  the  number  are  three  species  of  two  winged  flies  (Diptera), 
whose  larvae  subsist  exclusively  upon  Plant-lice,  and  several  species  of 
Lady  birds  (Coccinellidce]  which,  both  as  larvaB  and  as  perfect  beetles, 
rely  to  a  very  great  extent  upon  this  source  for  their  food  supply. 

Remedies  for  Aphis. — Moderately  strong  applications  of  whale-oil  soap, 
or  the  kerosene  washes  recommended  for  Scale-insect,  are  perfectly 
effective  in  killing  the  Orange  Aphis,  and  will  not  injure  the  young 
growth  upon  which  they  are  found. 

THE   OREEN  SOLDIER- BUG. 

(Raphigaster  hilaris.  Fitch.) 

[Fig.  74.] 

A  large  green  Plant-bug  is  sometimes  observed  to  suck  tender  shoots 
of  Orange,  causing  them  to  wither  and  die.  The  same  insect  is,  to  a 
certain  extent,  predaceous,  and  has  been  reported  as  sucking  Cotton 
Worms  and  other  insects,  for  which  reason  it  has  usually  been  classed 
among  beneficial  insects.  The  full-grown  bug  is  bright  green  in  color, 
with  a  very  fine  yellowish  line  around  the  entire  margin  of  the  insect, 
and  a  black  dot  at  the  outer  angles  of  each  abdominal  joint.  The  form 

*  Described  in  Report  of  the  Commissioner  of  Agriculture  for  1879,  p.  208. 

t  Mr.  Ashmead  has  described  another  minute,  black  parasite,  which  he  bred  from 
the  Orange  Aphis,  and  to  which  he  gives  the  name  Stenomesius  (?)  aphidicola.  (Orange 
Insects,  p.  67.)  Three  of  the  flies  issued  from  the  body  of  a  single  Aphis,  and  it  may 
be  a  secondary  parasite,  preying  upon  the  Trioxys. 


160  INSECTS    AFFECTING    THE    ORANGE. 

is  broadly  oval,  the  legs  slender  and  of  the  same  color  as  the  body. 

Length,  17mm  ($&  inch). 
The  following  account  of  ravages  committed  by  the  Kaphigaster  is 

from  a  correspondent  in  Florida.  It  affords  a  good  example  of  the 
sudden  rise  into  importance  as  a  pest  of  an  insect 
which  is  ordinarily  a  quite  insignificant  enemy  of  the 
Orange. 

*  *  *  "You  also  request  observations  on  the 
Green  Soldier-bug.  I  forward  by  same  mail  twigs  of 
the  orange  tree  injured  by  the  bug.  The  insects  are 
coupling  now.  The  females  will  soon  lay  the  eggs  in 
a  cluster  on  a  leaf,  straddling  over  them  while  laying. 

FIG.  73.—Raphigaster  J       & 

hiiaris.  (After  The  young  appear  in  the  latter  part  of  February  or 
the  first  part  of  March.  As  observed  by  the  eye  the 
young  are  black,  with  white  spots,  which  color  they  retain  until  nearly 
full  grown,  when  they  acquire  wings  and  change  to  a  bright  green. 
How  this  is  done  I  do  not  know.  They  mature  very  quickly,  and 
increase  with  surprising  rapidity,  continuing  to  breed  until  November. 
In  the  spring  and  early  summer  they  confine  their  attacks  principally 
to  garden  vegetables  and  succulent  weeds.  They  are  particularly 
abundant  on  tomato-vines,  egg-plants,  turnip-tops,  and  mustard,  sel- 
dom doing  much  damage  to  orange  trees  at  this  season.  When  pea- 
vines  are  well  grown,  about  or  a  little  before  the  time  of  blossoming, 
they  abandon  nearly  everything  for  the  pea- vines.  Last  year  they  to- 
tally destroyed  my  garden.  Not  one  tomato  came  to  perfection.  Where 
the  insect  had  inserted  its  sucking-tube  a  reddish-yellow  spot  ap- 
peared. When  cut  the  fruit  was  full  of  lumps  and  totally  devoid  of 
flavor.  The  tomato-vines  grew  so  enormous  a  crop  that  the  ground  was 
almost  covered  by  the  fallen  fruit.  Last  year  I  had  35  acres  planted  in 
cow-pea  vines,  which  bore  an  enormous  crop  of  peas ;  but  not  enough 
sound  peas  could  be  gathered  to  plant  5  acres  additional  land.  Later 
it  was  impossible  to  find  a  sound  pea.  I  attempted  to  turn  under  the 
vines,  but  so  luxuriant  was  the  growth  that  it  could  not  be  done.  To- 
wards the  end  of  August  the  pea -vines  were  dead  or  dying,  when  the 
bugs  swarmed  to  the  orange  trees,  killing  nearly  all  the  new  growth. 
Immense  numbers  were  killed  by  keeping  men  constantly  going  over 
the  grove,  shaking  the  trees,  and  killing  all  that  fell  on  the  ground. 
The  wingless  individuals  were  readily  killed,  but  the  larger  number 
of  the  mature  insects  saved  themselves  by  flight.  This  method  of  de- 
struction was  kept  up  until  the  middle  of  December,  by  which  time 
very  few  were  found.  On  very  cold  days  the  winged  insects  were  nearly 
dormant  and  could  not  fly.  I  have  the  trees  frequently  searched  now, 
but  rarely  find  the  bug.  The  number  of  the  insects  is  incredible. 
When  thoroughly  shaken,  the  ground  under  the  trees  would  be  alive 
with  the  fallen  insects,  and  two  days  later  just  as  many  would  be  found. 
I  despaired  of  getting  rid  of  them  until  the  cold  weather  commenced, 


HEMIPTEKOUS    INSECTS    ON    ORANGE.  H>1 

\vheu  I  found  the  number  rapidly  decrease  until  their  nearly  total  ex- 
tinction. 

"As  to  the  damage.  The  bug  first  attacks  the  latest  growth,  which 
wilts  and  droops  while  the  bug  is  sucking ;  in  a  few  days  the  shoot  is 
dead ;  the  same  eye  soon  sends  out  another  shoot  which  shares  the  fate 
of  its  predecessor,  and  so  on  until  the  eye  has  the  appearance  of  a  large 
bunch,  as  you  will  see  on  twigs  sent.  After  all  the  tender  growth  has 
been  destroyed  the  bug  inserts  his  sharp  sucking  tube  in  the  previous 
growth  which  has  nearly  hardened.  Here  I  can  only  give  you  the  facts 
and  my  theory ;  it  is  a  fact  that  the  insect  sucks  such  wood,  but  the 
damage  does  not  follow  so  quickly ;  but  very  soon  after,  on  such  wood 
known  to  be  sucked,  numerous  bumps  appear,  which  crack  and  exude 
a  sticky  sap,  white  at  first,  but  soon  a  rusty  red,  and  hard.  Later  on 
the  insects  suck  the  juice  from  fully-matured  wood  (an  inch  or  more  in 
diameter);  on  this  wood  the  bumps  do  not  appear,  but  the  same  kind 
of  sticky  sap  exudes  in  tears,  which  soon  harden  and  redden  and  are 
what  I  understand  by  "  red  rust."  That  the  cause  and  effect  are  strictly 
true  I  can  only  surmise,  but  this  much  I  and  my  men  have  seen  :  the  in- 
sects sucking  the  sap  as  stated  and  the  branches  where  sucked  having 
the  appearance  described.  In  the  winter  months  I  have  found  clusters 
of  the  bugs  on  the  stocks  of  the  buds,  two  inches  in  diameter,  and  always 
an  exudation  of  sap  at  these  places,  which  I  have  never  observed  to 
redden  as  in  the  instances  stated  above.  Why  this  is  so,  and  why  the 
insect  leaves  the  more  tender  bud  above  to  suck  the  sap  from  harder 
wood  nearer  the  roots,  I  can  offer  no  suggestion.  At  first  I  was  strongly 
inclined  to  think  that  red  rust  was  caused  by  soil-poisoning,  but  if  so, 
why  is  it  that  trees  have  grown  for  so  many  years  on  the  same  soil  and 
never  had  this  disease  until  the  introduction  of  the  Green  Bug  f  To 
illustrate :  When  I  bought  this  place  ten  years  ago  there  was  a  field  of 
five  acres  which  had  been  in  partial  cultivation  several  years,  and  on 
which  grew  spontaneously  the  tomato  and  mustard  plant,  the  two  plants 
on  which  the  insects  thrive  the  best.  (At  present  I  can  only  find  the 
insect  on  the  mustard.)  Since  my  purchase  I  have  kept  this  field 
constantly  growing  pea  vines,  as  well  as  the  forty  other  acres  which 
I  have  in  orange  trees,  thus  giving  every  encouragement  to  the  in- 
crease of  the  pest.  Adjoining  this  old  field  was  a  wild  orange  grove 
in  a  dense  forest.  Many  of  the  sour  stumps  had  large  sweet  buds, 
neither  the  buds  nor  sour  trees  giving  any  signs  of  the  red  rust  until 
the  winter  following  the  clearing,  and  after  a  crop  of  pea- vines  had  been 
grown  among  the  trees.  Now  the  trees  in  this  wild  grove  are  just  as 
much  damaged  as  in  the  old  field  adjoining.  Another  case  I  will  men- 
tion, and  not  trespass  further  on  your  patience.  Five  miles  distant  is 
the  grove  of  L.  Merritt,  a  wild  grove  budded.  The  buds  are  six  years 
old  and  ought  to  be  bearing  heavy  crops,  but  an  occasional  bloom  is  all. 
The  trees  have  been  in  an  unhealthful  and  udie  back"  condition  for  sev- 
eral years.  When  visiting  his  grove  in  the  fall  of  1881, 1  told  him  I  had 
6521  oi 11 


162  INSECTS    AFFECTING    THE    ORANGE. 

some  trees  in  the  same  condition  and  was  inclined  to  think  the  Green 
Bug  was  the  cause.  Since  that  time  he  has  persistently  hunted  the  bug, 
whipping  it  out  of  the  large  trees  with  poles,  and  killing  wherever 
found ;  also  he  stopped  planting  peas.  I  have  just  visited  his  grove  and 
found  bnt  two  twigs  damaged,  and  could  not  find  a  specimen  of  the 
bug.  The  trees  have  changed  so  remarkably  in  this  grove  that  it  was 
past  recognition.  Instead  of  a  dense  crop  of  dead  twigs  all  over  his 
grove,  as  at  a  previous  visit,  the  trees  had  nearly  doubled  in  size,  and 
had  a  very  large,  healthy  growth  of  branches  in  place  of  the  dead  twigs. 
I  hear  his  trees  are  now  in  profuse  bloom.  I  do  not  think  that  washes 
will  do  much  damage  to  the  bug.  Very  strong  whale-oil  soap  rarely 
kills.  Whale-oil  soap,  1  pound;  kerosene  oil,  1  pint;  water,  12  pints; 
sometimes  kills  when  sprayed  over  them,  nearly  always  when  immersed. 
Pure  kerosene  kills,  but  not  always  instantly. 

u  The  Green  Bug  has  a  parasite.  I  do  not  know  what,  but  I  frequently 
find  their  shells  with  the  inside  devoured.  Last  winter  I  buried  a  num- 
ber to  see  if  plowing  under  would  kill  them.  In  ten  days  none  were 
dead ;  in  three  weeks  20  per  cent,  were  dead,  nothing  remaining  but  the 
shells;  in  six  weeks  all  but  one  were  dead,  empty  shells  remaining. 
The  living  insect  I  put  in  a  bottle  with  a  little  earth  over  it,  hoping  to 
find  the  parasite,  but  unfortunately  in  about  ten  days  the  bottle  was 
broken,  the  Green  Bug  was  dead,  the  shell  empty  as  in  the  other  in- 
stances. 

"  At  present  the  insect  is  very  rare  here ;  if  found  at  all,  generally  on 
the  mustard  plant  or  weed  locally  known  as  nightshade.  Yesterday, 
while  showing  a  lemon  tree  to  some  visitors,  I  found  some  of  the  twigs 
drooping  and  remarked  it  looked  like  the  work  of  the  Green  Bug.  One 
was  found  under  a  leaf  close  to  his  work.  I  send  you  one  of  the  shoots. 
If  at  any  time  you  may  consider  the  subject  of  sufiBient  importance  to 

send  a  trained  observer  in  the  field,  I  will  be 
happy  to  see  him  here  and  place  every  facil- 
ity at  his  disposal."— [JAMES  FRANKLIN, 
West  Apopka,  Fla.,  January  31, 1883. 

THE  THICK-THIGHED  METAPODIUS. 

(Metapodius  femoratus.  Fab.) 
[Figs.  74  and  75.' 

A  large  dark-brown  bug,  emitting  an  un- 
pleasant odor  when  handled,  is  addicted  to 
sucking  the  juices  of  the  Orange,  attacking 
either  the  succulent  shoots,  the  flowers,  or 
FIG.  74.— Metavodius  femoratus.      the  fruit.    It  has  a  heavy,  clumsy  body,  with 

(After  Glover.)  .  ,  ,,   *"    ,,  1,1-1 

projecfrng  angles  to  the  thorax;  the  thighs 

of  the  hind  pair  of  legs  are  swollen  and  spiny,  and  the  shanks  of  the 
same  pair  are  flattened  with  jagged  edges.  The  adult  bug  is  nearly  one 


HKMLPTEROUS    IXSKCTS    OX    ORANGE.  J  63 

inch  long.     Although  sluggish  in  habit,  it  takes  wing  when  disturbed, 
and  flies  heavily  with  a  loud,  buzzing  noise. 

The  eggs  have  the  form  of  an  oval  casket,  triangular  in  section,  an  d 
are  quite  large;  3mm  (-ffo  inch)  in  length.  They  are  laid  singly  upon 
the  leaves  of  plants,  and  are  very  beautiful  objects, 

opalescent,  and  gleaming  like  a  drop  of  molten  gold.       ^       /> 

Figs.  76  a  and  b  show  the  egg  with  the  exit  hole  of     (. j)     c_V  j 

the  larva.  FIG.  75.— Egg  of  Met- 

The  young  make  their  exit  through  a  large  hole       forigXud?1* 
eaten  in  the  end.    The  young  bugs  are  brightly  va- 
riegated with  red  and  black,  and  their  bodies  bristle  all   over   with 
spines.    They  grow  more  somber  in  color  with  each  casting  of  the  skin, 
and  gradually  approach  the  adult  in  form  and  color. 

OTHER   SUCKING  BUGS. 

Metapodius  terminalis  Dallas. — This  species  can,  with  difficulty,  be 
distinguished  from  the  preceding,  and  the  same  account  may  be  given 
of  its  life  and  habits.  Both  species  of  Metapodius  vary  greatly  in  size, 
but  M.  terminalis  is  usually  the  larger  and  heavier  of  the  two.  M.fem- 
oratus  is  the  commoner  species  in  the  cotton-growing  States,  and  M. 
terminalis  is  more  abundant  in  the  orange  districts  of  Florida. 

Like  the  Green  Soldier  bug  (Raphigaster  hilaris),  the  species  of  Meta- 
podius are  known  to  prey  upon  other  insects,  particularly  upon  cater- 
pillars, which  are  filled  with  the  juiceS  of  plants,  and  there  may  be  often 
a  doubt  as  to  whether  they  are  injurious  or  beneficial. 

Euthochtha galeator  (Fab.).  (Fig.  77). — This  is  another  foul-smelling 
bug,  having  the  general  shape  and  appearance  of 
Metapodius.  It  is  however  a  smaller  and  lighter-col- 
ored insect;  and  the  shanks  of  the  hind  legs  are  slen- 
der. The  color  is  rusty-brown,  and  the  length  of 
the  adult  insect  is  16mm  (-ffe  inch). 

The  eggs  of  Euthochtha  galeator  resembles  those 
of  Metapodius,  but  are  only  one-third  as  large,  and 
are  laid  in  irregular  clusters  on  leaves  or  stems  of 
plants.  Their  color  is  a  ruddy  gold. 

The.- young  bugs  are  purple-black,  with  orange 
heads  and  crimson  abdomens.  Their  bodies  are 

irorv  crn  n  \r  FIG.  76.— Euthochtha  gal- 

kpiny.  eator.    (Original.) 

The  habits  of  this  bug  do  not  differ  from  those  of 
Metapodius.  It  is  a  very  common  and  often  a  very  destructive  insect. 

Other  species  of  plant-sucking  bugs  will  be  found  doing  occasional 
damage  to  tender  growth  on  Orange,  but  the  above  are  the  largest  and 
best  known  of  this  class  of  offenders. 


CHAPTER  XL 

INSECTS    AFFECTING    THE    BLOSSOM    AND    FBUIT,    AND 
SCAVENGER  INSECTS. 

INSECTS  AFFECTING  THE  BLOSSOMS. 

During  the  season  of  blooming,  insects  of  many  species  are  seen  flit- 
ting about  the  trees,  attracted  thither  by  the  fragrance  of  the  blossoms, 
and  feeding  upon  the  nectar,  which  they  secrete  in  abundance.  The 
greater  number  of  these  visitors  are  not  only  harmless  to  the  plant,  but 
are  even  of  the  greatest  service,  in  securing  the  fertilization  of  the  flow- 
ers, which  could  not  otherwise  be  accomplished. 

In  fact,  it  is  a  fair  inference  that  its  fragrance  and  its  sweets  serve 
no  other  purpose  in  the  economy  of  the  flower  than  to  call  to  its  aid 
friendly  insects  which,  in  their  restless  movements  from  flower  to  flower, 
bear  with  them  and  distribute  widely  the  fertilizing  pollen  dust. 

A  few  injurious  insects,  however,  frequent  the  blossoms.  These  are 
all  sucking-bugs,  and  they  cause  the  buds  to  blast  and  the  flowers  to 
fall  prematurely,  by  tapping  the  juices  from  their  stems  and  other  parts. 
Among  the  most  injurious  are  the  Green  Plant-bug,  Raphigaster  hilaris 
Fitch,  mentioned  in.  the  preceding  chapter,  and  the  Leaf-footed  Bug, 
Leptoglossus  phyllopus  (Linn.),  an  insect  which  will  be  considered  among 
those  especially  injurious  to  the  fruit. 

THBIPS  TRITICI  (?)  Fitch. 

[Fig.  77.] 

By  far  the  most  common  insect  found  in  orange  blossoms  is  a  little 
yellowish  bug,  whose  slender  body  measures  but  lmm  (^-5-  inch)  in 
length.  The  color  of  the  eyes  is  dark  red  or  brown ;  all  the  other  parts 
are  clear  honey  yellow.  The  adults  have  narrow  wings  fringed  with 
hairs.  These  hairs  are  characteristic  of  the  family,  and  replace  the 
membranous  parts  of  the  wing  of  most  other  insects. 

Notwithstanding  the  rudimentary  structure  of  their  wings,  these  in- 
sects are  capable  of  active  flight,  and  they  also  have  the  power  of  leap- 
ing. 

The  Orange  Thrips  inhabits  all  sweet-scented  flowers.  In  Lilies  and 
Eoses,  as  well  as  in  orange  blossoms,  they  sometimes  swarm  in  countless 
numbers,  and  do  great  damage  whenever  they  become  unduly  abundant. 

From  orange  blossoms  they  are  seldom  wholly  absent.  They  appear 
however  to  feed  for  the  most  part  upon  the  stamens  and  petals,  from 
164 


THE  COTTON  STAINER  OR  RED  BUG. 


165 


a,  Thrips  en- 
living  speci- 
c,  leg,  much 


which  they  suck  the  bland  and  fragrant  oil.  In  the  Orange,  these  parts 
of  the  flower  are  naturally  deciduous,  and  the  effect  of  the  attacks  of 
the  Thrips  is  to  hasten  their  fall ;  for  the  most  part  leaving  uninjured 
the.  fruit  producing  pistil,  which  moreover  will  not  fail  to  have  been 
fructified  with  the  pollen  which  these  active  midgets  distribute  over 
every  part.  Figure  5  on  Plate  XI  shows 
an  orange  blossom  infested  with  these  in- 
sects. The  Orange,  being  a  profuse  bloom- 
er, commonly  sets  more  fruit  than  it  can 
mature,  and  is  constantly  throwing  off  the 
surplus  from  the  time  when  the  buds  begin 
to  open  until  the  branches  are  relieved  of 
their  burdens  at  the  harvest.  A  large 
share  of  the  energy  of  the  tree  is  expended 
uselessly  in  the  fruit  which  falls  to  the 
ground  prematurely,  and  is  lost. 

The  operations  of  the  Thrips  are  confined 
to  the  flowers  and  therefore  tend  to  antici- 
pate and  prevent  this  waste,  by  thinning  a 

5    FIG.  77. -Thrips  trititi: 

out  the  superabundant  bloom  at  the  outset,     larged,  drawn  from 

,.         .  ,   ,  meiis;    b,    antenna; 

I"  or  this  reason  the  insect  is  more  often  a  enlarged.  (Original.) 
friend  than  a  foe  to  the  plant,  and  were  it  not  for  the  fact  that  its 
numbers  sometimes  increase  inordinately  and  to  such  an  extent  as  to 
effect  injuriously  the  forming  crop,  it  could  not  be  classed  among  the 
insect  enemies  of  the  Orange. 

The  Orange  Thrips  is  frequently  an  annoyance  to  persons  occupied  in 
flower  gardens  where  Lilies  and  Roses  are  in  bloom.  It  settles  upon  the 
hands  an.d  face,  and  bites  sharply,  although  without  poisonous  irrita- 
tion. 

Remedies. — A  moderately  strong  solution  of  whale-oil  soap,  one  pound 
to  four  or  five  gallons  of  water,  will  suffice  to  destroy  this  insect  if 
sprayed  upon  the  flowers  in  fine  spray.  Applications  of  pyrethrum 
will  also  effectively  reduce  their  numbers.  It  is  best  used  in  liquid,  de- 
livered in  fine  spray  upon  the  flowers.  One  ounce  of  the  powder  in 
each  gallon  of  water  is  sufficient  to  destroy  the  Thrips.  The  powder 
must  be  kept  suspended  by  frequent  agitation  of  the  liquid. 

INSECTS  AFFECTING  THE  FRUIT. 

THE    COTTON   STAINER   OR   RED   BUGr. 

(Dysdercus  suturellus  Herrich-Sch.) 
[Plate  XI,  Fig.  4.] 

This  Soldier-bug,  well  known  to  cotton -growers  in  Florida,  as  occa- 
sioning great  loss  by  puncturing  the  cotton  bolls  and  injuring  the  fiber, 
has  recently  been  found  destructive  to  oranges  by  puncturing  the  rind 


166  INSECTS  AFFECTING  THE  ORANGE. 

and  causing  the  fruit  to  drop  from  the  trees  and  rot  rapidly.  Attention 
was  first  called  to  this  new  habit  of  the  bug  by  letters  to  the  Depart- 
ment of  Agriculture  from  South  Florida,  in  December,  1879.  Since 
that  time  numerous  reports  have  been  received  of  excessive  injuries 
done,  especially  in  cases  where  cotton  is  raised  among  or  in  close  proxim- 
ity to  the  orange  trees. 

The  Cotton  Stainer  may  be  distinguished  from  all  other  Soldier-bugs, 
some  of  which  resemble  it  superficially,  by  its  rather  oval  form,  deep 
coral-red  color,  and  white  markings,  which  form  a  collar-ring  behind 
the  head,  and  a  border  upon  each  joint  of  the  body.  The  wings  of  the 
young  are  mere  pads  of  black  color,  but  in  the  adult  they  cover  the 
body,  and  are  crossed  with  narrow  lines  of  white,  forming  the  shoulder- 
straps,  from  which  these  insects  take  the  name  "  Soldier- bugs." 

Broods,  Habits,  &c. — There  are  many  broods  during  the  warm  months 
and  even  in  mid- winter  the  young  may  often  be  found. 

The  principal  food  of  the  bug  is  the  oil  of  cotton  seed,  to  obtain  which 
it  punctures  the  hard  seed-coats.  It  also  feeds  upon  the  seeds  of  other 
Malvaceous  plants,  although  the  precise  species  attacked  have  not  been 
ascertained.  In  winter  the  Bed  Bug  may  be  found  gathered  in  vast 
numbers  upon  the  heaps  of  waste  cotton  seed  about  the  gin  houses. 

The  eggs  are  oval  in  shape,  amber-colored,  with  a  pearly  luster,  and 
present,  under  a  lens,  a  pattern  of  closely  reticulated  lines.  They  have 
been  sent  to  the  Department  of  Agriculture  from  the  Indian  Eiver, 
Fla.,  in  April,  "  laid  in  a  group  of  twenty-one  upon  the  under  side  of  an 
orange  leaf."  *  That  this  disposition  of  the  eggs  is  normal  may  be  some- 
what doubtful.  In  winter  at  least,  and  around  gin  houses,  the  eggs  are 
dropped  loosely  in  the  sand,  and  among  the  heaps  of  cotton  seed  upon 
which  the  bugs  are  feeding. 

Attacks  upon  the  Orange. — In  January  and  February,  if  the  weather 
is  mild,  the  Eed  Bugs  desert  the  fields  where  they  have  lingered  upon 
the  dead  trash  and  waste  of  the  cotton,  and  suddenly  make  their  ap- 
pearance in  the  orange  groves.  Usually  this  takes  place  only  in  groves 
adjoining  fields  that  have  been  planted  in  cotton,  but,  as  they  are 
strong  flyers,  the  bugs  not  unfrequently  migrate  in  considerable  num- 
bers to  a  distance  even  of  several  miles. 

At  first,  only  adults  are  seen ;  these  at  once  attack  the  fruit  upon  the 
trees.  A  week  or  ten  days  later,  the  wingless  young  appear;  always 
upon  the  ground,  clustering  upon  the  fallen  fruit.  If  the  trees  are  not 
stripped  and  the  fruit  harvested  before  the  young  brood  become  adult 
and  acquire  wings,  the  entire  crop  will  be  lost.  Even  the  packing-house 
is  not  safe  from  invasion,  and  fruifc  is  apt  to  be  destroyed  after  it  has 
been  gathered  and  stored  in  the  bins. 

In  puncturing  the  orange,  the  bugs  insert  their  slender  sucking  beak, 
often  its  entire  length,  and  although  the  oil  of  the  rind  forms  their 
principal  food,  they,  nevertherless,  frequently  regale  themselves  with 

*  Report  of  the  Commissioners  of  Agriculture  for  1879,  p.  204. 


THE  COTTON  STAINER  OR  RED  BUG.          167 

draughts  of  juice  from  the  pulp  within,  and  are  sometimes  seen  to  suck 
the  juices  from  the  surface  of  split  or  injured  fruit,  tapping  it  with  the 
tips  of  their  probosces,  after  the  manner  of  flies. 

The  sucking-tube,  having  the  fineness  of  a  hair,  leaves  no  visible 
wound  upon  the  outside  of  the  fruit,  and  within  no  indication  of  its 
passage.  An  orange  which  has  been  attacked  therefore  shows  no  out- 
ward sign  of  injury  ;  nevertheless,  a  single  puncture  causes  it  to  drop 
in  a  few  hours  from  the  tree,  and  to  decay  in  one  or  two  days 

It  is  quite  useless  to  pack  for  shipment  to  a  distance  the  fruit  from  a 
grove  which  is  attacked  by  Ked  Bugs,  since  the  unsound  fruit  decays  in 
the  packages  and  soon  ruins  the  whole. 

Geographical  distribution. — The  Cotton  Stainer  is  an  inhabitant  of 
warm  climates.  It  is  found  in  great  abundance  in  the  Bahamas,  where, 
according  to  Mr.  E.  A.  Schwarz,*  it  annually  destroys  a  large  part  of 
the  cotton  crop.  From  the  Bahamas  or  other  West  India  islands  it 
may  have  been  introduced  into  the  extreme  southern  portions  of  the 
cotton  belt,  in  the  United  States.  In  Florida  it  has  not  been  reported 
as  occurring  north  of  Gainesville,  in  Alachua  County,  and  it  is  unknown 
to  cotton -planters  in  the  northern  part  of  that  county,  although  a  famil- 
iar insect  in  cotton  fields  everywhere  south  of  Gainesville. 

The  taste  for  oranges  appears  to  have  been  recently  acquired.  Mr. 
Glover,  in  the  Agricultural  Keport  for  1875,  gives  an  account  of  the  in- 
sect and  its  depredations  upon  cotton,  but  does  not  mention  it  among 
the  insects  noted  as  injurious  to  the  Orange.  It  should,  however,  be 
remarked  that  at  the  date  of  Mr.  Glover's  observations  comparatively 
few  bearing  orange  groves  existed  in  the  more  southern  portion  of  the 
State. 

In  1879  the  insect  first  attracted  the  attention  of  orange-growers, 
and  the  crop  of  that  year  was  injured  by  it  in  several  widely  separate 
portions  of  the  fruit  belt.  In  various  parts  of  the  State  it  has  since  be- 
come a  well  known  and  much  dreaded  pest,  and  has  occasioned  very  se- 
rious losses. 

Freedom  from  Attacks  of  Enemies. — The  Red  Bug  is  one  of  those  showy 
insects  which  are  probably  possessed  of  an  acrid  flavor,  disagreeable  to 
other  animals,  and  are  in  consequence  not  much  preyed  upon  by  ene- 
mies. Certain  it  is  that  the  Bed  Bug  is  not  eaten  by  fowls  or  other 
birds,  nor  has  any  enemy  of  its  own  class  been  hitherto  observed  to  at- 
tack it.  The  eggs  will  very  probably  be  found  to  have  parasites,  as  is 
the  case  with  most  other  Hemiptera,  but  none  have  as  yet  been  discov- 
ered 

Remedies  and  remedial  Measures. — In  default  of  aid  from  predatory 
animals  it  remains  for  man  alone  to  combat  this  pest.  Its  extermina- 
tion, in  view  of  its  gregarious  habits,  would  not  be  a  matter  of  great 
difficulty,  if  concerted  action  over  wide  areas  could  be  secured.  As  was 

*  Report  upon  Cotton  Insects,  Department  of  Agriculture.  1879.  Appendix  I,  p. 
347. 


168  INSECTS   AFFECTING    THE    ORANGE 

long  ago  suggested  by  Mr.  Glover,  in  his  report  above  mentioned,  the 
bugs  may  be  attracted  to  small  heaps  of  sugar  cane  trash,  with  which 
Paris  green  or  some  other  poison  should  be  mixed ;  or  the  bugs,  when 
collected  upon  piles  of  cotton  seed  in  winter,  may  be  destroyed  by 
drenching  them  with  boiling-hot  water.  The  experience  of  several  cot- 
ton-planters with  this  last  method  has  shown  it  to  be  practicable,  but 
to  be  effective  it  must  be  thoroughly  carried  out.  As  the  eggs  cannot 
all  be  reached  and  destroyed  by  the  hot  water,  the  operation  needs  to 
be  repeated  several  times  at  such  frequent  intervals  that  the  bugs  are 
not  allowed  to  reach  maturity  and  deposit  fresh  eggs. 

In  the  orange  grove  effective  traps  may  be  made  with  refuse  oranges, 
orange  peel,  &c.,  and  the  bugs,  when  thus  collected,  may  be  destroyed 
with  the  kerosene  washes  used  for  Scale-insects.  The  kerosene  solu- 
tions will  also  be  more  effective  than  hot  water  in  reaching  and  killing 
the  eggs. 

The  Bed  Bug  can  never  become  permanently  attached  as  an  enemy 
to  the  orange  tree,  since  the  fruit  which  alone  supplies  it  with  food 
lasts  only  a  few  weeks,  and  during  the  balance  of  the  year  the  insect 
must  seek  its  subsistence  elsewhere.  It  is  therefore  an  enemy  to  be 
dreaded  only  in  the  vicinity  of  cotton  fields  and  gin  houses,  in  districts 
where  cotton  is  largely  planted,  or  lastly,  and  with  less  probability,  in 
case  thickets  containing  numerous  wild  Malvaceous  plants  furnish  the 
bugs  with  a  supply  of  food  during  the  months  when  the  Orange  is  not 
in  fruit. 

In  South  Florida,  at  least,  the  planting  of  cotton  in  the  vicinity  of 
orange  groves  will  necessarily  be  abandoned.  Throughout  the  orange 
district  the  acreage  planted  in  cotton  has  never  been  large,  and  it  is 
for  many  reasons  likely  to  diminish  rather  than  to  increase.  With  the 
abandonment  of  cotton  planting,  the  Red  Bug  may  be  expected  to  dis- 
appear from  this  region. 

THE   LEAF  FOOTED  BUG. 

(Leptoglossus  pliyllopus  Linn.) 
[Fig-  78.] 

This  is  a  chocolate-brown  bug,  three  quarters  of  an  inch  in  length. 
It  has  the  shanks  of  the  hind  legs  very  broadly  flattened,  and  the  edges 
jagged,  resembling  a  tattered  leaf  fragment;  hence  its  popular  name. 
The  markings,  a  white  bar  across  the  folded  wings,  and  a  small  spot  of 
the  same  color  on  each  of  the  leaf- shaped  shanks,  are  very  character- 
istic, and  render  this  species  easily  distinguishable  among  other  bugs 
of  the  same  family.  The  young  bugs,  with  undeveloped  wings,  show 
the  brighter  red  color  of  the  body,  and  do  not  acquire  the  peculiar  flat- 
tened hind  shanks  until  nearly  adult. 

The  eggs  are  golden  brown  in  color,  and  are  laid  in  a  single  row  01 
chain,  along  a  stein  or  tbe  leaf  rib  of  a  plant.  They  are  cylindrical. 


THE    MEXICAN    FRt'IT    WORM.  169 

flattened  on  the  under  side  and  at  the  ends,  and  are  closely  applied  end 
to  end,  forming-  a  stiff,  cylindrical  rod  in  which  each  egg  appears  as  a 
joint  or  cell.  The  young  issue  through  a  large  bole  eaten  in  the  upper 
side  of  the  egg. 

The  normal  food  of  this  bug  in  the  South  is  a  large  Thistle,  upon  the 
heads  of  which  young  and  old  may  be  found  clustering  and  sucking  the 
juices  of  the  plant.  The  young  bugs  are 
rarely  found  in  Florida  except  upon  the 
Thistle,  or  similar  succulent  plants,  but 
the  adult  bugs,  being  strong  on  the 
wing,  make  excursions  to  very  great 
distances,  and  enter  the  orange  groves 
at  the  time  of  blooming,  to  suck  the 
opening  buds  or  tender  shoots.  Again 
they  may  be  iound  attacking  the  ripen- 
ing fruit,  and  causing  it  to  drop  in  con- 
sequence of  their  punctures.  The  dam- 
age done  in  this  way  is  often  very  con- 
siderable, and  in  some  reported  cases 
has  amounted  to  an  almost  total  loss  of 
the  crop. 

.....      „        .,        ,.  ~F\G.l%.—Lepto(jlossuspTiyllopus.  (Original.) 

Like  many  bugs  of  this  iamily,  they 

are  particularly  active  in  hot  weather,  and  it  is  then  very  difficult  to 
get  within  reach  of  the  adult  insects,  as  they  take  wing  readily  and 
fly  away.  But  in  cool  or  cloudy  weather  they  are  more  sluggish  and 
may  easily  be  found  and  killed  by  hand-picking,  or  by  knocking  them, 
into  a  bag  or  net  with  a  stick. 

Where  Thistles  are  abundant  this  bug  is  sure  to  prove  a  serious 
pest,  as  the  Thistles  form  a  propagating  ground  from  which  they  spread 
to  a  distance.  A  single  large  patch  of  Thistles  has  been  known  to  infect 
a  wide  area,  but  when  these  were  cut  down  and  destroyed,  the  bugs  in 
time  disappeared  from  the  groves  in  the  neighborhood  and  gave  no  fur- 
ther trouble. 

THE  MEXICAN  FRUIT  WORM. 

An  unknown  worm,  of  perhaps  an  inch  in  length,  is  said  to  be  very 
destructive  to  oranges  in  Mexico.  It  penetrates  the  fruit  to  the  core, 
and  feeds  upon  the  pulp,  both  fresh  and  after  it  has  begun  to  rot  in  con- 
sequence of  the  attack. 

A  few  years  ago  a  very  large  percentage  of  the  oranges  sold  in  the 
markets  at  Yera  Cruz  contained  these  worms,  and  were  entirely  uneat- 
able. It  is  said  that  no  mark  upon  the  outside  of  the  fruit  reveals  the 
presence  of  the  worm  within, 

In  the  absence  of  any  definite  knowledge  in  regard  to  this  insect,  it 
is  only  possible  to  point  out  the  danger  of  its  introduction  first  into  the 


170 


INSECTS   AFFECTING   THE   ORANGE. 


groves  of  Louisiana  and  then  into  Florida  by  means  of  oranges  im- 
ported from  Mexico  at  the  port  of  New  Orleans.* 

SCAVENGER  INSECTS. 

INSECTS  FEEDING  UPON  DEAD  WOOD  AND  BARK. 


TREE-INHABITING  ANTS. 

Several  species  of  ants  which  live  in  trees  make  their  nests  in  the  dead 

wood  of  the  Orange,  more  especially 
in  twigs  and  smaller  branches  which 
have  been  killed  by  frost  The  wood 
of  these  winter-killed  shoots  being 
corky  and  easily  excavated,  they  are 
frequently  hollowed  out  by  ants,  and 
serve  as  places  of  deposit  for  their 
eggs  and  young. 

Cremastogaster  lineolaia  (Say).  [Fig. 
79.J  This  is  one  of  the  commonest  of 

^Oly^  ^"^^~^\  ^e  sPec^es  which  have  the  above 

^  '  '  habit.  It  is  jet-black,  shining,  and 

has  a  broadly  triangular  abdomen, 
which  it  elevates  in  a  threatening 
manner  when  excited. 

The  species  is  very  abundant  upon 
Oak  and  other  forest  trees.  It  at- 
tends the  various  honey-producing 
insects  found  upon  trees  and  feeds 
upon  their  honey-dew  without  doing 
any  violence  to  the  insects  them- 
selves. Its  presence  upon  the  orange 
tree,  therefore,  is  of  very  slight  im- 
portance either  for  good  or  evil. 

Other  species  of  ants  which  have 
been  observed  to  make  their  nests  in 
orange  twigs  probably  have  the  same 
habits,  and  if  not  positively  benefi- 
cial, certainly  do  little  harm  to  the 
tree,  and  none  of  them  gnaw  or  do  injury  to  the  growing  parts. 

*An  Australian  inoth,  Ophideres  fullonica  (L.),  is  said  to  pierce  oranges  with  its  pro- 
boscis and  suck  the  juices  of  the  pulp.  In  an  article  entitled  "Les  Ldpidopteres  & 
Trompe  Perforante,  Destructeurs  des  Oranges,"  M.  J.  Kiinckel  describes  and  figures 
the  proboscis  of  this  insect,  and  shows  its  special  adaptation  to  this  end.  (Comptea 
Rendus  des  Stances  de  1'Acade'mie  des  Sciences,  Paris,  30  Aout  1875.) 


FIG.  79. — Cremastogasterlineolata:  a,  b,  worker 
major;  c,  head  of  do.;  d,  female;   e, 
/,  worker  minor.     (After  McCook.) 


INSECTS    FEEDING    ON    BARK   AND    DEAD    WOOD. 


171 


THE    ORANGE   SAWYER. 

(Elapliidion  inerme  Newman.) 

4 

This  insect  has  been  described  in  Chapter  VIII,  and  is  there  shown  to 
be  injurious,  under  a  careless  sys- 
tem of  pruning,  in  which  the  ends 
of  branches  are  left  untrimraed, 
with  sufficient  dead  wood  to  at- 
tract the  parent  beetle,  but  not 
enough  to  support  the  larvae ;  so 
that  the  latter  are  driven  by  hun- 
ger to  enter  and  feed  upon  the  liv- 
ing wood.  It  appears,  therefore, 
that  under  natural  conditions  this 
beetle  is  merely  a  scavenger.  Its 
grub  feeds  upon  the  wood  of  many 
trees,  and,  like  most  members  of 
the  Longicorn  family,  thrives  only 
upon  diseased  and  devitalized  tis- 
sues, or  upon  wood  which,  though 
dead,  has  not  entirely  parted  with 
its  sap  and  become  hard  and  dry. 

Fig.  80  represents  the  larva  of 
E.  parallelum,  a  closely  allied  spe- 
cies, having  the  same  habits  as  the  Orange  Sawyer,  but  which  lives  in 
the  Oak,  &c. 

THE  ORANGE  FLAT-HEADED  BORER. 

(Chrysobothris  chrysoela  111.) 
[Plate  XIV,  Fig.  8.] 

Dead  twigs  and  branches  of  Orange  are  frequently  found,  upon  which 
the  bark  is  cracked  and  loosened,  so  that  it  comes  off  at  a  touch,  bring- 
ing away  with  it  considerable  dust  from  the  wood  lying  immediately 
beneath,  a  thin  layer  of  which  has  been  reduced  to  powder.  When  the 
loose  bark  and  sawdust  are  removed,  the  surface  of  the  branch  presents 
an  eroded  appearance,  indicating  the  path  of  an  insect.  The  edges  of 
the  track  form  a  succession  of  semicircular  curves,  as  if  made  by  the  sweep 
of  a  miniature  scythe.  It  is,  in  fact,  the  gallery  of  an  extremely  thin- 
bodied  grub  or  sawyer,  made  partly  in  the  bark  and  partly  in  the  wood, 
and  always  filled  with  comminuted  wood,  which  has  passed  through  the 
digestive  organs  of  the  grub,  and  has  been  voided  and  deposited  be- 
hind it  as  the  insect  made  its  way  through  the  wood.  The  cell  in  which 
the  pupa  is  formed  is  excavated  in  the  solid  wood.  It  lies  parallel  with 
but  beneath  the  gallery,  with  which  it  is  connected  at  one  of  its  ex- 


ant 

FIG.  80.  —  Elaphidion  parallelum :  a,  larva  from 
above ;  b,  from  beneath  ;  /,  ligula-like  process, 
behind  the  labial  palpi ;  Ibr,  labrum  ;  mx,  maxilla ; 
mx',  meutum  ;  ant,  antemia.  (After  Packard.) 


172  INSECTS   AFFECTING   THE    ORANGE. 

tremities.  The  short  passage  connecting  the  pupa  cell  with  the  gallery 
is  carefully  filled  with  wood  dust,  firmly  packed  in  place,  so  that  even 
when  the  bark  is  removed  and  the  gallery  exposed  to  view,  the  mouth 
of  the  cell  remains  concealed,  and  is  only  disclosed  upon  the  exit  of  the 
beetle.  The  cell  is  then  found  to  be  broad  and  shallow,  oval  in  outline, 
and  lined  with  a  silken  layer  that  is  almost  invisible  by  reason  of  its 
delicacy. 

The  Beetle. — In  spring  or  early  summer  there  issues  a  very  handsome 
little  beetle,  broadly  oval  in  form,  and  about  8IU1U  (-^  inch)  in  length. 
The  colors  of  the  body  are  metallic  bronze,  greenish  below  and  purple 
above.  Upon  the  wing-cases  are  ten  large  spots  of  brilliant  emerald 
green. 

The  Larva. — The  form  of  the  larva  is  characteristic  of  the  family.  It 
has  the  second  joint  greatly  enlarged,  forming  a  broad,  flattened  disk, 
into  which  the  first  joint  and  the  small  head  are  sunken,  only  the  black 
tips  of  the  jaws  appearing  beyond  the  cleft  in  the  anterior  border.  The 
succeeding  joints  form  a  tail-like  body,  which  is  less  than  half  as  wide 
as  the  enlarged  joint.  In  life  the  body  is  usually  curved  strongly  to  one 
side  or  the  other,  giving  it  still  more  the  appearance  of  an  appendage. 
The  large  joint  is  covered  upon  both  of  its  flattened  faces,  with  minute, 
horny  denticulatious,  which  serve  to  hold  the  body  firmly  against  the 
smooth  walls  of  the  burrow  while  the  jaws  are  forced  into  the  wood. 

The  body  of  the  lava  is  naked,  or  with  scattered  and  nearly  invisible 
hairs,  soft,  white,  and  without  legs.  It  moves  but  slowly  in  its  gallery, 
and  only  by  means  of  the  contraction  and  expansion  of  the  enlarged 
flattened  joint. 

The  pupa  presents  no  especial  peculiarities,  and  merely  outlines  the 
form  and  members  of  the  perfect  beetle. 

Habits  and  Life-history. — The  eggs  are  laid  upon  the  bark  of  dead 
orange  branches,  and  probably  also  on  Hickory  and  other  close- textured 
woods.  The  branches  attacked  are  invariably  dead  and  quite  dry,  but 
still  retaining  their  bark.  The  larva  never  penetrates  the  living  parts 
of  the  tree,  and  will  perish  of  hunger  if  the  supply  of  dead  wooft  and 
bark  is  not  sufficient  for  its  support.  The  Iarva3  of  different  ages  are 
found  during  the  latter  part  of  summer.  Some  of  them  change  to  pupae 
in  the  fall,  while  others,  after  excavating  their  pupa  cells,  occupy  them 
during  the  winter  as  Iarva3,  and  undergo  their  transformations  in  the 
spring.  Of  those  which  pupate  in  the  fall,  some  become  perfect  insects 
before  cold  weather,  and  beetles  will  be  found  in  the  cells  as  early  as 
January;  they  do  not,  however,  leave  their  retreats  until  summer 
weather  has  begun.  The  beetles  continues  to  appear  as  late  as  May 
and  June. 

As  a  scavenger,  assisting  in  the  return  to  earth  and  air  of  the  dead 
and  useless  material  that  has  been  assimilated  by  the  plant,  this  can  only 
be  considered  a  useful  insect,  and  certainly  one  that  is  incapable  of  do- 
ing any  injury  to  the  orange  tree,  either  by  causing  disease  or  by  direct 
loss  of  wood  or  bark. 


INSECTS    FEEDING    ON    BARK    AND    DEAD    WOOD.  173 

THE   CYLINDRICAL  BARK-BORER. 

(Rypothenemus  eruditus  Westwood.'i 
[Plate  XIV,  Fig.  1.] 

This  minute  beetle  is  frequently  an  object  of  suspicion  from  its  pres- 
ence in  great  numbers  in  twigs  killed  by  dieback.  Jt  is  1.6llim  (T^  inch) 
in  length,  dark  brown  in  color,  cylindrical,  and  obtusely  rounded  at 
both  ends.  Under  a  lens  it  has  a  hoary  appearance,  owing  to  the  short, 
stout  hairs  with  which  all  parts  of  the  body  are  clothed.  On  the  wing- 
cases  these  stout  hairs  are  arranged  in  numerous  longitudinal  rows, 
and  the  interspaces  between  the  rows  of  hairs  are  deeply  and  coarsely 
pitted  or  punctate.  The  head  is  directed  downwards  and  is  not  seen 
from  above.  The  declivity  of  the  thorax  above  the  base  of  the  head  is 
covered  with  minute  tooth  like  asperities. 

The  larva  as  well  as  the  beetle  itself  feeds  upon  dry  corky  wood  and 
bark  of  various  trees,  and  upon  plants  having  soft  or  porous  tissues,  such 
as  are  found  in  the  Grape  and  many  other  vines.  They  riddle  the  dead 
wood  and  bark  with  galleries,  and  quite  rapidly  reduce  it  to  powder. 

In  the  Orange  their  galleries  are  seldom  found  in  solid  wood,  but  in- 
variably occur  in  the  bark  and  in  small  twigs  when  from  any  cause 
they  have  been  deprived  of  life  and  become  dry.  Succulent  shoots 
killed  by  frost  or  disease  attract  the  beetles  in  great  numbers  as  soon 
as  they  become  dry  and  brittle;  but  no  part  of  the  tree  is  attacked  as 
long  as  it  retains  its  sap  or  remains  moist.  The  insect  is  therefore  en- 
tirely harmless  in  its  operations,  and  beneficial  rather  than  injurious  to 
vegetation. 

Life-history. — The  larva  of  Hypothenemus  is  a  minute  white  grub, 
with  a  thick  and  stout  cylindrical  body,  strongly  curved,  and  without 
legs  or  other  organs  of  locomotion,  save  that  by  the  contractile  move- 
ments of  its  body  joints,  it  is  enabled  to  crawl  slowly  through  its  bur- 
rows. The  head  is  small,  and  all  the  parts  surrounding  the  mouth,  with 
the  exception  of  the  pair  of  stout  jaws,  are  so  minute  that  they  can  be 
discerned  only  after  careful  dissection  upon  the  stage  of  a  microscope. 

The  family  Scolytidw,  to  which  this  beetle  belongs,  number  in  the 
United  States  at  least  two  hundred  species,*  divided  among  numerous 
genera.  All  of  them  have  wood  boring  habits,  and  members  of  the  same 
group  resemble  each  other  closely.  The  Iarva3  of  the  different  species 
are  for  the  most  part  indistinguishable ;  the  points  of  difference,  if  any 
exist,  are  so  minute  that  they  have  escaped  observation. 

The  pupa  is  formed  in  a  little  cell,  walled  off  from  the  galleries  made 
by  the  larva.  It  shows  the  form  of  the  beetle,  and  is  white,  turning 
brown  as  it  approaches  maturity. 

The  eggs  are  white,  oval  in  shape,  and  are  scattered  by  the  mother 
either  singly  or  in  little  groups  at  random  in  the  galleries  which  she 
excavates. 

"About  one  hundred  aud  seventy  species  have  been  described. 


174  INSECTS   AFFECTING   THE    ORANGE. 

Broods. — There  does  not  appear  to  be  any  definite  number  of  broods. 
The  beetles  are  rather  more  abundant  in  spring  and  early  summer,  and 
the  iarvje  in  midsummer  and  winter ;  but  the  insect  propagates  at  all 
seasons,  and  its  development  is  only  interrupted  by  frosty  weather.* 

OTHER  BEETLES  BOEING  IN  ORANGE  WOOD. 

Tn  addition  to  the  species  hitherto  mentioned,  which  are  so  frequently 
found  in  the  wood  of  the  Orange  that  may  properly  be  considered  a 
part  of  the  regular  fauna  of  the  tree,  there  are  numbers  of  other  wood 
eating  Coleoptera,  which  are  less  obviously  connected  with  the  plant, 
but  occasionally  feed  upon  it,  and  have  been  bred  from  the  dead  limbs 
and  twigs.  A  few  species  demand  notice. 

Two  of  these,  Leptostylus  Mustus  Lee.,  and  Hyperplatys  maculatus 
Hald.,  are  closely  allied  Lougicorn  beetles,  and  belong  to  a  group  of 
that  family,  all  the  species  of  which  are  wood- scavengers,  feeding  only 
upon  dead  portions  of  plants. 

Leptostylus  Mustus  Lee.  (Plate  XIV,  Fig.  2)  is  an  ash-gray  insect,  with 
a  rather  broad  and  flattened  body,  the  upper  surface  of  which  is  broken 
by  minute  elevated  points.  The  terminal  third  of  the  wing-cases  is 
darker  in  color,  and  this  darker  portion  is  separated  from  the  remainder 
by  sharply  defined  lines  meeting  in  a  point  upon  the  center  line. 
Length,  7.6mm  ( x%  inch).  The  antenna  are  one- third  longer  than  the  body. 

The  larvae  are  cylindrical,  slightly  flattened  sawyers,  having  the  first 
joint  of  the  body  somewhat  enlarged;  the  head  is  very  small,  and  almost 
concealed  within  the  enlarged  first  joint;  color  pallid,  except  the  jaws, 
which  are  chitinous  brown. 

The  larva  tunnels  dead  branches  the  wood  of  which  is  not  too  hard, 
or  excavates  galleries  under  dead  bark  of  the  Orange,  filling  up  the 
passage  behind  it  with  tightly  packed  sawdust.  It  transforms  to  the 
perfect  beetle  at  the  end  of  its  gallery,  in  a  cell-like  cavity  formed  by 
the  movements  of  the  larva  in  the  surrounding  mass  of  loose  woody 
fragments. 

The  beetles  appear  in  April  and  May,  and  there  is  a  supplementary 
brood  in  September,  although  the  perfect  insects  frequently  remain  in 
their  cells  all  winter. 

Hyperplatys  maculatus  Hald.  (Plate  XIV,  Fig.  3)  is  a  somewhat  smaller 
beetle  than  the  preceding,  and  its  form  is  more  slender  and  flattened. 
The  color  of  the  body  is  ash-gray,  spotted  above  with  dots  of  velvet 
black,  and  with,  a  large  splash  of  the  same  on  each  wing-case  near  the 
tip;  the  legs  are  black,  variegated  with  red;  the  antennae  are  much 
longer  than  the  body,  and  are  also  variegated  red  and  black.  Length, 
6mm  (-nnr  inch). 

In  its  habits  this  beetle  does  not  differ  from  Leptostylus  biustus,  and 
the  larvae  of  the  two  species  resemble  each  other  closely. 

*  Further  notes  concerning  the  habits  of  this  beetle  will  be  found  in  an  article  by 
Mr.  E.  A.  Schwarz,  in  the  Bulletin  of  the  Brooklyn  Ent.  Soc.,  vol.  VII,  page  84. 


INSECTS   FEEDING    ON   DECAYING   FRUIT.  175 

AmaurorMnus  nitens  Horn. — This  is  a  small,  elongate  beetle,  shining 
black  in  color,  and  provided  with  a  short  beak  or  snout. 

It  is  not  uncommonly  found  boring  in  winter-killed  twigs  of  Orange, 
or  in  portions  of  wood  and  bark  which  have  been  softened  and  rendered 
porous  by  the  action  of  a  wood-destroying  fungus.  The  larva  and  other 
immature  stages  have  never  been  observed. 

The  family  of  the  Cossonidce,  to  which  this  beetle  belongs,  comprises 
small  insects,  all  of  which,  as  far  as  their  habits  are  known,  feed  upon 
dead  bark,  pith,  or  spongy  wood,  and  fungus.  The  above  species  is  as 
harmless  as  others  of  its  family.  It  enters  and  feeds  upon  the  wood 
after  all  life  has  left  it,  and  is  probably  attracted  by  the  presence  of  a 
fungus  to  the  diseased  portions  which  it  infests. 

INSECTS  FOUND  IN  WOUNDS  AND  FOOT-EOT  SORES. 

Bleeding  wounds,  especially  sores  in  which  fermentation  of  the  sap 
is  taking  place,  are  very  attractive  to  insects  of  many  kinds.  It  there- 
fore frequently  happens  that  some  harmless  sap-feeding  insect  is  mis- 
taken, by  those  who  are  ignorant  of  its  habits,  for  the  originator  of  the 
mischief. 

A  list  of  insects  which  through  misapprehensions  of  this  sort  have 
been  reported  by  orange-growers  as  causing  foot-rot,  includes  (1)  Sap- 
feeders  ;  beetles  of  the  families  Nitidulidce  and  Monotomidce,  which 
live  in  all  stages  upon  the  fermenting  sap  of  plants.  (2)  Euphoria  sepul- 
chralis  (Fab.),  a  Lamellicorn  beetle,  which  is  not  unfrequently  found 
sipping  the  sap;  and  the  white,  thread-like  maggots  of  small  flies,  which 
almost  invariably  make  their  appearance  in  sour  sap.  (3)  Midas  cla- 
vatus  Drury  (Plate  XIV,  Fig.  4),  a  large  black  fly,  with  an  orange- colored 
band  on  the  abdomen,  which  hovers  about  the  diseased  spots  in  order 
to  prey  upon  flies,  and  other  insects  attracted  to  the  flowing  sap.  (4) 
Scavengers,  feeding  upon  the  dead  wood  and  bark;  these  include  besides 
the  Termites,  of  which  mention  has  been  made  in  a  previous  chapter, 
several  sawyers  or  Iarva3  of  beetles  belonging  to  the  Longicorn  family, 
but  of  unknown  species.  (5)  A  number  of  minute  beetles,  Lcemo- 
plilceus,  LathridiuSj  Sacium,  Hesperobcenus,  and  others,  commonly  found 
under  the  dead  bark  of  trees,  after  it  has  been  loosened  by  the  gnaw- 
ing of  wood-eating  insects.  They  are  for  the  most  part  predatory  upon 
the  other  insect  inhabitants  of  these  lurking  places,  and  their  larvae 
may  be  found  pursuing  and  devouring  the  young  of  the  wood-scaven- 
gers, or  even  making  war  upon  each  other. 

INSECTS  FEEDING  UPON  DECAYING  FEUIT. 

SAP-BEETLES.    (Family  Nitidulidce.) 

Two  species  of  this  sap-loving  family  are  so  constantly  found  in  rot- 
ting oranges,  and  also  in  injured  fruit,  before  it  has  fallen  from  the  tree, 
as  sometimes  to  occasion  the  suspicion  that  they  are  responsible  for  the 
splitting  of  the  rind  at  the  time  when  the  orange  is  maturing.  It  has, 


176  INSECTS   AFFECTING    THE    ORANGE. 

however,  been  ascertained  that  these  beetles  only  attack  the  orange 
when  the  rind  has  been  ruptured  by  accident  or  disease,  or  when  it  is 
softened  by  decay. 

Carpophilus  mutilatus  (Fab.;  Plate  XIV,  Fig.  5)  is  dull  red-brown, 
with  the  disk  of  the  wing-covers  lighter;  the  latter  do  not  reach  the  end 
of  the  body,  and  leave  the  last  two  joints  exposed  to  view.  The  length 
of  the  adult  is  2.8mm  (ffe  inch). 

The  larva  has  a  rather  long,  cylindrical  body  divided  into  simple 
rings  or  joints  ;  the  color  is  dull  white,  vrith  the  head  and  first  joint  of 
the  body  brown  ;  the  last  joint  terminates  in  a  pair  of  notched  spines  or 
conical  projections  toothed  at  the  base. 

Epurcea  cestiva  (Linn. ;  Plate  XIV,  Fig.  6)  is  shining,  uniformly  yellow- 
ish brown;  the  wing-covers  nearly  cover  the  body,  leaving  only  the  tip 
of  the  last  joint  exposed.  The  insect  is  smaller  than  the  preceding; 
length,  2.2">'»  (Tfo  inch). 

The  habits  of  these  two  beetles  are  very  similar  and  they  are  al  ways 
found  together,  although  the  Epura3a  is  usually  present  in  greater  num- 
bers than  the  Oarpophilus. 

In  September  they  appear  in  great  numbers  in  every  grove  where 
rotting  fruit  is  allowed  to  remain  upon  the  ground.  The  active  Iarva3, 
as  well  as  the  perfect  insects,  soon  swarm  in  the  rotting  fruit,  and  being 
active  in  flight,  the  beetles  seek  out  and  penetrate  the  split  or  injured 
fruit  even  upon  the  trees. 

They  can,  however,  scarcely  be  considered  injurious  insects,  as  they 
are  not  capable  of  penetrating  the  fruit  of  their  own  accord,  but  merely 
take  advantage  of  any  chance  opening  to  gain  admittance  to  the  pulp. 
The  effect  of  their  attack  is  simply  to  hasten  by  some  hours  the  decay 
which  inevitably  follows  any  external  injury  to  the  rind. 

The  pupa3  are  formed  in  the  earth ;  those  of  rEpurraa  just  beneath  the 
surface,  and  those  of  Oarpophilus  at  a  depth  of  several  inches.  They 
occupy  small  oval  cavities  made  by  the  movements  of  the  larva. 

Development  in  these  beetles  is  very  rapid ;  the  interval  between 
broods  does  not  exceed  twenty -five  days.  Of  this  period,  about  ten 
days  is  passed  as  larva  and  eight  or  nine  days  as  pupa;  the  remaining  six 
or  seven  days  are  occupied  by  the  beetles  in  coupling  and  ovipositing, 
and  by  the  hatching  of  the  eggs. 

WINE  OK  POMACE  FLY  OF  THE  ORANGE. 

Associated  with  the  two  beetles  mentioned  above  is  a  little  pale  yel- 
low fly  of  a  kind  that  is  familiar  to  most  housekeepers  under  the  name 
of  u wine  fly"  or  "vinegar  fly."  It  has  a  rosy-red  head  and  brick-red 
eyes ;  the  joints  of  the  abdomen  are  bordered  above  with  black.  Length 
of  the  fly,  2.6"»n  (•&  inch). 

The  maggots  of  this  fly  are  found  in  great  numbers  in  company  with 
the  larvae  of  the  sap-beetles  in  rotting  oranges,  through  the  pulp  of 


INSECTS   FEEDING    ON   DECAYING   FRUIT.  177 

which  they  burrow  in  every  direction  and  greatly  increase  the  rapidity 
of  decay. 

The  maggot  is  transparent  white,  with  a  cylindrical  body,  thickest  at 
the  posterior  end,  and  tapering  to  a  sharp  point  at  the  head ;  the  body 
joints  are  very  prominently  ringed.  At  the  posterior  end  a  pair  of 
projections  form  the  principal  breathing  organs.  The  head  ends  in  a 
pair  of  hooked  jaws,  which  have  the  raking  movement  common  to  most 
fly  larvae.  The  dark  color  of  the  jaws  and  frame- work  which  consti- 
tutes their  base  renders  them  visible  through  the  transparent  walls  of 
the  body. 

In  pupating,  the  larva  enters  the  earth  a  short  distance,  or  remains 
attached  to  the  under  side  of  the  orange  as  it  lies  upon  the  ground. 
The  larva  contracts  and  its  skin  hardens,  forming  a  casket-shaped 
puparium,  about  one-third  as  wide  as  long.  The  puparium  is  chest- 
nut-brown in  color ;  it  retains  the  breathing-tubes  of  the  larva,  but 
is  distended  and  slightly  altered  in  form  by  the  hardening  of  all  the 
parts. 

The  wine-fly  undergoes  all  its  transformations  within  two  weeks. 
This  rapidity  of  development  is  evidently  necessary,  as  the  insect  is 
dependent  upon  the  juices  of  the  orange,  not  only  for  its  subsistence  in 
the  larva  state,  but  also  for  the  moisture  necessary  to  sustain  life  in  the 
pupa. 

OTHER  SPECIES. 

The  two  beetles  and  the  wine-fly  above  mentioned  sometimes  become 
annoying  pests  in  the  packing-house  when  piles  of  decaying  fruit  are 
allowed  to  remain  about  the  premises,  but  are  easily  banished  by  clear- 
ing away  the  refuse,  and  maintaining  cleanliness.  In  the  grove,  if  the 
dropped  oranges  are  picked  up  i  egularly,  and  the  ground  about  the 
trees  kept  clean,  these  insects  will  rarely  make  their  appearance.  If, 
through  carelessness  in  this  regard,  they  are  allowed  to  become  numer- 
ous and  infest  the  grove,  thorned  and  split  fruit,  which  might  other- 
wise be  used  for  wine-making,  will,  owing  to  their  attacks,  be  rendered 
useless  for  this  and  other  purposes,  even  before  it  has  fallen  from  the 
trees. 

Other  closely  allied  beetles  and  other  species  of  flies  are  found  to  in- 
fest injured  or  rotting  fruit.  Two  only  can  be  mentioned  at  present; 
they  are — 

(1.)  Smicrips  hypocoproides  Eeiter,  a  minute  Nitidulid  introduced  from 
the  West  Indies,  but  which  has  become  quite  abundant  in  parts  of  the 
southern  United  States,  and  is  found  feeding  upon  sap  and  also  in  rot- 
ting cotton  bolls. 

(2.)  Europs  pallipennis  Lee.,  a  rare  Monotomid  beetle. 

Fruit-eating  Ant. — A  small  dark-brown  ant,  a  probably  undescribed 
species  of  Lasiua,  is  sometimes  found  gnawing  the  pulp  of  split  oranges 
upon  the  tree.    A  stream  of  the  ants  may  be  seen  carrying  bits  of  the 
fruit  down  the  trunk  of  the  tree. 
G52I  o  I 12 


178  INSECTS   AFFECTING   THE    ORANGE. 

INSECTS  IN  DRY  FRUIT. 
BLASTOBASIS  ciTRicoLELLA  Chambers. 

This  small  moth,  belonging  to  the  family  Tineidse,  is  described  iii  the 
Keport  of  the  Commissioner  of  Agriculture  for  1879,  p.  207,  where  the 
following  note  concerning  it  occurs : 

"  From  a  dry  orange  which  was  found  at  Jacksonville,  Fla.,  in  the 
latter  part  of  January,  and  preserved  on  account  of  its  being  infested 
by  a  small  beetle  (Arceocerus  fasciculatm),  there  issued  rather  unex- 
pectedly on  March  17  a  small  gray  Tineid  moth,  which  was  referred  to 
Mr.  Chambers  for  determination.  *  *  *  "  The  full  description  is 
given  on  the  same  page. 

ORANGE-EATING  TINEID.15 

Another  minute  moth  of  the  same  family  as  the  preceding  (Tineidce) 
was  bred  from  the  pupa  found  in  a  crevice  of  the  rind  of  a  split  orange. 
The  pupa  was  enveloped  loosely  with  silk,  in  which  were  entangled  the 
droppings  of  the  larva,  and  was  otherwise  surrounded  with  evidences 
that  the  insect  had  fed  upon  the  dry  portions  of  the  rind.  The  moth 
issued  early  in  October  acd  proved  a  very  handsome  insect  of  dark  color, 
with  scales  of  lustrous  lead-color  on  the  upper  wings  and  body,  the  sur- 
face having  a  violet  sheen.  The  head  and  thorax  are  iridescent  dove- 
color.  On  the  margin  of  the  upper  wing,  at  its  base,  is  a  membranous 
flap  (costal  fold),  which  can  be  folded  beneath  the  wing  or  opened  widely, 
disclosing  a  lining  of  delicate  hairs,  arranged  in  three  tufts,  the  lower 
one  forming,  when  erect,  a  rosette  of  lemon-yellow  color ;  above  this  a 
tuft  of  orange  yellow,  and  the  upper  tuft  a  pencil  of  purple  hairs. 

ARCEOCERUS  FASCICULATUS  (De  G.). 

This  little  brownish  beetle  is  commonly  found  in  dry  or  blasted  bolls 
of  cotton.  It  is  also  said  to  be  injurious  to  coffee  in  Brazil.  In  the  Re- 
port of  the  Commissioner  of  Agriculture  for  1879,  p.  206,  mention  is  made 
of  its  occurrence  in  a  dry  orange.  The  larva  and  pupa,  as  well  as  the 
.  perfect  insect,  were  obtained  at  the  same  time. 

WHITE  ANTS   (TERMITES)   IN  FRUIT. 

The  fruit  of  the  Citron,  when  growing  upon  recumbent  branches  and 
when  touching  the  earth,  is  frequently  entered  by  Termites  and  entirely 
.destroyed  by  them.  Oranges  which  have  fallen  from  the  trees  and  are 
allowed  to  remain  upon  the  ground  are  also  attacked,  but  less  fre- 
.quently  than  the  citron.  The  Termites  feed  upon  the  thick  inner  rind 
of  the  citron,  and  upon  the  membranous  divisions  m  the  orange,  They 


INSECTS    FEEDING    OX    DRY    FRUIT.  179 

outer  the  fruit  from  beneath,  through  a  small  perforation  made  in  the 
rind.  The  Termites  never  ascend  the  trees  or  attack  fruit  which  is  not 
resting  upon  moist  earth.  Their  appetite  for  this  sort  of  food  is  not 
very  strong,  and  the  loss  they  inflict  cannot  be  considered  serious.  If 
citrons  are  attacked  the  fruit  should  be  raised  from  the  ground  or  al- 
lowed to  rest  upon  a  dry  support,  and  the  ground  around  and  under  the 
bushes  should  be  frequently  stirred  with  a  rake. 


CHAPTER  XII. 

PEEDATOEY  INSECTS. 

INSECTS  PREYING  UPON  APHIS. 

LADY-BIRDS.—  COCCTNELLIDJE. 

Several  species  of  this  family  have  already  been  noticed  as  predatory 
upon  Scale-insects  ;  nearly  all  the  species,  and  they  are  very  numerous, 
prey  to  a  greater  or  less  extent  upon  Aphis.  Of  the  larger  forms,  which 
are  familiar  everywhere  under  the  name  of  Lady-birds,  four  species  are 
commonly  found  feeding  upon  the  Orange  Aphis  in  our  groves.  They 
are  Chilocorus  bivulnerus  (Muls.)  ;*  Exochomus  contristatus  (Muls  )  ;t  Cy 
cloneda  sanguined  (Linn.);f  and  Hippodamia  convergens  Gue"r.§  These 
have  all  been  mentioned  as  preying  upon  scale-insects.  Among  the 
smaller  members  of  this  familj7  are  numerous  species  of  the  genus  Scym- 
nus,  which  prey  upon  Plant-lice,  and  most  of  them  are  found  from  time 
to  time  upon  the  orange  trees.  The  form  in  Scymnus  is  rounded  and 
very  convex;  the  color  in  most  of  the  species  is  a  somber  brown,  some- 
times relieved  with  blotches  of  dull  red  or  yellow.  The  body  is  always 
hairy.  In  size  the  species  range  from  one-tenth  to  one-twentieth  of  an 
inch  in  length.  They  are  apt  to  resemble  each  other  closely,  and  in  some 
groups  the  species  are  distinguishable  the  one  from  the  other  only  on 
the  closest  analysis. 

The  larva  of  Scymnus  is  rather  thick  and  short,  the  body  dark  brown, 
purple,  or  black,  but  entirely  covered  above  with  tufts  of  white  wax, 
which  are  easily  rubbed  off  in  handling  the  insect. 

The  pupa  is  found  within  the  split  skin  of  the  larva,  as  with  the  larger 
species  of  Lady-birds. 

SCYMNUS  CAUDALIS  Lee. 

In  this  species  the  body  is  black,  with  the  head  and  parts  of  the 
thorax  red  ;  the  end  of  the  body  and  the  legs  yellowish-red.    Length, 
hr  inch). 


*  Black,  with  two  red  spots. 

t  Smaller  in  size.     Red,  with  two  black  spots. 

t  Blood-rod  or  brick-red,  without  spots. 

$  Orange-red,  with  five  or  six  spots  on  each  wing-cover. 


INSECTS   PREYING   ON   THE    ORANGE   APHIS.  181 

This  is  the  commonest  and  one  of  the  largest  species  found  among 
Plant-lice  on  the  Orange  in  Florida.  Certain  other  species,  almost 
equally  common,  are  entirely  black,  and  differ  the  one  from  the  other 
only  in  size,  and  in  characters  too  minute  for  popular  description. 

The  larvae  of  all  the  species  bear  white  flocculent  tufts,  and  have  no 
marks  by  which  the  species  can  be  readily  distinguished.  They  are 
quite  active  when  disturbed,  but  are  usually  seen  quiescent  in  the  midst 
of  the  unresisting  herd  of  Aphis,  feeding  upon  the  young  lice. 

They  undergo  their  transformations  upon  the  leaves  among  the  re- 
mains of  the  Aphis  colonies  destroyed  by  them  and  other  enemies.  The 
pupa  is  held  in  the  split  skin  of  the  lar^a,  and  is  dark-colored  like  the 
body  of  the  latter. 

SYRPHVS  FLIES.— SYRPHID&. 

Whenever  colonies  of  Aphis  are  found  on  the  Orange  there  will  almost 
invariably  be  found  among  them  slug-like  larvae,  which  creep  about 
among  the  Plant-lice  with  a  leech-like  movement,  now  contracting  into 
an  almost  globular  mass,  and  again  elongating  like  the  joints  of  a  tele- 
scope. The  minute  terminal  joint,  which  constitutes  the  head  of  the 
larva,  is  observed  to  possess  a  pair  of  retractile  horny  hooks,  which 
work  forwards  and  back,  in  and  out  of  the  mouth,  like  a  rake.  As  the 
larva  advances  with  a  groping  motion,  for  it  is  quite  blind  and  eyeless, 
the  outstretched  neck  and  head  sweep  the  surface,  and  the  jaws  con- 
tinue their  raking  movement  until  they  strike  the  body  of  an  Aphis. 
Immediately  the  jaw-hooks  grapple  their  unresisting  victim,  and  soon 
through  the  transparent  walls  of  the  body  the  sucking  stomach  is  seen 
pulsating  and  drawing  through  the  oesophagus  in  a  continuous  stream 
the  green  juices  of  the  plant-louse. 

When  actively  engaged  in  feeding  these  larvae  continue  with  the 
greatest  voracity  to  empty  one  louse  after  another,  until  they  have  de- 
stroyed dozens  ot  them  ;  and  their  bodies,  distended  with  the  contained 
juices,  become  translucent  green  in  color.  When  filled  to  repletion,  the 
larva  falls  into  a  lethargy,  lasting  two  or  three  hours ;  during  which 
the  processes  of  digestion  change  the  juices  of  the  body  to  varying 
shades  of  brown,  and  dark  masses  of  fecal  matter  gradually  form  in 
the  intestines.  The  curious  changes  of  color  in  the  semi-transparent 
larvae  are  therefore  due  entirely  to  the  condition  of  the  body-contents. 
Full  fed  individuals  usually  have  a  tinge  of  flesh  color,  owing  to  the 
formation  of  glandular,  creamy  masses  of  fat,  which  have  a  roseate  hue. 
When  fasting  through  scarcity  of  food,  the  fat  is  absorbed  and  the  body 
becomes  dark-brown  and  opaque.  While  feeding  the  larva  is  translu- 
cent green  ;  while  digesting  the  colors  change  to  olive  and  brown,  with 
distinct  markings  of  rectdish  brown  and  black. 

Transformations. — When  full  fed  the  larva  attaches  itself  by  means 


182  INSECTS   AFFECTING   THE    ORANGE. 

of  a  pair  of  terminal  prop-legs,  aided  by  a  viscid  secretion  which  it 
voids,  and  which  in  drying  glues  it  to  the  surface  of  the  plant.  The 
body  becomes  distended  and  thickened,  losing  in  length  what  it  gains 
in  girth.  The  skin  of  the  larva  is  not  split  or  shed,  but  hardens  and 
forms  the  puparium,  which  protects  the  true  pupa  within.  In  the  pupa- 
riurn  the  shape  of  the  larva  is  profoundly  altered,  the  body  joints  are 
obliterated,  the  anterior  end  becomes  swollen  and  broadly  rounded,  and 
the  form  tapers  suddenly  behind. 

The  perfect  fly  issues  by  pushing  off  the  convex  end  of  the  puparium, 
which  splits  at  the  suture  between  two  of  the  old  larval  joints,  and  re- 
leases a  circular  cap,  in  the  shape  of  a  watch-glass. 

The  duration  of  the  egg  and  larva  periods  in  these  Aphis-eating  flies 
is  short;  the  egg  hatches  in  -forty-eight  hours  after  it  is  laid,  and  the 
larva  becomes  full  grown  and  forms  its  pupa  in  five  or  six  days.  About 
ten  days,  the  average  time  with  insects  having  many  broods,  are  passed 
in  pupa.  The  reason  of  this  extremely  rapid  development  in  the  first 
two  stages,  the  egg  and  larva,  becomes  obvious  when  we  consider  how 
brief  is  the  existence  of  the  Aphis  itself,  and  how  suddenly  its  col- 
onies appear  and  disappear;  for  the  life  of  a  colony  of  Aphis  is  also 
very  short.  Upon  the  Orange  the  Aphis  can  feed  only  upon  the  very 
tender  young  leaves;  in  a  short  time  these  harden,  and  then  the  colony 
must  scatter;  but  frequently,  long  before  that  time,  their  numbers  are 
reduced  almost  to  extermination  by  enemies  and  parasites.  As  the 
Syrphus  larvae  cannot  follow  the  winged  insects,  they  must  make  the 
best  of  their  limited  opportunities  and  feed  quickly  or  perish  of  starva- 
tion. It  is  curious  to  mark  how  nature  in  the  case  of  these  insects  has 
responded  to  the  necessities  of  the  situation  and  given  their  Iarva3  rest- 
less activity,  great  rapacity,  and  destructive  powers,  notwithstanding 
their  slow  locomotion,  and  also  a  remarkably  brief  egg  period,  so  that 
this  wingless,  blind,  and  almost  legless  maggot  is  enabled  to  compete 
with  more  perfectly  organized  rivals  in  the  food  struggle  which  takes 
place  over  every.  Aphis  colony. 

Broods,  &c.— The  Iarva3  of  these  Syrphus  flies  feed  only  upon  Aphis 
and  depend  upon  them  for  their  existence.  They  therefore  appear  and 
disappear  with  the  colonies  of  the  latter,  and  the  broods  may  be  sup- 
posed to  follow  rapidly  one  upon  another  during  the  seasons  of  growth, 
when  the  appearance  of  new  shoots  upon  the  Orange  gives  support  to 
numerous  colonies  of  Aphis. 

The  seasons  of  growth  in  the  Orange,  after  the  renewal  of  the  foliage 
in  the  early  spring,  depend  in  a  great  measure  upon  the  prevalence  of 
rains  and  vary  from  year  to  year,  but  are  usually  three  or  four  in  num- 
ber during  the  year.  The  colonies  of  Aphis  and  likewise  their  Syrphus 
enemies  are  most  abundant  in  June  and  September. 

Three  representatives  of  the  family  Syrphida?  are  found  among  Aphis 
on  the  Orange.  They  belong  to  the  genus  Baccha. 


INSECTS  PREYING  ON  THE  ORANGE  APHIS. 


183 


THE  FOUR- SPOTTED  APHIS-FLY.* 

(Baccha  babista  Walker.) 
[Figs.  81,  82  and  83.] 

This  is  a  rather  slender  fly,  with  a  large,  well-rounded  head,  and  a 
club  shaped  hind  body,  supported  on  a  slender  stalk  or  peduncle;  the 
eyes,  which  cover  the  greater  part 
of  the  head,  are  mahogany -brown; 
the  thorax  black,  with  a  metallic 
luster,  and  with  a  golden-yellow 
shield ;  the  wings  are  transparent; 
the  clab  of  the  abdomen  brown, 
marked  with  four  pale  triangular 
spots.  (Fig.  81.)  Length,  10mm 
(A  i«ch). 


FIG.  82.—  Baccha  babista,  larva. 
(Original.) 


FIG.  81.— Baccha  babista,  adult.    (Original.) 


The  larva  (Fig.  82)  has  a  cylindrical  body,  ^greenish,  with  a  longitud- 
inal band  of  dull  red  on  the  back;  the  joints,  about  equal  in  size,  ex 
cept  the  first  three,  which  are  tapered,  and  form  a  re- 
tractile neck ;    the  surface  is  covered  with  very  short, 
stiff  hairs,  giving  it  a  velvety  appearance ;  each  joint 
of  the  body  is  armed  with  a  row  of  soft  spines  above 
and  a  pair  of  fleshy  prop  legs  below.Length,  when  at 
rest,  7.5 min  (-^  inch). 

The  puparium,  or  chrysalis  (Fig.  83),  has  the  form 
of  a  cone,  with  one  side  flattened  and  fastened  to  the 
surface  of  the  leaf;  the  large  end  is  broadly  rounded, 
convex;  the  color  varies  from  dirty  white  to  dull  yel- 
low, and  there  are  more  or  less  distinct  cross-shaped 
markings  upon  the  back;  the  spines  of  the  larva  shrink 
to  minute  prickles  on  the  puparium. 

The  eggs  are  elongate-oval,  brilliant  white,  the  surface  marked 
with  diamonds  by  obliquely  intersecting  engraved  lines.  They  are 
deposited  by  the  parent  fly  singly  upon  the  leaves  among  Plant-lice. 

Parasites. — Minute  Chalcid  parasites  prey  upon  the  Syrphus  larva, 


FIG.  83. — Baccha  ba- 
bixta,    puparium: 

a,  doi'8Jil    view; 

b,  lateral     view. 
(Original.) 


*  This  very  common  species  has  been  described  by  Mr.  Ashinead  under  the  name 
Conopsl  quadrimaculata.     (Orange  Insects,  page  69.) 


184  INSECTS    AFFECTING    THE    ORANGE. 

and  issue  from  the  puparium,  in  numbers  varying  from  six  to  eighteen, 
through  a  number  of  small  holes  which  they  gnaw  in  its  top  and  sides. 
They  are  from  lmm  to  2mm  in  length,  and  have  the  dark  bronze  and 
metallic  colors  with  hyaline  and  iridescent  wings  so  common  in  this 
family  (Chalcididce). 

THE  DUSKY- WINGED  APHIS-FLY. 

(Baccha  lugens  Loew.) 
[Fig.  84.] 

Another  species  of  Baccha,  scarcely  less  common  than  the  preceding, 
has  a  more  leech-like  larva,  in  form  flattened  and  dilated  behind,  but 
with  the  anterior  joints  lengthened  into  a  very  mobile  and  extensile 
neck.  The  surface  of  this  larva  is  nearly  smooth,  without  the  spines  or 

velvet  hairs  of  the  first  species.  In  color 
the  larva  is  dark,  inclining  to  purple  when 
not  feeding,  with  cream-colored  blotches, 
tinged  with  pink.  The  length  in  repose 
is  about  8mm  (£fe  inch). 

The  puparium  (Fig.  84)  is  dull  brown, 

FIG.  84  —  Baccha  lugens,  puparium.     gourd-shaped  ;  the  anterior  portion  greatly 

inflated  and  behind  suddenly  flattened  and 

contracted  to  form  a  sort  of  handle.  The  terminal  spiracles  of  the  larva 
are  seen  at  the  tip  of  the  handle-like  abdomen,  where  they  form  a  pair 
of  wart-like  prominences.  • 

The  fly  does  not  differ  greatly  in  form  from  the  preceding;  it  has  eyes 
of  brighter  red,  and  the  wings  are  distinctly  clouded  with  spots  of  brown ; 
the  thorax  less  shining,  dark  bronze;  the  shield  (metathorax)  dark 
bronze,  like  the  thorax;  abdomen  thicker,  less  broadly  dilated  at  the 
end,  uniform  brown  in  color.  The  size  of  the  imago  varies  greatly,  from 
8mm  (-*<&  inch)  (small  males)  to  12mra  (£&  inch)  (large  females). 
The  egg  is  indistinguishable  from  that  of  Baccha  babista. 

THE  RUDDY  APHIS-FLY. 

(Baccha  cognata  Loew). 

A  third  species  of  this  genus  is  found  in  company  with  the  preced- 
ing species  preying  upon  Aphis,  sometimes  upon  Orange,  but  more  fre- 
quently upon  different  kinds  of  Plant:lice  found  on  herbaceous  plants 
and  weeds  of  the  garden.  In  this  species  the  form  of  the  fly  and  its 
larva  approach  closely  to  that  of  B.  lugens,  but  they  are  somewhat  more 
slender  and  smaller  than  either  of  the  preceding  species.  In  the  per- 
fect fly  the  color  of  the  eyes  is  mahogany-brown ;  the  thorax  black, not 
shining;  the  wings  densely  clouded  with  red- brown;  the  abdomen  dull 
red,  and  very  slightly  dilated  at  the  tip. 


INSECTS   PREYING    ON    THE    ORANGE    APHIS. 


185 


FTQ.  85.  — The 
Pruinos* 
A  p  h  i  a  -  fl  y, 
larva.  (Orig- 
inal ) 


Larva. — The  maggot  has  the  form  and  smooth  surface  of  B.  lugens, 
but  is  more  transparent  and  lighter  in  color,  yellowish-green  and  white 
predominating. 

THE  PRUINOSE  APHIS-FLY.* 

[Figs.  85  and  86.] 

A  very  common  enemy  of  the  Orange  Aphis  is  a  small  two-winged 
fly.     Its  young  is  a  greenish,  slug-like  maggot,  3mm  (Jfo  inch)  in  length ; 
the  body  is  flattened  beneath,  convex  above,  with  two  deep  longitudinal 
furrows  on  the  back ;  the  joints  of  the  head  and  neck  are 
small  and  tapering,  as  in  the  larva  of  Syrphus,  and  can  be 
greatly  extended  or  entirely  withdrawn  into  the  body;  the 
body  behind  is  rather  broadly  rounded ;  from  the  upper 
surface  near  the  hind  margin  arises  a  pair  of  diverging 
appendages  like  the  horns  of  a  snail ;  the  ends  of  these 
appendages  are  open  pores,  and  the  apparatus  constitutes 
the  principal  spiracles,  through  which  the  animal  breathes ; 
the  surface  of  the  larva  is  roughened  with  minute  knob- 
like  excrescences. 

When  ready  to  transform  into  pupa,  the  larva  glues  it- 
self to  the  surface  of  the  leaf  by  means  of  a  black  gum. 
The  body  of  the  larva  shortens  and  thickens,  becomes  oval 
in  shape,  and  assumes  a  golden-brown  color,  the  breathing  tubes  are 
now  very  prominent,  the  lateral  furrows  of  the  larva  are  not  obliter- 
ated, but  divide  the  puparium  into  longitudinal  lobes,  and  appear  as 
broad  bands  of  darker  color  upon  the  surface  of  the  casket. 

When  vacated  by  the  fly  the  puparium  splits  in  a  ring  near  the  an- 
terior end,  releasing  the  tip  in  the  form  of  a  conical  cap  the  cap  also 
splits  across  the  middle,  dividing  into 
two  valve-like  halves,  only  one  of  which 
is  usually  thrown  off  by  the  fry  in  its 
exit. 

The  fly  (Fig.  86)  is  a  small,  thick 
bodied  insect,  about  2mra  (T£Q  inch)  in 
length,  with  deep  purple  eyes,  transpa- 
rent wings,  and  particolored  legs;  tho 
body  is  bluish-white  (pruinose),  with 
sparsely  placed  black  hairs  ;  the  upper 
surface  of  the  thorax  is  marked  with 
four  longitudinal  stripes  of  umber- 
brown.  The  egg  is  white,  elongate  oval,  with  fine  longitudinal  lines ;  it 
is  fastened  to  the  surface  of  the  leaf  among  the  living  Aphis. 

Transformations. — What  has  been  said  of  the  habits  and  transforma- 

*Dr.  S.  W.  Williston  writes  concerning  this  species:  "They  are  evidently  An- 
thomyida,  but  I  cannot  place  them  in  any  of  the  European  genera.  I  am  acquainted 
with  a  number  of  the  Authomyid  genera,  but  this  species  differs  from  any  I  know  iu 
the  few  bristles  on  the  head  and  faqe." 


Fio.  86.— The  Prninose  Aphia-fly. 
inal.) 


(Orig- 


186 


INSECTS    AFFECTING    THE    ORAXGE. 


tions  of  the  Aphis-eating  Syrphus-flies  will  apply  equally  to  this  insect, 
and  it  is  found  in  company  with  them  not  alone  upon  the  Orange,  but 
among  various  species  of  Aphis  on  other  plants  as  well. 

Parasite. — A  minute  Hymenopterous  fly  (a  Pteromalid)16  attacks  the 
larva  and  issues  from  the  puparium  through  round  holes  eaten  in  its 
side.  Two  specimens  of  the  parasites  were  bred  from  a  single  puparium 
of  the  fly.  They  issue  in  September. 


FIG.  87.—Polistes  americanus. 
Comstock.) 


(After 


OTHER  PREDATORY  INSECTS  FREQUENTING  THE  ORANGE. 

PREDATORY  WASPS. 
POLISTES  AMERICANUS  (Fabr.). 

[Figs.  87  and  88.] 

This  large  red  wasp  is  fond  of  making  its  home  under  the  dense  foliage 
of  the  orange  tree,  and  suspends  its  comb  of  paper  to  the  branches. 

It  is  a  large  species,  and  its  sting  is 
equal  in  severity  to  that  of  the-white-faced 
hornet.     Fortunately,  it  is  not  an  irritable 
wasp,  and  is  little  inclined   to   use  its 
weapon,  except  when  its  nest  is  attacked. 
Like  most  insects  of  its  kind  this  wasp 
is  carnivorous,  and  to  a  great  extent  preys 
upon  caterpillars  and  soft-bodied  insects. 
With  these  it  feeds  its  young,  first  masti- 
cating the  food  into  a  pulpy  ball,  in  order 
that  it  may  readily  be  swallowed  by  its 
young,  which  are  not  provided  with  horny  jaws,  and  then  presenting  it 
to  the  latter  in  their  cells  in  much  the  same  fashion  that  a  bird  feeds 
its  nestlings.    Not  only  the  grubs  are  fed  in  this  way,  but  also  the  young- 
wasps  which  have  recently  issued  from  the  pupa,  and 
which  do  not  for  some  time  leave  the  nest  or  take  part 
in  the  labors  of  the  colony. 

The  nest  consists  of  a  single  comb  or  layer  of  cells, 
which  is  increased  in  size  by  the  addition  of  new  cells 
around  the  edges  until  it  sometimes  attains  the  diam- 
eter of  10  or  12  inches.  The  comb  is  not  protected  by 
a  covering  of  paper,  as  in  the  nest  of  a  hornet,  but 
the  cells  are  built  with  the  mouth  downwards,  and 
the  back  of  the  comb  is  made  very  thick  and  strong, 
so  that  it  sheds  water. 
The  wasps  make  their  comb  of  wood  masticated  to  a  pulp.  They  may 
be  seen  gathering  for  this  purpose  from  fence  rails  and  uupainted  wood 
surfaces  the  fibers  beaten  out  by  the  action  of  the  weather.  The  leaf- 
rolling  caterpillars  which  injure  the  buds  and-  tender  shoots  of  the  Or- 
ange form  a  very  considerable  portion  of  the  food  of  all  colonies  of  Pol- 


FIG.  88.— Pollutes  nest 
in  spring.  (After 
Riley.) 


PREDATORY    INSECTS    FREQUENTING    THE    ORANGE.  187 

istes  which  have  established  themselves  in  the  vicinity  of  orange  groves. 
Numerous  other  insects  are  also  destroyed  by  them.  The  orange-grower 
should  not,  therefore,  be  concerned  to  find  them  building  their  nests  in 
his  orange  trees,  and  it  is  greatly  to  his  interest  to  allow  them  to  remain. 
The  ordinary  operations  of  cultivating  and  pruning  rarely  disturb  these 
insects,  who  pay  no  attention  to  the  methodical  movements  of  the  hor- 
ticulturist, and  only  resent  a  direct  attack.  Before  the  time  for  gather- 
ing the  oranges  the  nests  are  usually  deserted  by  the  wasps  and  the 
colonies  dispersed,  for  they  do  not  continue  to  breed  during  the  winter 
months  even  in  Florida. 

THE   VASE-MAKER  WASP. 

(Eumenes  fraterna  Say ) 

[Fig.  89.] 

This  is  also  a  useful  predatory  wasp,  and  is  never  known  to  use  its 
sting  unless  caught  and  held  in  the  hand.  It  is  -^  inch  in  length-;  the 
color  is  black  with  white  markings.  The  abdomen  is  borne  on  a  slender 
stalk  or  peduncle,  and  forms  a  rounded  knob,  prolonged  at  the  extrem- 
ity in  a  rather  blunt  point.  Each 
side  of  the  swollen  portion  of  the 
abdomen  is  marked  with  a  white 
spot. 

The  female  of  this  wasp  is  sol- 
itary and  makes  single  cells  of 
mud  and  sand,  which  she  attaches 
to  various  plants,  and  not  infre- 
quently to  the  twigs  of  orange 
trees.  These  mud  cells  are  almost 
spherical,  about  three-fourths  inch. 

FIG.  89.— a,  the  Vase-Maker  Wasp ;  &,  nest ;  c,  nest 

111    diameter;     the    Walls     are   thin         showing  interior  stored  with  caterpillars.    (After 
,  ~         .,        '  ,  .  Kiley.) 

and  fragile;  they  have  an  opening 

which  is  provided  with  a  projecting  lip  or  ring  and  the  structure  re- 
sembles a  globe-shaped  flask,  with  a  very  short  neck.  Within  the  cell 
the  female  deposits  a  single  white  egg.  She  then  packs  it  with  small 
caterpillars,  each  of  which  is  paralyzed  and  rendered  helpless  by  a  stab 
from  her  sting,  and  seals  the  opening  with  soft  mud. 

Each  female  constructs  a  number  of  cells,  but  scatters  them  about, 
seldom  placing  more  than  one  or  two  in  the  same  place.  When  filled 
and  sealed  up  they  are  abandoned.  The  grub  of  the  wasp  feeds  upon 
the  caterpillars  stored  for  its  use ;  when  all  are  consumed  it  forms  its 
pupa  within  the  cell,  and  in  due  course  of  time  issues  as  a  perfect  in- 
sect, removing  with  its  jaws  the  earthen  stopper  of  its  doorway. 

Broods. — There  are  broods  in  spring  and  fall.  The  summer  months 
are  passed  as  pupae,  anjl  the  winter  as  perfect  insects. 


188  INSECTS  AFFECTING  THE  ORANGE 

Parasites. — This  wasp,  in  common  with  many  other  cell-making  Hy- 
menoptera,  has  an  enemy  which  destroys  the  grub  and  occupies  its 
place  within  the  cell,  issuing  in  its  stead  through  a  round  hole  made  in 
its  side.  This  parasite  is  a  brassy-green  Cuckoo-bee  belonging  to  the 
genus  Chrysis.  It  is  remarkable  for  its  bright  metallic  green  or  blue 
color,  hard  texture,  and  coarsely  pitted  surface,  and  the  peculiar  form 
of  the  abdomen,  which  is  abruptly  truncate  behind  and  hollowed  from 
the  under  side  and  is  capable  of  folding  over  upon  the  head  and  breast, 
protecting  the  members  in  its  hollow  under  surface,  and  making  of  the 
insect  almost  a  compact  ball.  This  position  the  insect  is  apt  to  assume 
when  captured  or  disturbed.  The  perfect  insect  is  llmm  in  length 
(-^Q  inch)  when  fully  extended.17 

Other  parasitic  Hymenoptera  have  been  bred  from  the  cells  of  this 
wasp,  but  some  of  them  (Braconidce)  are  parasitic  upon  the  caterpillars 
stored  as  food  by  the  wasp,  and  not  upon  the  young  of  the  wasp  itself. 
The  eggs  of  these  parasites  existed  in  the  bodies  of  the  caterpillars  be- 
fore they  were  captured  and  placed  in  the  cells  by  the  mother  wasp, 
and  it  is  noteworthy  that  such  parasitized  caterpillars  are  not  eaten  by 
the  wasp-grub;  probably  because  they  are  soon  destroyed  by  their  in- 
ternal enemy,  and  their  bodies  rapidly  become  too  hard  and  tough  for 
the  weak  jaws  of  the  wasp-grab.  It  is  also  to  be  remarked  that  the 
poisoned  sting  of  the  wasp  while  paralyzing  the  caterpillar,  does  no  in- 
jury to  its  internal  parasite,  but  the  latter  completes  its  transformations 
as  well  shut  up  within  the  tightly  sealed  cell  of  the  wasp  as  under  nor- 
mal conditions  in  the  open  air.  The  parasite  fly,  having  cut  its  way 
out  of  the  hardened  skin  of  the  caterpillar,  finds  itself  still  inclosed 
within  the  wasp  cell,  the  walls  of  which  it  is  unable  to  penetrate,  and 
it  therefore  remains  imprisoned  until  released  by  the  exit  of  the  wasp, 
for  the  presence  of  the  caterpillar  parasite  in  its  cell  in  no  way  inter- 
feres with,  the  transformations  of  the  latter. 

THE  CAMEL-CRICKETS  OB  SOOTHSAYERS. 

These  are  large  insects,  with  attenuated  bodies  and  long,  slender 
legs,  the  first  pair  of  which  are  elbowed  and  provided  with  sharp  spines 
and  hooks  for  capturing  and  holding  their  prey.  The  latter  consists  of 
insects  of  any  sort,  not  protected  by  too  hard  a  shell  or  other  covering, 
but  chiefly  of  flies  and  soft-bodied  active  larvaB.  The  camel- crickets  do 
not  molest  Bark-lice,  or  other  sedentary  insects,  and  do  not  prowl  about 
or  spy  into  hidden  places  in  search  of  food,  but  lie  in  wait  for  their 
prey,  taking  only  that  which  comes  within  their  reach;  or  they  creep 
cautiously  and  slowly  upon  any  small  moving  object  which  their  keen 
and  watchful  eyes  discover  in  their  vicinity.  When  within  reach  of 
their  prey,  they  seize  it  with  the  rapidity  of  lightning,  and  hold  the. 
struggling  victim  firmly  clasped  between  the  spines  and  grappling 
hooks  of  their  fore  legs.  \  *'  v 


PREDATORY    INSECTS    FREQUENTING    THE    ORANGE. 


189 


Their  manner  of  feeding  is  very  unlike  that  of  other  insects,  and  re- 
minds one  of  a  monkey  eating  fruit  j  they  appear  to  masticate  their  food 
very  deliberately  before  swallowing,  biting  off  a  piece  from  time  to  time, 
while  they  hold  it  in  their  claws. 

The  head  swings  upon  a  very  mobile  neck,  and  can  be  turned  so  far  to 
the  side  as  to  look  almost  directly  backwards  over  the  shoulders.  Their 
quick  movements  betray  an  alertness,  in  striking  contrast  with  the 
feigned  sluggishness  of  habit.  This  evidence  of  watchfulness,  while 
the  insect,  with  fore-arms  folded,  and  claws  clasped  in  the  attitude  of 
prayer,  remains  motionless  and  apparently  absorbed  in  meditation, 
gives  an  irresistably  comic  air  of  hypocrisy  to  its  actions.  These  pecu- 
liar habits  were  well  known  to  the  ancients,  for  the  group  is  represented 
by  numerous  species  in  many  parts  of  the  world,  and  they  early  received 
the  name  Mantis  (prophet,  or  soothsayer). 


MANTIS   CAROLINA. 

[Figs.  90  and  91.] 

This,  the  largest  of  our  species,  is  not  very  abundant  in  Florida,  but 
is  sometimes  seen  upon  orange  trees,  catching  every  moving  insect  that 
comes  within  the  reach  of  its  claws.  It  is  yellowish  green  in  color,  and 


FIG.  90.—  Mantis  Carolina :  a,  female;  b.  male.     (After  Eiley.) 

about  two  inches  in  length.  It  has  wings  in  the  adult  state,  which 
somewhat  resemble  folded  leaves  ;  each  fore-wing  bears  a  brown  spot; 
in  some  exotic  species  the  center  of  this  spot  is  transparent,  and  resem- 
bles a  hole  eaten  in  the  leaf  by  some  insect.  There  is  but  one  brood 
each  year.  The  young  hatch  in  early  summer  and  complete  their  growth 
in  the  latter  part  of  the  season.  The  large  egg-masses  are  glued  to  the 


190 


INSECTS    AFFECTING    THE    ORANGE. 


twigs  of  trees ;  they  are  elongate,  irregularly  oval,  about  an  inch  in 
length,  and  contain  forty  or  fifty  eggs.  The  eggs  (Fig.  91)  occupy  flat- 
tened cells  placed -in  two  ranks,  alternating  with  each  other;  the  cluster 
of  cells  has  a  braided  or  woven  appearance,  but  consists  simply  of  a  con- 
tinuous ribbon  of  mucus  folded  in  close  flutiugs,  and  having  an  egg 
deposited  in  the  bight  or  angle  of  eacli  fold.  The  eggs  are  deposited 
simultaneously  with  the  deposition  of  this  ribbon  by  the 
mother  insect,  and  the  whole  mass  is  at  first  soft  and 
flexible,  but  rapidly  hardens  by  exposure  to  the  air. 

MANTIS  MISSOURIENSIS  ? 

In  this  species  the  body,  though  over  two  inches  long, 
is  but  little  thicker  than  a  darning  needle  ;  the  legs  are 
very  long  and  so  slender  that  they  seem  hardly  compe- 
tent to  sustain  the  weight  of  even  so  meager  a  body. 
The  extreme  attenuation  of  all  its  parts,  and  the  light 
brown  color  of  the  insect,  afford  it  protection  from  en- 
emies, and  enable  it  to  advance  unnoticed  upon  its  prey. 
Its  ghost-like  form  is  difficult  to  detect  upon  plants,  and 
it  has  the  appearance  of  a  straw  caught  in  spiders' 
webs,  an  illusion  which  the  insect  with  apparent  design 
strengthens  by  frequently  giving  to  its  body  a  swaying 
motion  as  if  vibrated  by  air  currents. 

This  species  is  very  common,  and  is  frequently  seen 
upon  the  Orange  as  well  as  upon  other  plants.  It  has 
a  spring  and  fall  brood.  The  egg-masses  are  brick-red 
in  color,  about  half  an  inch  long,  and  flattened  upon  the 
sides.  They  are  usually  deposited  between  the  folds  of 
a  dry  leaf  or  in  crevices  of  the  bark.  The  structure  is 
the  same  as  in  the  preceding  species,  but  the  cells  are 
more  distinct  and  regularly  placed.  The  food  of  this  Mantis  consists 
chiefly  of  small  flies,  and  neither  this  nor  the  preceding  species  are  of 
much  importance  to  the  cultivator  of  plants,  since  they  do  not  at  all  dis- 
criminate between  his  friends  and  foes,  and  do  not  seek  out  or  destroy 
the  more  insidious  enemies  which  lurk  in  hiding  places,  or  those  which 
protect  themselves  with  a  covering  or  scale. 


FIG.  91. — Eggs  of 
Mantis  Carolina. 
(After  Riley.) 


SOLDIER-BUGS. 

Among  the  true  bugs  (Hemiptera)  are  numerous  predatory  species,  of 
which  not  a  few  frequent  the  orange  trees.  It  is  not  easy  to  distin- 
guish the  predatory  from  the  plant-sucking  kinds,  and,  indeed,  in  some 
instances,  the  same  bug  has  both  habits.  The  most  noteworthy  in- 
stance of  this  is  iu  the  case  of  Raphigaster  hilaris,  already  noticed  in 
Chapter  IX,  This  species,  on  occasion  a  very  destructive  pest  of  the 
plant,  is  at  other  times  a  useful  iuSeet,  killing  au4  sucking  the  juices  of 


PREDATORY    INSECTS    FREQUENTING    THE    ORANGE.  19  L 

plant  enemies,  particularly  the  leaf-eating  caterpillars.  Others  of  the 
Soldier-bugs  feed  upon  the  juices  of  the  plant  for  a  short  time  after 
hatching,  and  afterwards  live  exclusively  upon  insects. 

The  most  rapacious  of  the  bugs  belong  to  the  family  Reduviidas,  and 
have  the  head  well  separated  from  the  body  by  a  more  or  less  slender 
neck  ;  they  possess  a  stout,  curved  beak  and  long  legs,  well  fitted  for 
rapid  movements.  Many  of  these  species  bristle  with  spines,  especially 
in  the  younger  stages,  and  the  usual  colors  are  dark  brown  variegated 
with  red. 

THE   SPIDER-LEGGED   SOLDIER-BUG. 

(Leptocorisa  tipuloides  Latr.) 
[Plate  VI,  Fig.  4.] 

This  species  has  already  been  discussed  among  the  enemies  of  Bark- 
lice  (see  Chapter  VI).  It  is  very  commonly  seen  upon  the  Orange,  and 
frequents,  often  in  great  numbers,  trees  infested  with  Lecanium  Scales, 
and  not  only  sucks  the  juices  of  the  Bark-lice,  but  also  captures  ants 
and  other  insects  which  are  attracted  by  the  lice. 

This  predaceous  bug  should  not  be  confounded  with  the  plant-sucking 
Red  bug  (Dijsflcrcus  suturellus),  which  does  injury  to  the  fruit.  In  Lep- 
tocoris  i  the  form  is  slender ;  the  body  seven-tenths  of  an  inch  long  and 
the  legs  longer  than  the  body  ;  the  colors  are  orange  and  black. 

The  stouter  form  and  deep  red  color  of  the  Red-bug  render  the  two 
species  distinguishable  at  a  glance. 

Leptocorisa  must  be  classed  among  beneficial  insects,  sinc.e  it  feeds  to 
some  extent  upon  Plant-lice  and  Bark-lice ;  but,  like  many  predatory 
bugs,  it  captures  and  destroys  indiscriminately  the  friends  as  well  as 
the  foes  of  the  plant.  Possibly  at  times  it  subsists  almost  entirely  upon 
the  honey-dew  ejected  by  Plant-lice.  Acids  as  well  as  sweets  appear 
to  be  suited  to  its  taste,  and  it  is  one  of  the  few  insects  known  to' prey 
upon  ants,  the  juices  of  whose  bodies  are  strongly  flavored  with  formic 
acid. 

The  following  soldier-bugs  form  part  of  a  great  army  of  pmlaceous 
insects  which  frequent  the  orange  tree,  but  have  no  very 
close  connection  with  the  plant  or  its  especial  fauna. 

THE  RAPACIOUS  SOLDIER-BUG. 

(Sinea  multispinosa,  De  Geer.) 

[Fig.  92.1 

FIG.  92  —Sinea  mul- 

Colors  brownish,  with  a  red  stripe  along  the  upper       ttspinosa.    (Alter 
surface  of  the  abdomen.     The  body  is  slender,  but  less 
so  than  Leptocorisa.    The  young  bugs  are  said  to  feed  upon  Plant-lice  j 
the  atUiltSj  boweyer,  attack  insects  of  large  size. 


192 


INSECTS    AFFECTING    THE    ORANGE. 
THE   WHEEL-BUGr. 

(Prionotus  cristatusj  Linn.) 
[Fig.  93.] 


FIG.  93.— Prionotua  cristatut.    (After  Glover.) 


This  large  bug  is  not  uncommon  in  orange  groves.  Its  body  and  legs 
are  covered  with  a  coat  of  very  fine,  close  down,  giving  it  an  ash-gray 
color  5  the  thorax  rises  in  a  semi  circular  ridge,  which  is  provided  with 
short,  projecting  spines,  regularly  placed,  like  the  teeth  of  a  cog-wheel ; 
the  head  is  small,  but  is  armed  with  a  powerful  beak,  which  is  capable 
of  giving  a  poisonous  stab,  more  painful  to  man  than  the  sting  of  a 
hornet. 

Mr.  Glover,  in  the  Eeport  of  the  Commissioner  of  Agriculture  for 
1875,  gives  an  extended  account  of  this  insect,  a? , v^iows  that  it  is  very 
voracious  in  all  its  stages ;  the  young  prey  upon  Aphis  and  other  small 
or  soft-bodied  insects,  and  after  paralyzing  them  with  their  deadly  sting 
suck  and  empty  them  of  their  juices. 

The  eggs  are  urn-shaped,  as  shown  in  the  figure,  and  are  deposited  in 
large  clusters,  firmly  cemented  to  each  other,  and  placed  in  all  sorts  of 
situations,  but  usually  upon  some  firm  support,  su,ch  as  the  trunk  of  a 
tree  or  the  side  of  a  building,  or  fence  rail. 

The  young  wheel  bugs  are  bright  red  with  black  markings. 

The  Green  Soldier-bug  (Raphigaster  liilaris  Fitch),  the  two  species 
of  Metapodius  (M.  femoratus,  and  M.  terminalis),  with  the  closely  allied 
species,  Euthochtha  galeator  Fabr.,  have  already  been  noticed  as  partly 
plant-feeding,  but  with  rapacious  habits  also. 


INNOXIOUS   INSECTS    FREQUENTING   THE    ORANGE.  193 

INNOXIOUS  INSECTS. 

CASE-BEARERS  ON  ORANGE. 

The  trunks  of  orange  trees  are  favorite  feeding-grounds  for  the  larvae 
of  several  small  moths  of  the  family  Tineidre,  which  protect  their  bodies 
with  cases  formed  of  fragments  of  their  food  material.  In  the  case  of 
those  species  which  are  met  with  upon  orange- tree  trunks  the  food  con- 
sists of  lichens  or  other  minute  cryptogams  found  growing  upon  the 
bark. 

A  very  common  species  belongs  apparently  to  the  genus  Goleophora. 
Its  case  is  dull  white,  about  the  size  and  somewhat  the  shape  of  a  grain 
of  oats;  it  is  rather  smooth  outside,  and  seems  to  be  formed  of  finely 
comminuted  bark. 

THE   ORANGE   CASE -BEARING  TINEID. 

(Coleotechnites  citriella  Chambers.) 

This  species  was  first  made  known  in  the  Keport  of  the  Commissioner 
of  Agriculture  for  1879,  which  contains  the  following  account  of  its 
habits.  Mr.  Chambers7  descriptions  of  the  genus  and  species  will  be 
found  in  the  same  report,  page  206 : 

"At  Manatee,  Fla.,  in  the  latter  part  of  April,  I  found  upon  the  trunk 
of  an  orange  tree  the  case  of  a  Tineid  larva.  This  case  was  rather  slen- 
der, llmm  (.43  inch)  long,  and  rather  pointed  at  the  hinder  extremity. 
It  was  dark  gray  in  color,  resembling  the  bark  upon  which  it  was  found, 
and  was  apparently  composed  of  small  bits  of  lichens  and  excremental 
pellets,  with  much  gray  silk.  The  moth  issued  March  6,  and  upon  be- 
ing referred  to  Mr.  Chambers  proved  to  be  a  new  species  representing 


a  new  genus." 


BARK  CLEANERS. 


Among  the  host  of  harmless  insects  that  from  time  to  time  make  their 
appearance  upon  the  orange  tree,  there  is  a  group  of  scavengers  that 
frequent  the  trunks  and  assist  in  cleansing  the  bark,  by  devouring  the 
fungi,  molds,  or  excreta  of  other  insects  that  befoul  its  surface.  Of 
these  the  most  conspicuous  examples  are  certain  nerve- veined  insects 
(Neuroptera)  belonging  to  the  genus  Psocus. 

Psocus  VENOSUS  Burm. 

The  adult  of  this  species  is  smoky-brown ;  head  dark  bronze ;  an- 
tenna dusky,  lighter  at  the  base,  densely  hairy  in  the  male;  thorax  mar- 
gined with  yellow ;  fore-wings  almost  black,  the  three  basal  veins  yellow, 


194  INSECTS   AFFECTING   THE    OEANGE. 

with  a  triangular  spot  of  yellow  color  (pterostigma)  near  the  margin 
toward  the  tip  j  hind-wings  smoky,  hyaline  ;  feet  yellowish,  with  dusky 
tips ;  length  5mm  to  8mm  (-&  to  •&-  inclO- 

These  little  animals  are  seen  upon  the  trunks  of  orange  trees  in  flocks 
numbering  from  a  dozen  to  forty  or  fifty  individuals.  They  feed  in 
companies  and  browse  upon  the  lichens  which  they  cleanly  remove  from 
the  bark,  leaving  a  clear  space  behind  them.  The  colonies  consist  of 
one  or  more  families  and  include  individuals  of  all  ages,  the  wingless 
young  herding  with  the  adult  insects. 

The  adults,  although  winged,  do  not  readily  take  flight.  When 
alarmed  the  troop  huddles  together  for  mutual  protection  like  sheep, 
but  if  directly  attacked,  or  when  seized  with  a  sudden  panic,  they  scatter 
in  every  direction  and  run  nimbly  over  the  bark,  with  which  their  drab 
colors  harmonize  so  closely  that  they  are  not  easily  distinguished  upon 
its  surface.  If  left  undisturbed,  the  herd  in  a  short  time  reassembles 
and  quietly  resumes  its  methodical  attack  upon  the  lichens. 

The  eggs  are  oval,  glistening  white ;  they  are  laid  upon  the  bark  in 
batches  of  15  to  30,  deposited  on  end  in  several  rows  obliquely  overlap- 
ping each  other,  and  the  batch  is  protected  by  an  oval,  convex  shield  of 
comminuted  wood  which  surrounds  and  adheres  closely  to  the  eggs. 

The  females  watch  their  eggs,  and  as  soon  as  they  are  hatched  lead 
their  young  ones  forth  to  pasture. 

This  delicately  organized  insect  is  fond  of  shade  and  moisture  and  is 
most  commonly  seen  in  densely- shaded  groves  and  old  gardens.  It  is 
not  restricted  to  the  orange,  nor  is  it  compelled  to  live  upon  plants 
alone ;  it  may  thrive  on  walls  or  fences,  wherever  lichens  grow.  The 
smooth  bark  of  the  orange,  when  conditions  favor  the  growth  of  fungi, 
affords  excellent  pasturage  to  this  Psocus  and  it  frequently  becomes 
very  abundant. 

It  is  hardly  necessary  to  point  out  that  to  the  extent  of  its  feeble 
powers  this  is  a  useful  insect,  and  its  presence  should  excite  no  alarm. 
Psocus  venosus  is  more  distinctively  a  northern  than  a  southern  insect 
and  does  not  inhabit  the  extreme  southern  portion  of  the  orange  dis- 
trict in  Florida.  The  adult  insects  hibernate  and  begin  breeding  early 
in  the  spring. 

THE   ORANGE  PSOCUS. 

(Psocus  citricola  Ashmead.) 

This  is  a  smaller  species  than  the  preceding.  Length  2.5mm  to  3mm 
(TOO-  to  TO^O  inch).  The  color  is  white  or  pale  yellow;  the  adults  have 
very  transparent,  hyaline  wings.  At  all  ages  the  semi-transparent 
body  shows  the  color  of  the  intestinal  contents,  which  varies  consider- 
ably with  the  condition  and  nature  of  the  food.  This  consists  of  the 
wax  and  other  soft  excretions  of  Bark-lice,  of  honey-dew,  and  probably 


INNOXIOUS    INSECTS    FREQUENTING    THE    ORANGE.  195 

also  of  minute  fuugi  or  their  spores,  which  germinate  on  leaves  and 
bark  infested  with  insects. 

The  eggs  are  pearly-white  and  are  laid  in  hollows  upon  orange  leaves, 
in  clusters  of  ten  or  twelve,  tightly  covered  with  a  shield  of  black  ex- 
cremeutitious  matter.  Over  this  is  stretched  a  light  canopy  of  web,  in 
which  are  entangled  a  few  minute  black  grains  of  excrement.  The  ex- 
treme transparency  of  the  egg  envelopes  as  well  as  of  the  animal  itself 
affords  an  unusually  favorable  opportunity  for  the  study  of  the  changes 
that  precede  its  birth. 

Just  before  hatching  the  embryos  lie  with  their  backs  to  the  surface 
of  the  leaf  and  are  not  curled  in  the  egg,  but  the  head  only  is  bent  over 
upon  the  breast.  As  the  egg-shell  is  absolutely  transparent  and  the 
embryo  very  nearly  equally  so,  all  internal  changes  of  form  can  be 
plainly  seen. 

In  hatching,  the  first  movement  seen  is  the  formation  of  air  bubbles, 
which  pass  in  rapid  succession  between  the  mouth  organs  aud  collect 
in  a  larger  bubble  within  the  head  of  the  embryo.  From  time  to  time 
this  larger  bubble  passes  through  the  constriction  of  the  neck  and  dis- 
appears in  the  body  cavity.  The  head  of  the  embryo  gradually  swells, 
elongates,  and  distends  the  elastic  egg-shell  at  the  end,  until  this  finally 
bursts  and  the  young  insect  protrudes  its  body,  curving  upwards  and 
forwards. 

Air  continues  to  pass  through  the  neck  into  the  abdomen,  which  be- 
comes greatly  distended  and  elongated,  showing  the  segments.  A  mus- 
cular movement  not  connected  with  the  passage  of  the  air  bubbles  is 
seen  in  the  frontal  part  of  the  head  and  the  occiput  is  frequently  drawn 
inwards,  forming  a  deep  depression. 

The  bursting  of  the  first  larval  skin  was  not  witnessed,  but  it  evidently 
takes  place  soon  after  the  abdomen  is  fully  distended.  The  larva  re- 
mains for  many  hours  in  an  erect  position,  with  the  tip  of  the  body 
clasped  by  the  egg-shell  and  the  cast  larval  skin.  The  head,  at  first 
elongate,  becomes  transverse  and  there  is  a  general  contraction  and 
change  of  form  in  all  the  parts. 

After  the  larva  has  freed  itself  from  the  ^egg-shell  and  envelopes,  the 
abdomen  is  gradually  contracted  by  the  exertion  of  considerable  and 
long-continued  muscular  effort  and  changes  from  a  cylindrical  to  a  cor- 
date form. 

The  process  of  hatching  occupies  several  days,  and  the  young,  as  we 
have  seen,  make  their  entrance  into  the  world,  like  a  marsupial,  in  a 
somewhat  rudimentary  condition. 

The  Orange  Psocus  lives  chiefly  upon  the  leaves  of  plants,  associated 
in  small  flocks  or  families.  It  passes  the  greater  part  of  its  life  hiding 
under  the  canopies  of  web  erected  over  the  egg-clusters.  Here  the 
mother  awaits  the  appearance  of  her  brood,  and  here  the  young  insects 
cluster,  sallying  forth  from  time  to  time  with  the  adult  in  search  of 
food. 


196  INSECTS   AFFECTING   THE   ORANGE. 

The  species  breeds  continuously  in  summer  and  some  eggs  are  hatched 
even  in  winter.  The  adult  insects  hibernate  in  protected  places,  but 
are  more  delicate  than  their  northern  relative  and  probably  do  not 
extend  beyond  the  region  in  which  the  Orange  is  grown. 

The  operations  of  this  Psocus  are  apparently  of  trifling  importance ; 
it  is,  however,  one  of  the  commonest  of  orange  insects  and  as  such  at- 
tracts considerable  attention. 


APPENDICES. 


APPENDIX   I. 

THE  ME  ALT  BUG  AT  OEANGE  LAKE,  FLORIDA. 

[Extracted  from  a  letter  by  Jos.  Voyle,  Gainesville,  Fla.,  June  12,  1884.     Reprinted 
from  Bulletin  4,  Division  of  Entomology,  U.  S.  Department  of  Agriculture,  p.  85.] 

Having  business  near  Orange  Lake  during  the  past  week,  I  visited  several  orange 
groves.  I  found  all  of  the  Florida  varieties  of  Scale-insects  in  abundance.  Oranges 
are  already  rusty,  and  the  Rust-mite  in  many  places,  on  both  leaves  and  fruit,  in  such 
large  numbers  as  to  give  a  distinct  coloration,  distinguishable  at  a  distance  of  ten 
feet. 

But  the  most  destructive  insect,  at  present  absorbing  all  the  attention  of  the  orange- 
growers  there,  is  the  Mealy-bug,  Dactylopiua  destructor*  This  insect  causes  the  fruit 
to  rot  under  the  colonies.  A  favorite  place  of  lodgment  is  at  the  stem,  under  the 
calyx ;  the  result  is,  the  fruit  drops. 

I  staid  there  three  days  to  examine  methods  used  and  experiment  in  their  destruc- 
tion. 

The  cotton  y  armor  repels  all  watery  solutions. 

The  methods  used  are :  spraying  each  separate  colony  with  pure  kerosene  by  means 
of  bellows  atomizers;  and  mechanical  action — rubbing  or  pinching  each  separate 
colony  (by  colony  I  mean  the  little  clusters  consisting  of  from  ten  to  several  hundred 
individuals) ;  this  is  done  by  the  fingers. 

I  examined  the  trees  that  had  been  treated  with  the  kerosene  spray  and  found  both 
the  leaves  and  fruit  spotted  yellow.  I  was  also  informed  that  fruit  saved  in  this  way 
two  years  ago  was  useless,  having  absorbed  the  odor  of  kerosene.  The  effective 
progress  made  by  the  means  used  is  trifling,  in  consideration  of  the  work  to  be  done. 
I  tried  experiments  with  solutions  of  murvite  sprayed  on,  but  with  no  good  result ; 
then  tried  kerosene  butter,  using  thick;  milky  solution  of  murvite,  which  combines 
in  exactly  the  same  way  as  with  cow's  milk,  and  found  that  an  effective  emulsion 
could  thus  be  made. 

After  using  and  watching  the  action  of  this  for  some  time,  I  saw  that  the  interior  in- 
sects of  a  dense  mass  were  protected  by  the  exterior  ones ;  further  experiments  were 
made  to  meet  this  difficulty.  By  watching  the  men  at  work  I  saw  that  nearly  every 
infested  orange  was  handled  to  turn  all  of  its  sides  to  the  eye ;  that  wherever  a  large 
colony  found  lodgment  in  a  fork  of  twigs  or  in  a  depression  of  the  bark  they  were 
handled,  also  that  the  bunches  of  Spanish  moss  (Tillandsia)  formed  formidable  breed- 
ing places.  All  of  these  require  force  for  their  dislodgment. 

A  strong  stream  of  water  was  tried  and  proved  effective,  but  laborious,  and  the  in- 
sects falling  to  the  ground  were  not  killed. 

Experiments  with  solution  of  murvite,  made  under  a  microsocope,  showed  that  in 
all  cases  where  the  solution  came  into  actual  contact  with  the  skin  of  the  insect  the 
bug  was  instantly  killed.  Acting  upon  this  and  the  knowledge  gained  by  previous 
observation  and  experiment,  I  tried  the  effect  of  a  fine,  solid  stream  issuing  under 
pressure,  using  a  solution  of  murvite,  one  part,  to  water  two  hundred  and  fifty  parts. 

197 


198  INSECTS   AFFECTING   THE    ORANGE. 

The  results  were  excellent ;  the  solution  heing  forced  into  the  colonies  broke  them  up, 
and  coming  into  contact  with  the  insects  killed  them,  the  method  of  working  being 
one  man  at  the  pump,  another  to  guide  the  stream.  The  apparatus  improvised  be- 
ing badly  adapted  to  the  purpose  is  very  awkward.  The  work,  although  about  four 
times  as  fast  as  with  the  bellows  atomizer,  is  not  adequate  to  the  economical  require- 
ments. This  method  has  the  merit  of  no  loss  by  damage  to  fruit  or  leaves  by  the  ma- 
terial used ;  the  waste,  falling  on  the  leaves  and  branches,  will  exterminate  both  scale - 
insects  and  rust-mites,  these  being  plentiful,  but  neglected  in  the  presence  of  the  more 
pressing  necessity  of  saving  the  growing  crop  from  destruction  by  the  Mealy-bug. 


APPENDIX    II. 

EXPERIMENTS  WITH  INSECTICIDES. 

[In  part  a  reprint  of  matter  published  in  the  Report  of  the  Entomologist,  Annual  Re- 
port of  the  Commissioner  of  Agriculture  for  1881-'82.  pp.  120-126.] 

TABLE  I.— KEROSENE  EMULSIONS. 

In  Table  I  are  given  the  results  of  seventeen  experiments  with  kerosene  in  milk 
emulsions  of  varying  strength.  When  the  percentage  of  Coccids  killed  is  given,  this 
was  obtained  by  cutting  twigs,  leaves,  and  portions  of  infested  bark  from  all  parts  of 
the  tree,  and  examining  microscopically. in  the  laboratory  large  numbers  of  the  scales 
upo  n  them.  Under  the  head  of  young  Coccids  are  included  all  those  which  have 
well-formed  scales  but  have  not  begun  to  lay  eggs.  The  youngest  Bark-lice,  or 
those  which  have  not  yet  molted,  were  almost  invariably  killed,  and  are  not  included 
in  the  enumeration. 

'The  percentage  of  young  Coccids  killed  is  given  separately,  including  under  this 
head  all  ages  between  the  formation  of  the  permanent  scale  and  the  appearance  of 
eggs,  but  no  larvaB  before  the  first  molt ;  the  latter  were  in  nearly  every  case  all  killed. 
Of  scales  which  contained  eggs  three  classes  were  examined  and  the  percentage  of 
each  obtained:  (1)  Scales  in  which  a  portion  only  of  the  eggs  were  destroyed;  (2) 
Scales  in  which  all  the  eggs  were  killed ;  (3)  Scales  in  which  no-eggs  were  killed. 

Purple  Scales  (Mytilaspis  cilricola)  were  not  abundant,  but  appear  to  be  somewhat 
less  readily  destroyed  than  Long  Scale.  All  the  experiments  were  made  upon  young 
orange  trees  from  three  to  six  years  old.  An  Aquapult  pump  of  medium  size  was 
used,  and  in  each  case  the  trees  were  sprayed  from  the  ground  and  on  four  sides. 
Where  the  trees  were  more  than  eight  or  ten  feet  in  height  the  upper  branches  did 
not  receive  the  spray  with  sufficient  force,  and  show  in  some  cases  a  smaller  percent- 
age of  Bark-lice  destroyed  than  the  lower  portions  of  the  same  tree.  For  full-grown 
trees  a  larger  pump  is  needed,  and  the  apparatus  should  be  placed  in  a  cart  or  other- 
wise raised  above  the  ground  when  used. 

The  emulsions  used  were  made  as  follows : 

No.  2.  Kerosene,  1  pint ;  sour  cow's  milk,  2  fluid  ounces,  dashed  with  a  ladle ;  2 
drachms  of  powdered  chalk  were  first  added  to  the  milk,  and  2  ounces  water  during 
the  stirring. 

An  imperfect  emulsion,  not  readily  suspended  in  water. 

No.  3.  Kerosene,  I  quart ;  solution  of  condensed  milk,  3  parts ;  water,  5  parts,  12 
fluid  ounces. 

Emulsion  made  by  spraying  through  the  Aquapult  pump  and  back  into  the  pail. 
Stable,  and  readily  suspended  in  water. 

No.  9.  Kerosene,  1  quart ;  condensed  milk,  12  fluid  ounces,  diluted  with  water,  36 
ounces ;  emulsified  with  the  Aquapult. 

No.  10.  Kerosene,  25.6  fluid  ounces ;  condensed  milk,  4.8  fluid  ounces ;  water,  14.4 
ounces;  emulsified  with  pump. 

No.  11.  Kerosene,  2  quarts ;  condensed  milk,  12  fluid  ounces  (1  can) ;  water,  20 
ounces;  with  pump. 

No.  13.  Kerosene,  2  quarts,  4  fluid  ounces ;  condensed  milk,  12  fluid  ounces  ;  water, 
24  ounces;  with  pump. 

199 


200 


INSECTS   AFFECTING   THE    ORANGE. 


TABLE  1.  —  Kerosene  emulsions. 

1 

Bark,  leaves,  and  twigs  of  lower  branches. 
Thorns  from  upper  branches.  November  10,  a  few  gravid  females  still 
living,  also  4  few  young  scales  forming  from  eggs  recently  hatched. 
Second  application  effectively  cleared  the  tree  of  scales  ;  only  an  oc- 
casional gravid  scale  found  alive  on  upper  branches. 
No  appreciable  effect  upon  eggs  or  mature  coccids. 
Thickly  infested  bark  of  lower  limbs.  Upper  branches  give  variable 
results. 
Bark,  twigs,  and  leaves  from  all  parts.  Prolonged  examination  ;  not  a 
living  .coccid  or  egg  can  be  found.  Mites  swarm  under  the  dead 
scales  and  have  probably  completed  the  work  of  the  wash. 

Result  about  the  same  as  in  No.  24,  or  slightly  less  effective  and  vari- 
able. 
Variable;  some  branches  give  poor  results.  Evidently  not  enough 
liquid  used  lor  thorough  application. 
Small  tree,  but  not  sufficient  wash  used.  Effect  on  Long  Scale  about 
equal  to  No.  25.  Lecanium  Scales  killed  only  where  the  spray  struck 
with  force 
Small  tree,  but  amount  of  wash  applied  entirely  insufficient.  Many 
branches  show  no  effect.  Very  fow  Long  Scale  killed. 
Result  about  the  same  as  in  No  24.  Second  application  four  days 
later. 
Almost  complete  extermination  of  Long  Scale.  A  few  living  coccids 
found  upon  a  twig  from  upper  branches.  On  the  same  twig  a  few 
,  living  Chaff'  Scale  were  also  iound. 

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202  INSECTS   AFFECTING  THE   ORANGE. 

Cost  of  kerosene  wash. — The  following  is  the  estimated  cost  for  a  standard  wash 
of  whale-oil  soap  and  kerosene  emulsion  containing  67  per  cent,  of  oil,  and  diluted  1 
to  9: 

Kerosene,  2  gallons,  retail  at  20  cents $0.40 

Soap,  i  pound,  retail  at  10  cents 5 

Water,  1  gallon 0 

Emulsion,  3  gallons 45 

At  wholesale  rates,  18  cents  for  kerosene  and  8  cents  for  soap,  three  gallons  of  emul- 
sion cost  40  cents  =  13£  cents  per  gallon.  One  gallon  of  emulsion  =  10  gallons  of 
diluted  wash ;  cost,  15  cents.  Cost  of  wash  per  gallon,  1^  cents. 

With  the  "Aquapult"  pump  and  " Cyclone"  nozzle,  four  gallons  of  wash  is  suffi- 
cient for  thirty  nursery  trees  of  one  and  two  years  from  the  bud.  Cost  per  tree,  two- 
.tenth  cent. 

Trees  which  have  been  transplanted  and  have  made  two  years'  average  growth  in 
the  grove  (3  or  4  years  from  the  bud)  require  about  two-thirds  of  a  gallon  of  wash. 
Cost,  I  cent  per  tree.  Bearing  trees  of  full  size  will  require  from  5  to  10  gallons  of 
wash.  Cost,  7  to  15  cents ;  average  about  10  cents  per  tree. 

TABLE  2.— WHALE-OIL  SOAP. 

In  Table  2  are  given  the  results  of  experiments  with  solutions  of  whale-oil  soap 
applied  in  fine  spray  to  all  parts  of  the  trees  by  means  of  the  aquapult  pump.  The 
solutions  were  all  applied  hot,  being  either  solid  when  cool  or  too  thick  for  spraying 
through  the  pump. 


APPENDIX    II. 


203 


Remarks. 

Tree  infested  with  Long  Scale  and  a  few  scattered  Chaff  Scale; 
nearly  every  coccid,  old  and  young,  killed  ;  a  very  few  Chaff  Scale 
still  alive;  eggs  of  both  scales  absolutely  uninjured;  tree  rather 
large;  not  enough  liquid  used. 
Long  Scale  completely  exterminated;  eggs  and  young  probably  de- 
stroyed by  mites;  living  Chaff  Scale,  nearly  all  young  or  nearly 
adult,  numerous  on  some  parts. 
Small  tree  ;  very  thorough  application  ;  at  noon  in  the  sun. 

Both  Long  and  Chaff  Scale  completely  exterminated  upon  nearly  all 
pnrts  of  the  tree:  several  twigs,  however,  have  escaped  thorough 
wetting,  and  are  still  moderately  infested  with  one  or  both  kinds  of 
scale. 
Tall  tree  ;  difficult  to  cover  with  liquid  ;  adult  female  coccids  not  all 
killed. 
A  few  individual  Long  Scale  found  alive  on  some  branches  •  1  or  2  per 
cent,  living. 
Small  tree  ;  Long  Scale  which  have  not  completed  the  first  molt  are 
all  killed;  the,  proportions  given  include  coccids  from  passed  first 
molt  to  adult;  a  few  Chaff  Scale  seen,  all  living;  no  gravid  fe- 
male coccida  killed. 
Small  tree;  thorough  application;  a  few  Chaff  Scale  intermingled 
seem  not  to  have  been  affected. 
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204  INSECTS   AFFECTING   THE    ORANGE. 

TABLE  3. — LYE  SOLUTIONS. 

The  following  is  a  synopsis  of  experiments  with  potash  and  soda  in  caustic  solutions : 

Experiments  with  potash. — Experiment  No.  90. — Solution,  1|  pounds  potash  to  1  gallon 
water.  Applied  in  fine  spray  to  two  thrifty  young  trees,  about  four  years  old.  Leaves 
and  tender  shoots  wilted  visibly  and  changed  color  during  the  application,  showing, 
a  few  minutes  later,  spots  of  brown.  Two  days  after  the  application  all  the  leaves 
were  dead  and  dried  up  as  if  by  fire,  and  remained  adhering  to  the  branches.  Young 
growth  entirely  killed  and  pitted  with  holes.  Three  weeks  later  all  branches  under 
one  inch  in  diameter  were  found  to  be  entirely  killed,  the  bark  of  larger  branches 
partly  destroyed,  the  bark  of  trunk  blackened  and  hardened,  but  not  destroyed.  Upon 
the  latter  buds  had  begun  to  appear.  Upon  those  portions  of  the  tree  where  the  bark 
was  entirely  destroyed  the  insects  themselves  were  destroyed,  but  one-tenth  of  the 
scales  upon  the  dead  bark  contained  living  eggs.  Where  the. bark  was^not  entirely 
destroyed  half  of  the  Coccids  and  more  than  half  of  their  eggs  escaped.  The  tops  of 
both  trees  were  killed  and  their  shape  and  symmetry  ruined.  A  40  per  cent,  kerosene 
emulsion  would  have  been  as  effective  in  destroying  the  Scale-insect,  and  would  have 
had  no  appreciable  effect  on  the  tree.  A  67  per  cent,  emulsion,  which  would  have 
exterminated  the  insects,  would  have  partially  defoliated  the  most  thickly  infested 
branches,  without  affecting  the  vigorous  portions  of  the  tree. 

Experiment  No.  91. — Solution,  1  pound  potash  to  1  gallon  water.  Applied  to  two 
small  trees  very  badly  infested  with  Scale-insects.  Owing  to  the  enfeebled  condition 
of  the  trees,  the  effect  of  the  lye  was  as  severe  as  in  the  preceding  experiment.  Five 
weeks  later  one  of  the  trees  was  recovering,  the  other  dying,  and  Scale-insects  in  both 
cases  increasing. 

Expei'iment  No.  94. — Solution,  two-thirds  pound  potash  to  1  gallon  water.  Applied 
to  several  young  trees.  Nearly  all  the  leaves  dropped  and  many  branches  killed. 

Experiment  No.  92. — Solution,  one-half  pound  potash  to  1  gallon  water.  Applied  to 
two  small  trees  badly  infested  with  Long  Scale.  Both  trees  badly,  one  completely, 
defoliated.  Tender  bark  and  smaller  branches  killed.  Four  or  five  weeks  later  the 
trees  were  recovering,  but  young  brood  of  Scale-insect  had  thickly  coated  all  the 
living  branches. 

Experiment  No.  95. — Solution,  four-tenths  pound  potash  to  1  gallon  water.  Applied 
to  a  tree  of  medium  size  and  in  good  condition.  Great  injury  to  foliage  and  tender 
bark.  One  month  later  the  trees  were  recovering,  but  Scale-insect  increasing. 

Experiment  No.  93.— Solution,  three-tenths  pound  potash  to  one  gallon  water.  De- 
vitalized branches  completely  defoliated ;  other  portions  less  severely  affected.  Bark 
blackened  and  hardened.  One  month  later  trees  recovering ;  Scale-insect  not  dimin- 
dimiuished  in  numbers. 

Experiment  No.  96. — Solution,  one-fourth  pound  potash  to  1  gallon  water.  Applied 
to  a  vigorous  tree.  Tree  not  severely  defoliated.  Four  weeks  later  Scale-insect  in- 
creasing. 

Experiment  No.  86. — Solution,  one-sixth  pound  potash  to  1  gallon  water.  Applied  to 
a  tree  rather  badly  infested,  but  still  vigorous.  Tree  slightly  defoliated.  Scale- 
insect  not  checked  and  no  eggs  killed. 

Experiments  with  soda  lye. — The  strongest  application  of  soda  lye,  two-thirds  pound  to 
1  gallon  water,  was  not  more  severe  in  its  effects  upon  the  tree  than  one-half  this  amount 
of  potash  applied  in  Experiment  No.  93.  The  bark  was  blackened,  but  not  destroyed, 
and  the  tree  was  severely  defoliated.  The  application  had  no  permanent  effect  in 
removing  the  Scale-insects,  but  these  were  afterwards  destroyed  by  an  application  of 
kerosene  emulsion,  and  the  tree  in  consequence  fully  recovered  its  vigor.  The  remain- 
ing experiments  with  soda  lye — 1  pound  to  2, 1  pound  to  2i,  and  1  pound  to  3  gallons 
of  water,  respectively  (Nos.  43,  44,  and  45)— failed  to  check  the  increase  of  the  Scale- 
insect.  One  year  later  these  trees  had  lost  instead  of  adding  to  their  growth,  and  ap- 
peared to  be  in  dying  condition,  the  continued  presence  of  the  insects  having  prevented 
a  recovery  from  the  effects  of  the  lye.  The  Scale-insects  were  subsequently  removed 
by  applications  of  kerosene,  and  the  trees  began  to  improve  rapidly. 


APPENDIX    II. 


205 


Remarks. 

• 

Only  a  few  Chaff  Scales  examined  ;  all  of  them  alive. 
Long  Scale  only.  No  appreciable  result. 
Long  and  Chaff  Scale  together.  No  result  whatever. 
Do. 
All  small  branches  killed,  bark  of  trunk  burned  and 
hardened,  but  not  dostroyed,  pushing  out  adventitious 
buds.  Upon  portions  where  bark  is  utterly  destroyed 
8  per  cent,  of  the  scales  have  eggs  nil  alive. 
Tree  badly  injured,  completely  defoliated  and  killed 
back  to  larger  branches. 
Tree  reduced  to  trunk  and  one  living  branch,  the  latter 
covered  with  new  brood  of  scale. 

Several  trees.  Kesults  unequal. 

July  4.  Two  trees,  branches  more  or  less  killed  back  ; 
trees,  however,  recovering.  Living  branches  thickly 
coated  with  forming  brood  of  Long  Scale.  Application 
not  effective. 
Chaff  Scale  very  slightly  affected.  Eggs  all  alive. 
Adult  females  of  Long  Scale  part  killed.  Females  of 
Chaff  Scale  not  killed.  July  4  trees  recovering, 
Scales  as  bad  as  before. 
Few  Long  Scales  examined,  few  or  no  eggs  killed. 
Scales  increasing.  No  appreciable  effect. 
A  few  young  killed.  Eggs  hatching. 
Tree  covered  with  new  brood  of  Long  Scale.  No  effect. 

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^'o'o'o'o     "o         "§             "o     "o             "oo         "p      o 
ccojcflco     PH         PH            PH     PH            PnPn         PH     PH 

•*u9ura9dx9  jo'wqran^; 

C3  CO  -^  1C  O                      rH                     *4*         (M                     ^2?               52        SS 
•^^^^0>                 0>                 Oi)       0                 00            Oi       00 

206  INSECTS   AFFECTING   THE   ORANGE. 

TABLE  4. — CRUDE  CARBOLIC  ACID  (OIL  OF  CREOSOTE). 

In  Table  4  are  given  results  of  experiments  with  carbolic  acid  in  solution  and  com- 
bined with  other  substances. 

In  experiment  No.  27,  9  fluid  ounces  of  carbolic  acid  was  applied  to  a  single  tree 
about  five  years  old.  The  tree,  which  was  badly  infested  with  Long  Scale,  and  had 
many  branches  dead  and  dying,  was  severely  defoliated,  and  lost  some  moribund 
branches,  but  recovered  in  six  weeks  and  pushed  out  new  growth  in  midwinter. 

In  experiment  No.  30  a  pint  measure  of  crumbled  carbolic  soap  was  applied.  The 
actual  amount  of  acid  contained  in  this  soap  did  not  exceed  2  fluid  ounces.  The  ex- 
termination of  Long  Scale  was  complete.  The  tree,  which  was  very  badly  infested 
and  in  poor  condition,  was  almost  completely  defoliated  and  lost  half  its  branches, 
but  recovered  very  rapidly  and  pushed  out  new  leaves  within  thirty  days.  (January 
25.) 

In  experiment  No.  21  the  other  substances  added  to  the  carbolic  solution  increased 
the  injury  to  the  foliage  of  the  tree  and  it  was  very  severely  checked,  but  entirely  re- 
covered and  was  stimulated  to  vigorous  growth  at  a  time  when  all  surrounding  trees 
were  dormant. 

In  the  remaining  experiments,  13,  14,  15,  and  12,  the  quantity  of  carbolic  acid  used 
was  not  sufficient  to  kill  the  Scale-insects.  The  effect  upon  the  trees  was  also  very 
slight. 


APPENDIX    II. 


207 


208 


INSECTS   AFFECTING   THE   ORANGE. 


• 


31  ?l«s«  i  . 

3«  *Sft^8    ^    ** 

|1  Hill  "  I 

ll  S*?l  I  si 


*  -^ 


3  § 

H       H) 


6   1 


'P9!!!3!  9uoa  'sSS^ 


•penr^l  eppooo  Stra 


T9itR  n^  ' 


•patn^i  sppooo  Sanoi 


2 


i!il 

.g^txss     a  a  a-aS  a<N  «s  Sa^g's-Pai  HO* 

P  H     W         W  OOUM 


ni  p9sn  '^unonn;    !ppB 


o  o 

3  « 

«  s 

w  t-5 


•aoqnmji          5 


APPENDIX    II.  209 

TABLE  5.— BISULPHIDE  OF  CARBON. 

In  table  5  are  given  the  results  of  several  experiments  with  this  insecticide.  The 
emulsion,  of  which  the  ingredients  are  given  in  the  table,  was  formed  by  beating  to- 
gether with  a  spatula  the  carbon  and  lard  oil  and  then  adding  the  milk  and  water, 
and  emulsifying  in  the  same  manner. 

The  trees  in  experiments  40  and  41  were  very  severly  checked,  although  not  seriously 
injured,  and  all  subsequently  recovered.  In  experiment  39  the  mixture  was  applied 
during  a  rain,  and  was  entirely  without  effect  upon  the  tree  or  scale. 


210 


INSECTS    AFFECTING    THE    OEANGE. 


i  1 


1  I 


-  I 

a  a 


Chaff  Sc 
.  pergan 


•pguR  spioooo  Sanoi 


•uoi^aitnexo  jo  9jBQ[ 


pa^njip  jo  ;unoiuy 


_ 

I«TS   W 


c«  a  o  K  .5  ^^  w;  c  a 


«° 


S§ 


•^U90iij9dx9  jo  agqnrajji;          3 


APPENDIX    II.  211 

TABLE  6. — SILICATE  OF  SODA. 

Table  6  gives  the  results  of  a  single  experiment  in  which  silicate  of  soda,  in  the 
form  of  a  thick  liquid,  was  diluted  ten  times  and  applied  in  fine  spray. 

In  other  trials,  with  stronger  solutions,  the  best  result  obtained  was  80  per  cent, 
of  the  young  Coccids  killed,  and  trees  were  cleared  of  scale  by  repeated  applications 
at  interval0  of  several  weeks ;  but  in  these  cases  the  bark  was  hardened  and  the 
growth  of  the  trees  somewhat  checked. 


212 


INSECTS    AFFECTING    THE    ORANGE. 


'P8lttTl  9UOU 


•paitJ5[  epioooo  Sanoi 


'P9UR  9UOU 


pd^nm>  jo  ^anoaiy 


•uoi^oiiddB  eiSuis  ui  pasu  ^anorav 


II 

^  =3 


•    a 


0 


Jo 


•jaerajjedxe  jo  aequmji         §J 


APPENDIX    III. 

THE  COITION  OF  BAG  WORMS. 

The  following  is  an  extract  from  an  account  of  certain  Australian  Bag- worms,  by 
William  W.  Saunders,  as  read  before  the  Entomological  Society  of  London,  February 
1, 1847.* 

"August  30. — On  this  day  I  first  observed  a  yellowish  white  substance  protruding  at 
the  lower  end  of  the  largest  cases,  which  upon  close  examination  proved  to  be  a  por- 
tion of  the  females  in  the  imago  state,  one-third  of  their  bodies  being  exposed.  About 
an  hour  afterward,  examining  the  cases  again,  I  found  the  females  had  receded,  and  in 
opening  a  case  the  female  moth  became  evident  within,  and  thus  they  emerge  and 
recede  as  occasion  may  require..  The  female  is  a  lo,rge  apterous  moth,  with  a  very 
little  of  the  ordinary  appearance  of  an  insect  of  the  moth  kind.  The  length  is  about 
If  inches,  diameter  full  half  an  inch,  color  yellowish  white,  fawn,  or  buff;  head  and 
three  first  segments  of  the  body  naked  and  glossy  on  the  upper  part;  feet  very  short. 
Antennae  none,  or  at  least  not  visible  to  the  unassisted  eye ;  anal  segment  of  the 
body  clothed  all  round  with  a  dense  covering  of  silky  down  [42]  of  a  deeper  color  than 
the  rest  of  the  body ;  ovipositor  well  developed. 

" September  5. — Examined  some  of  the  females,  no  males  having  yet  appeared.  Two 
or  three  were  dead ;  one  nearly  so,  having  deposited  a  great  number  of  ova  in  the 
pupa  case,  which  were  enveloped  in  a  short  silky  material.  When  the  female  has  de- 
posited all  her  ova,  she  is  literally  nothing  but  thin  skin,  which  soon  desiccates,  leav- 
ing room  for  the  young  larvae  to  pass.  I  have  examined  other  species  of  Oiketicus,  and 
find  all  the  females  are  apterous. 

"September  20. — A  male  imago  appeared  this  morning.  It  had  been  in  active  opera- 
tion a  good  while,  as  evinced  by  its  wings,  being  much  broken  at  the  tips  and  other- 
wise much  abraded.  It  is  an  insect  of  very  peculiar  construction,  and  seems  to  have 
some  affinity  with  Zeuzera.  It  has  the  extraordinary  power  of  extending  the  abdo- 
men to  2  inches  in  length,  and  of  turning  and  twisting  it  in  all  directions.  When  in 
this  state  it  has  alternate  rings  of  black  and  yellow,  with  a  curious  appendage  at  the 
extremity.  The  male  appears  very  eager  to  accomplish  the  grand  object  of  nature, 
namely,  the  continuation  of  its  species,  as  its  existence  appears  to  be  of  short  dura- 
tion. The  large  fat  or  rather  distended  females  have  not  room  to  turn  their  bodies 
so  as  to  present  the  generative  organs  conviently  to  the  male,  consequently  the  immense 
development  of  the  abdomen  in  the  males  is  of  the  greatest  importance ;  but  it  appears 
very  extraordinary  that  the  head  of  the  female  should  be  inverted,  when  it  is  known 
that  she  never  emerges  from  the  case  unless  by  accidentally  falling  therefrom,  which 
position  obliges  the  male  when  in  the  act  of  coition  to  stretch  his  abdomen  all  along 
the  side  of  the  female  full  If  inches.  This  peculiarity  appears  to  me  to  be  the  design 
of  the  all-wise  Creator,  in  order  to  afford  a  secure  place  for  the  defenseless  larvae,  viz, 
that  of  the  pupa-case  of  their  parent,  from  which  they  emerge  after  the  disappearance 
of  their  mother's  body,  and  immediately  form  themselves  silken  cases  covered  with 
small  pieces  of  anything  they  can  procure,  arranged  in  every  respect  like  the  larger 
ones." 

*  Remarks  on  the  habits  and  economy  of  a  species  of  OiTceiicua  found  on  shrubs  in 
the  vicinity  of  Sydney,  N.  S.  W.,  by  W.  W.  Saunders,  esq.,  F.  L.  S.,  &c.  Drawn  up 
from  notes  furnished  by  W.  Stephenson,  esq.  Transactions  of  the  Entomological  So- 
ciety of  London,  Vol.  V.  1847-1849.  pp.  40-33. 

213 


214 


INSECTS   AFFECTING   THE    ORANGE. 


Recently  Professor  Riley  lias  given  a  more  detailed  and  exact  account  of  the  man- 
ner by  which  the  act  of  coition  takes  place.  A  portion  of  his  article  which  was 

published  in  the  Scientific  American  Supple- 
ment of  April  3,  1878,  and  republished  in  the 
Proceedings  of  the  Biological  Society  of  Wash- 
ington, Vol.  ii,  1882-'4,  p.  81,  is  here  reproduced: 
"  We  have  seen  that,  by  means  of  the  partial 
elongation  of  her  puparium  and  her  partial  ex- 
traction therefrom,  the  female  is  able  to  reach 
with  her  head  to  the  extreme  lower  end  of  her 
follicle,  causing,  in  doing  so,  the  narrow  elastic 
portion  of  the  follicle  to  bulge,  and  the  orifice 
to  open  more  or  less,  as  it  repeatedly  did  while 
the  larva  was  yet  feeding,  whenever  the  excre- 
ment had  to  be  expelled.  Fig.  94,  a,  shows  a  fol- 
licle cut  open  so  as  to  exhibit  the  elongated  pu- 
pariuni,  and  the  female  extended  from  it  as  she 
awaits  the  male ;  &  represents  this  degraded  fe- 
male more  in  detail.  A  cursory  examination  of 
the  male  shows  the  genital  armature,  which  is 
always  exposed,  to  consist  of  (1)  a  brown,  horny, 
bilobed  piece,  broadening  about  the  middle, 
narrowing  to  and  notched  afc  tip,  concave,  and 
furnished  with  a  tuft  of  dark  hairs  at  tip  inside ; 
(2)  a  rigid  brown  sheath,  upon  which  play  (3) 
the  genital  hooks  or  clasps,  which  are  also  con- 
cave inside,  strongly  bifid  at  tip,  the  inner  finger  furnished  with  hairs,  the  outer 

produced  to  an  obtuse  angle  near  tip,  and 
generally  unarmed  (Fig.  95,  e).  In  re- 
pose, this  armature  appears  as  in  Fig.  95, 
c,  from  beneath,  and  as  at  d,  from  above, 
and  is  well  adapted  to  prying  into  the 
opening  of  the  follicle.  The  male  abdo- 
men is  telescopically  extensile,  while  the 
tip  easily  bends  or  curves  in  any  direc- 
tion, but  most  naturally  beneath,  as  at 
&,  where  it  is  represented  enlarged  about 
six  times,  and  with  all  the  genital  parts 
expanded ;  k,  the  fixed  outer  sheath ;  /, 
the  clasps  ;  g,  a  pale  membranous  sheath 
upon  which  the  prseputium  (h)  plays,  as 
on  the  finger  of  a  glove;  i,  the  fleshy  elas- 
tic penis,  armed  with  retorse  hairs,  and 
capable  of  extending  to  nearly  one-fourth 
of  an  inch ;  j,  showing  the  end  still  more 
fully  enlarged.  With  this  exposition  of 

FIG.  95.— THYRIDOPTERYX  EPHEMER^FORMIS :  j-fflil_  linf  pa^i^  nli«prvp.rl  nr  o-pnprillv 
b,  The  end  of  male  abdomen  from  the  side,  show-  details,  not  easily  observed  or  generally 
ing  genitalia  extended ;  c,  genitalia  in  repose,  ven-  understood,  the  act  of  fecundation  is  no 
tral  view ;  d,  do. ,  dorsal  view  ;  e,  tip  of  bifid  clasp ;  „ 

j,  tip  of  penis;  all  enlarged.    (After  Riley.)  longer  a  mystery." 


FIG.  94.— THYRIDOPTERYX  EPHEMER^E- 
FORMIS  :  a,  Follicle  cut  open  to  show  the 
manner  in  which  the  female  worts  from 
her  pnparium  and  reaches  the  end  of  the 
bag,  natural  size ;  6,  female  extracted  from 
her  case,  enlarged."  (After  Eiley.) 


]STOTES. 


NOTE  1  (p.  59).— Mr.  Howard  states  that  this  Tetrastichus  has  never  since  been  bred, 
and  that  the  material  is  too  poor  for  determination.  April  18,  1885, 1  bred  two  addi- 
tional species  of  parasites  from  the  Florida  Ceroplastes  at  Crescent  City,  which  were  de- 
termined by  Mr.  Howard  as  (1)  Coccophayus  vividus  Howard  (see  Bulletin  5,  Division  of 
Entomology,  U.  S.  Dept.  Agr.,  page  24,  species  37)  which  I  had  previously  bred  from 
Lccauium  hesperidum,  on  Orange,  at  Crescent  City.  (2)  A  species  of  Encyrtus  repre- 
sented by  one  $  which  was  mounted  in  balsam  and  so  badly  crushed  as  to  admit  only 
of  a  generic  determination. 

NOTE  2  (pp.  69  and  77). — In  looking  up  the  saved  material  in  order  that  this  species 
might  be  determined,  but  a  single  crippled  and  inferior  specimen  was  found,  and 
Professor  Riley  prefers  not  to  describe  it  for  the  present  from  this  unsatisfactory 
specimen. 

NOTE  3  (p.  79). — This  parasite  was  handed  to  Mr.  Howard,  who  has  given  me  the 
following  concerning  it : 

"  While  at  first  glance  I  determined  the  Leptocorisa  egg-parasite  for  you  as  a  species 
of  Telenomus,  a  more  careful  subsequent  study,  and  a  comparison  with  a  number  of 
Mayr's  types  of  this  genus,  show  that  it  belongs  rather  to  the  allied  genus  Hadronotus 
of  Foerster.  The  great  majority  of  the  species  of  the  subfamily  Sceliouiu£e,  to  which 
these  two  genera  belong,  are  egg-parasites.  This  species  may  be  described  as  fol- 
lows: 

"  HADRONOTUS  LEPTOCORISA  n.  sp. 

"Female. — Length,  1.4mm ;  expanse,  2.5mm.  Head  and  face  evenly  covered  with  small 
round  punctures,  except  in  the  facial  impression,  whichis  transversely  striate;  anten- 
nae subclavate;  lateral  ocelli  nearly  touching  the  margins  of  the  eyes.  Mesonotum  a 
trifle  smoother  than  the  head  and  furnished  with  a  very  fine  white  pubescence. 
First  segment  of  the  abdomen  dorsally  longitudinally  striate;  remain  ing  segments 
closely  covered  with  fine  round  punctures ;  ventral  surface  sparsely  punctate.  Color, 
black ;  scape,  brown  ;  all  coxae,  black;  all|trochanters,  femora,  tibiae,  and  tarsi,  light 
brown ;  mandibles  and  wing-veins,  light  brown. 

" Male. — Length,  1.3mm ;  expanse  2.ttmm.  Antennae  filiform.  In  other  characters  re- 
sembling the  $ ." 

"Described  from  many  $  and  $  specimens,  bred  from  the  eggs  of  Leptocorisa  tipu- 
loides,  at  Crescent  City,  Fla.,  by  H.  G.  Hubbard." 

NOTE  4  (p.  80). — These  bugs  belong  to  the  genus  Rhinacloa,  but  the  species  is  un- 
determined. 

NOTE  5  (p  81). — This  species  is  so  far  undetermined.  It  is  a  beautiful  and  well- 
marked  species,  the  prevailing  color  being  brown.  The  mesoscntum  has  two  yellow 
stripes  converging  posteriorly,  the  mesoscutellum  is  entirely  yellow,  the  metaseutel- 
lum  is  marked  with  yellowish,  and  the  abdomen  has  yellow  rings. 

Just  as  these  notes  are  going  to  press,  I  am  able  to  add  the  following  concerning 
this  species,  received  from  Mr.  Cresson  : 

"  The  specimen  arrived  minus  its  abdomen,  but  judging  from  what  is  left  it  seema 
to  belong  to  the  genus  Hemiteles.  I  have  looked  over  the  material  belonging  to  that 

215 


216  INSECTS   AFFECTING   THE    ORANGE. 

genus  in  the  society's  collection,  and  do  not  find  anything  there  agreeing  with  your 
specimen.  I  do  not  think  it  has  been  described,  but  as  I  have  never  worked  up  the 
genus,  I  cannot  say  definitely  that  it  is  new." 

NOTES  6,  7,  8,  9,  and  10  (pp.  83  and  84). — These  mites  were  mounted  in  balsam  for 
subsequent  study  by  Professor  Riley,  with  a  view  of  possible  determination.  He  has 
kindly  examined  them  and  furnished  the  following  notes  and  descriptions: 

"The  so-called  'Hairy  Orange  Mite'  (Note  6)  is  one  of  the  'Harvest-mites'  belong- 
ing to  the  section  Eupodidce  and  comes  nearer  to  Penthalodes  Murray  than  to  any  other 
defined  genus,  having  6-jointed  legs  of  about  equal  length.  It  may  be  "described  as 
follows : 

"PENTHALODES  MYTILASPIDIS  n.  sp.  Average  length,  0.3mm.  Broadly  oval;  ab- 
domen tapering  to  a  point.  Color  dark  red,  with  pale  hairs.  Head  distinctly  sep- 
arated, narrow,  elongate,  conical.  Mandibles  scissor-like,  projecting.  Palpi  inserted 
at  apex  of  cephalothorax,  close  to  the  head,  stout,  4-jointed,  the  first  joint  stoutest, 
first  and  second  of  about  equal  length,  third  shortest,  the  fourth  ending  in  a  stout, 
curved  claw  at  the  base  of  which  an  elongate  Oval  thumb  is  inserted.  Eyes  barely 
discernible  near  the  side  of  the  cephalothorax  between  the  first  and  second  pairs  of 
legs.  Cephalothorax  rounded  in  front,  merging  posteriorly  into  the  abdomen,  so  as  to 
leave  no  distinct  division  except  in  shrunken  specimens.  Surrounded  by  rather  long 
and  stout  bristles,  about  8  on  each  side,  and  with  two  rows  of  similar  bristles  dor- 
sally.  Legs  about  equal  in  length,  the  first  pair  very  slightly  longest ;  third  joint 
longest.  Claws'  3,  much  curved  at  tip,  the  middle  one  curved  upwards. 

"  Of  the  '  Spear-head  Mite'  (note  7)  the  mounted  specimens  are  unfit  for  study  and 
no  determination  can  be  made  of  them. 

"  The  so  called  '  Spotted  Mite '  (note  8)  is  also  represented  by  such  poor  specimens 
from  the  Orange  CoecidaB  that  they  could  not  be  used  for  determination,  but  I  have 
obtained  a  closely-related  species  from  twigs  containing  the  eggs  of  Cicada  septendecim, 
and  have  thus  been  able  to  make  out  its  characters.  It  belongs  to  the  Beetle-mites  or 
OribatidaD,  and  the  one-clawed  section ;  but  it  cannot  strictly  be  placed  in  any  defined 
genus.  As  I  would  not  care  to  erect  a  new  genus  in  these  fragmentary  notes,  the 
species  may  be  described  under  the  genus  Hermannia,to  which  it  approaches  nearest 
structurally,  though  bearing  no  great  resemblance  to  the  commoner  species  of  that 
genus. 

"HERMANNIA  (?)  TRINEBULOSA  n.  sp. — Length,  0.38mm.  Color  whitish,  pellucid. 
Pyri form, surface  apparently  smooth  and  polished:  three  dusky  abdominal  patches, 
one  large  and  central,  and  one  at  each  lower  side  with  a  central,  elongate-ovoid  cor- 
neous plate ;  two  dorsal  rows  of  rather  long  hairs,  with  a  few  others  at  sides,  a  rather 
stouter  one  on  each  shoulder,  and  three  anal  pairs,  the  intermediate  or  second  pair 
longest— all  very  minutely  barbed.  Cephalothorax  broadly  conical,  bluntly  rounded 
in  front,  separated  from  the  body  by  a  distinct  transverse  suture;  on  each  side  towards 
the  base  is  a  conspicuous,  strongly  clavate  bristle.  Palpi  6-jointed,  the  2nd  joint  as 
long  as  the  others  together.  All  legs  of  about  equal  length,  6-jointed  ;  terminal  joint 
longest,  tapering  quite  suddenly  frqm  about  the  middle  to  the  end,  especially  in  the 
posterior  pair  of  legs.  Claw  simple,  large,  and  strongly  curved.  All  legs  sparsely 
beset  with  rather  long,  simple  bristles,  which  are  most  numerous  on  the  terminal 
joint. 

"  Of  figs.  39  and  40  (notes  9  and  10)  the  slides  are  not  to  be  found,  but,  judging  from 
the  figures,  the  former  is  a  Tyroglyphns,  the  species  of  which  are  very  commonly  found 
preying  on  animal  matter,  and  the  latter  a  Sejus,  one  of  the  Gamasid  genera.  I  should 
not  care  to  describe  them  by  name  without  study  of  the  specimens." 

NOTE  11  (p.  98).— Prof.  H.  W.  Wiley,  chemist,  U.  S.  Department  of  Agriculture, 
gives  the  following  reactions  of  sulphur  upon  lime,  treated  with  boiling  water. 

"  Depending  on  the  proportion  of  sulphur  used,  the  products  may  be  considered  as 

follows: 

.     3  CaO  -f  S6=2  CaS  2+  CaS2O3 
Calcium  disulphide -}-  Calcium  thiosulphate 
"  Or,  with  a  greater  amount  of  sulphur, 

3  CaO  -f  Si2=2  CaS5  -f  CaS2O3 
Calcium  penlasulpltide  -f-  Calcium  thiosulphate. 
"In  fact,  probably  both  reactions  go  on  at  once,  and  even  more  complicated  ones. 


NOTES.  217 

"The  reaction  of  lime  in  the  act  of  slaking  on  sulphur  would  probably  be  small, 
owing  to  the  short  time  during  which  the  heat  would  continue." 

NOTE  12  (p.  153.) — The  specimens  of  this  parasite  were  turned  over  to  Mr.  Howard, 
who  has  given  me  the  following  description  : 

"MlOTROPIS   PLATYNOT.E   n.  sp. 

"Female.—  Length,  1.65mm;  expanse,  3.0mm.  Head  broader  than  thorax;  vertex 
broad;  ocelli  very  close  together ;  scape  reaching  almost  to  vertex.  Pro  and  meso  scutum 
somewhat  rugose  ;  mesoscutellum  nearly  smooth  ;  metathoracic  carina  well  marked. 
Hiud  coxa}  with  an  external  longitudinal  groove.  Abdomen  moderately  long  oval, 
flattened.  Color  uniform  honey- yellow  (in  dry  specimens;  Mr.  Hubbard,  in  his  gene- 
ral description,  says:  "  Honey  yellow  ;  head,  lemon-  yellow  ") ;  eyes  and  ocelli,  dark 
red ;  tip  of  scape,  dorsal  surface  of  pedicel,  and  all  of  flagellum,  dusky ;  two  large 
occipital  dark  spots,  sometimes  confluent ;  abdomen  biownish  at  lateral  border  and 
with  a  brownish  central  spot  varying  in  size  ;  legs,  light  honey-yellow. 

"Male. — Slightly  smaller  than  female ;  abdomen  widening  from  base  to  near  ex- 
tremity. Face  with  two  converging  black  streaks  from  insertion  of  antennas  10  mid- 
dle ocellus;  hind  tibia)  with  a  distinct  dusky  tinge  near  extremity ;  abdomen  more 
distinctly  edged  with  brown  and  with  a  central  translucent  spot. 

"Described  from  5£,  19  ;  bred  from  larva  of  Platynota  rostrana,  at  Crescent  City, 
Fla.,  in  September,  by  H.  G.  Hubbard. 

"  This  species  will  probably  ultimately  form  a  new  genus,  as  in  the  structure  of  the 
thorax  at  least  it  differs  from  the  descriptions  of  Miotropis.  It  is,  however,  more 
nearly  related  to  this  genus  than  to  any  other  Elachistid  genus,  and  I  therefore  place 
it  here  temporarily. " 

NOTE  13  (p.  153). — This  species  was  also  referred  to  Mr.  Howard,  who  describes  it  as 
follows : 

UGONIOZUS  HUBBARDI  n.  sp. 

u Female.—  Length,  2Amm ;  expanse,  4.4mm.  Face  and  notum  very  sparsely  punctured 
and  furnished  with  fine  white  pile ;  also  delicately  shagreened  in  addition  to  the 
round  punctures.  Abdomen  very  smooth  and  shining  and  ovate-acuminate  in  form ; 
somewhat  pilose,  especially  towards  tip.  Wings  clear ;  stigma  brown,  with  a  hya- 
line spot  at  its  center  ;  stigmal  cell  nearly  complete.  Color  black  ;  all  legs,  includ- 
ing coxa3,  honey-yellow  ;  mouth-parts  and  antennas  honey-yellow. 

"  Described  from  1  $  specimen,  bred  in  October,  from  the  larva  of  Platynota  rostrana, 
at  Crescent  City,  Fla.,  by  H.  G.  Hubbard,  for  whom  I  have  named  the  species." 

NOTE  14  (p.  154). — This  is  evidently  a  dark  form  of  Caccecia  olsoletana  Walk,  which 
Professor  Riley  has  bred  from  oak,  but  it  doubtless  has  several  food-plants,  as  it  is 
allied  to  the  wide-spread  and  polyphagic  Caccecia  rosaceana  Harr.,  which  feeds  on  rose, 
apple,  peach,  cherry,  yellow  birch,  plum,  cotton,  clover,  honeysuckle,  bean,  straw- 
berry, Negundo  aceroides,  Cornus  stolonifera  and  Cralcegus  spp. 

NOTE  15  (p.  178). — The  single  specimen  of  this  species  preserved  is  badly  damaged 
and  minus  all  the  head  parts.  It  appears  to  be  a  Blastobasis,  like  .the  species  which 

immediately  precedes  it. 

NOTE  16  (p.  Ib6).— This  parasite  was  referred  to  Mr.  Howard,  who  has  given  mo  the 
following : 

"  PACHYNEURON  ANTHOMYI.E  n.  sp. 

"Female.—  Length,  1.4"°m;  expanse,  2.6mm;  greatest  width  of  fore  wing  0.56mm. 
Head,  face,  and  thorax  delicately  shagreened;  antenna  inserted  at  the  middle  of  the 
face ;  scape  reaching  to  the  first  ocellus ;  club  flattened,  oval.  Petiole  of  the  abdomen 
slightly  punctured.  Abdomen  flattened,  oval.  Subc  jstal  vein  of  fore  wing  with  seven 
strong  forward-directed  bristles.  Mesoscutellum  not  especially  prominent.  Rear 
coxae  with  four  or  five  bristles  above  at  tip.  Color,  very  dark  metallic  green ;  scape 
of  antennas  honey-yellow ;  pedicel  dark  above,  yellow  below ;  flagellum  light  brown ; 
all  legs  honey-yellow ;  front  and  middle  coxae  brownish  above,  verging  upon  metallic 
green  at  base ;  hind  COXSB  metallic  green  ;  all  femora  brownish  in  the  middle,  honey- 
yellow  at  either  extremity  ;  wing  veins  dark  brown. 

Male.  —Length,  l.lmm;  expanse,  2.5mm.  Antenna  slenderer  than  in  the  $  and 
markedly  pilose.  Abdomen  flattened,  spatulate  in  form.  Color,  metallic  green, 
lighter  and  more  brilliant  than  in  the  female;  legs  of  a  brighter,  nearly  leonon,  yel- 
low ;  femora  without  the  brownish  central  band. 


218  INSECTS   AFFECTING   THE    ORANGE. 

"  Described  from  1  £,19  specimen  bred  by  Mr.  Hubbard  at  Crescent  City,  Fla., 
September  6,  from  the  pnparium  of  an  undescribed  An  thorny  id  fly,  called  by  Hub- 
bard  'the  Pruinose  Aphis-fly.' 

"  This  species  may  be  at  once  distinguished  from  P.  altiscuta  Cook,  the  only  other 
described  American  species  of  the  genus,  by  its  smaller  size,  its  less  prominent  scutel- 
lum,  more  oval  abdomen,  and  by  the  coloration  of  its  legs  and  antennae. 

"Pachyneuron  altiscuta  is  said  by  Professor  Cook*  to  have  been  bred  in  large  num- 
bers from  a  scale  insect  on  basswood,  probably  Lecanium  tilice  Fitch,  and,  as  he  there 
quotes  me  as  saying,  the  only  other  recorded  instance  which  I  can  find  of  the  breed- 
ing of  Paohyneuron  is  the  case  of  P.  aphidis,  bred  from  an  Aphis  by  Reinhard.  It  is 
not  at  all  likely,  however,  that  species  of  this  genus  infest  both  Hemiptera  and  Dip- 
tera,  and  as  Professor  Cook  found  a  Syrphus  larva  feeding  upon  the  eggs  of  his  Le- 
canium, it  seems  probable  that  P.  altiscuta  comes  from  this  dipterous  larva.  The  same 
may  be  the  case  with  P.aphidis.  The  circumstantiality  of  Mr.  Hubbard's  notes  leaves 
no  doubt  as  to  the  breeding  of  P.  anthomyia  from  the  puparium  of  the  Anthomyid." 

NOTE  17  (p.  188). — This  species  has  since  been  determined  as  Chrysis  fasciata  Fabr. 

*  Notes  on  injurious  insects.  Entomological  Laboratory,  Michigan  Agricultural  Col- 
lege [1884]. 


EXPLANATION  TO  PLATES. 


PLATE  I. 

YOUNG  ORANGE  TEEE,  HEALTHY  AND  DISEASED. 

(From  photographs.) 
FIG.  1.  Young  Orange  tree  in  healthy  condition.      |  FIG.  2.  Young  Orange  tree  in  diseased  condition. 

PLATE  II. 

DIE-BACK  OP  THE  ORANGE. 

(Original.) 


FIG.  1.  Die-back  of  the  Orange,  natural  size  and 


slightly  enlarged. 


FIG.  2.  Bark  fungus  on  twigs  of  Orange  infested 
with  Long  Scale,  natural  size  and  slightly 


enlarged. 
PLATE  III. 

COMMON  ARMORED  SCALES  OF  THE  ORANGE. 

(From  Comstock's  Report  for  1880.) 


FIG.  1.  Hytilispis  citricola  (Pack.) :  1,  scales  on 
Orange,  natural  size ;  la,  scale  of  female, 
dorsal  view;  1&,  scale  of  female  with 
ventral  scale  and  eggs ;  Ic,  scale  of  male, 
enlarged. 


FIG.  2.  Mytilaspis  gloverii  (Pack.):  2,  scales  on 
Orange,  natural  size ;  2a,  scale  of  female, 
dorsal  view;  2&,  scale  of  male;  2c,  scale 
of  female  with  ventral  scale  and  eggs, 
enlarged. 

FIG.  3.  Parlatoria  pergandii  Comst. :  3a,  scale  of 
female;  3&,  scale  of  male,  enlarged. 


PLATE  IV. 

TWIGS  OF  ORANGE  INFESTED  WITH  LONG  SCALE. 

(Original.) 
FIG.  1.  Larger  branch  sparsely  covered.  |  FIG.  2.  Twig  thickly  covered.' 

PLATE  V. 

CHAFF  SCALE  OF  THE  ORANGE. 

(Original.) 
PLATE  VI. 

ENEMIES  OF  BARK-LICE. 


FIG.  1.  Aphelinus  mytilaspidis:  a,  the  parasite; 
6,  antenna;  c,  larva,  enlarged.  (After 
Riley.) 

FIG.  2.  Hyperaspidius  coceidivomg :  a,  larva,  en- 
larged ;  6,  head  of  larva,  much  enlarged ; 
c,  side  of  head,  showing  eyes  and  an- 
tenna, still  more  enlarged;  d,  beetle. 


(Original.) 


FIG.  3.  Dakruma  coccidivora :  a,  egg;  &,  larva;  c, 
pupa ;  d,  moth,  enlarged ;  e,  moth  at  rest 
upon  a  bark-louse,  natural  size.  (After 
Com  stock.) 

FIG.  4.  Leptocorisa  tipuloides,  slightly  enlarged. 
(Original.) 

FIG.  5.  Roseate  Orange   Mite,  greatly  enlarged. 


(Original.) 


PLATE  VII. 


APPARATUS  FOR  SPRAYING  ORANGE  TREES. 

(From  a  photograph.) 


(219) 


220 


EXPLANATION   TO   PLATES. 


PLATE  VIII. 

OEANGB  RUST. 

(A;  erBubbard.) 
PLATE  IX. 

KATYDIDS  ON  ORANGE. 

(After  Comstock.) 


TIB.  1.  Microcentrumretinerve:  1,  adult;  la,  eggs; 
16,  young,  natural  size. 


FIG.  2.  Eupelmua  mirabilis:  2,  female;  2a,  male, 
enlarged;  2&,  eggs  of  katydid  from  which 
E.  mirabilis  has  emerged,  natural  size. 


FIG.  1.  Papilio  eresphontes,  adult. 


PLATE  X. 

ORANGE  DOG. 

(Original.) 

FIG.  4.  Papilio  eresphontes,  head  of  full-grown 


FIG.  2.  Papilio  eresphontes,  full-grown  larva,  nat- 
ural size. 

FIG.  3.  Papilio  eresphontes,  head  of  full-grown 
larva  with  horns  extended,  from  the 
side,  natural  size. 


larva  with  horns   extended,   from   the 
front,  natural  size. 
FIG.  5.   Papilio  eresphontes,  chrysalis  suspended 


on  twig,  natural  size. 


PLATE  XI. 


MISCELLANEOUS  ORANGE  INSECTS. 

(Original.) 


FIG.  1.  Papilio  eresphontes,  twig  of  orange,  show- 
ing eggs  and  young  larva,  natural  size. 

FIG.  2.  Papilio  eresphontes,  larva,  one-third  grown, 
natural  size. 


FIG.  3.  Empretia  stimulea,  full-grown  larva,  nat- 
ural size. 

FIG.  4.  Dysdercus  suturelliis,  enlarged  one-third. 

FIG.  5.  Thrips  tritici  on  Orange  blossoms,  natural 
size. 


PLATE  XII. 


BAG-WORMS  AND  PARASITES. 


FIG.  1.  Thyridopteryx  cphemcrceformis :  a,  larva ; 
6,  pupa  of  male ;  c,  adult  female ;  d,  adult 
male ;  e,  sack  of  female  cut  open,  show- 
ing pupa-case  and  eggs ;  /,  larva  carry- 
ing  case ;  g,  sacks  of  young,  natural  size. 
(After  Riley.) 

FIG.  2.  Young  Bag-worms  (Oiketic^^jpmiug 
\  their  sacks,  a  to  e;  /,  sack  of  young 
completed,  enlarged.  (Original.) 


FIG.  3.  Hemiteles  thyridopterigis :  a,  'male ;  6,  fe- 
male; c,  sack  of  hag- worm  cut  open, 
showing  cocoons  of  parasite,  natural 
size.  (AfterRiley.) 

FIG.  4.  Pitnpla  conquisitor,  slightly  enlarged. 
(After  Comstock.) 

FIG.  5.   Crypttis  inquisitor.     (After  Riley.) 


PLATE  XIII. 

MISCELLANEOUS  ORANGE  INSECTS. 

(Original.) 


FIG.  1.  Anceglis  demissalis,  web-tangle  of  the 
caterpillars  and  spider,  natural  size :  a, 
larva;  b,  moth,  slightly  enlarged. 


FIG.  2.  Aphis  of  the  Orange:  a,  wingless  female; 
b,  winged  female ;  c,  parasitized  female, 
greatly  enlarged ;  d,  colony  on  leaf,  all 
parasitized,  slightly  enlarged. 

FIG.  3.   Trioxys  testaeeipes,  greatly  enlarged. 


PLATE  XIV. 


MISCELLANEOUS  ORANGE'  INSECTS. 


FIG.  1.  Hypoihenemus  eruditus,  enlarged. 

FIG.  2.  Leptostylus  biustus :  a,  beetle,  enlarged ;  b, 

work  and  cocoon  cell,  natural  size. 
FIG.  3.  Hyperplatys  maculatus,  enlarged. 
FIG.  4.  Midas  clavatus,  natural  size.    (He-drawn 

from  Harris.) 


(Original.) 

FIG.  5.   Carpophilus  mutilatus,  enlarged. 

FIG.  6.  Epurcea  cestiva,  enlarged. 

FIG.  7.  Pomace-fly  of  the  Orange:  a,  adult  fly;  6, 

larva ;  c,  puparium,  all  enlarged. 
FIG.  8.   Chrysobothris  chrysoela,  enlarged. 


REPORT  DN  INSECTS  AFFECTINB  THE  ORANGE 


PLATE 


YOUNG  ORANEETREE  HEALTHY  AND  DISEASED 


REPORT    ON    INSECTS     AFFECTING    THE    ORANGE. 


Plate  H. 


I)!K    HACK    OK   TH  K    OK* AMOK. 


Report  on  Insects  affecting  the  Orange. 


PLATE  III. 


d£ 


Fig.  3 


THE  COMMON  ARMORED  SCALES  OF  THE  ORANGE. 


REPORT    ON    INSECTS     AFFECTING    THE    ORANGE. 


Plate  W. 


TWIGS  OF  ORANGE    INFESTED  AVITH  LONG    SCALE. 


REPORT    ON    INSECTS     AFFECTING    THE    ORANGE 


Plate 


L  Sullivan  del 


CHAFF  SCALE  "  OF  THE  CHANGE  . 


Report  on  Insects  affecting  the  Orange. 


PLATE  VI. 


ENEMIES  OF  BARK-LICE. 


Report  on  Insects  affecting;  the  Orange 


PLATE  VII. 


APPARATUS  FOR  SPRAYING  ORANGE  TREES. 
(From  a  photograph  taken  in  the  field.) 


REPORT    ON    INSECTS     AFFECTING    THE    ORANGE 


Plate  VIJI. 


A. H<>..,,  jr., 


RUST  OK  'I'HI-;    ORANGE. 


on  Insects  affecting  the  Orange. 


PLATE  IX. 


KATYDIDS  ox  ORANGE. 


REPORT    ON    INSECTS     AFFECTING    THE    ORANGE. 


Plate  X. 


A.Hcif  n  A  <'ii.l.illi.l!.i 


THE    "ORANGE     DOG 


REPORT    ON    INSECTS     AFFECTING    THE    ORANGE. 


M  I SC  K  LI A ISTEOUS    ( ;K  A  NG 1]    I  NS'K  ( '  rl\S  . 


Report  on  Insects  ali'ccliim  rite  Oran.m 


PLATE  XII. 


tl 


BAG  WORM  AND  PARASITES. 


REPORT  ON  INSECTS  AFFECTING  THE  DRANEE 


PLATE  XIII 


MISCELLANEOUS  DRANGE  INSECTS 


REPORT  DN  INSECTS  AFFECTING  THE  DRANEE 


PLATE  XIV 


Ftg.5. 


ISAACTRIEDENWALO  UITH  BAl-TO 


MISCELLANEDUS  GRANGE  INSECTS 


INDEX. 


Acarina  feeding  on  Scale-insects,  81. 
Acridiidae  injuring  the  Orange,  138. 
Acridium  alutaceum,  136. 

americanum,  136. 
obscurum,  136. 
Aletia  xylina,  9. 

Ammonia  as  a  remedy  for  Scale-insects,  99. 
Amaurorhinusnitens,  175. 
Anaeglis,  77. 

demissalis,  80, 155. 
Angular- winged  Katydid,  134. 

Injury  to  €he  Orange,  134. 
Life-history,  134. 
Parasite,  134. 

Anthomyid  fly  preying  upon  Aphis,  185. 
Antigaster  mirabilis,.  134. 
Ants  attracted  by  honey  secretion  of  plant-lice,  8, 

130. 

Fruit-eating  species,  177. 
indicating  presence  of  injurious  insects,  8. 
Injuries  caused  by,  129. 
preying  upon  Scale-insects,  70. 
Remedies  and  preventives,  130. 
sucked  by  Leptocorisa,  191. 
Tree-inhabiting  species,  170. 
Aphelinus  aspidioticola,  24. 
fuscipennis,  24. 
mytilaspidis,  70. 
Aphis,  the  Orange,  157. 
Aphis-fly,  Dusky- winged,  184. 
Tour-spotted,  183. 
Pruinose,  185. 
Buddy,  184. 
Aphycus  ceroplastis,  59. 

flavus,  24. 

Apparatus  for  spraying  trees,  101. 
Apple  Scale,  70. 
Appendix  I,  197. 
H,  199. 

in,  213. 

Aquapult  pump,  93. 
Araeocerus  fasciculatus,  178. 
Armored  Scales  (see  Diaspinae). 
Artace  pnnctistriga,  150. 
Cocoon,  150. 
Moth,  150. 
Parasite,  150. 
Artipus  floridanus,  133. 
Ashes  as  a  remedy  for  Kust-mite,  120. 
Ashmead,  W.  H.,  quoted,  44,  133. 
Aspidiotus  aurantii,  28, 32. 
citri,  34. 

flcus,  28,  34, 43, 86. 
nerii,  35. 


Baccha  babista,  183. 
cognata,  184. 
lugens,  184. 
Bag- worms,  144. 

Coition  of,  213. 
Common  Bag- worm,  144. 
Cylindrical  Bag-worm,  148. 
Northern  Bag-worm,  147. 
Orange  Basket-worm,  148. 
Unnamed  species  of,  149. 
Bark-cleaners,  193. 
Bark-fungus,  2. 
Bark-lice  (see  Scale-insects). 
Barnacle  Scale,  59. 

Adult  female,  59. 
Development,  60. 
Egg,  60. 
Food-plants,  61. 
Geographical  distribution,  61. 
Young  larva,  60. 
Basket- worm  (see  Bag-worm). 
Beneficial  insects,  general  habits  of,  6. 
Birds  transporting  Scale-insects,  43. 
Bisulphide  of  carbon  as  a  remedy  for  ants,  130. 

for  Scale-insects,  99. 

White-ants,  124. 

Table  of  experiments  with, 

209. 
Black  Scale  of  California,  53. 

Adult  female,  53. 
Development,  54. 
Eggs,  54. 
Food-plants,  54. 
Geographical  distribution,  54. 
Natural  enemies,  55. 
Young  larva.,  54. 
Blastobasis  citricolella,  178. 

sp.,  218. 
Blood-red  Lady-bird,  73. 

Habits,  73. 
Larva,  73. 
Pupa,  73. 

Brachys  ovata,  132. 

Braconidaa  bred  from  cells  of  Eumenes,  188. 
Broad  Scale,  48. 
Caco3cia  rosaceana,  217. 
Calotermes  castaneus,  125. 
Camel-crickets,  188. 

Food,  188. 
Habits,  189. 

Capnodium  citri,  4,  50,  62,  63. 
Carbolic  acid  as  a  remedy  for  Kust-mite,  118. 

Scale-insects,  97. 
Table  of  experiments  with,  206. 

221 


222 


INDEX. 


Carpophilus  mutilatus,  176. 
Habits,  176. 
Larva,  176. 

Case-bearers  on  Orange,  193. 
Caution  in  applying  penetrating  insecticides,  120. 
Ceroplastes  arteniisise,  59. 

cirripediformis,  59,  62. 
fainnairii,  60. 
floridensis,  56,  60,  61,  62. 
rusci,  59,  60. 
vinsonii,  60. 

Chaff-Scale,  2, 37, 42, 75, 86. 
Eggs,  38. 
Foraale  insect,  37. 
Pood-plants,  39. 
Introduction,  86. 
Habitat,  39. 
Life-history,  38. 
Number  of  generations,  38. 
Origin,  39. 
Parasites,  39. 
Scale  of  female,  37. 

male,  37. 

Winged  male,  38. 
Young  larva,  38. 
Chplcisrobusta,  139, 141. 
Chalk,  a  band  of.  as  a  barrier  for  ants,  131. 
Chapin,  Dr.  S.  F.,  quoted,  67. 
Cbilocorus  bivulnerus,  71,  72,  180. 
Chiloneurus  dactylopii,  66. 
Chion  cinctus,  121. 
Chionaspis  citri,  40. 

enonymi,  40,  41. 
Chrysis  parasitic  on  Eumenes  fraterna,  188. 

fasciata,  218. 
Chrysopa,  7, 69. 

Larva  feeding  on  Scale-insects,  80. 
citri,  81. 
oculata,  80. 

Chrysobothris  chrysoela,  171. 
Chrysomphalus  flcus,  86. 
Cicada  septendecim,  216. 
Coccid-eating  Dakruma,  76. 

Earlier  states,  76. 
Habits  of  larva,  76. 
Natural  history,  76. 
Coccidae  of  the  Orange  tree,  13. 
Coccinse,  A  subfamily  of  Coccidse,  14. 

General  characteristics  and  habits,  63. 
Coccinellidae  (gee  Lady-birds). 
Coccophagus  cognatus,  51. 
lecanii,  51. 
vividus,  215. 
Coccus  hesperidum,  4. 

Cockroach  associated  with  Orange  Web- worm,  156. 
Coition  of  Bag- worms,  213. 
Cold,  Effect  of,  on  Scale-insects,  46. 
Coleoptera  injuring  the  twigs  and  leaves,  132. 

preying  upon  Scale-insects,  71. 
Coleopterous  borers,  121, 125. 
Coleotechnites  citriella,  193. 
Common  Bag- worm,  144. 
Larva,  144. 
Life-history,  145. 
Male  moth,  145. 
Maternal  instinct,  145. 


Common  Bag- worm. 

Parasites,  146. 

Process  of  forming  the  bag,  146. 
Mealy-bug,  61, 86. 

introduced  on  living  plants, 

86. 

Orange  Sawyer,  125. 
Beetle,  126. 
Injuries,  127. 
Larva,  125. 
Precautions,  127. 
Remedies,  127. 
Comstock,  Prof.  J.  H.,  quoted,  18, 28, 33,  35, 40, 53, 

65,59,64,154,178,193. 
Comys  bicolor,  52. 
Conopsf  quadrimacalata,  183. 
Cork-colored  Orange  Tortricid,  152. 
Larva,  152. 
Life  history,  152. 
Moth,  152. 
Parasites,  153,  217. 
Remedy,  152. 

Cossonidse,  Food-habits  of,  175. 
Cost  of  Kerosene  wash,  202. 
Cotton  Stainer,  165. 

Attacks  upon  the  Orange,  168. 

Effect  of  its  puncture,  166. 

Egg  and  oviposition,  166. 

Food-habits,  166. 

General  characteristics,  166. 

Geographical  distribution,  167. 

Not  a  permanent  enemy  of  the  Orange, 

168. 

Not  subject  to  attacks  of  enemies,  167. 
Eemedies,  167. 
Cotton  Worm,  9. 
Cottony  Cushion  Scale,  66. 
Food-plants,  67. 
Life-history,  67. 
Male,  68. 

Number  of  broods,  68. 
Ravages,  67. 

Crematogaster  lineolata,  170. 
Creosote,  Oil  of,  as  a  remedy  for  Scale-insects,  97. 
Table  of  experiments  with,  206. 
Crude  Carbolic  Acid,  Table  of  experiments  with, 

206. 

Cyclone  nozzle,  100. 
Cycloneda  sanguinea,  73, 180. 
Cylindrical  Bag- worm,  148. 
Cylindrical  Bark -borer,  173. 

Appearance  of  the  beetle,  173. 
Gallery  made  by  the  larva,  173. 
Life-history,  173. 
Dactylopius,  2,  4. 

adonidum,  68,  86. 
destructor,  14,  63,  64,  79. 
longifllis,  64. 
Dakruma  coccidivora,  76. 

paUida,  77. 
Destructive  Mealy-bug,  64. 

Adult  female,  64. 
Eggs,  64. 

Food-plants,  64,  66. 
Life-history,  65. 
Male,  64. 


INDEX. 


223 


Destructive  Mealy-bug,  Natural  enemies,  66. 

Young  larva,  64. 
DiaspinoB,  a  subfamily  of  Coccid»,  14. 

Agencies  assisting  their  distribution, 

43. 

Conditions  favorable  to  their  distribu- 
tion, 45. 

Generally  present  on  Orange  trees,  42. 
Growth  of  the  scale,  16. 
Influence  of  climate,  46. 
Larva,  15. 
Life-history,  15. 
Male  and  its  development,  17. 
Natural  checks,  47. 
Nature  of  the  scale  covering,  18. 
Ravages,  42. 

Usual  course  of  the  pest,  45. 
Dichelia  sulphureana,  154. 
Die-back,  1. 
Dropping  of  fruit,  5. 
Dusky- winged  Aphis-fly,  184. 

Chrysalis,  184. 
Imago,  184. 
Larva,  184. 

Dysdercns  suturellus,  165, 191. 
Egg-parasite  of  Katydid,  134. 

Orange  Leaf-roller,  153. 
Elaphidion  inenne,  125, 171. 

parallelum,  126, 171. 
Empretia  stimnlea,  140. 
Cocoon,  142. 
Larva,  141. 
Moth,  142. 
Parasite,  142. 
Encyrtus,  215. 

artacece,  150. 
flavus,  52,  59. 
inquisitor,  66. 
Epitragus  tomentosus,  75. 
Epurasa  aestiva,  176. 
Enmenes  fraterna,  187. 
Eupelmns  mirabilis,  134. 
Euphoria  sepulchralis,  175. 
Europs  pallipennis,  177. 
Euthochtha  galeator,  163, 192. 
Exochomus  contristatns,  72,  180. 
Habits,  72. 
Larva,  72. 

Experiments  with  Insecticides,  199. 
Fallow,  Dr.  W.  G.,  on  Orange  smut,  4. 
Flat-headed  Borer  of  the  Orange,  171. 
Beetle,  172. 

Gallery  made  by  the  larva,  171. 
Habits  and  life-history,  172. 
Larva,  172. 
Pupa  cell,  171. 
Foot-rot  of  the  Orange,  3. 

Remedies,  3. 
Forest  trees  affording  protection  against  Scale- 

insects,  88. 
Four-spotted  Aphis-fly,  183. 

Chrysalis,  183. 
Egg,  183. 
Imago,  183. 
Larva,  183. 
Parasite,  183. 
Franklin,  James,  on  Green  Soldier-bug,  160. 


Fruit-eating  ant,  177. 
Fruit  Worm,  The  Mexican,  169. 
Fumago  salicina,  4. 
Fungus  diseases  of  the  Orange,  1. 
Bark- fungus,  2. 
Die-back,  1. 
Foot-rot,  3. 
Smut,  3. 

Fur,  A  band  of,  as  a  barrier  for  ants,  131. 
Glover's  Orange  Mite,  82. 

Changes  in  shape  of  body,  82. 
Eggs,  82. 

Goniozus  hubbardi,  153, 217. 
Gossamer  spiders  transporting  Scale-insects,  44. 
Gossyparia  mannipara,  13. 
Grasshoppers  injuring  the  Orange,  9, 135. 
Grass-worm,  150. 
Green  Soldier-bug,  159, 190. 

Appearance  in  immense  numbers,  159. 
Food-plants,  159. 
Nature  of  damage  done,  161. 
Predaceous  habits,  190. 
Hadronotns  leptocorisse,  215. 
Hag-moth  caterpillar,  142. 
Hairy  Orange  Mite,  83. 

Description,  216. 
Egg,  83. 
Young,  83. 

Hedges  as  a  protection  against  Scale-insects,  88 
Hemerobius  feeding  on  Scale-insects,  81. 

Larva,  81. 

Hemiptera  injurious  to  the  Orange,  157. 
Predatory  species,  78, 190. 
Preying  upon  Scale-insects,  78, 79. 
Hemipteron  associated  with  Orange  "Web-worm, 

79, 156. 
Hemispherical  Scale,  55. 

Adult  female,  55. 
Egg,  56. 
Food-plants,  56. 
Geographical  distribution,  56. 
Locomotive  power,  56. 
Young  larva,  56. 
Hemiteles  thyridopterygis,  146, 147. 

sp.,  215.. 

Hermannia  trinebnlosa,  216. 
Jlesperobaenus  sp.,  175. 
Hippodamia  convergens,  73, 180. 
Larva,  73. 
Parasite,  74. 
Pupa,  74. 

Homalotylus  obscurus,  74. 

Howard,  L.  O.,  Description  of  Hymenopterous  para- 
sites, 215, 216,  217, 218. 
Hymenoptera  preying  upon  Scale-insects,  70. 

Predatory  species,  186. 
Hymenopterous  parasites  of  Bark-lice,  70. 
Hyperaspidius  coccidivorus,  69, 75. 
Hyperplatys  maculatus,  174 . 
Hypothenemus  eruditus,  173. 
Icerya  purchasi,  63, 66. 
Ichneumon  concitator,  148. 
Injurious  insects,  General  habits  of,  6. 

Seasons  of  greatest  activity,  9. 
Shade   favorable    to    their   in* 

crease,  8. 
Innoxious  insects,  7, 193.. 


224 


INDEX. 


Insecticides,  Apparatus  for  applying,  100, 101. 
Application  of  liquid,  100. 
Caution  in  applying,  120. 
Experiments  with,  199. 
Insect-fauna  of  the  Orange,  Summary  of,  5. 
Beneficial  insects,  6. 
Distinguishing  friends  from  foes,  7. 
Injurious  insects,  6. 
Innoxious  insects,  7. 
Insects  affecting  the  blossoms,  164. 
fruit,  165. 

root  and  crown,  121. 
trunk  and  branches,  125. 
twigs  and  leaves,  132. 
feeding  upon  dead  wood  and  bark,  170. 

decaying  fruit,  175. 
found  in  dry  fruit,  178. 

wounds  and  foot-rot  sores,  175. 
Predatory,  80. 
preying  upon  Aphis,  180. 

Bark-lice,  69. 
Katydid,  Protective  resemblance  of,  5. 

The  Angular- winged,  134. 
Kermes,  14. 

Kerosene  as  a  remedy  for  Bust-mite,  118. 
Scale-insects,  92. 
White  ants,  124. 

Kerosene  emulsion,  Best  season  for  applying,  95. 
Effect  of,  upon  the  Orange,  94. 
Formula  for  improved,  94. 
Mode  of  applying,  100, 101. 

preparing,  93. 
Precautions  in  the  use,  94. 
Table  of  experiments  with, 

199. 
Lace- wings,  7, 69. 

Eggs,  81. 
Habits,  80. 
Imago,  80. 
Larva,  80. 
Life-history,  80. 
Pupa,  80. 
Parasite,  80. 
Lady-birds,  7. 

preying  upon  Aphis,  180. 

Scale-insects,  69, 71. 
transporting  Scale-insects,  43. 
Laemophlceus,  175. 
Lagoa  opercnlaris,  140. 
Cocoon,  140. 
Larva,  140. 
Life-history,  141. 
Moth,  141. 
Parasites,  141. 
Laphygma  frugiperda,  150. 
Chrysalis,  151.% 
Egg,  150. 
Larva,  151. 
Moth,  151. 

Larger  Leaf-roller,  154, 217. 
Lathridius,  175. 
Leaf-eating  ant,  132. 
Leaf-footed  bug,  168. 

Attacking  the  Orange,  169. 
Characteristics,  168. 
Eggs,  168. 


Leaf-footed  bug. 

Habits,  169. 

Normal  food-plants,  169. 
Prevention,  169. 

Leaf-rollers  injurious  to  the  Orange,  151. 
General  characteristics,  151. 
Life-history,  151. 

LecaniniB,  a  subfamily  of  Coccidae,  14. 
Extent  of  inj  uries,  61. 
General  characteristics,  48. 
Life-history,  48. 
Lecanium  hemisphaericum,  55. 
hesperidum,  14, 48, 78. 
oleae,  53,  61. 
tilisfi,  218. 
Lepidoptera  injurious  to  the  Orange,  137. 

preying  upon  Scale-insects,  76. 
Leptocorisa  tipuloides,  78, 191, 215. 
Leptoglossus  phyllopus,  164, 168. 
Leptomastix  dactylopii,  66. 
Leptostylus  biustus,  174. 
Beetle,  174. 
Larva,  174. 

Limacodes  scapha,  140, 143. 
Cocoon,  144. 
Larva,  143. 

Lime  as  a  remedy  for  Rust-mite,  120. 
Liquid  insecticides,  100. 

Fineness  and  force  of  spray,  100. 
Means  of  applying,  103. 
Proper  seasons  for  applying,  102. 
Several  applications  necessary,  101. 
Locusts  injuring  the  Orange,  135. 
Long  Scale,  14, 42,  75,  77. 

Brood  periods,  22. 
Eggs,  21. 

Female  insect,  20. 
Geographical  distribution,  24. 
Growth  of  the  Scale,  19. 
Introduction  into  Florida,  25,  86. 
Life-history,  21. 
Parasites,  23. 
Scale.of  female,  20. 

male,  20. 

Winged  male,  20. 
Young  larva,  21. 
Lubber  Grasshopper,  135. 

Absence  of  enemies,  136. 
Life-history,  135. 
Remedies,  136. 
Wandering  habits,  135. 

Lye  Solutions,  Table  of  experiments  with,  204. 
Manna  produced  by  a  Scale-insect,  13. 
Mantis  Carolina,  189. 

Characteristics,  189. 
Egg-mass,  190. 
missouriensis,  190. 
Characteristics,  190. 
Egg-mass,  191. 
Food,  191. 
Mealy-bug,  2, 4, 14, 79. 

at  Orange  Lake,  Florida,  197. 
The  Common,  63,  86. 
Destructive,  64. 
Mealy-bugs  Food-plants,  63. 

General  characteristics,  63. 


INDEX. 


225 


Mealy-bugs,  Habits,  63. 
Metapodius  femoratus,  162,  192. 
terminalis,  163,  192. 
Mexican  Fruit  "Worm,  169. 
Microcentrum  retinerve,  134. 
Microgaster  parasite  of  the  Bag- worm,  147. 
Midas  clavatus,  175. 
Miotropis  platynotse,  153,  217. 
Mites  preying  upon  Scale-insects,  69,81. 
Glover's,  82. 
Habits,  82. 

Hairy  Orange,  83, 218. 
Importance,  81. 
Orbicular,  85. 
Rhizoglyphus,  84. 
Spear-bead,  83, 216. 
Spotted,  84, 216. 
Undetermined,  84,216. 
Monomorium  carbonarium,  132. 
Mytilaspis  citricola,  26, 39, 42, 75. 

gloverii,  14, 19, 42, 75, 77, 86. 
pomorum,  15. 

Naked  Scales  (see  Lecaninae). 
Naphthaline  for  ants,  130. 
Neuroptera  preying  upon  Scale-insects,  80. 
Northern  Bag- worm,  147. 
Nothris  citrifoliella,  154. 
Nothrus  ovivorus,  85. 
Notolomus  basalis,  133. 
Odontota  rubra,  133. 
Oiketicus  abbotii,  144. 

Oil  of  creosote  as  a  remedy  for  Scale-Insects,  07. 
Table  of  experiments  with,  206. 
Oncideres  cingulatus,  128. 
Opbideres  fullonica,  170. 
Orange  Apbis,  157. 

Birth  of  the  young,  138. 

Descriptive,  157. 

Enemies,  180. 

Influence  of  climate  on  development 

158. 

Injuries,  159. 
Natural  history,  157. 
Parasite,  158. 
Remedy,  159. 
Basket-worm,  148. 

preying  upon  Scale-insects,  69. 
Case-bearing  Tineid,  193. 
Chionaspis,  40. 

Abundant  in  Louisiana,  40. 
Scale  of  female,  40. 

male,  40. 
Dog,  5,  137. 

Descriptive,  137. 
Food-plants,  138. 
Life-history,  138. 
Parasites,  139. 
Protective  resemblance,  5, 
Remedies,  139. 
Orange-eating  Tineid,  179. 

Flat-headed  Borer,  171. 
Leaf-notcher,  133. 
Orange  leaf  Nothris,  154. 
Mites,  81. 
Psocus,  194. 
Sawyer,  171. 


Orange  Thrips,  164. 

Beneficial  rather  than  injurious 

165. 

Injury  done  to  the  blossoms,  165. 
Remedies,  165. 

tree,  enfeebled  condition  of,  fosters  Scale- 
insects,  45. 

How  affected  by  Scale-insects,  45. 
Organic  diseases,  L 
Systems  of  cultivation,  a 
"Web  worm,  155. 

Descriptive,  156. 

Earlier  states,  156. 

Number  of  broods,  157. 

Other  insects  associated  with  it, 

155, 156. 

Protective  resemblance,  155. 
Remedies,  157. 
The  web,  155. 

Organic  diseases  of  the  Orange,  L 
Bark-fungus,  1. 
Die-back,  1. 
Dropping  of  fruit,  5. 
Foot-rot,  3. 
Smut,  3. 

Splitting  of  fruit,  4. 
Oyster-shell  Bark-louse,  15,  85. 

Mode  of  growth,  15. 
Pachnaeus  opalus,  133. 
Pachyneuron  altiscuta,  218. 
an  thorny  iae,  218. 
aphidis,  218. 
Pale  Dakruma,  77. 

Palmetto  brushes  for  scrubbing  the  trees,  90. 
Papilio  cresphontes,  137. 
Parasites,  General  importance  of,  7. 
Parlatoria  pergandii,  2, 37, 42, 75, 86. 
Penthatodes  mytilospidis,  216. 
Pergande,  Th.,  Notes  on  Orange  Mites,  84. 
Perilitns,  81,  215. 
Phobetrum  pithecium,  140,  142. 
Cocoon,  143. 
Larva,  142. 
Moth,  143. 

Pixnpla  conquisitor,  147. 
inquisitor,  147. 

Plataceticus  gloverii,  69, 148. 
Platynota  rostrana,  152, 154, 217. 
Polistes  americauus,  186. 
Habits,  186. 
Nest,  186. 

Poly  sp  bin  eta  albipes,  153. 
Pomace-fly  of  the  Orange,  176. 

9  Life-history,  177. 

Potash  as  a  remedy  for  Rust-mite,  110. 

Scale-insects,  96. 
Predatory  insects,  180. 

Lepidoptera,  76. 
Wasps,  186. 

Prionotus  cristatus,  192. 
Pruinose  Aphis-fly,  185. 
Imago,  185. 
Larva,  185. 
Parasite,  186, 218. 
Puparium,  185. 
Psocus  citricola,  194. 


226 


INDEX. 


Psocas  venosus,  193. 
Psyche  confederata,  148. 

Unknown  species,  148. 
Purple  Scale,  26,  42,  75. 
Egg,  26. 
Female,  26. 
Life-history,  27. 
Male,  26. 

Origin  and  spread,  27. 
Parasites,  27. 
Scale  of  female,  26. 

male,  26. 
Young  larva,  27. 
Pyrethruni  as  a  remedy  for  ants,  130. 

Rust-mite,  11H 
White  ants,  124. 
Rapacious  Soldier-bug,  191. 
Baphigaster  hilaris,  159,  163,  164,190,192. 
Bed  Bug  (see  Cotton  Stainer). 
Bed  Scale  of  California,  32. 

Distribution,  34. 
Formation  of  Scale,  34. 
Scale  of  female,  33. 

male,  33. 
Bed  Scale  of  Florida,  28, 86. 

Development,  28. 
Introduction,  86. 

Number  of  annual  generations,  32. 
Origin  and  distribution,  32. 
Scales  of  male  and  female,  28. 
Winged  male,  28. 
Young  larva,  29. 
Bhinacloa  sp.,  215. 

Bhizoglyphus  preying  upon  Scale-insects,  84, 216. 
Biley,  Prof.  C.  V.,  descriptions  of  mites,  216. 

on  coition  of  bag  worms,  214. 
Bomalea  microptera,  135. 
Buddy  Aphis-fly,  184. 
Bust  of  the  fig,  105. 

Orange,  105. 

Discoloration  of  the  fruit,  105. 
not  influenced  by  soil  and  cultiva- 
tion, 113. 

preventive  measures,  114. 
remedies,  113. 
the  rust-mite  its  cause,  106. 
rings  of  rust  on  the  fruit,  110. 
rusty  oranges  superior  to   bright 

fruit,  112. 
Bust-mite  of  the  Orange,  107. 

Confined  to  the  Citrus  family,  112. 
Description  of  the  eggs,  108. 
mite,  107. 
Distribution,  113. 
Effect  of  attacks  upon  the  foliage,  11?. 

fruit,  107, 110. 
Food,  109. 

Influence  of  weather,  111. 
Life-history,  108. 
Modes  of  spreading,  111. 
Numerical  abundance,  109. 
Periods  of  increase,  113. 
Preference  for  half  shade,  110. 
Bapidity  in  development,  115. 
Transported  by  birds  and  spiders,  111. 
Uncertainty  as  to  its  origin,  113. 


Bust-mite  of  the  Orange. 

Wandering  habits,  107, 109. 
Sacium,  175. 

Saddle-back  Caterpillar,  141. 
Sap-beetles,  175. 
Sap-feeding  insects,  175. 
Sawyers,  121, 125. 

Scale-devouring  Hyperaspidius,  75. 
Habits,  75. 
Larva,  75. 
Pupa,  75. 
Scale-eating  Tineid,77. 

Earlier  states,  78. 
Habits  of  larva,  77. 
Moth,  78. 

Number  of  broods,  78. 
Scale-insects  afl'ecting  the  Orange,  13. 

Agencies  assisting  their  distribution,  43. 
Characteristics,  13. 

Conditions  favorable  to  their  increase,  45, 
Division  into  subfamilies,  14. 


Generally  present  on  Orange  trees,  42. 
Infection  from  nursery  stock,  87. 
Influence  of  climate,  46. 

cold,  46. 

Insect  enemies,  69. 
Introduced  on  imported  plants,86. 
Oscillations  in  numerical  increase,  46. 
Parasites,  47. 

Precautionary  measures,  87. 
Protected  by  Spider-webs,  43. 
Bavages,  42. 
Bemedies,  91. 

Effective  remedies,  92. 
Popular  fallacies,  91. 
Secretions,  13. 
Spreading,  87. 
Scavenger  insects,  170. 
Scolytidse,  General  habits  of,  173. 
Scymnus  bioculatus,  66. 
caudalis,  180. 
Larva  and  habits,  180. 
Various  species  preying  on  Aphis,  180. 
Sejus  sp.,  216. 
Silicate  of  soda  as  a  remedy  for  Scale-insects,  99. 

Table  of  experiments  with,  211. 
Sinea  multispinosa,  191. 
Siphonophora  multispinosa,  191. 
Skiff-caterpillar,  143. 
Slug-caterpillar,  140. 
Smicrips  hypocoproides,  177. 
Smut  of  the  Orange,  3,  62,  63. 
Soda  lye  as  a  remedy  for  Scale-insects,  98. 
Soldier-bug,  The  Green,  159,  190. 
Soldier-bugs  as  predatory  insects,  190. 
Solenopsis  xyloni,  129. 

Destroying  their  colonies,  130. 
Habits,  130. 

Preventive  measures,  131. 
Soothsayers,  188. 
Spear-head  Mite,  83. 

Spider  associated  with  Orange  Web-worm,  155. 
Spider- webs  protecting  Scale-insects,  43. 
Spider-legged  Soldier-bug,  78,  191. 
Eggs,  79. 


INDEX. 


22? 


Spider-legged  Soldier-bug. 

rood-habits,  78,  191. 
Life-history,  79. 
Parasite,  79. 

Spiders  transporting  Rust-mites,  111. 
Scale-insects,  43. 
Splitting  of  fruit,  4. 
Spotted  Mite,  83,216. 

Description,  216. 
Stenomesius  (?)  aphidicola,  159. 
Stinging  caterpillars,  14u. 

Sulphate  of  iron  as  a  remedy  for  Scale-insects,  99. 
Sulphur  as  a  remedy  for  Rust- mite,  116. 

Scale-insects,  91. 
Sulphur-colored  Tortricid,  154. 
Sulphurated  lime  aa  a  remedy  for  Scale-insects,  98. 
Sulphuric  acid  as  a  remedy  for  Scale-insects,  93. 
Syrphus,  7, 181. 
Syrphus-fly  larvae,  181. 

Characteristics,  181. 
Change  of  color,  181. 
Mode  of  feeding,  181. 
Number  of  broods,  181. 
Rapid  development,  181. 
Transformations,  181. 
Tachina-fly  parasitic  on  Orange  Dog,  139. 
Tap-root  borers,  121. 
Telenomus,  215. 
Termes  flavipes,  122. 
Termites  (see  White  ants). 
Tetrastichus,  59,  215. 
Thick-legged  Metapodius,  162. 
Egg,  163. 

Insectivorous  habits,  163. 
Toung  bug,  163. 
Thrips  tritici,  164. 
Thyridopteryx  ephemerseformis,  147. 

Coition  of,  214. 
Tineid,  Case-bearing,  on  Orange,  193. 

larvae  preying  on  Scale-insects,  69, 77, 78. 
The  Orange-eating,  178. 

Scale-eating,  77. 
Tomocera  californica,  55. 
Tortricidre  injurious  to  the  Orange,  151. 
Tree  cockroach  associated  with  Orange  "Web-worm, 

156. 

Tree-inhabiting  ants,  170. 
Trichogramma  minuta,  153. 
pretiosa,  153. 
Trioxys  testaceipes,  159.- 
Turtle-back  Scale,  14,  48,  61. 

Attended  by  ants,  50. 
Brood  periods,  50. 
Excretion  of  honey,  50. 
Food-plants,  52. 
Fnll-grown  insect,  48. 
Geographical  distribution,  52. 
Gregarious  habits,  49. 
Injury,  61. 
lletamo'rphosis,  49. 
Parasites,  50. 


Turtle-back  Scale. 

Young  larva,  49. 
Twice-stabbed  Ladybird,  71. 
Habits,  72. 
Larva,  71. 
Pupa,  72. 
Twig-girdler,  128. 

Food-plants,  128, 
Natural  history,  128. 
Remedies,  129. 

Typhlodromus  oleivorus,  107. 
Tyroglyphus  (?)  gloverii,  82. 
mali,  84,  85. 
sp.,  216, 

Vase-maker  wasp,  187. 
Cell,  187. 
Habits,  187. 
Parasites,  188. 
Voyle,Jos.,  on  effect  of  cold  on  Scale-insects,  41"- 

on  Mealy-bug.  197. 
Wax  Scale,  56. 

Adult  female,  56. 
Eggs,  57. 
Food-plants,  58. 
Geographical  distribution,  58. 
Life-history,  57. 
Natural  checks,  59. 
Nature  of  waxy  covering,  58. 
Number  of  annual  broods,  58v 
Parasites,  59. 
Young  Larva,  57. 
Waxy  Scales  (see  Lecaninae). 
Web-makers  injurious  to  the  Orange,  154". 
Whale-oil  soap  as  a  remedy  for  Rust-mites,  I15L 

Scale-insects,  95i_ 
Table  of  experiments  with,  2G2~ 
Wheel-bug,  192. 

Characteristics,  192. 
Eggs,  192. 
White  ants,  3,  6,  9,  321,  178. 

Found  in  the  fruit,  178. 
Habits,  121. 
Injuries,  122. 

Nature  of  their  galleries,  123; 
Precautionary  measures,  123. 
Remedies,  124. 
White  Scale,  35,  56. 

Distribution,  35. 
Food-plants,  36. 

Number  of  annual  generation*,  3T,_ 
Scales  of  male  and  female,  35. 
Winged  male,  35. 
Wiley,  Prof.  H.  W.,  on  reactions  of  sulphur  «n 

lime,  217. 

Williston,  Dr.  S.  W.,  on  an  Anthomyid  fly,  18&. 
Wine  Fly  of  the  Orange,  176. 

Life-history,  177. 
Winter-killed  branches,  5. 
Wood-lice  (see  White  ants). 
Yellow-banded  Ichneumon,  147. 


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