5
DDS sad Lee ae ee 1 TTR 5-28 1 a i etre rose ee Sie An 28 6
1c SA eee a 1p eesti (Ee te et a) 2 Se) 2 8
4) so Soca (hl ose 10 ae eae | [Lem fn he 1 Dae! We 22 aes 5
13) Sy Neca A ae 5 ing 3 | A | are | Dal) 2a" a Srp es 8
Totals Be ill Blt Te eae ee | a Le 2 eS SGU Al: SO: P95; lpels
pee | 0.21 021/023), 120) 351) 4-1) 0.1) O10) 0.2) 1e3)74-6]' 5:29), 2..3)77 9024
*Per trap per night.
Note: Catch also included 2 male 4. kochi and 1 female 4. barbirostris.
8 PROC. ENT. SOC. WASH., VOL. 36, NO. 1, JAN., 1934
TABLE: 6.
ANOPHELES ADULTS CAUGHT IN EARTH-LINED TRAPS PLACED NEAR
A CARABAO SHED (UNLIGHTED).
_SPECIES
DATE | A. minimus | A. subpictus
A. vagus TOTALS
var. flavirostris|var. indefinitus| A. tessellatus | var. limosus
Me cre | Te! [ae] ae) eee ae eee) P| Pana |e rss a |
June
1 ae tere re oa Bae ae 1 3} 412.) 25) 47 17 | 42) 59) 20) ) 47am
20 Set eule al 5}. 6. 3 | 6) 9 | 14) 33)> 47) 1949 eee
21 3| 7) 10 5 | 12) 17 Sy) DT 6a | 2Ole Sil 24 A ee
22 1H Ts ea | Li PA} Wy 2 DB Be 22S se
28 APN e245 | e282 |(P il Fiano eee 2°) 2) 3) 11) T4324 ee
24 Bille 2h lees St ela 2) 2°) 5.) 10) 15)5 39) eae
July
2 pmereil) eisye || ice) le wl 81 sO) LT 31) 4a) (25), 223)" 225) Ae 7 ee
Soe || Sens 26 2) Lote (6) ZN Le De 3 Be Da a eo)
4 Poe QP 280). 2. eG a8 ee ee 4] 41} 45) 7) 59) "66
oy Be Del Dio oD 1) LOI DI esa ees ae 3 | 31) 34) S|) S2 iam
6 1 Dg S20 Sei 220 |i sae a | ee eee 5.| 42) 47| 963 ia
7 IM ees aes) eee lf wy APA SI a ees A 2)|) 35) ~37) 6) SOS
8 1 IW Pee as 21) 1S ess |e ee 1 |: 32}. 33) - .3)) asi eee
11 1 LS i A re Bt SS lect [LE aed ees 1'| 24; 25) - (2) 223iseeaia
12 1 TOES 2 11 ih | WentO| se sect sete | eer 3)| 219] 22)" S| eoi ee
13 1 UN ee at a 3) 1] 2) 25) a5) V7)" Se eee
14 1 Na | eee) CL ae) Reese [Pal le ee 3 | 22) 25). 3)0 27h
15 1a eee 1 ee, S|) Beef -cesee Eee | We 1)| 26) 27| 4), Sire
Totals | 21 | 38 | 59 | 27 | 162} 189) 15 | 20 | 35 | 85 | 464] 549] 148] 684) 832
Aver.* | 1.2} 2.1) 3.3] 1.5{/9.01/10.5] 0.8] 1.1] 1.9] 4.7] 2.6/30.5| 8.2138.0/46.2
*Per trap per night.
Note: The catch also included 1 female 4. barbirostris and 2 male A. kochi.
MR pepe fe
PROC. ENT. SOC. WASH., VOL. 36, NO. 1, JAN., 1934 = 9)
TABLE 7.
ANOPHELES ADULTS CAUGHT IN UNLINED TRAPS PLACED NEAR
CARABAO SHED AND BAITED WITH CARABAO DUNG
(UNLIGHTED).
SPECIES
DATE | A. minimus | A. subpictus A. vagus pores
var. flavirostris|var. indefinitus| A. tessellatus | var. limosus
TONNE UE a eco Rs WO Mia eset] ar. | Mtoe |Paes eons
June
2" OE ieal ae eae a aoe Sud Wis $25 Ue eae te Cee a TE LOS Tad 12) eal:3
AQ) 5 aie ae Ce TS ee ro ke 1 JL lc ceee [em eee PS Th ey) Sy) al 1S}) let
Pal Geret ||P 2. 2 2 1 3 Ae 1 1 2 ii Signs 136
Pak | tank) Shieron|) IE eee 1 1 ese OD ee lee AS ls TAs
2) Dah eevee Ol Eaeceeeee Wee Me eee eae Dip | eee 1 1 (Ease 3 Sia 6 6
ek a ell tana eae Gea eee 1 1 ia eee 1 l Th 2: Aiea 9
27 el eee 2 OP's eee 1 1 |e) ee 3 1 ! 3 4) 7 2 6 8
21S Mai Rae 1 i! leas B Bip || ehciel teeeetee ooh | ae Fo Ue 205 20 eee, 24, 24
Di Dye A 2 5 yp Pe Geeta mene colle ae 1 4 5 OQ} ie
SSS a ee a2 a Be 1 Io ag al ee (| 2 Ge 6 6 31009
7S) TF a. Sa a a ee a 1 ng eee ee OO el eB 6 (eee MAS
BNO) 2 Gl ee ea | Se oe ae 5 Giga ees 223) ey Melee 2 7 Ole 12) 14
July
11 (ges REA a ae a 1 jeer Se Meese Owed AEE 2 7) ae Si ess
Totals 2 8 | 10 Si 2730 3 3 Ui |) Ges) O)7A| IY] | sz Sis)
CANS eam Cen ORG O5Si eee See eee EL 4 ONSaESO 723802101 55110. Shes
*Per trap per night.
Note: The catch also included 1 male 4. fuliginosus, 1 male and 2 female 4. kochi.
10
TABLE 8.
PROC. ENT. SOC. WASH., VOL. 36, NO. 1, JAN., 1934
ANOPHELES ADULTS CAUGHT IN EARTH-LINED TRAPS PLACED NEAR
CARABAO SHED AND BAITED WITH CARABAO DUNG
(UNLIGHTED).
SPECIES
DATE | A. minimus | A. subpictus A. vagus es
var. flavirostris\var. indefinitus| A. tessellatus | var. limosus
MR Fe a el) SR el te a eae cee
June
19 ese eee DP ess |) Ee) al Py 2.) So) 8} 231%) 7a
CAV AVI ce eel 1 eel ee 5 oo bo 1} 29) 3 3 |) <20) - 23/9 4a 28 es
Dlari,|\.see 1 Dy! Sale reas A Vie? a 3) 4S 6; 11
Dy [bee 1 1 ees A 2 Ue) eae Sealy 9) 1h) 3a) 16a
fg (aie Sete [nd See | es | (a SH Shah Al heal tl jy) | 9) alt
Dee ie Dee Dl 10 BS eee eee PA yg 2h) gel 6] 7| 2a) 7 oS aes
Dp 1 fies 2) Ie cea mie UA 22 soot ieee lie es aI 2 ee 2| 13] 15) 44) SSiseee
D6 Biel 2s Bei, Sedo, wale ace Sas a eae 1 17) 18) 2) e220) eeee
27 De) Pe ee) eT SUTIN 7a | eres Coen 3 9 12) S| ee ae
28 DNS 28 rcv TA Malle |) OB ae 1 1} 5) 15) 20) etSs eee ees
29 1 Do oe) eel LN eee alee 3 3 6) 9 Sa a es
30 BP F3s5|| Bae! 2a Oe, 2 a oe Peo | 2 | 12) 14) 3 oes
July
1 DB, fej) eee oes ene esate Gal 1 ee OAS Mo Pale
Totals 6) 269) 325) 1S 485) 63" 7) 171) 248) 305 135 el65|) ssa 26 ees
Aver* 0.5). 220)2.511.2) 3.74.9] 0.5) 1.3) 1.7) 225) 10.) 1301-405) ee ee
*Per night per trap.
Note: The catch also included 1 female 4. barbirostris, 2 male A. kochi and 2 female
A. fuliginosus.
PROC. ENT. SOC. WASH., VOL. 36, NO. 1, JAN., 1934 11
TABLE 9.
ANOPHELES ADULTS CAUGHT IN AN UNLINED TRAP
PLACED UNDER
AN OCCUPIED HOUSE NEAR A STREAM
BREEDING-PLACE (UNLIGHTED).
SPECIES
DATE | d. minimus | A. subpictus
var. flavirostris|var. indefinitus| A. tessellatus
A. vagus TOTALS
var. limosus
Me eel Pee]! Me || ae or Mes Se ors |e Set
June
Sy AG ee al KAN eS pe 2 ee See eae fa Poe ie 6) 8
21S 9g (ehabea | in IWC Sl eS Le Be elfen I ae il |} fe ON 28 | Plot:
Oana | eee eR he elf US fe tee I Sh) Ae ie Gr P2935
2S Mootle 4 |k See al eS Pee aie 1 iM | a fe We el Sr DS Se WA 1 1
25) oy (ese EE Be eran 1p age ea ea: 0 VE nee Mo Ae ian area se 2) Loy 12
Shy 9 RS sl Be cae a a Mot esa Fe: 20 Ue SIRT Meek I oc a ee) Gl 2 8| 10
Ab oe) |S ee |ae TSP ie PEE ae a ea 2 es 5193 i 8
2), We caed eed ees OP Ria ia el eel eee | ana apes Slee Se 2
(Tse ee wal eee 20 rae (a? Te) a Sa LOAs TSe Ss L8ih 23
AE DS ae nee INN OFS? Sood (ee ee el Pate a Sites: |) LOS
3) Py as ls et a IDG Be ce ieee (Siete ee ee eee Sh 4, 6
i)» IE Se be se Nel Ee Bs Ta Ui Sc | aa Pe 1a eae Ly a 2
1) oe Ras Pt ee a Ea DEAS ep a| Bs Seem yee ene 1 4, 1 S16
LL | eer | ol | esl te nr Sorelle ned 2 lh Maile 2 3|) 1 23
Totals Dae] Sees L204 R65 Siei| aa BSP | eS9- 1225415721
SS hee ee Bee 1p? (a ea Op Di. 2 No 2 Se I aioe aed
*Per trap per night.
Note: The catches also included 1 male 4. barbirostris.
For the catches between July 2 and 8 inclusive the trap was covered with bushes.
12
PROC. ENT. SOC. WASH., VOL. 36, NO. 1, JAN., 1934
TaB_e 10.
ANOPHELES ADULTS CAUGHT IN EARTH-LINED TRAPS PLACED
UNDER AN OCCUPIED HOUSE NEAR A STREAM
BREEDING-PLACE (UNLIGHTED).
DATE
SPECIES
A. minimus
var. flavirostris
TOTALS
A. subpictus A. vagus
var. indefinitus| A. tessellatus | var. limosus
Bh ee, |) | Ue eae tee tre i ore i ee te ee
June
25 7 6 ies? A P2936 || aed! 3 5 15] 42) 57
26 5 6 M1 13) S548 2 + 6 22} 43) 65
Dif 11 5 16} 22), 433i" 65) 5 2 1 3 30} 49} 79
28 3, | 10 13}) 24) 83) O72 = 1 1 32} 54} 86
29 3 7 10 PAPA SNC) (ERR PI eae eal[Poce 28) 33) <6i
30 8 3 6)» 10) eS 25a 1 2) 22) 228 50)
July
1 reece. 1 IY ac 1 PA fee eee (0 9 4; 13
2 5 5 10 Ti 435 SOW 2) soe ala: 16| 72) 88
3) 3 4 7. 12) 36) 4803.) 10") 18 26) 65)5 9
4 3 3 6) 32 [PSS 18'S |e ce eal ee 31} 93) 124
5 3” ae: TN 2A G2 "83/30 |) Sale 8a Meo S 4 aan
6 3 6 9) 43) 69) 112 3 + Vi 50} 101} 151
7 37) 4 T\ 44) FOWL) 35-45) 77) WSO SS atts
8 1 2 3) 14) 49) 63) 2 3 5 23) 63) 86
0 mR | eae Poe 1 1 8 OH si l7A 1 3 14, 13} 27
10) Sasa) Re alba lI cee 2 4 Glass 1 1 Hf ASH)
11 i D 1 1 7) Wok Pro Ke ewe ASS | Romie 24| 22) 46
Totals 55 | 67 | 122) 263} 629} 892} 25 | 50 | 75 | 410] 86411274] 753]1610/2363
Aver.* | 1.6] 1.9| 3.6] 7.7 |18.5/26.2/0.7] 1.5] 2.2 |12.1/25.4/38.6/22.1|17.9169.5
*Per trap per night.
Note: Two traps were used. For the catches between July 2 and 8 inclusive the
traps were covered with bushes. The catches also included 2 female 4. hyrcanus var.
sinensis, 1 male and 1 female 4. barbirostris, 4 male and 2 female 4. kochi.
Ek es es
PROC. ENT. SOC. WASH., VOL. 36, NO. 1, JAN., 1934 13
TABLE 11.
ANOPHELES ADULTS CAUGHT IN EARTH-LINED TRAP PLACED
NEAR CARABAO SHED. TRAP LIGHTED.
SPECIES
DATE A. subpictus
A. vagus TOTALS
var. indefinitus var. limosus
M. F. T. M. F. Th M. F. iE
June
25 1 23 24 Gul LT 127 7 | 144] 151
OY Tan oer eee 7 Tl eee 88 SSe |e! 95 95
Dien WN oes. 54 ey IBS: rab B eet 88 192) | 9192
OLE, iam | ee ae 14 UE Fa Pe ee Ud TM ae es 91 91
DS rn in| Sees 53 oye) | ieee 150) SISOb) oes 203 | 203
SO gee Gat eeecreee 29 DORR ots 126 Ne D260 et ee te L5S5e he hSS
July
al See 29 DOP | eetise A 45 cee ee 74 74
Totals L 9209: |, 210 Ga), TAS eso 7 | 954 || 961
Averages: || O. 1 9)-2929' 1930-011) “O29 | 106.4|'107.3)) 1120 | 136631 137-3
*Per trap per night.
Note: The catch also included 1 female 7. tessellatus, and 1 female 4. barbi-
rostris, but no A. minimus var. flavirostris.
14 PROC. ENT. SOC. WASH., VOL. 36, NO. 1, JAN., 1934
TaBLeE 12.
ADULT ANOPHELINES CAUGHT IN EARTH-LINED TRAP HAVING
COLORED LIGHT AND PLACED NEAR CARABAO SHED.
SPECIES
Bevis pe A. subpictus A. vagus Tenses
o var. indefinitus var. limosus
Light M. F. ste M. F. ae M. F. zi
July
2 Red 0 18 18 0 87 37 | 0 105 | 105
3 Green 0 21 Pl 0 62 62] 0 83 83
+ Blue 0 26) (2G n 0 78 78 | O 104 | 104
5 Yellow | 0 39 39510 81 81 0 120 } 120
6 Brown 0 11 1 eo 367|) #360! =O 47 | 47
7 Gray 0 22 220 57 oul |) 79 79
8 Pink 0 15) 15 0 48 48 | 0O 63 63
Note: No adult 4. minimus var. flavirostris were caught and no males of any
species. This trap was right beside those used in Tables 5 and 6 from the dates
given.
TaBLeE 13.
ANOPHELES ADULTS CAUGHT IN TRAPS PLACED IN A RICE
FIELD (UNLIGHTED AND 500 M. FROM HOUSES).
ONE EARTH-LINED ONE UNLINED
SPECIES TRAP TRAP
M. F. TMs he [
A. minimus var. flavimostris 0 0 0 0) 0) 0
A. subpictus var. indefinitus.........2---------- 1 0 1 0 0 0
Ya ley AGING N GEN ey OE OSOIS. ese ee ee 4 3 7 0 0) 0
WO tals eee oe Roce eccrine See eee 5 3 8 0 0 0
Average per night per trap -...............- O27 | OF44\ MeO} |. | eee | eee
Note: These traps were in place for one week. Catches were made each
morning from July 16 to 22 inclusive.
REFERENCES
1. Russett, P. F. Daytime Resting Places of Anopheles Mosquitoes in the
Philippines. First Report. Philip. Jour. Sci. 46 : 639-649, 1931 (Dec.).
2. Russett, P. F. Daytime Resting Places of Anopheles Mosquitoes in the
Philippines. (Second Report). Proc. Entomol. Soc. Washington 34 : 129-
138, 1932 (Nov.).
PROC. ENT. SOC. WASH., VOL. 36, NO. 1, JAN., 1934
TaB_Le 14.
15
COMPARISON BETWEEN UNLINED TRAPS AND DIFFERENT
SIZES OF EARTH-LINED TRAPS
(UNLIGHTED.
NEAR STREAM BANK).
AUGUST 4
TRAPS =
a eas) =
NEW STYLE
A. minimus var. flavirostris _| 4 6 1 6 1 18
A. subpictus var. indefinitus _| 3 2 0 0 0 5
ae FARILOS SE iW Se ee OM} © 1 Oneal D
A. vagus var. limosus 7a\ oa Suily Ll i || 30
MLO tal si eoes Se eets et hos 8 We | 1G |} a ay Bi SS
A. miniums var. flavirostris _| 7|10}10) 9] 11] 47
A. subpictus var. indefinitus | 2} O0|] O| O|} O D
a ouiM LOSS CLIT Sime eee @ |) 8| 4) 5 18
A. vagus var. limosus __.........-. FF S|) iG} 6 | 4 || Be
sliotals Meee ee GN UGH S42 LOS 208 105
A. minimus var. flavirostris _| 4) 5 | 7]|16]13] 45
A. subpictus var. indefinitus _| O0| 0} 0} O| O 0
SMALL
PARSE SSCIIGIL Sere ee OF On 2a), 7a) 0)" sg
A. vagus var. limosus Go| whe) Se | Syl esta pal
AiG tall so eee eal eo Se lO Se 2 Sale26n es
EARTH-LINED TRAP TOTALS 38 | 42 | 52 | 64 | 49 | 245
A. minimus var. flavirostris _| 0| 0} O| O| O 0
Op STYLE A. subpictus var. indefinitus _| 0| 0} 0} O| O 0
(2 traps) La be HOGHA NATE Sa cose ee tens else QO} @}) @O} OO} @ 0
A. vagus var. limosus S|) 6 Si WO} @] te
WMO Galli pts Were me ies Se A Be |) 60, S| Ou Om 4
Earth-lined traps—average per trap per night 16.3.
Unlined traps—average per trap per night 1.4.
Of the 4. minimus var. flavirostris caught in earth-lined traps, 23 were males
and 87 females.
a.
(tee
Tye. Fr oper pall
“7 copings ah
Ais CiuTee SA
$
|
| 7 ”, *
i
i
'
uf
rf
a
€
i
4
‘
=)
= ,
\4
rt J
’
y ears
4
Pe 7
5 “
‘ WE
+h
3
r
4 Tiwi
7) 8 Fr
P
4
J ve
PROC. ENT. SOC. WASH., VOL. 36 PLATE |
Figure 7—Unlined (old style) mosquito trap. Showing inside catching chamber
removed.
Figure 2.—Unlined (old style) trap ready for use.
[17]
PLATE 2 PROC. ENT. SOC. WASH., VOL. 36
Figure 3.—New style trap lined with earth. Front open. Top removed for
photograph.
[18]
PROC. ENT. SOC. WASH., VOL. 36 PLATE 3
Figure 4.—New style trap lined with earth. View showing interior.
[19]
PLATE 4 PROC. ENT. SOC. WASH., VOL. 36
Figure 5.—New style trap lined with earth showing method of removing mosquitoes.
Note drip cans on top.
Figure 6.—New style trap lined with earth showing position near a carabao shed.
[ 20]
PROC,
ENT. SOC. WASH., VOL. 36
Figure 7.—New and old style traps side by side for test.
PLATE 5
PROC. ENT. SOC. WASH., VOL. 36, NO. 1, JAN., 1934 23
TWO NEW SPECIES OF PLEOCOMA (COLEOPTERA: SCARA-
BAEIDAE).
By A. C. Davis, Takoma Park, Mad.
Pleocoma remota, n. sp.
Broadly oval, robust, dorsum slightly flattened, fimbriate and clothed beneath
with yellow hair. Head very dark brown or blackish, closely punctate above,
ocular canthi impunctate; eyes moderately prominent, much flattened, slightly
cut into in front by the ocular canthi and rather deeply behind by the lobes
of the genae, so that about two thirds of the total area is ventral, set into the
head obliquely so that the anterior margins are each about 0.3 mm. nearer
the mid-line than the posterior margins, where they disappear under the pro-
notum; clypeus small, heavy, reflexed, sharply obtusely emarginate at apex,
the anterior margins sinuate, apices bluntly rounded and nearly truncate,
lateral margins rounded; anterior margins of ocular canthi sinuate, inclined
posteriorly from a right angle to the mid-line, apical angles and posterior
margins broadly rounded; horn of vertex fairly long, heavy, rounded at apex,
quadrate in cross-section, the anterior angles of the horn continued as oblique
ridges on the frons, terminating on each side at the junction of the ocular canthus
with the clypeus.
Pronotum black, glabrous, less than twice as wide as long, widest at basal
two fifths; anterior angles, sides, and basal angles all included in one sweeping
curved margin; disc evenly, moderately coarsely, and rather closely punctate,
posterior median impression distinct, anterior median impression broad and
deep, giving a retuse appearance to the profile of the pronotum.
Scutellum subtriangular, almost covered with tawny hair.
Elytra chestnut brown, wider at the humeri than the base of the pronotum,
conjointly nearly as wide as long, widest at about the apical third; costae
hardly elevated, smooth, impunctate; geminate striae distinct but not deep,
not attaining the apices of the elytra, delimited by large shallow punctures;
sutural striae moderately deep; elytral intervals coarsely and sparsely punctate
and slightly rugose.
Body beneath castaneous, femora darker, and tibiae nearly black.
Length 22.5 mm., maximum width 14 mm.
Antennae brown, first joint conical; second subglobular, transverse, four
fifths as wide as first; third subcylindrical, pentagonal in outline as viewed from
above, seven tenths as long as the first joint,! widest at apical fifth; joints 2 and 3
together almost or quite equal in length to the first; fourth joint shorter than
the third and about equal in width, pentagonal in outline; fifth joint wider than
the fourth and about as long, joints 4 and 5 together shorter than the third;
sixth joint transverse, angulate, with a short process; seventh joint with a
short lamella a little more than one third as long as the joint and lamella of the
eighth; joints 8 to 11 forming the club, the ninth joint longest, the tenth nearly
‘In speaking of the joints composing the antennal club, the terms “‘length”’
and “width” are reversed, the length being considered as that of the joint and
lamella across the long axis of the antenna.
24 PROC. ENT. SOC. WASH., VOL. 36, NO. 1, JAN., 1934
as long, the eleventh shorter than the tenth, and the eighth shorter than the
eleventh.
The thorax in profile is distinctly retuse, although not so pronouncedly so as
in P. staff Schauf. and P. edwardsi Lec. The geminate striae do not reach the
apex of the elytra, a peculiarity found also in staff. The first geminate stria is
interrupted behind the middle by an offset laterally of about its own width,
the inner stria of the pair resuming on a line with the outer one, and terminating
abruptly a short distance posterior to this point.
Type locality —Utah.
Type.—Male (Cat. No. 50124) in the collection of the United
States National Museum.
The female of this species is not known.
P. remota differs from P. behrensi Lec. and P. fimbriata Lec.,
nearest to which it belongs in the genus, in color, in the hairy
scutellum (which was probably completely covered with hair
when the specimen was first taken), in the different proportions
of the antennal joints, in the blunt apical horn, and in the
elytral characters. The species resembles P. staff Schauf.
very closely in all except the number of joints in the antennal
club, and might easily be taken for an off-color specimen of
that species. Since the unique type is labelled “Utah,” and is
from the collection of J. B. Smith, there is little doubt that this
is the specimen concerning which the note in the Proceedings
of the Entomological Society of Washington (vol. I, 1885,
p. 33) upon Utah as a new territory for Pleocoma behrensi
was written.
Pleocoma simi, n. sp.
Broadly oval, robust, dorsum flattened, fimbriate and clothed beneath with
yellow hair. Head dark brown, closely but rather lightly punctate, densely
clothed with long yellow hair; ocular canthi impunctate; eyes prominent,
round; clypeus reflexed, not or very slightly emarginate at center, apices rather
sharply rounded, lateral margins rounded, upper surface densely clothed with
yellow hair; anterior margins of ocular canthi at right angles to the mid-line,
anterior and posterior angles lacking, the outer half being very nearly semi-
circular in outline as viewed from above; horn of vertex conical, pointed.
Pronotum chestnut brown, less than twice as wide as long (6.5 by 11.8 mm.),
of even maximum width from about the middle to the posterior fifth, anterior
and posterior angles broadly rounded; disc finely and sparsely punctate at the
median base, more coarsely and closely punctate toward the sides, where the
punctures tend to confluesce; posterior median impression distinct, anterior
median impression long, involving the anterior three fifths of the length of the
pronotum, fairly wide and deep, coarsely and extremely closely punctured;
anterior margin of pronotum and anterior median impression sparsely clothed
with long yellow hair. At each side of the disc, equally distant from the mid-
line and the lateral margin, and at about the basal third, is a large, shallow,
circular pit. The pronotum is retuse in profile.
PROC. ENT. SOC. WASH., VOL. 36, NO. 1, JAN., 1934 25
Scutellum transverse, posterior margin rounded, clothed with yellow hair,
which, with that of the base of the pronotum, nearly conceals the surface.
Elytra chestnut brown, wider at the humeri than the base of the prothorax,
one sixth longer than wide conjointly, widest at apical third; sutural striae
moderately deep; costae slightly elevated, smooth, impunctate, not attaining
the apices of the elytra; geminate striae faint, consisting of widely separated,
small, shallow punctures; elytral intervals finely and sparsely punctate.
Body beneath castaneous, densely clothed with long yellow hair.
Length 24 mm., maximum width 13.6 mm.
Antennae brown, first joint subconical; second joint transverse, wider than
long; third joint almost twice as long as wide, subconical, joints 2 and 3 together
slightly more than three fourths as long as the first; fourth joint transverse;
fifth joint of about the same length, but wider, angulate; sixth joint transverse,
longer than the fifth, twice as wide as long; seventh joint as long as the sixth,
with a short process; joints 8 to 11 forming the club, the ninth and tenth equal
and longest, the eleventh shorter, and the eighth shorter than the eleventh.
Type locality—Cleveland, Oregon. Collected by W. J.
Kocker.
Ty pe.—Male (Cat. No. 50136) in the collection of the United
States National Museum.
This species may be distinguished from P. dehrensi and
P. fimbriata, to which it seems most closely related morpho-
logically, by the color, the hairy scutellum, and the densely,
heavily punctured and hairy anterior median impression of the
pronotum. From P. remota it differs in the characters of the
striae and the shorter third antennal joint.
The unique type was very kindly given me by Mr. R. J.
Sim, of Moorestown, N. J., for whom I take pleasure in naming
the species.
26 PROC. ENT. SOC. WASH., VOL. 36, NO. 1, JAN., 1934
MINUTES OF THE 451ST REGULAR MEETING OF THE ENTO-
MOLOGICAL SOCIETY OF WASHINGTON, DECEMBER 7, 1933.
The 451st regular meeting of the Entomological Society of Washington was
held at 8 p. m., Thursday, December 7, 1933, in Room 43 of the new building of
the National Museum. Mr. C. T. Greene, president, presided. There were
present 39 members and 20 visitors. The minutes of the previous meeting were
read and approved.
Under the heading “Election of Officers,” the following officers were elected
for 1934:
IBGE eit Re weiss Sine Sa abe oie OR ee ON J. S. Wave
TASTE ATA GEN AVA 1 oe es eee wee B. A. Porter
WCCONG VAG ECS 111) eee eee ae ee S. B. Fracker
SAUL OP OR etna Roel Se eee Oe Pe W. R. Watton
(IRCGONATIERSCCTEL GTi) sea eee ee ee F. M. WabD Ley
Corresponding Secrétary=Vreasurer 2 nce S. A. RoHwer
Additional executive board members... W. H. Larrimer
H. E. Ewine
F. L. CAMPBELL
Nominee as Vice-President to Washington Academy
Of SSCLENCEASe 2... OE ee Ee ee Haroitp Morrison
Before the election Mr. Rohwer stated that the Society had for years used the
principle of a nominating ballot where a contest was involved, but often sus-
pended the rules and did away with the nominating ballot, making elections by
acclamation. All the above offices were filled by unanimous ballot except the
position of second vice-president, and the position on the executive committee
left vacant by Doctor Fracker’s election as second vice-president.
A motion was passed that the president appoint committees to draw up
suitable resolutions on the recent deaths of C. H. Popenoe and H. F. Wickham.
Dr. C. B. Philip and Dr. Bruce Mayne, of the Public Health Service, “‘sleep-
ing-sickness”’ investigations, on invitation, greeted the society.
Under the heading ‘‘Notes and Exhibition of Specimens,” Dr. S. B. Fracker
discussed the present status of the pink bollworm in the United States. He
stated that the species had lately been found in a Georgia locality, but that the
infested area in Florida had apparently been reduced as compared with last
year, and that the species had not been found in the Salt River Valley of Arizona
in either 1932 or 1933.
The regular program consisted of a communication by Dr. C. L. Marlatt
entitled ‘Early days in entomology in Washington.”
Dr. Marlatt spoke briefly of his first impressions of Washington, and of his
early connection with the Society as a member and officer. He then spoke in
detail of the Society and its meetings in the nineties and early in the present
century, characterizing a number of the members. He also mentioned the
social features connected with the meetings in this period, especially when the
Society was smaller and could be entertained in the homes of the members.
This talk was discussed by Busck, Aldrich, McIndoo, Greene and Morrison.
The meeting adjourned at 9:50 Pp. M.
F. M. Waptey,
Recording Secretary.
Actual date of publication, February 2, 1934.
VOL. 36 FEBRUARY, 1934 No. 2
PROCEEDINGS
OF THE
ENTOMOLOGICAL SOCIETY
OF WASHINGTON
CONTENTS
GREENE, CHARLES T.—_TACHINID FLIES WITH AN EVANESCENT
INCLUDING) ASNEW “GENUS AND FIVE NEW SPECIES 2... = 5 3 =. Diy,
MATHESON, ROBERT—NOTES ON PSOROPHORA (JANTHINOSOMA) HORRIDUS
DAR ERAN AINTAIBG 657 Sed S ares Saaes bam h eh ee atta A oe A tee ete Saha Chl
ROHWER, S. A.——DESCRIPTIONS OF FIVE PARASITIC HYMENOPTERA 3486 43
PusiisHeD Montuiy Excerpt Jury, AuGust AND SEPTEMBER
BY THE
ENTOMOLOGICAL SOCIETY OF WASHINGTON
U. S. NATIONAL MUSEUM
WASHINGTON, D. C.
Entered as second-class matter March 10, 1919, at the Post Office at Washington, D. C., under
Act of August 24, 1912.
Accepted for mailing at the special rate of postage provided for in Section 1103, Act of October
3, 1917, authorized July 3, 1918,
THE
ENTOMOLOGICAL SOCIETY
OF WASHINGTON
OrcanizeD Marcu 12, 1884.
The regular meetings of the Society are held in the National Museum on the
first Thursday of each month, from October to June, inclusive, at 8 Pp. M.
Annual dues for members are $3.00; initiation fee $1.00. Members are
entitled to the ProcEEDINGs and any manuscript submitted by them is given
precedence over any submitted by non-members.
OFFICERS FOR THE YEAR 1933.
Hanpraty Fae Sapien i is eS es ee SO ES .. .L, 0; HOWARB
President? Sines Ne et eo ee Oe ee J. S. WADE
First Vace=President (2... NB ee os net i en ss 3 Ae ORS BS
eco A) srezbresiaens “tk > Rees, SO Se S. B. FRACKER
IRCCOTAINEAS CCT ELAR) ee ei ee ene .. . By MM WADERM
Corresponding Secretary=Treasurer.. . 2. ....+s:: S. A. ROHWER
Bureau of Entomology, Washington, D. C.
GGT rE ee OO sn eee eee W. R. WALTON
Bureau of Entomology, Washington, D. C.
Executive Committee: THE Orricers and W. H. Larrimer, H. E. Ewinec,
F. L. Campsett.
Representing the Society as Vice-President of the Washington Academy of
SCHOREES cas 2. “i. Sac Sy RC ee Bee ee H. MORRISON
PROCEEDINGS
ENTOMOLOGICAL SOCIETY OF WASHINGTON.
Published monthly, except July, August and September, by the Society at
Washington, D. C. Terms of subscription: Domestic, $4.00 per annum;
foreign, $4.25 per annum; recent single numbers, 50 cents, foreign postage extra.
All subscriptions are payable in advance. Remittances should be made payable
to the Entomological Society of Washington.
An author of a leading article in the ProcEEp1NGs will be given 10 copies of
the number in which his article appears. Reprints without covers will be fur-
nished at the following rates, provided a statement of the number desired
accompanies the manuscript:
4 pp. 8 pp. 12pp. 16pp.
50 copies 2.00 4.00 6.00 8.00
100 copies 2225 4.50 6.75 9.00
Certain charges are made for illustrations and there are available rules and
suggestions governing the make-up of articles. Immediate publication in any
number may be obtained at the author’s expense. All manuscripts should
be sent to the editor.
PROCEEDINGS OF THE
ENTOMOLOGICAL SOCIETY OF WASHINGTON
WOL.. 36 FEBRUARY, 1934 No.
i)
TACHINID FLIES WITH AN EVANESCENT FOURTH VEIN,
INCLUDING A NEW GENUS AND FIVE NEW SPECIES.
By Cuartes T. GREENE,
Bureau of Entomology, U. S. Department of Agriculture.
INTRODUCTION.!
The dipterous family Tachinidae contains several genera
that have the fourth longitudinal vein evanescent at its tip.
Those genera having this unusual character are widely scattered
throughout this large family of parasitic flies. The object of
this paper is to bring these genera together for convenience
in making determinations. While this character is not a natural
one it may be used very nicely for grouping these sixteen genera
comprising twenty species. Me/anomelia aterrima Strobl and
Besseria melanura Meigen, both European species, are not in-
cluded in my table because I was unable to secure a specimen
of either species. All of the species treated in this paper, in-
cluding the new ones, are in the U. S. National Museum collec-
tion.
The head, palpus, and right wing of each species included
in this paper are shown for the convenience of persons interested
in this group of flies. The palpus is figured principally to show
its difference in form and size as among the different species.
Here, I wish to acknowledge my thanks to Dr. J. M. Aldrich
for his friendly assistance.
TABLE OF SPECIES.
eViettts tone: Ebrce Or HVe, EISELE neces ewe ee 13
Veins bare or at most with 1 to 3 bristles at base of third vein_............ 2
2. Without the usual bristles at base of third longitudinal vein... aes
With at least one bristle at base of third longitudinal vein... 4
3. Anterior and posterior crossveins very much approximated; wing
slightly infuscated; third antennal joint long and slender. (Texas
aaah [Rayne eael) ee oe Bezzimyia busckii Townsend (page 29).
Anterior crossvein normally located near middle of discal cell; wings
of a slightly milky white color; third antennal joint short and
Moinceduatathe apexmi(HUnape) = sate ca fe ae nae
Melizoneura albipennis Robineau-Desvoidy (page 29).
1See Appendix.
28 PROC. ENT. SOC. WASH., VOL. 36, NO. 2, FEB., 1934
4. Posterior crossvein. present. =e eee eee 6
Posterior crossveitivabsent:...2 ee ee ee 5
5. Wing milky white in color; first longitudinal vein with a single bristle
near the apex; bristles on facial ridge extending upward to slightly
above lower edge of eye. (New England and Canada)...
Dichaetoneura leucoptera Johnson (page 29).
Wing hyaline; first longitudinal vein without apical bristle; bristles on
facial ridge extending upward about one third the eye height
(Europe) es te ee eee Phytomyptera nigrina Meigen (page 30).
6. Wing with a concavity at its apex; two bristles at base of third vein;
costal vein with an enlargement at its apex and ending at the
tip of the third veins (Blondaleteern 2 ee eee
Roeseliopsis floridensis, new species (page 30).
Wine notias;above!.. 2 eee eee ee ee vf
7. Eye unusually large; third joint of antenna with the dorso-apical
corner pointed and slightly upturned; arista thickened on basal
fifth; vibrissae located far above oral margin. (New Jersey and
Colorad) ers. cots cok ck eh on ee ee a oe
Hemithrixion oestriforme Brauer and Bervenstamm (page 31).
Eye normal in size; antenna and arista not as above; vibrissae located
near Oral margin»... See aes et 8
8. Facial ridge with bristles to the middle; length of penultimate joint
of arista equal touts diameter: a 9
Facial ridge with only a few bristles above the vibrissa; penultimate
joint of arista much longer than its diameter_.2. 32 =. 2 eee 10
9. Third antennal joint long, slender, and tapering towards the apex;
parafacial much wider than third antennal joint; facial ridge broad,
with several bristly hairs outside the usual row of bristles
(Georeial) pee Roeseliopsis americana Coquillett (page 31).
Third antennal joint long, broad, the apical end truncate, with the
dorso-apical angle sharp; parafacial narrower than width of third
antennal joint; facial ridge narrow, with only a single row of
loysricya Kew, x... wl =) ee. Se . P. W. OMAN
Corresponding Secretary-Treasurer. . 5... s+... S. A. ROHWER
Bureau of Entomology, Washington, D. C.
EQUlOr. os cpio eRe ee ae lO: eee W. R. WALTON
Bureau of Entomology, Washington, D. C.
Executive Committee: THE Orricers and W. H. Larrimer, H. E. Ewrne,
F. L. CampseE.t.
Representing the Society as Vice-President of the Washington Academy of
WELEMEES coe .g\ 5, ye IE york See a ee H. MORRISON
PROCEEDINGS
ENTOMOLOGICAL SOCIETY OF WASHINGTON.
Published monthly, except July, August and September, by the Society at
Washington, D. C. Terms of subscription: Domestic, $4.00 per annum;
foreign, $4.25 per annum; recent single numbers, 50 cents, foreign postage extra.
All subscriptions are payable in advance. Remittances should be made payable
to the Entomological Society of Washington.
An author of a leading article in the ProcEEpincs will be given 10 copies of
the number in which his article appears. Reprints without covers will be fur-
nished at the following rates, provided a statement of the number desired
accompanies the manuscript:
4 pp. 8 pp. 12pp. 16 pp.
50 copies 2.00 4.00 6.00 8.00
100 copies 2.25 4.50 6.75 9.00
Certain charges are made for illustrations and there are available rules and
suggestions governing the make-up of articles. Immediate publication in any
number may be obtained at the author’s expense. All manuscripts should
be sent to the editor.
PROCEEDINGS OF THE
ENTOMOLOGICAL SOCIETY OF WASHINGTON
WOT: 36 APR 9S4. No. 4
NEW SPECIES AND A NEW GENUS OF NORTH AMERICAN
DELTOCEPHALINE LEAFHOPPERS (HEMIPTERA :
HOMOPTERA).
By P. W. Oman, U. S. Bureau of Entomology.
The descriptions which follow are those of apparently new
forms which the writer has encountered in the course of his work
during the past year and a half. Since representatives of nearly
all the species of the genus are available, a key to Sanctanus
Ball is included.
Sanctanus tectus, n. sp.
(ek, ash, Liners, JAN, 184, (Ce)
Similar to fasciatus in size but with a more angular vertex and less brown
coloration. Color and color pattern resembling those of Deltocephalus arun-
dineus. Length 4-4.5 mm.
Color.—Face pale, with three transverse black bands, one across the apex
of the clypeus, one below the antennae, and one below the margin of the vertex.
Vertex creamy, with a pair of small black spots at the apex and a large irregularly
shaped pair on the disk next the ocelli, the latter always connected with the
black band on the front, the former usually so. A pair of small dark spots on
posterior margin of vertex. Pronotum with a rectangular black spot on the
anterior margin medially and an irregular spot behind each eye, disk brownish
iridescent, margins irregularly pale. Elytra with basal portions milky, a
fuscous spot on disk of each clavus and three fuscous spots on each costal
margin, one next the milky area, one before the first nervure to costa, and one
in outer apical cell; veins milky to yellowish, bordered with fuscous, cells
embrowned except along costal margins. Tips of male plates black.
Structure —Vertex similar to that of fusconotatus but broader and more
sharply angled, more produced than that of sanctus, margins rounded to front.
Elytra broad and flaring, venation typical of the genus.
Genitalia.—Last ventral segment of female with a broad, blunt, median tooth
which is attached only basally to remainder of segment. Segment each side
of tooth roughly truncate posteriorly. Male plates broad basally, tapering to
narrow tips, plates together triangular.
The markings and genital characters will distinguish this species from others
in the genus.
76 PROC. ENT. SOC. WASH., VOL. 36, NO. 4, APR., 1934
Holotype male and allotype female from Deep Creek, Vir-
ginia, collected from Arundinaria tecta by the writer, Sept. 9,
1933. Paratypes, numerous specimens with the above data
and others collected at the same locality by L. D. Anderson
on Oct. 8 and Oct. 31, 1933. The writer has also examined
specimens from Florence, South Carolina, collected in May,
September, and October by O. L. Cartwright and sent to the
writer for study by J. O. Pepper of the Pennsylvania Department
of Agriculture. Types in collection of United States National
Museum (Cat. No. 50369), paratypes in collections of L. D.
Anderson and J. O. Pepper.
Key to THE NortH AMERICAN SPECIES OF SANCTANUS!
1. Ground color pale salmon red with a transverse, black-margined white
band at the apex of the clavus and an orbicular black spot in the
outer apical cell of cach elytron. eee. ....... = ... ee orbiculatus Ball
Color not/as above...-2..2.02. 03. Z
2. (1) Dorsal color pattern consisting of brown or yellowish brown and
ivory. Brownish area on disk of corium not broken by broad
white or pale veins) =. | Ae ee ee 5
Dorsal color pattern lacking in distinct browe and ivory contrasts.
Markings on corium consisting mostly of brownish intracellular
infuscations which are darker around the margins. Veins on
disk of cortum broadtand pale = ae 3
3. (2) Upper one half of face uniformly black, clypeus and portions of
adjacent sclerites unmarked c....0¢ 0. ee Oe 4
Face not as above, black marks consisting of broken transverse bands,
onevaf which crosses) theiclypeus 2. ee tectus, n. sp.
4. (3) Markings on disc of vertex fuscous..................fusconotatus Osborn 2
Markings on disc of vertex pale orange... aestuarium Del. & S. 2
5: (2) phiacerwithidistinet transverse black banc Se === ae een 6
Hace without distinct transverse blackybands= === == a anon 7
6. (5) Median length of vertex equal to or shorter than one half its width
at anterior margin of eyes. Dorsal markings usually dark brown.
Menethe4s5=5.25) min... es eae A ee cruciatus Osborn
Median length of vertex distinctly greater than one half its width at
anterior margin of eyes. Dorsal markings usually pale brown.
Length 445mm... 2.2112. Ape aseiote Oshima
7. (5) Elytra apically without reticulations, vertex angled... sanctus Say
Elytra apically with numerous reticulations, vertex bluntly rounded...
limicolus Osborn
1 The writer has not examined specimens of eburneus DeLong. It appears
to be related to fusconotatus and tectus.
2 The writer believes that fusconotatus and aestuarium are extremes of a
single species in which the marks on the vertex are variable.
PROC. ENT. SOC. WASH., VOL. 36, NO. 4, APR., 1934 77
Hebecephalus scriptanus, n. sp.
Gis higss Di bs)
Related to /abeculus and blandus but differing from both in having the female
genital segment produced and unnotched. Length of female 2.75-3 mm.
Color.—Ground color cinereous. Frontal sutures brown to fuscous, frons with
broken transverse brown bars basally and an irregular brown spot medially.
Vertex with a brown spot next each eye and an elongate brown B or figure 8
mark on each side of median line, this sometimes interrupted along anterior
margin of vertex. Pronotum with three pairs of longitudinal brown stripes,
these sometimes nearly obsolete. Scutellum with two pairs of narrow longi-
tudinal brown lines. Elytra grayish subhyaline, margins of cells embrowned.
Structure.—Vertex bluntly right angled, broader and shorter than in docanus,
about as in /abeculus, distinctly longer than pronotum. Elytra about equal to
abdomen in length, venation typical of the genus.
Genitalia.—Last ventral segment of female with lateral margins short, pos-
terior margin triangularly produced.
Holotype female from Mustang Mt., Ariz., June 12, 1933,
collected by the writer. Paratypes, 6 females from the above
locality, 3 taken on June 12 and 3 on June 20, by R. H. Beamer
and the writer. Type and paratypes in United States National
Museum collection (Cat. No. 50370), paratypes in collection of
University of Kansas.
Laevicephalus aridus, n. sp.
(Biss kigs. By 'G:)
Similar in size and coloration to monticolus (Gillette and Baker), but with the
vertex more bluntly angled and the female genital segment without a median
tooth on posterior margin. Length 2.75-3 mm.
Color —Pale greenish white. Front with faint brownish bars; vertex with
faint brownish dashes each side of apex, these sometimes extended into narrow-
ing stripes across pronotum. Ocelli black, eyes green.
Structure.—Vertex bluntly angled in female, equalling pronotum in length,
more rounded in male and distinctly shorter than pronotum. FElytra extending
well beyond tip of abdomen, venation irregular, outer anteapical cell often
small or nearly absent.
Genitalia.—Last ventral segment of female comparatively long, lateral
margins short, lateral angles rounded, median portion produced and narrowing,
with sides of produced portion sinuate, posterior margin truncate or faintly
bilobed, often appearing distinctly incised. Male plates broad basally, tapering
sharply to acute tips which reach slightly over half way to apex of spiny pygofer.
This species is best separated from all others of the genus except convergens
by the genital characters, while from that species it may be separated by the
smaller size and blunter head.
Holotype female, allotype male, and 1 female paratype from
Copper, Ariz., collected by the writer June 30, 1933. Types in
collection of the United States National Museum (Cat. No.
50371).
78 PROC. ENT. SOC. WASH., VOL. 36, NO. 4, APR., 1934
Laevicephalus bocanus, n. sp.
(Pl 13, igseet, 1.)
Resembling /abeculus but smaller, more slender, and with a more produced
and angled vertex. Length of female 2.75 mm.
Color —Ground color pale creamy white to gray. Face slightly embrowned;
dorsum with a light brown longitudinal vitta on each side extending from anter-
ior margin of vertex to anterior margin of scutellum, narrowing posteriorly.
Pronotum with an additional faint longitudinal vitta behind each eye. Elytra
gravish subhyaline, margins of cells embrowned.
Structure.—Vertex produced and pointed, length nearly equal to greatest
width and distinctly greater than length of pronotum. Elytra about equalling
abdomen in length, venation typical of the genus.
Genitalia.—Last ventral segment of female with lateral margins short, median
portion well produced and narrowing posteriorly, apex with a small notch.
Described from 2 females, holotype and paratype, collected
at Boca Chica, Texas, May 30, 1933, by the writer and Mrs.
Oman. Types in the collection of the United States National
Museum (Cat. No. 50372).
Deltocephalus laredanus, n. sp.
(Pl. 13, Figs. J.—K.)
Pale yellowish brown with four fuscous spots on the anterior margin of the
vertex and a cream colored stripe dorsally. More closely related to several
South American species than to the known North American forms. Length
3 mm.
Color.—General ground color brownish testaceous. Face unmarked except
for a small fuscous dot below each ocellus. Dorsum with a cream or ivory
colored stripe extending from apex of vertex to apex of scutellum, widening
slightly posteriorly, and continued to apex of claval sutures by the cream colored
commissural margins of the elytra. Vertex with a triangular fuscous spot on
the anterior margin each side of the apex next the median stripe and another
irregular and often indistinct one next ocellus. Pronotum with lateral margins
narrowly creamy and traces of two creamy longitudinal stripes each side of the
median stripe. Median stripe usually margined with fuscous on scutellum.
Elytra subhyaline, veins whitish, often faintly margined with fuscous.
Structure.—Vertex well produced and bluntly angled, slightly shorter than
pronotum in length. Elytra extending well beyond tip of abdomen, venation
typical deltocephaloid.
Genitalia.—Last ventral segment of female narrowed posteriorly, exposing
underlying membranes, posterior margin broadly and shallowly excavated, with
a small median tooth. Male plates small, together roughly triangular, with
lateral margins concave and tips blunt.
Holotype male, allotype female, and numerous paratypes of
both sexes collected by the writer near Laredo, Texas, June 3,
PROC. ENT. SOC. WASH., VOL. 36, NO. 4, APR., 1934 79
1933. Also 1 male paratype labeled Austin, Texas, May, 1905,
in collection of FE. D. Ball. Types in the collection of the United
States National Museum (Cat. No. 50373), paratypes in col-
lection of E. D. Ball.
Genus BALDULUS, new genus.
Small, elongate leafhoppers, related to Cicadula in the characters of the
venation of the elytra and wings, but with the elytra long and slender as in
Balclutha, the head narrow and produced and angled as in De/tocephalus. Also
resembling Cicadulina but with a more produced vertex and with one more apical
cell in both elytra and wings.
Face elongate, triangular, margin of genae slightly sinuate below the eyes.
Vertex triangularly produced and rounding to the front, median length slightly
less than length of pronotum. Head, including eyes, equal to pronotum in
width. Elytra elongate and slender, with two anteapical and four apical cells
and distinct appendices. Wings with three apical cells.
In the species known to the writer the color is pale yellowish with a black
spot on the margin of vertex, above or sometimes slightly anterior to each
ocellus. Markings of pronotum and scutellum consisting of more or less distinct
longitudinal vittae of pale yellowish brown to brown.
Type of the genus, Ba/dulus montanus, n. sp.
This genus will also include De/tocephalus elimatus Ball *
from Mexico, which the writer believes to be congeneric with
B. montanus in spite of its peculiar, elongate genitalia in both
sexes (Pl. 13, Figs. N, O,) and slightly shorter vertex.
Baldulus montanus, n. sp.
(PI. 13; Figs, ..M.)
Smaller than e/imatus, with a more angled vertex and darker markings on
vertex and pronotum. Length 3.25-3.5 mm.
Color.—General ground color pale yellow. Face unmarked except for a small
fuscous dot below each ocellus, these sometimes obsolete. Vertex with a small
fuscous spot at apex, a larger, black, triangular pair above and a little anterior
to the ocelli, a fuscous quadrangular pair on the posterior margin next the eyes,
and a faint brown pair between these. In pale specimens the spot at the apex
and the inner basal pair may be obsolete. Pronotum and scutellum with a
longitudinal brownish-fuscous vitta each side of the median line, emphasizing
a broad creamy median stripe. Traces of two additional brownish vittae later-
ally on pronotum. Elytra with veins and commissural line to apices of clavi
white, cells embrowned except along costa and sometimes apically.
Structure.—Vertex nearly twice as long medially as next the eyes, median
length slightly less than length of pronotum. Pronotum truncate posteriorly,
median length about one half the width.
Genitalia.—Last ventral segment of female about one and one half times as
3 Can. Ent., vol. 32, p. 345, 1900.
80 PROC. ENT. SOC. WASH., VOL. 35, NO. 4, APR., 1934
long as preceding segment, posterior margin truncate or slightly sinuate. Male
valve broad, bluntly angled posteriorly. Male plates together triangular,
apices terminating in divergent ligulate processes about one half as long as the
rest of the plates. Apex of aedeagus usually visible between tips of plates.
Aedeagus with shaft long and nearly straight, extending posteriorly; apex
curved upward and with two pairs of processes at tip, one pair long and slender
and extending anteriorly along the shaft, the other pair curved first upward
and then anteriorly, forked near base, the upper fork crooked and shorter than
the lower fork.
Holotype male, allotype female, and numerous paratypes of
both sexes from the Santa Rita Mts., Ariz., collected June 27,
1933, by the writer. Other paratypes from the same locality;
20 specimens collected June 26, 1933, by R. H. Beamer, and
20 specimens collected July 6, 1933, by E. D. Ball. Holotype,
allotype, and paratypes in the U nited States National Musem
collection (Cat. No. 50374), paratypes in the collection of E. D.
Ball and the University of Kansas.
EXPLANATION OF PLATE.
A, head and thorax, B, male genitalia, and C, female genitalia of Sanctanus
tectus; D, head and thorax, and E, female genitalia of Hebecephalus scriptanus;
F, head and thorax, and G, male genitalia of Laevicephalus aridus; H, female
genitalia, and I, head and thorax of L. bocanus; J, male genitalia, and K, head
and thorax of Deltocephalus laredanus; LL, head and thorax, and M, male geni-
talia of Baldulus montanus; N, female genitalia, and O, male genitalia of B.
elimatus Ball. All drawings show an enlargement of approximately 30 diameters.
A NOTE ON THE DISTRIBUTION OF EUMERUS NARCISSI
SMITH (DIPTERA : SYRPHIDAE)
By Ranpatt Latta,
Bureau of Entomology, U. S. Department of Agriculture, Sumner, Wash.
In a previous publication (A Comparative Study of the Species
of Eumerus known as the Lesser Bulb Flies. Monthly Bul.
Calif. Dept. Agr. Vol. XXII, Nos. 2-3, Feb.—March, 1933,
p. 147) the distribution of Humerus narcissi Smith in the United
States was mentioned as being confined to California and Ore-
gon. The species is quite common in bulb districts in California,
but only one specimen had been found in Oregon, that near
Portland at a large bulb ranch. In 1931 one pair were collected
in a greenhouse on Long Island, New York, by Blanton and
Spruijt (The Species of Eumerus on Long Island. Jour. Econ.
Ent. Vol. 26, No. 2, Apr. 1933, p. 515). During the past summer
a single male was collected at Morning Sun, Iowa, by Helen Latta,
from flowers near a bed of naturalized daffodils. Future col-
lections in the eastern and southern bulb growing sections will
probably reveal more occurrences of this species.
PROC. ENT. SOC. WASH., VOL. 36 PLATE 13
S TECTUS
(A-C)
L. BOCANUS D.LAREDANUS
\\
,
8. MONTANUS | 8 ELIMATUS
th (L-M) N (N-O)
82 PROC. ENT. SOC. WASH., VOL. 36, NO. 4, APR., 1934
A NEW GENUS AND SPECIES OF THE FAMILY GELECHIIDAE
(LEPIDOPTERA).
By Avucust Busck,
Bureau of Entomology, U. S. Department of Agriculture.
CREMONA, new genus.
(Plate 10, Figs. 1-5.)
Labial palpi long, recurved; second joint somewhat thickened with rough
scaling, slightly furrowed in front; terminal joint shorter than the second, also
somewhat thickened with scales and rough on frontal edge; apex pointed.
Maxillary palpi minute. Tongue short, spiralled. Antennae simple, shorter
than fore wing, slightly serrate towards the tip in the males. Face, head, and
thorax smooth.
Fore wing smooth, costal and dorsal edges nearly straight and parallel;
termen evenly rounded; apex bluntly pointed; 12 veins, 7 and 8 stalked to costa;
6 out of stalk of 7 and 8 to termen; 2, 3, 4, and 5 nearly equidistant; 2 and 3
from before end of cell; 9, 10, and 11 nearly equidistant; 11 from middle of cell;
9 somewhat variable, more or less approximate to stalk of 7 and 8; 14 furcate
at base; lc faint at base, outer half obsolete.
Hind wings as wide as fore wings; costa nearly straight, slightly bulging before
middle; dorsum nearly straight; termen rounded, sinuate before apex; apex
produced, pointed; 8 veins, 8 straight to apical third of costa; 6 and 7 long-
stalked, enclosing apex; 5 much nearer to 4 than to 6, but distant from both and
nearly parallel to 4; 3 and 4 variable, separate or approximate or sometimes
connate; 2 parallel to 3. Posterior tibia heavily clothed with long hairs.
Male genitalia (pl. 10, fig. 5) with uncus weakly developed, short, blunt,
thumb-like, with a few stiff hairs; socii undeveloped; gnathos very long, abruptly
curved, with pointed apex. Harpes divided; upper arms long, slender, pointed,
heavily haired on outer half; lower arms short, stout, pointed; anellus two small,
triangular plates. Aedoeagus short, stout, curved, with pointed apex and with
rounded base; no cornuti. Vinculum large, rounded.
Female genitalia (pl. 10, fig. 4) with short, protruding, chitinized lips to the
ostium; ductus bursa rather short, chitinized in posterior end and twisted once
upon itself; bursa globular, with a small, inverted, pointed signum.
Type: C. cotoneastrt.
The genus is allied to Ge/echia of authors, but differs in the
venation, having vein 6 of fore wing out of stalk of 7 plus 8 and
veins 3 and + of hind wing normally separate as in Te/phusa,
from which genus it differs in the smooth fore wings. The
genitalia are typical of the family, but easily differentiated
generically.
The genus Ge/echia, as at present used, comprises a hetero-
geneous aggregation and the name must eventually be restricted
to the forms agreeing with the genotype, the European Gelechia
rhombella Schittermiller, which has veins 3 and 4 of fore wings
stalked (a character which may not prove dependable) but
PROC. ENT. SOC. WASH., VOL. 36, NO. 4, APR., 1934 83
which has very characteristic genitalia, differing essentially
from those of the bulk of the species at present included in the
genus, which represent several good generic groups.
Cremona cotoneastri, new species.
Labial palpi dark fuscous, flecked with ochreous, especially on inner surfaces
and on terminal joint. Antennae blackish fuscous with narrow light ochreous
annulations. Face light fuscous mixed with ochreous. Head and thorax dark
fuscous with each scale narrowly tipped with ochreous. Fore wings uniformly
dark fuscous, mixed with silvery white; each scale dark with base and extreme
tip silvery; no other markings; cilia concolorous. Hind wings dark fuscous, a
shade lighter than the fore wings; cilia gray. Abdomen blackish fuscous with
the tips of the long protruding harpes light gray. Legs dark fuscous, tarsi with
narrow ochreous annulations.
Alar expanse 12-14 mm.
Habitat, Portland, Oregon.
U. S. National Museum Type No. 50252.
Foodplant, Cotoneaster horizontalts.
Reared in good series by Mr. J. R. Roaf and submitted for
identification by Dr. Don C. Mote, Entomologist, Oregon State
Agricultural College.
The moth appeared during June and July.
The foodplant belongs to a northern temperate Old World
genus of ornamental shrubs of the family Rosaceae, which in
late years has been introduced into various parts of the world
for horticultural purposes. The home of Cotoneaster horizontalis
is China and it seems probable that the insect is also of Chinese
origin. For this reason I sent specimens to Edward Meyrick in
England, who is well acquainted with the Chinese microlepi-
doptera and he has kindly advised me that he agrees with me,
that “‘the insect is quite new and undoubtedly a new genus
allied to Gelechia,” and he is also disposed to believe it of Chinese
origin, though “I have been studying a considerable number of
Chinese forms lately and have not so far come across anything
‘like it”? (Meyrick).
I take the occasion again to express my thanks to the vener-
able dean of microlepidopterists for much professional help
through nearly forty years. The workers in this field, in all
parts of the world, are fortunate in being able to consult his
extensive knowledge, which he so liberally shares.
If we are correct in this suspected origin and recent intro-
duction of Cremona cotoneastri, this species should be watched
as a potential danger to American fruit; it is quite possible
that the species may find other rosaceous plants more to its
liking than the original hostplant, as did another Asiatic intro-
duced microlepidopteron (Laspeyresia) Grapholitha molesta Busck,
‘the well known oriental fruit moth.
PLATE 14 PROC. ENT. SOC. WASH., VOL. 36
Cremona COorOoneastry Buscr
[84]
PROC. ENT. SOC. WASH., VOL. 36, NO. 4, APR., 1934 85
EXPLANATION OF PLATE.
Cremona cotoneastri Busck.
Fig. 1. Venation of fore wing.
Fig. 2. Venation of hind wing.
Fig. 3. Details showing variations of veins 4 of hind wing:
Fig. 4. Genitalia of female.
Fig. 5. Genitalia of male.
Figures drawn under author’s supervision by Mrs. Eleanor A. Carlin of the
Bureau of Entomology, U. S. Department of Agriculture.
A NEW NORTH AMERICAN MAGDALIS FROM BLUE SPRUCE
(COLEOPTERA : CURCULIONIDAE)
By L. L. Bucnanan, U. S. Bureau of Entomology.
The species described below was received from O. W. Collins,
of the Gipsy Moth Laboratory of the Bureau of Entomology,
U. S. Department of Agriculture, Melrose Highlands, Mass.,
who states that the specimens were reared in Massachusetts
from Colorado blue spruce, Picea pungens Engelmann var.
glauca. The figures were drawn by Mrs. E. A. Carlin. Measure-
ments to determine length of rostrum and location of antennal
socket were made along dotted lines “a” and “b” respectively,
as shown in figure 3.
Magdalis piceae, new species.
Length, 3.8-4.3 mm. A rather slender species of the genti/is group. Moder-
ately shining, glabrous above, black, antennal scape generally rufescent apically;
pronotum with a narrow, polished, impunctate, median line which is abbre-
viated before and behind; femoral tooth unusually small, sometimes subobsolete
on hind legs; tarsal claws simple.
Rostrum as long as, or slightly longer than, prothorax, more slender and rising
more abruptly from head in female; surface shining except at base, finely and
closely punctate; antennal socket slightly in front of middle (male) and at or
slightly behind middle (female). Scape passing anterior eye margin in both
sexes, first funicular segment a little longer and much stouter than second,
which is not more, and generally less, than twice as long as wide and usually
a little shorter than third and fourth together; club longer in male than in
female. Head feebly alutaceous, with closely set punctures that are larger but
apparently shallower than those on rostrum, interocular puncture small, eyes
in male a little larger, more convex, and closer together above than in female.
(In male, distance between eyes above is to width of rostrum at base as 3% is
to 6, approximately.) Prothorax about as long as wide at middle, sides broadly
and feebly rounded, divergent at hind angles, apical constriction not deep;
pronotal punctures dense and scabrous at margins, becoming less dense on disk,
where they are often separated by narrow but flat and shiny intervals, the
86 PROC. ENT. SOC. WASH., VOL. 36, NO. 4, APR., 1934
\
I
\N\
NER
Fig. 1, dorsa! outline; fig. 2, pronotum; fig. 3, side view of male (a, length of
rostrum; b, location of antennal socket); fig. 4, male antenna; fig. 5, female
antenna.
general surface more or less convex. Elytra feebly widened behind, surface
rather weakly alutaceous, moderately shining; strial punctures deep, clean-cut,
closely set; on disk, the intervals nearly flat, each with a fairly regular single
row of generally distinct punctures which may be here and there, and especially
toward sides, somewhat confused or in a partly double row. Thoracic sternites
densely punctate, side pieces of mesosternum and metasternum clothed with
pale, plumose scales; abdominal sternites a little less densely punctate, first
sternite of male feebly impressed; first tarsal segment of hind leg elongated,
rather more so in male than in female.
Type Jlocality—Dover, Mass., 6/3/33; Ex. Blue Spruce;
Gip. Moth Lab. 12164 U 108.
Other locality —White Mts., N. H., Peabody River, VII-
15-1925, A. Nicolay.
Type (male), allotype, and 8 paratypes.—Cat. No. 50284,
Us So N, M:
PROC. ENT. SOC. WASH., VOL. 36, NO. 4, APR., 1934 87
Described from 10 specimens, 9 from type locality, 1 from
New Hampshire.
The black color, slender form, moderately shining surface,
comparatively narrow prothorax with its polished median line,
small femoral tooth, and slightly enlarged antennal club of
male, form a combination of characters unknown to me in any
other species.
By the small femoral tooth piceae is most closely related to
vitiosa Fall but that Californian species is considerably smaller
(3.1-3.3 mm.), more densely punctate, duller in luster, and with
the median pronotal line not polished.
RECORDS OF HYMENOPTEROUS PARASITES OF TICKS IN
THE UNITED STATES.
By F. C. BisHopp,
Principal Entomologist, Bureau of Entomology, U. S. Department of Agriculture.
The widespread occurrence of Rocky Mountain spotted fever
in the United States as reported in recent years has stimulated
interest in the several species of ticks concerned in the trans-
mission of this malady and in their natural enemies.
Exact information on the distribution and abundance of the
two known hymenopterous parasites of ticks which occur in
this country is meager. These parasites, [xvodiphagus texanus
and Hunterellus hookeri, were both described by Dr. L. O.
Howard.’ The type specimens of the former were reared from
nymphs of the rabbit tick, Haemaphysalis leporis-palustris,
collected by J. D. Mitchell on a cotton-tail rabbit in Jackson
County, Texas, May 8, 1907. Although many collections of
nymphs of this tick have been made in various parts of Texas
and in other States only one other parasitized lot has been
collected by workers in the Bureau of Entomology. This was a
collection of Haemaphysalis leporis-palustris nymphs taken from
the road-runner or chaparral cock (Geococcyx californianus) at
Reagan Wells, Tex., on April 28,1914, by D. C. Parman. This
lot consisted of 17 nymphs, two-thirds to fully engorged. Four
of these proved to be parasitized. From 3 of these 11 parasites
emerged. These were identified by the writer as [xodiphagus
texanus Howard. This is the only record of the collection of this
parasite since the type material was reared.
Hunterellus hookeri appears to have much wider distribution
as reported by H. P. Wood.? This parasite occurs in Texas,
1L. O. Howard, 1907. A Chalcidid parasite of a tick. Ent. News, Vol. 18,
pp. 375-378. 1908. Another chalcidoid parasite of a tick. Can. Ent. Vol. 40,
pp. 239-241.
*H. P. Wood, 1911. Notes on the life history of the tick parasite, Hunterellus
Hookeri Howard. Journ. Econ. Ent. Vol. 4, pp. 425-431.
88 PROC. ENT. SOC. WASH., VOL. 36, NO. 4, APR., 1934
California, Mexico, and Portuguese East Africa. Our work
since 1911 has not added greatly to the known distribution
except for the collection of 4 lots of parasitized nymphs of
Rhipicephalus sanguineus Latr. in South Miami, Florida, in
1931 by Mrs. S. G. Martin. These ticks were all taken on dogs.
The first lot, collected September 6th, consisted of 127 well
engorged nymphs, 7 of which were parasitized. The second
lot consisted of 35 nymphs, a few of which were parasitized.
These were collected September 14th. The third collection,
October 9, consisted of 15 nymphs, 13 of which were parasitized.
The fourth consisted of 45 nymphs collected October 24. Among
these 15 were parasitized, 14 of which produced a total of 85
parasites.
This species was also reared from a single nymph of Derma-
centor vartabilis Say which was collected, together with several
engorged nymphs of Amblyomma americanum L., on a cow
October 15, 1931, on Capers Island, S. C., by E. K. Moore.
The nymphs of 4. americanum were not parasitized. The
parasites from South Miami and Capers Island were identified
by A. B. Gahan. In 1929 a number of nymphs of Dermacentor
parasitized by the French species Jxodiphagus caucurtei Buysson
were released on Capers Island by Dr. Joseph Bequaert of
Harvard University.
H. O. Schroeder of the Bureau of Entomology has found this
parasite to be more or less common in the vicinity of Brownsville,
Tex., in the past two years, but has not found parasitized ticks
in other parts of the State.
A NEW VARIETY OF PLEOCOMA.'!
By A. C. Davis, Takoma Park, Mad.
Pleocoma conjungens Horn Variety hirsutus, n. var.
General appearance as in Pleocoma conjungens. Elytra shining black, margins
with a brownish tinge, pronotum piceous, brown at sides.
Head above, including ocular canthi, closely punctate and thickly covered
with long yellow-brown hair; ocular canthi with the anterior margins curving
forward of a right angle with the long axis of the body, apices acute, rounded,
lateral margins nearly straight, posterior angles obtuse but distinct.
Pronotum slightly less than twice as wide as long (6 by 11.8 mm.), black,
brown at sides, with an occasional hair upon its surface; posterior median
impression nearly lacking; lateral pits lacking; transverse ridge lacking, the
basal part of the pronotum being smoothly and evenly convex to the declivity,
anterior median impression distinct and moderately deep, very heavily and
coarsely punctate, and rather densely clothed with long yellow-brown hair.
Scutellum sparsely, finely punctate, and sparsely clothed with short hair.
! Order Coleoptera; family Scarabaeidae.
PROC. ENT. SOC. WASH., VOL. 36, NO. 4, APR., 1934 89
Legs and body beneath brown, very densely clothed with long yellow-brown
hair.
Antennae almost exactly as in the specimen of P. conjungens labeled as the
type in the collection of the Academy of Natural Sciences of Philadelphia,
except in the proportions of antennal joints 1 to 3, which are 1.2, 0.3, and 1.0mm.
in length, respectively, as compared with 0.7, 0.25, and 0.8 mm. in the type.
Type locality.—Between Lebec and Saugus, in Los Angeles
County, Calif., in the Sierra Madre Mountains. Collected by
Re Drabusk:
Type.—Male in the collection of the Los Angeles Museum.
This specimen was lent to me for study by L. J. Muchmore.
Among Mr. Lusk’s effects the following data, attached to a
letter of inquiry from Mr. Muchmore, were found by Earl Hakes:
“Found on the 22d day of January, 1933, about 7 miles this
side of the summit on the Ridge Route. There were hundreds
of these bugs flying through the air just below the snow line
about 5 Pp. M.”
This variety, while close to P. conjungens in most respects,
seems to differ from the typical form enough to justify at least
a varietal name. It may be separated from conjungens by the
color, different shape of the ocular canthi, the more parallel
sides of the horn of the vertex, the extreme hairiness of the head
and anterior part of the pronotum, the heavily punctate anter-
ior median impression, and the slightly different proportions
of the first 3 antennal joints.
ON THE IDENTITIES OF CHALCIDOID TICK PARASITES
(HYMENOPTERA).
By A. B. Gauan,
Sentor Entomologist, Bureau of Entomology,
United States Department of Agriculture.
The discovery that Rocky Mountain spotted fever, a tick-
borne disease, has become established in several widely separ-
ated sections of the United States and is becoming an increas-
ingly important problem, has stimulated a keen interest in the
natural enemies of ticks.
So far as known the only important insect enemies of ticks
are minute chalcidoids belonging to the family Encyrtidae.
The first record of one of these parasitic insects attacking a tick
was published by L. O. Howard (/) in 1907 when he described
Ixodiphagus texanus. The following year Howard (2) described
a second genus and species from Texas which he called Huntere/-
lus hookeri and in 1912 Ixodiphagus caucurtei was named and
described by R. du Buysson (5) from France. A paper by R. A.
90 PROC. ENT. SOC. WASH., VOL. 35, NO. 4, APR., 1934
Cooley (/9) published in 1929 apparently implies (p. 267)
that all three of these names refer to the same insect. As will
be shown later, however, [xodiphagus texanus and Hunterellus
hookeri are quite distinct species while 7. caucurtei is identical
with Hunterellus hookeri.
In another article by Prof. Cooley (20) published in 1930 and
giving an account of his trip to Africa for the purpose of investi-
gating tick parasites, it is stated that G. A. H. Bedford of the
Veterinary Research Laboratory at Onsderpoort, Transvaal,
had discovered a chalcid that attacked adult ticks. It is also
related that Dr. L. E. Robinson, parasitologist of the Cooper
Technical Bureau, some years previously had received a box of
adult Amblyomma hebraeum Koch from Cape Province and that
upon being opened later in England the box was found to con-
tain adult chalcids that had emerged in transit and which were
different from the species discovered by Bedford. The conclu-
sion is drawn that it is reasonably certain that there exist in
Africa two new chalcidoid parasites of ticks. A review of tick
parasite work published by Prof. Cooley (2/) later in the same
year, however, stated that the alleged tick parasite discovered
by Bedford had been identified by the present writer as Mor-
moniella vitripennis (Walker), a common parasite of blowflies,
and was probably not a parasite of ticks at all. The same review
indicated that attempts to obtain examples of the supposed tick
parasite taken by Robinson had failed and the identity of the
species could not be established.
At present therefore only two species of tick parasites are
definitely known to exist, viz, /xodiphagus texanus Howard and
Hunterellus hookeri Howard. These two species bear a close
resemblance to each other and may easily be confused if exam-
ined only superficially. Both are small, robust, black species,
with the antennae 11-jointed and clavate in the female, 10-
jointed and nearly filiform or weakly clavate in the male; head
as broad as thorax, broadly but not deeply concave behind;
eyes distinctly hairy; mesoscutum weakly shagreened and
uniformly clothed with rather coarse hairs; wings normal in
size, the marginal vein about as broad as long, stigmal about
as long as marginal and post-marginal combined, oblique
hairless streak from stigmal vein distinct; propodeum medially
very short; abdomen broader than long, shorter than the
thorax, the ovipositor concealed.
Despite the resemblance, however, they are distinct enough
to be maintained as separate genera. The following dichotomy,
together with the accompanying figures, should make it possible
to distinguish the two species without much difficulty.
PROC. ENT. SOC. WASH., VOL. 36, NO. 4, APR., 1934 91
DicHoToMy FoR SEPARATION OF Jxodiphagus texanus AND Hunterellus hookeri.
Head, viewed dorsally, very nearly or quite three times as broad as long;
fronto-vertex nearly twice as broad as long and not flattened; ocellar
triangle distinctly obtuse, the postocellar line much longer than a line
from the anterior ocellus to a posterior ocellus; ocelli rather large, the
ocellocular line about equal to the diameter of an ocellus; antennae inserted
distinctly below middle of head and distinctly below a line connecting lower
extremities of eyes, the distance from antennal socket to anterior margin
of clypeus equal to about half the distance between antennal sockets;
scape four or five times as long as thick, not expanded beneath; antennal club
of female obliquely truncate from base of second segment, subacute at
apex; funicle joints of male antenna not longer than broad, the club
2-jointed and a little broader than the funicle joints; /abial palpi 3-jointed,
the second joint very short; maxillary palpi 4-jointed, the second and third
joints each broader than long and shorter than either the first or last joint;
mesoscutum and scutellum moderately convex, the scutellum polished ex-
cept for very weak reticulation on the basal one third; angle between
stigmal and postmarginal veins distinctly less than 45°; antennae fusco-
testaceous; tibiae and tarsi nearly uniformly testaceous, as are also the
trochanters and apices of femora; wing subhyaline.
Ixodiphagus texanus Howard.
Head viewed dorsally, about twice as broad as long; fronto-vertex in the
female not twice as broad as long, flattened and more or less horizontal, in
the male more transverse than in the female but usually not so short as in
I. texanus; ocellar triangle large, the postocellar line only a little longer
than a line from the anterior to a posterior ocellus; ocelli not large and the
lateral ones separated from the eye margin by a distance greater than the
diameter of an ocellus; antennae inserted at about the middle of head, slightly
above the lower extremities of eyes, the distance from antennal socket to
anterior margin of clypeus approximately equal to the distance between
antennal sockets; scape not over three times as long as broad, with a distinct
flange-like expansion on the inner side beneath: club not strongly obliquely
truncate, more rounded at apex; funicle joints in the male all distinctly
longer than broad; /abial palpi 2-ointed; maxillary palpi either 3- or 4-
jointed (the third and fourth joints most often distinctly separated but
frequently completely joined together), when 4-jointed the second and third
joints subequal and always distinctly longer than broad; mesoscutum and
scutellum flattened, the scutellum weakly reticulated or shagreened on at
least the basal two thirds; angle formed by stigmal and postmarginal
veins approximately 45°; antennae dark brown to blackish, the scape
usually fusco-testaceous; legs brownish black with the trochanters, knees,
apices of tibiae and the tarsi reddish testaceous, the middle and hind tibiae
always dark brownish or blackish except at base and apex; forewing sub-
hyaline but usually with the area embracing the oblique hairless streak
more or less distinctly stained with fuscous.
Hunterellus hookeri Howard.
92 PROC. ENT. SOC. WASH., VOL. 36, NO. 4, APR., 1934
Fig. 1—A. Ixodiphagus texanus Howard. 1, Front view of head; 2, side view
of head; 3, labial palpus; 4, maxillary palpus; 5, antenna of female;
6, antenna of male.
B. Hunterellus hookeri Howard. 1, Front view of head; 2, side view of
head; 3, labial palpus; 4, maxillary palpus, normal; 4a, maxillary
palpus (third and fourth joints connate); 5, antenna of female;
antenna of male, normal; 6a, other antenna from same individual
as 6, abnormal.
Ixodiphagus texanus Howard.
This species was originally described in 1907 (/) from several
females reared from nymphs of Haemaphysalis leporis-palustris
(Packard) taken on wild rabbits in Jackson County, Tex.
Although the species has been mentioned frequently in literature
there is to date no published record of its again having been
reared or collected.
The original type material of 7. ¢exanus in the U. S. National
Museum is in poor condition and as a consequence the identity
of the species was in some doubt until recently. In April, 1933,
a consignment of twenty specimens was received for identifica-
tion from R. A. Cooley through F. C. Bishopp, the labelling
of which was as follows: “Parasite on Ixodes hexagonus var.
cookei Packard on woodchuck, Mayfield, Idaho, June 28, 1932.
Reared through fourth generation from the original. Bishopp
No. 20657.” All of the specimens were labeled alike. Eleven
specimens of this lot were identified by the writer as Hunterellus
hookeri and the other nine specimens as [xodiphagus texanus.
PROC. ENT. SOC. WASH., VOL. 36, NO. 4, APR., 1934 93
The material was also examined by C. F. W. Muesebeck, who
concurred in the identifications.
In the absence of a complete history of the specimens involved,
it is impossible to explain the obvious contradiction between
these identifications and the above indicated labeling. The two
species of parasites are distinguished by good structural charac-
ters and can not be progeny of the same parents. Unless some
mistake was made in labeling a part of the specimens, 1t appears
certain either that the original stock of parasites comprised two
species which were carried along together through the fourth
generation or else that there was some contamination introduced
in the course of the breeding work. Following the discovery
that two species were involved, Dr. Bishopp obtained from
Prof. Cooley and submitted to the writer for examination several
specimens said to be the original stock from which the experi-
ment was started. Whether or not this material included the
actual parents used in starting the experiment, or constituted
merely a part of the original rearing from a tick on a woodchuck
taken at Mayfield, Idaho, from which the original parents were
selected, the writer was not informed, but since the specimens
submitted apparently emerged from the same individual tick
nymph as did the parent stock, it appears practically certain
that the specimens used as parents were of the same species.
All of the specimens submitted proved to be Hunterellus hookert.
It therefore appears certain that the experiment was started
with this species alone and that J/xodiphagus texanus was
introduced later by accident, perhaps upon some animal used
as host to the ticks. According to Fred A. Morton (/8) rabbits
were used for quantity production of ticks in the laboratory,
and since the original host of /. texanus was Haemaphysalis
leporis-palustris, the rabbit tick, it 1s possible that a parasitized
tick of this species may have been inadvertently introduced on
one of these animals. Whatever the explanation, it is to be
questioned whether the specimens of J. fexanus actually had
as their original host Jxodes hexagonus var. cookei as indicated
by the labeling. Likewise the locality from which the specimens
came can not be stated definitely.
Hunterellus hookeri Howard.
Syn. [xidophagus caucurtei Buysson.
Hunterellus hookert was described in 1908 (2) from four
females and six males reared from nymphs of RAipicephalus
texanus Banks (now recognized as a synonym of R. sanguineus
Latreille) collected on a dog at Corpus Christi, Tex. Ixodi-
pPhagus caucurtei was proposed in 1912 (5), being based upon
specimens reared by E. Brumpt from nymphs of [xodes ricinus
Linnaeus taken on deer at Chantilly and at Fontainebleau,
France.
94 PROC. ENT. SOC. WASH., VOL. 36, NO. 4, APR., 1934
As already stated, H. hookeri and I. caucurtei are believed
to be identical. This opinion is based upon a comparative study
of authentic material in the U. S. National Museum. Included
in this material are the types and many other undoubted
specimens of H. hookeri from Texas and other parts of the
United States as well as the following representatives of J.
caucurtei: A series of 21 specimens reared from Ixodes ricinus
by E. Brumpt at Paris, France; a large series received from
S. B. Wolbach, reared from Rhipicephalus sanguineus collected
in the Forest of Fontainebleau, France; and a third large series
received through J. Bequaert and representative of the French
stock which was first introduced on Naushon Island, Mass.,
and later into Montana and Dewees Island, S. C. The types of
I. caucurtei in the Museum of Natural History in Paris were
also examined by the writer in 1927, but these were not before
him when the comparative study was made. The caucurtei
material mentioned differs in no discernible way from typical
Hunterellus hookeri. The development and habits as recorded
by H. P. Wood for hooker: (4) and by Brumpt (6), Cooley (/7),
and others for caucurtei seem to agree. Both have been
shown freely to attack closely related and in some instances the
same species of ticks. There is no apparent reason to doubt,
therefore, that the two names represent the same widely
distributed species.
Hunterellus hookeri together with its synonym has received
frequent mention in literature. According to C. P. Lounsbury
(3) an unsuccessful attempt was made to introduce it into
South Africa in 1908. In 1911 H. P. Wood (4) gave an account
of its life history as a parasite of RAipicephalus sanguineus
Latreille in Texas and recorded it also as having been reared
from Dermacentor parumapertus marginatus Banks collected at
Green Valley, Calif.; from R. sanguineus at Monterey, Mexico;
and from the same host taken at Lourengo Marques, Portuguese
East Africa. E. Brumpt (6), in 1913, gave details of its life
history in France as a parasite of Ixodes ricinus Linnaeus,
stated that it also attacked Haemaphysalis concinna Koch in
nature, and reared it experimentally through Dermacentor
reticulatus Fabricius, D. venustus Banks (=andersoni Stiles),
and R. sanguineus. A paper by A. E. Shipley (7) in 1914,
entitled “Insects and War,” mentioned [xodiphagus caucurtet
as a ubiquitous enemy of all kinds of ticks. In 1915 A. da Costa
Lima (8) recorded the taking of Hunterellus hookeri at Rio de
Janeiro, Brazil, as a parasite of ticks on a dog. Nuttall, War-
burton, and Cooper (Y) in their monograph of ticks mention
the parasite records by Howard and Brumpt. In 1922 P. H.
Timberlake (/0) exhibited before the Hawaiian Entomological
Society specimens of hookeri said to have been taken on a dog
at Coimbatore, South India, and in 1923 G. N. Wolcott (//)
PROC. ENT. SOC. WASH., VOL. 36, NO. 3, MAR., 1934 95
recorded the species infesting Dermacentor nitens Neumann in
Porto Rico.
R. A. Cooley (/2), in 1927, gave an account of the introduc-
tion of J. caucurtei into the United States at Naushon Island,
Mass., for the purpose of combating the dog tick, Dermacentor
variabilis Say, and outlined plans for its introduction into Mon-
tana to combat the Rocky Mountain spotted fever tick, D.
andersoni Stiles. A very similar paper, published the same year
by Cooley (72a), further discussed the same subjects and gave
a brief review of literature together with a summary of the
life history of the French parasite. The following year F.
Larrouse, A. G. King, and W. B. Wolbach (/3) contributed a
short account of the Naushon Island experiment in which
the introduced parasite was shown to have survived the New
England winter, field collections of both D. variabilis and Ixodes
scapularis Say having yielded the parasite. The same year
Cooley (/#) stated that under certain circumstances this para-
site would oviposit in fed larvae of D. andersoni, but that when
eggs were deposited in a larva development was delayed until
the tick reached the nymphal stage. A series of articles pub-
lished in 1929 in the Seventh Biennial Report of the Montana
State Board of Entomology by R. A. Cooley (/5, 76), Fred A.
Morton (/7), and J. R. Parker and W. J. Butler (7S) discussed
various phases of the tick-parasite work at the Hamilton
laboratory and reviewed the previous work of others. The
previous record by Wood of RAipicephalus sanguineus as host
to Hunterellus hookeri at Lourenco Marques, Portuguese East
Africa, was stated by Cooley (/6, p. /7) to refer to R. evertsi
Neumann instead of sanguineus and two new distribution records
based upon material in the United States National Museum
were cited, viz.: Indo-China, bred from dog tick by E. Roubaud;
and Havana, Cuba, from unidentified nymphal ticks collected
by Dr. Etchegoyhen. Later in the same year Cooley (/9) gave
a short summary of tick parasite studies and recorded the
rearing of what was probably H. hookeri from Haemaphysalis
leachi (Audouin) collected at Durban, Natal, and from Hyalom-
ma aegyptium impressum Koch taken in the Pretoria district of
South Africa. The article already referred to as having been
published in 1930 by Cooley (20) states that a parasite closely
related to and possibly identical with caucurtei had been
discovered in the Transvaal preying on Hyalomma aegyptium
Linnaeus. In 1931, C. B. Philip (22, 23) announced the rearing
of H. hookeri from nymphs of R. sanguineus taken on dogs at
Apapa, near Lagos, Nigeria, in West Africa. A paper by
J. MacLeod (24, p. 398) in 1932 on the bionomics of the sheep
tick, Ixodes ricinus, stated that over a thousand nymphs of this
tick taken in England showed no parasitization by J. caucurtei
or any other species. In 1933 Cooley (25) again discussed
briefly the work with J. caucurtei in Montana.
96 PROC. ENT. SOC. WASH., VOL. 36, NO. 4, APR., 1934
From this brief review of the literature it will be seen that
Hunterellus hookeri is known to attack a large number of species
of ticks and that it has been recorded from Texas, California,
Massachusetts, Montana, Cuba, Puerto Rico, Mexico, Brazil,
France, Portuguese East Africa, Natal, the Transvaal, Nigeria,
Indo-China, and India. Specimens representative of all of these
locality records except the ones from Mexico, Brazil, Natal,
Transvaal, and Nigeria are now in the National Museum collec-
tion and have been reviewed in the preparation of these remarks.
The same collection contains specimens representing the follow-
ing as yet unpublished records: A large series of specimens from
South Miami, Fla., reared from Rhipicephalus sanguineus in
1931, under Bishopp Nos. 18033, 18184, 18187 and 16097; two
specimens from Charleston, S. C., reared from Dermacentor
variabilis, Oct. 15, 1931, under Bishopp No. 18183; and one
specimen from Ravalli County, Mont., said to have been reared
from the nest of a magpie by W. L. Jellison, June 3, 1932. To
these may be added the record already referred to in the discus-
sion of [xodiphagus texanus, of Hunterellus hookeri reared from
Ixodes hexagonus var. cookei taken at Mayfield, Idaho, on a
woodchuck.
The wide distribution of this species may be accounted for
by its propensity for attacking the ticks of domesticated animals,
especially dog ticks. In view of this well authenticated habit,
it seems reasonable to suspect that its distribution may be even
more general than indicated by the foregoing records, and the
suggestion is offered that before further attempts to introduce
the species into other regions or areas are undertaken, careful
investigation should first be made to determine whether or not
the species is already present in the area under consideration.
LITERATURE CITED.
(1). 1907, Howarp, L.O. A chalcidoid parasite of a tick. Ent. News 18,
pp. 375-378.
(2). 1908, Howarp, L. O. Another chalcidoid parasite of a tick. Canad.
Ent. 40, pp. 239-241.
(3). 1909, Lounssury, C. P. Parasite introductions. Cape Good Hope Ent
Rpt. 1908, pp. 64-65.
(4). 1911, Woop, H. P. Notes on the life history of the tick parasite Hunter-
ellus hookert Howard. Jour. Econ. Ent. 4, pp. 425-431, illus.
(5). 1912, Buysson, R. pu. Un Hyménoptére parasite des Jxodes. Arch.
Parasitol. 15, pp. 246-247, illus.
(6). 1913, Brumpr, E. Utilisation des insectes auxiliares entomophages dans
la lutte contre les insectes pathogenes. Presse Med. (Paris) No. 36,
pp. 359-361, illus.
(7). 1914, SHiptey, A. E. Insects and war. Brit. Med. Jour. No. 2811
(Nov. 14, 1914), pp. 831-832, illus.
(8).
(9).
(10).
(11).
(UD)
PROC. ENT. SOC. WASH., VOL. 35, NO. 4, APR., 1934 97
1915, Costa Lima, A. pa. O chalcidideo, Hunterellus hookeri Howard,
parasita do carrapato Rhipicephalus sanguineus Latreille, observado
no Rio de Janeiro. Rev. Vet. e Zootech. (Brazil) 5, p. 201, illus.
1915, Nurrai, G. H. F., Warsurton, C., anp Cooper, W. F. Ticks:
A monograph of the Ixodoidea, Part 3, pp. 534, 545, and 547. Cam-
bridge, England.
1922, TimBertake, P. H. Hunterrelus hookeri Howard in India. (Note)
Haw. Ent. Soc. Proc. 5, p. 10.
1923, Wotcorr, G. N. Insectae Portoricensis. Jour. Dept. Agr. Porto
Rico 7, p. 60.
1927, Cootey, R. A. A parasite of ticks. Mont. State Bd. Ent. Bien.
Rept. 6, pp. 15-17, illus.
(12a). 1927, CooLtey, R. A. Tick parasites. Med. Sentinel. Portland, Oreg.,
(13).
(14).
(15).
(16)
(17).
(18).
(19).
(20).
(24).
(25).
35 (No. 12), pp. 805-815.
1928, Larrousg, F., Kine, A. G., anp Wo.sacu, S. B. The overwinter-
ing in Massachusetts of Ixodiphagus caucurtei. Science 67, pp.
SHII=BESE
1928, Coo.try, R. A., anp Kouts, G. K. Egg laying of Ixodiphagus
caucurtet du Buysson in larval ticks. Science 67, p. 656.
1929, Cootey, R. A. Tick parasites. Mont. State Bd. Ent. Bien. Rept.
7 (1927-28), pp. LO=16.
1929, Cootey, R. A. Preliminary report on the tick parasite [xodiphagus
caucurtei du Buysson. Mont. State Bd. Ent. Bien. Rept. 7 (1927-28),
pp. 17-31, illus.
1929, Morton, Frep A. Quantity production of tick parasites. Mont.
State Bd. Ent. Bien. Rept. 7 (1927-28), pp. 32-35.
1929, Parker, J. R., anp Butter, W. J. Tick parasite liberation in
Montana during 1928. Mont. State Bd. Ent. Bien. Rept. 7 (1927-
1928), pp. 35-38.
1929, CooLey, R. A. A summary of tick parasites studies. So. African
Jour. Nat. Hist. 6, pp. 266-272.
1930, Cootey, R. A. The Montana tick parasite expedition to Africa.
Science 71, pp. 419-420.
. 1930, Cootey, R. A. Review of tick parasite work for 1929 and 1930.
Mont. State Bd. Ent. Bien. Rept. 8 (1929-30), pp. 16-25, illus.
. Puttip, C. B. Decourte en Afrique Occidentale d’Hunterellus hookeri
Howard, parasite des Ixodides. Ann. Parasitol. Humaine et Compar.
9) plies
. 1931, Puttip, C. B. Occurrence of a colony of the tick parasite Hunterellus
hookeri Howard in West Africa. U.S. Pub. Health Serv. Rpts. 46, pp.
2168-2172, illus.
1932, MacLeop, J. The bionomics of Ixodes ricinus L., the “sheep tick”
of Scotland. Parasitology 24, pp. 382-398, illus.
1933, Cootey, R. A. Observations sur [xodiphagus caucurtei du Buysson
dans l’ouest des Etats-Unis. Ann. Parasitol. Humaine et Compar.
Lipp. 22-23:
98 PROC. ENT. SOC. WASH., VOL. 36, NO. 4, APR., 1934
A REVIEW OF JAEGER’S ‘THE CALIFORNIA DESERTS.”
“The California Deserts,” by Edmund C. Jaeger, 12 mo. cloth, 207 pp., illus.,
maps, bibliog. Stanford California University Press, 1934. $2.00.
While the greater portion of the subject-matter of this volume
is not primarily of entomological interest, it is given notice here
because it contains not only an exceedingly interesting discus-
sion of the outstanding desert insects and their near relatives,
(chapter 5, pp. 45-66 inc., 10 illus.) but also records considerable
ecological and other information concerning arid region insects.
Among the principal insects considered are specialized desert
forms of grasshoppers, (Bootettix argentatus and Anconia
integra); crickets (Nemobius mexicanus); termites (4mitermes
arizonensis and Reticulotermes tibialis); scales (Tachardiella
larreae and Cerococcus quercus); leafhoppers (Oncometopius
lateralis); cicadas (Diceroprocta apache); robber flies (Rhapion-
idas xanthos); black flies (Leptonops kerteszi var. americanus);
salute flies (Hippaletes flaviceps); horse flies (Tabanus punctifer) ;
mosquitoes (Culex quinquefasciatus, Anopheles pseudopuncti-
pennis, Theobaldia inornata, and Psorophora spp.); darkling
beetles (Eleodes spp.); inflated beetle (Cysteodemus armatus);
ants (Messor pergandeit, M. andrei, Pogonomyrmex barbatus, P.
occidentalis and Myrmecocystus mexicanus); mutillids (Dasy-
mutilla satanus, D. arenivaga and D. gloriosa); butterflies
(Papilio multicaudata, Pieris beckeri, P. sisymbrii, Euchloe
creusa lotta, and others); and moths (Fucaterva variaria).
Related forms under consideration include scorpions, pseudo-
scorpions, spiders, mites, millipeds and the like. There are
also included discussion of effects of prolonged heat and extreme
droughts on various insects and on their eggs, the curious
summer sleep called aestivation, and related themes. Rich in
information about deserts and desert life, and written in a
sympathetic vein by one who gives abundant evidence of
possession of an ample fund of experience pertaining to his
subject, the book will prove to be a useful one to all desert
habitues. —F. S. Wade.
Actual date of publication, May 16, 1934.
VOL. 36 MAY, 1934 No. 5
PROCEEDINGS
OF THE
ENTOMOLOGICAL SOCIETY
OF WASHINGTON
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CONTENTS Se: Sa
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GAHAN, A. B..—~A NEW SPECIES OF CIRROSPILUS WESTWOOD (CHALCIDOIDEA) 12
HOOD, J. DOUGLAS—-TWO NEW GENERA AND SPECIES OF PHL OTHRIPID2
(GEELSAIN OPER S)) SABMENe ad on te so ee ee ae a Oe elle
MATHESON, ROBERT-—NOTES ON MOSQUITOES FROM SOUTH AMERICA,
WITH A DESCRIPTION OF A NEW SPECIES (DIPTERA: CULICIDAE) . . 119
SHANNON, RAYMOND C.—THE GENUS MANSONIA (CULICIDAE) IN THE
AIMTAZON] VANE ae ee as ee fs. ee Oe ee a OO
PusiisHED MontHiy Excepr Jury, AuGust AND SEPTEMBER
.
BY THE
ENTOMOLOGICAL SOCIETY OF WASHINGTON
U. S. NATIONAL MUSEUM
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Corresponding Secretary-Treasurer. . ©. ..... .; . 9. A. ROHWEE
Bureau of Entomology, Washington, D. C.
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ENTOMOLOGICAL SOCIETY OF WASHINGTON
VOL. 36 MAY, 1934 No, 5
THE GENUS MANSONIA (CULICIDAE) IN THE AMAZON
VALLEY .!
By Raymonp C. SHANNON.
The present communication is based on material collected
during a general mosquito survey in the Amazon region from
the latter part of March to the end of June, 1931.
The species of Mansonia of the Amazon are of particular
interest; they are the most troublesome of the wild mosquitoes
of the region and doubtlessly are to be included among the
outstanding pests of the country, so frequently alluded to by
travellers. One species in particular, M. indubitans, is very
troublesome at times, and at Iquitos, Peru, it invades houses
to such an extent as to be as annoying as both Stegomyia and
Culex fatigans combined. On the whole, however, mosquito
pests were not found to be as troublesome along the Amazon
as they are in certain other parts of the world, but this may
have been due to the season.
All but two of the known Brazilian species of Mansonia were
collected during the course of the survey; in addition, two
species (flaveolus and nigricans), which were hitherto known
only from the northern part of the continent and from the
West Indies, were obtained. The commonest and most widely
spread species of the genus (¢/ti//ans) was not found, although
it has previously been reported from the Amazon. The other
species not found (chrysonotum, Peryassti) is known, to date,
only from the coastal States of Brazil.
SYSTEMATIC NOTES ON THE SPECIES OF THE SUBGENUS
MANSONIA.
The male terminalia of the species—Vhese organs are very
distinctive in M. amazonensis and are fairly so in M. humeralis.
Among the other species which form the /itillans complex,
1 The studies and observations on which this paper is based were conducted
with the support and under the auspices of the International Health Division
of the Rockefeller Foundation. The writer wishes further to acknowledge
the opportunity granted him by the officials of the U. S. National Museum and
the U. S. Bureau of Entomology, to study the Culicidae in the U. S. National
Collection.
100, PROC. ENT. SOC. WASH., VOL. 36, NO. 5, MAY, 1934
however, they are very uniform. The style appears to be the
only structure showing distinctive differences. Unfortunately,
the differences are small and it is necessary to place the organs
consistently in the same position in order to avoid misinter-
pretations.
Howard, Dyar, and Knab (1912) have figured the terminalia
of M. titillans Wik. ) and M. flaveolus (Coq.); the distinguishing
features, however, are poorly indicated. Later, Dyar (1918)
reexamined those of M. flaveolus and concluded that the species
was a homonym of M. fitillans. In 1928 he stated that it was
merely an aberration of M. titillans. Bonne & Bonne-Wepster
(1925) give an accurate illustration of fiti/lans. These authors
were also the first to describe the terminalia of amazonensis
(Theo.).
Costa Lima (1929) gives the first illustrations for M. pseudo-
titillans (Theo.) and 1n addition gives photographic reproductions
of the terminalia of M. amazonensis and M. humeralis, although
the latter is stated to be M. titillans.
Dyar (1928) gives a figure of what he considered to be the
terminalia of M. humeralis, Dyar & Knab. An examination
of the specimen from which the illustration was made, however,
discloses the fact that what he had was a typical specimen of
M. titillans. This specimen was one of a series collected at
Barranquilla, Colombia, which included a number of female
M. humeralis, M. titillans, and what appears to be a new species
closely related to M. titillans. Dyar made two slide mounts
from this material, one of which he labeled M. ‘itillans. The
style of this specimen is much broader than in the true M.
titillans (See Chart I, Fig. 4) and may prove to be an undescribed
species. Because the second specimen differed from the first
he evidently considered it to be the male of M. Aumeralis, which
at that time was unknown. The only figure extant for the
terminalia of M. humeralis is, therefore, that given by Costa
Lima (1929), which, as stated above, he presented under the
name of M. titillans.
KerY TO THE SPECIES OF THE SUBGENUS Mansonia.
Adult Females.
1. Hind tibia rather strongly ciliate, at least on basal half, the girth
appearing a little larger than that of the femur; anterior corners
of the mesonotum with reddish brown areas clothed with golden
SCaleg wee we eta ee eet eee humeralis Dyar & Knab
Hind tibia not distinctly ciliate, the bia appearing more slender
than the femur... Set us et eer mre ts eli bs eM Red ee Se 2
2. Abdomen covered entirely with bright golden scales; mesonotum
generally yellowish brown, clothed with golden scales and isolated
PROC. ENT. SOC. WASH., VOL. 36, NO. 5, MAY, 1934 101
patches of dark scales; palpi of the female exceeding one-half
the length of the proboscis... flaveolus Coquillett
Abdomen mostly dark scaled; palpi of female less than one-half the
length of the proboscis... USE PEP epee picare Pe en at ek eh 3
3. Anterior portion of mesonotum reddish brown, clothed with small
POlGEMES Gal ecm: ee At eh TEs ee UE 2 ees amazonensis Th.
Mesonotum entirely reddish or dark brown, with sparse golden scales... 4
4. Antenna a little longer than the proboscis; palpi more than one-third
the length of the proboscis. A rather large species...
pseudotitillans Theo.
Anitennara httlershonterathani ties prODOSClSee ee oe ee 5
5. Palpi about one-third the length of the proboscis. Small to moderate
{INNS ZC ee et en ger a 1A ee eee oe ee Et titillans Walker
Palpi about one-fourth the length of the proboscis. Uniformly
SIMAUINS WECIES: = te eee ee ese ere aoe indubitans Dyar & Shannon
M. titillans and indubitans are difficult to distinguish one from the other. In
addition to the characters given in the key it may be noted that the last palpal
segment (a minute organ) is more conspicuous in pserdotitillans, intermediate
in fitillans and very small in imdubitans.
CHART.
1.M. indubitans D.$S
3. titillans (Wik)
‘ “elb 5. flaveolus C
% pseudotitillans (Th) 4.Variety() of Uitillans f See
(Barr anquilla, Colombia)
Inside view of the right side-piece and appendages of the terminalia
of the species of the Subgenus Mansonia. All drawn to the same scale.
102 PROC. ENT. SOC. WASH., VOL. 36, NO. 5, MAY, 1934
Mansonia (M.) titillans (Walker) 1848.
This species was not found by the writer in the Amazon region.
It has been reported from there on several occasions but the
records, in at least some of the cases, appear to be erroneous.
(1) Goeldi (1905) gives descriptions and colored illustrations.
These appear to be based on specimens of M. Aumeralis. He
also reproduces photographs of “‘¢zt//ans”’ in the act of oviposit-
ing. Quite obviously the specimen shown belongs either to
Psorophora confinnis (L. A.) or P. cingulata (Fabr.), both of
which closely resemble species of Mansonia.
(2) Converse (1914) states that larvae of M. titillans are
found in millions in the pools along the open ditches of Iquitos.
Most probably the larvae referred to belong to Psorophora con-
finnis or P. cingulata. The writer found great numbers of these
larvae in roadside ditches, etc., about Iquitos.
(3) Bequaert (1926) records M. titillans from Manaos. It is
probable that they belong to izdudbitans.
(4) The M. titillans reported by Costa Lima from Obidos and
Santarem, belong, at least in part, to Aumeralis.
(5) Newstead & Thomas (1910) and Gordon & Evans
(1922) also record M. titi/lans from the Amazon.
No doubt the species does occur in at least some part of the
valley.
Mansonia (M.) indubitans Dyar & Shannon, 1925.
M. indubitans has been described from females collected by
Bequaert on the Amazon at Belém, Santarem, and Itacoatiara,
and at Carmo, Rio Branco. Several specimens, including three
males, were collected at Tonantins. In April, 1931, it was
extremely abundant at Iquitos where it invaded the houses
along the river front in large numbers. Owing to its numbers,
its fearlessness in attack, and its activity at all hours of the day
and night, it appears to be fully as troublesome indoors as both
stegomyia and Culex fatigans combined. Very probably it has a
seasonal abundance and therefore may not be so annoying at
other seasons of the year. In fact, the mosquitoes were most in
evidence several days after a heavy rain, following which they
diminished rather rapidly in numbers. Usually, M. indubitans
was the most abundant species collected on animal bait and on
such occasions many individuals were observed to attack other
mosquitoes and from them suck out the blood which had already
been imbibed from the horse; the victimized mosquito mean-
while continued to feed until it had acquired another meal.
No Pistia was found growing about Iquitos; in fact this plant
was not observed on the Amazon above the mouth of the Rio
Javary. The roots of other aquatic plants were searched for
larvae but without success.
PROC. ENT. SOC. WASH., VOL. 36
H Goh
. MANSONIA
- MANSONIA
- MANSONIA
- MANSONIA
a Sain itRSS a se ac el
(MANSONIA) TITILLANS.
(RHYNCHOTAENIA) ALBICOSTA.
(RHYNCHOTAENIA) JUSTAMANSONIA.
(RHYNCHOTAENIA) LYNCHI.
PLATE 15
Drawings by Nelson Cerqueira.
[ 103 |
PLATE 16
PROC. ENT. SOC. WASH., VOL. 36
sisuauozewe eiuoSsUeL)
SUBIIGNPU) eiuOSUeY,
‘PP. ‘eavan bia aN
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ByeoOINse; BuosueW a
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ee ee
PROC. ENT. SOC. WASH., VOL. 36, NO. 5, MAY, 1934 107
The species was also found at Mandaos, Guajara-Mirim,
Porto Velho, and Fordlandia, and in the coastal state of Bahia.
Mansonia (M.) pseudotitillans (Theo.) 1901.
This species was found only at Teffé and at Tonantins.
Several males were collected at night on board a boat at the
latter locality. It has been recorded by Costa Lima from
Santarem and Obidos, and is known to occur in Surinam.
Mansonia (M.) flaveolus (Coquillett) 1906.
This species has been known to date only from a few specimens
collected in widely separate regions. A single male was collected
in St. Thomas, W. I., in 1906 (A. Busck) and a single female was
found in Panama, 1912 (A. Busck). It was subsequently placed
by Dyar (1918) as a homonym of M. ¢itillans and in 1928,
Dyareadas: ~ A. light yellow form occurs rarely, aberration
flaveolus Coquillett.” Tn addition, Bonne and Bonne- Wepster
(1925) record two males and one female of M. flaveolus (as a
variety of ¢iti/lans) from Paramaribo, Dutch Guiana.
In view of the history of this species and the great distances
between its known points of distribution, the discovery of
M. flaveolus in the Amazon Basin is of unusual interest. A
series of thirty specimens, including three males, was collected
at Teffé and at Tonantins, all on board ship, in company with
M. pseudotitillans, indubitans, and amazonensis. In addition to
the slight differences in the male terminalia as compared with
the other species, there is a striking difference in coloration and
in the length of the female palpi. These characters are listed
in the key to species.
Mansonia (M.) amazonensis (Theobald) 1901.
As far as is known, the present species has not been found
outside the Amazon Valley. The specimens collected were
one male and one female from Tonantins, and one female from
Manaos. They were recorded by Bequaert from Belém, and
Gordon & Evans from Macopa. Costa Lima states that he
found the species to be very abundant at Obidos and at San-
tarem. A series of specimens was collected by N. C. Davis at
Belém.
Mansonia (M.) humeralis Dyar & Knab, 1916.
Next to ©. titi/lans this species has the greatest known range
of any of the subgenus. It has been recorded by Dyar (1928)
from Colombia, Venezuela, British Guiana, and the Amazon
region. It also occurs in the middle coast states of Brazil.
New Amazon records are: Iquitos, Peru (April); Guajara-Mirim,
108 PROC. ENT. SOC. WASH., VOL. 36, NO. 5, MAY, 1934
Matto Grosso (May); Manaos, Amazonas (June). Only females
were captured.
Species of the Subgenus RHYNCHOTAENIA.
Six of the eight known species of this subgenus were found.
These are all included in the key to the species given by Shannon
(1931).
Mansonia (R.) nigricans (Coquillett) 1904.
Hitherto recorded only from Cuba, Panama, Colombia, and
Venezuela. Three females were collected at Iquitos, Peru
(April).
Mansonia (R.) albicosta (Peryassti) 1908.
Two females from Iquitos, Peru, and two from the Rio
Madeira, Guajara-Mirim. Also from Xerem and Belém,
Para (Bequaert, 1926). It occurs likewise in the coastal states
of Brazil, but has not been reported outside the country.
Mansonia (R.) justamansonia (Chagas) 1907.
Four females from Iquitos, Peru, and one from Guajara-
Mirim, Matto Grosso. It is also found in the coastal States
but has not been recorded outside Brazil.
Mansonia (R.) fasciolata (Lynch Arribalzaga) 1891.
— Mansonia venezuelensis (Theobald) 1912.
This species appears to be the dominant one of the subgenus,
occurring from Central America to Argentina; it frequently
outnumbers, in point of individuals, all the others combined.
It was common at Iquitos, nine males as well as a large series
of females being captured. A few specimens were taken at
Manaos. Bequaert and Davis have also collected it at Belém,
Para.
Dyar (1928) states that M. venezuelensis ditters from M.
fasciolata in the possession of light scales on the anterior margin
of the wing. However, this is a common characteristic of both
species. A comparison of material in the U. S. National col-
lection of both species disclosed no essential difference.
Mansonia (R.) arribalzagae (Theobald) 1903.
Although this species has a wide distribution, Panama and
Surinam, as well as the Amazon region, it is regarded as a rare
species. It was fairly abundant in heavily forested areas about
Iquitos, fifty-four specimens being collected. Males were
found rather commonly flying about the jungle, and seventeen
of them were net-captured. The species occurs in Panama and
PROC. ENT. SOC. WASH., VOL. 36, NO. 5, MAY, 1934 109
is also recorded by Gordon & Evans from the vicinity of Manaos,
Amazonas.
Mansonia (R.) lynehi Shannon, 1931.
This species has previously been known only from the type
specimens, two males and two females from Belém, Para
(N. C. Davis). They were collected with larger numbers of
M. arribalzagae. The two species, which closely resemble one
another, differ markedly in adult coloration from the other
species of the subgenus. Two males and two females of M.
lynchi were found in the same forested areas about Iquitos in
which arribalzagae occurred. Both species appear to be pri-
marily day fliers.
SUMMARY.
Eleven species of the genus Mansonia were collected in the
Amazon region (April, May, and June, 1931); five belong to
the subgenus Mansonia: indubitans, D. & S., pseudotitillans
(Th.), flaveolus (Coq.), humeralis D. & K., amazonensis (Th.);
and six to. the subgenus RKhynchotaenia: nigricans (Coq.),
albicosta (Pery.), justamansonia (Chagas), fasciolata (L. A.),
lynchi (Shan.), and arribalzagae (Th.). M. flaveolus (here removed
from fiti/lans as a homonym) and nigricans were previously
unrecorded from Brazil. Two Brazilian species, titi/lans (the
commonest and most widespread species of the genus) and
chrysonotum, were not found, although the former has been
recorded a number of times from the Amazon. All of the
records for ¢iti/lans, however, are possibly erroneous, although in
all probability the species is to be found somewhere in the
valley.
M. indubitans is the commonest and most annoying species
occurring in the region. In Iquitos, Peru, it invades the houses
in such large numbers that it is frequently as troublesome as
the two domestic species (Stegomyia and C. fatigans) combined.
Doubtlessly this species is to be classed as one of the outstanding
pests of the region so frequently alluded to by travelers; but its
annoyance probably is not so great as that caused by mos-
quitoes in many other parts of the world.
A new key is given for the American species of the subgenus
Mansonia and the characters of the male terminalia are dis-
cussed.
REFERENCES.
References to the original description of the species are not
given as they are to be found in several of the standard works
on Culicidae.
110 PROC. ENT. SOC. WASH., VOL. 36, NO. 5, MAY, 1934
Bequaert, J.
1926. In: Strong, et al., Medical Report Hamilton Rice 7th. Exped. to the
Amazon, 1924-1925. Part II, pp. 198-199.
Bonne, C. & Bonne-WepstTER, J.
1925. Mosquitoes of Surinam, a study of neotropical mosquitoes. Royal
Colonial Institute of Amsterdam, no. 21, Dept. Trop. Hyg. no. 13.
Converse, G. M.
1914. The sanitation of Peru. Public Hlth. Rep. Washington, D. C. 29
(46) : 3030-3040.
Costa Lima, A. Da.
1929. Sobre algumas especies de Mansonia encontradas no Brazil. Instituto
Oswaldo Cruz, Supplemento das Memorias, no. 12 : 297-300.
Goe.pi, E. A.
1905. Os Mosquitos no Para. Memorias do Museu Goeldi, IV, Para, Brazil.
Gordon, R. M. & Evans, A. M.
1922. Mosquitoes collected in the Mandos region of the Amazon. Annals
Liverpool School Trop. Med. and Parasit. 16 : 327.
DyareElaG:
1918. Ins. Ins. Mens., 6: 112.
Dyar, H. G.
1925. The subgenus of Mansonia. Ins. Ins. Mens., 13 : 140.
Dyar, H. G.
1928. The Mosquitoes of the Americas. Carnegie Institution of Washington,
DIC:
Howarp, L. O., Dyar, H. G., & Knap, F.
1912. Mosquitoes of North and Central America and the West Indies.
Carnegie Institution of Washington, 2 : plate 34, figs. 227 and 228.
Newsteap, R. & Tuomas, H. W.
1910. The Mosquitoes of the Amazon Region. Ann. Trop. Med. & Parasit.,
4: 141-149.
SHannon, R. C.
1931. The classification of Brazilian Culicidae with special reference to those
capable of harboring the yellow fever virus. Proc. Ent. Soc. Washington.
SG SOS
=
PROC. ENT. SOC. WASH., VOL. 36, NO..5, MAY, 1934 |
TWO NEW GENERA AND SPECIES OF PHLAZOTHRIPIDE
(THYSANOPTERA).
By J. Douctas Hoop, University of Rochester.
The two new genera described below are unusual in that they
are heavily sculptured and have seven-segmented antenne.
The types are in the author’s collection.
Genus STEGOTHRIPS nov.
(oréyos, a roof; OptW, a wood-worm—in allusion
to the form of the dorsum of the head.)
Body reticulate and tuberculate dorsally, non-shining. Head much longer
than wide, very deeply reticulated above; dorsum strongly elevated and arched
as seen from the side (Pl. 17, fig. 4), angulate and roof-like when observed from
the front; ventral surface concave; vertex rounded, slightly produced and over-
hanging, bearing the forwardly-directed median ocellus at its extremity,
without strong sete; eyes normal in position, small, rounded, finely-facetted,
larger on ventral surface of head, and strongly protruding; postocular sete
moderately long and stout, expanded at tip, arising from low tubercles; antenne
7-segmented but with a distinct suture on ventral surface between morphological
seventh and eighth segments, intermediate segments short, subglobose, pedicel-
late, with long sense-cones; mouth-cone heavy but acute, surpassing base of
prosternum. Prothorax short and broad (in the genotype much less than half
as long as head) with a deep transverse groove across middle, this groove with a
fovea at either end; pronotum minutely tuberculate, anterior margin curved,
posterior margin straight; epimeron largely fused with pronotum; all major sete
present, stout, expanded distally, and arising from slight eminences; legs
tuberculate, short; female with fore tarsus unarmed on inner surface but
with a strong downwardly-directed claw on outec surface at apex of first segment
(much as in many Urothripide); wings abruptly bent outward at middle but
not narrowed beyond, fore pair with the basal portion tuberculate, no accessory
setee. Abdomen with its segments short and transverse, in long-winged forms
with a shallow longitudinal groove for the reception of the wings, the major
sete on terga II-VIII (excepting the wing-retaining ones) short, stout, and
apically dilated, those on IX much longer; tube long (in the genotype more
than three times the length of tergum IX), thickened at sides, and constricted
at apex, with short terminal sete.
Genoty pe.
Stegothrips sel appear at first glance to take its proper
place in the Tribe Docessissophothripini, instead of in_ the
Phleothripini where I have assigned it. The type-genus of the
former tribe has the occipital region of the head elevated much as
in the present genus; in fact, the similarity in this respect
between Docessissophothrips titschacki Priesner and Stegothrips
barronis is so close that the conclusion that they are related is
almost inescapable.
bF2 PROC. ENT. SOC. WASH., VOL. 36, NO. 5, MAY, 1934
However, similarly elevated heads are found in such widely
different genera as Megalothrips, Phleobiothr ips, and Tricho-
thrips; but in the last genus they occur only in those species
whose heads and mouth-spines have become elongated. The long,
crested head has apparently been derived independently in
several different portions of the Tubuliferous series as the result
of mechanical necessity, so to speak, this being the only practi-
cable method for increasing the length of the mouth-spines without
decreasing the angle of their penetration. The character seems
to be purely an adaptive one and of no phylogenetic significance
whatever.
This genus is related to Strepterothrips Hood and to the new
genus described below, both of which it resembles in such
structural features as wing-form, the number of antennal seg-
ments, the general build of the abdomen (with its dorsal furrow,
in long-winged forms, for the reception of the wings), the long
tube, dilated sete, and dorsal sculpture. The italicized portions
of the diagnosis given above should serve, however, to dis-
tinguish it readily.
Stegothrips barronis sp. nov.
(Plate 17, Figs. 1-5.)
Female (macropterous).—Length about 1.5 mm. (distended, 1.8 mm.).
Color, by reflected light, blackish brown in head (black under low magnifications),
with median line of head brown behind eyes and about concolorous with re-
mainder of body; pterothorax paler at sides of notal plates, abdomen irregularly
paler along sides of terga II-VIII and in segment I, tube brownish orange and
tipped with black; subhypodermal pigmentation of two colors, white and red,
the former producing a conspicuous white spot where it shows through the
membrane between head and pronotum, a small white spot at anterior margin
of mesonotum, and a whitish spot, more or less variegated with the red pig-
mentation and interrupted by tergum I of abdomen, along sides and posterior
margin of metanotum; antenne brown in segment I (apex slightly paler),
clear lemon-yellow in II and III, blackish brown in IV—VII; legs blackish
brown, paler than head, with distal ends of all femora and proximal ends of all]
tibie yellow, tarsi brownish yellow, with darker brown cups. By ¢ransmitted
light the white markings are not visible; wings pale brown, the fore pair darker
in distal half and in anal area (“‘scale’’), with two narrow pale streaks in the
bend of the wing, one near each margin; hind wings with a pale median line
extending to near tip, in bend margined narrowly with nearly black and with
a minute clear spot near posterior margin.
Head (Pl. 17. fig. 1) about 1.77 times as long as greatest width, as broad
at basal third as across basal collar and 0.93 as wide at narrowest place between,
the cheeks nearly straight and converging to eyes, where they are rather abruptly
narrowed and only 0.8 as broad as at widest part; dorsum of head roof-like, very
strongly elevated along median line, where it is nearly carinate, much arched
as seen from the side (PI. 17, fig. 4), angulate and almost roof-like when observed
pw tte
PROC. ENT. SOC. WASH., VOL. 36, NO. 5, MAY, 1934 113
from the front, heavily polygonally reticulate (excepting along the nearly
smooth median line) with raised dark lines which in profile (as on the cheeks)
appear as tubercles, and with a number of distinct setigerous tubercles which
are more numerous and best seen along the cheeks, the smooth median area
narrow and bordered on either side with a very regular row of 8-10 slender
pointed sete; postocular sete strong, dilated at apex, 54 u long, arising slightly
in advance of posterior margin of eyes, and 1.44 times as far apart as the latter,
the measured interval between their bases 101 uw; vertex at a much lower level
than highest part of occiput, evenly rounded and slightly overhanging, bearing
the forwardly-directed anterior ocellus at its extremity, without strong sete, but
with four pairs of short sete, one of these directly between posterior ocelli,
one almost directly beneath them at sides of vertex close to eyes, one laterad of
median ocellus, and one about midway between this last pair and the first
mentioned; ocelli about 17 » in diameter, the posterior pair 45 w apart, the
median one 15 uw in advance of front margin of eyes. Eyes normal in position,
strongly protruding, but small, little more than one-fifth as long as head, about
1.5 times as long as wide, and nearly two-thirds ‘as wide as their interval.
Antenne (Pl. 17, fig. 2) hardly 1.1 times as long as head, segment VIII fused
with VII to form a large lanceolate and pedicellate segment which 1s the longest
in the entire antenna and has an incomplete transverse suture on ventral surface;
most of the segments roughened by distinct raised lines of sculpture; sense-cones
moderately long and slender, segments III, V, and VI each with one on either
side of apex, IV with two on either side, morphological seventh segment with
the usual dorsal one.
Prothorax (Pl. 17, fig. 1) along median dorsal line of pronotum only 0.33 (1)
as long as head and (inclusive of coxe) three times as broad as long, without
median thickening, but with a deep transverse groove across middle, this
groove with a large irregular fovea at each end; anterior margin of pronotum
emarginate, elevated at median line, posterior margin straight; surface of
pronotum and epimeron with numerous small tubercles, the latter sclerite
almost completely fused with pronotum; all major sete present, stout, expanded
distally, and arising from distinct eminences, the anterior marginals 30 yu,
anterior laterals 36 uw, midlaterals 27 u, epimerals 54 uw, posterior marginals 37 y,
coxals 30 u; mesonotum tuberculate like prothorax, metanotum with the
tubercles larger and more rounded. Legs short and stout, roughened by numer-
ous low anastomosing rug and many setigerous tubercles; fore tarsus without
tooth or claw on inner surface but with a strong downwardly-directed claw on
outer surface at apex of first segment. Wings bent abruptly outward at middle
(where they are slightly narrower than elsewhere), but not widened distally,
the fore pair without vestige of longitudinal vein; basal portion of fore wing
tuberculate in the region of the three subbasal sete, these equal in length (27 u
long), stout, flaring outward from base, and arising from low tubercles; distal
two-thirds of fore wing roughened; no accessory sete.
Abdomen broadest at segment II, equal in width to pterothorax, with a longi-
tudinal furrow for the reception of the wings, this furrow at sides in each of
terga II-VII with two pairs of brown wing-retaining set, of which the posterior
pair is in every case longer, broader, flatter, and less abruptly curved at extreme
base; posterior margins of these same terga each with two pairs only of major
114 PROC. ENT. SOC. WASH., VOL. 36, NO. 5, MAY, 1934
sete, both of them stout, dilated and divided at apex, arising from tubercles,
and pale in color, the inner pair longer and stouter than the outer, on tergum
V thei nner pair 65 w and the outer pair 42 4; tergum VIII (Pl. 17, fig. 3) with
the outer pair 75 uw, stigmata borne on low tubercles; IX (PI. 17, fig. 3) with the
dorsal pair of sete 135 uw and knobbed at tip, the upper lateral pair 240 u and
pointed; tergum I with the middle portion subrectangular and much longer
than wide; tube large, two-thirds as long as head, formed and sculptured as
shown in Pl. 17, fig. 3, about 2.7 times as long as greatest subbasal width and
2.5 times as broad near base as at apex, its longest terminal sete 100 y, its sides
thickened; entire dorsum of abdomen in segments II—-VIII and basal portion of
IX lightly sculptured with anastomosing lines which are weaker in the distal
half of the dorsal furrow in each of segments IJ—V and also in the lateral portions
of III-VII at base, prolonged into dark aspere at sides of segments and also
across base of segment II, some of the dark points projecting beyond posterior
margins of sides of segments II-VIII and of middle of IX.
Measurements of holotype (@): Length about 1.51 mm. (distended, 1.82
mm.); head, length 0.307 mm., greatest width (near base) 0.173 mm., width at
basal constriction 0.161 mm., least width (at posterior margin of eyes) 0.137
mm., width across eyes 0.158 mm.; eyes, length 0.067 mm., width 0.045 mm.,
interval 0.070 mm.; prothorax, median length of pronotum 0.103 mm., width
(inclusive of coxe) 0.308 mm.; pterothorax, greatest width 0.313 mm.; abdomen,
greatest width 0.312 mm.; tube (length of segment X only) 0.207 mm., width
near base 0.077 mm., width at apex 0.031 mm.
Antennalssegmentsues se eee a 23> ee Se Omen
Wenest ini (i) ee ee ee ee 35 53 53 51 44 42 58
WN itcl @sCgs) 222. = 8a tees ew O32) 335.31 385 29) Sees
Total length of antenna, 0.336 mm.
Described from one female taken on Barro Colorado Island,
Canal Zone, Panama, 1933 (probably in October), by Silvestre
Aviles, from a branch of sour orange [Hood No. 1075]. The
specimen was transmitted by Mr. James Zetek.
Genus ARCYOTHRIPS nov.
(dpxis, a net; Oply, a wood-worm—in allusion to the
net-like reticulation of the head and _ pronotum.)
Body reticulate dorsally, non-shining. Head longer than wide, deeply
‘reticulated above; dorsum somewhat elevated and arched as seen from the
side; vertex rounded and slightly overhanging, bearing the forwardly-directed
median ocellus at its extremity, without strong sete; eyes relatively small, ex-
tending onto ventral surface in a forward direction and not at all involving
sides of head; postocular sete very short; antenne 7-segmented, without trace
of suture on ventral surface between morphological seventh and eighth segments,
intermediate segments short, globose, pedicellate, II particularly large, III
much shorter and narrower than either II or IV; mouth-cone acute, attaining
base of mesosternum. Prothorax of normal form, reticulated above, with a
shallow curved impression across middle and a shallow fovea on each side
Samy
ee
PROC. ENT. SOC. WASH., VOL. 36, NO. 5, MAY, 1934 115
between mid-lateral seta and the curved anterior margin, posterior margin
curved; epimeron not fused with pronotum; all major sete present, very short,
broadly expanded, from base and hence somewhat fan-shaped, all arising from
slight eminences; legs short, with minute tubercles, all of which are setose, and
anastomosing ruge; female with fore tarsus unarmed and without a down-
wardly-directed claw on outer surface at apex of first segment; wings bent
abruptly outward at middle, where they are narrowest, and slightly expanded
apically, fore pair with the basal portion tuberculate, no accessory sete. Ab-
domen with its segments short and transverse, in long-winged forms with a
distinct longitudinal groove for the reception of the wings, the major sete
on terga II-VIII (excepting the wing-retaining ones) short, stout, and dilated;
tube long (in the genotype more than twice the length of tergum IX), not
thickened at sides, narrowed rather than constricted at apex, with terminal
sete about half its length.
Genotype.—Arcyothrips africanus sp. nov.
From S¢repterothrips this genus differs principally in lacking
the two pairs of strong and very prominent expanded sete
on the vertex and occiput, and in having the postocular sete
minute.
Arcyothrips africanus sp. nov.
(Plate 18, figs. 1-4.)
Female (macropterous).—Length about 1.3 mm. (distended, 1.6 mm.).
Color dark brown with head and tube blackish brown, pterothorax paler along
anterior and posterior margins,! abdomen slightly paler along median line and
distinctly so at base of segment I and in segment IX; head, thorax, and sides of
abdomen with bright red subhypodermal pigmentation; legs concolorous with
body, slightly paler at bases of femora, apices of tibie, and in tarsi; wings pale
brown, the fore pair darker at tip and along anterior margin at base, with a
short black median vein in bend, beyond the vein with an indistinct pale streak
paralleling both margins of wing, pale in about posterior half of basal fourth;
hind wings with dark median vein extending to near tip, this vein nearly black
just before middle, the membrane of the wing nearly white behind it in about
basal fifth and again briefly just before middle where the vein is nearly black,
the wing darkest in its full width between these white areas and in distal portion;
antenne nearly blackish brown, segments IV-VII and sides of II darkest,
III yellow in pedicel and pale yellowish brown beyond.
Head (Pl., 18 fig. 1) about 1.18 times as long as greatest width, broadest
at posterior margin of eyes, the cheeks perfectly straight and converging between
1 T suspect that in life this species, like all of its close relatives, is marked with
white. Such markings are due to the presence in the fat body of an opaque,
light-reflecting substance which disappears after a short time in alcohol or other
preservatives. If this suspicion is correct, the white will certainly show through
the integument along the posterior margin of the metathorax and in the first -
abdominal segment, and possibly also along the front margin of the mesothorax
and in the membrane between the head and prothorax.
116 PROC. ENT. SOC. WASH., VOL. 36, NO. 5, MAY, 1934
this point and one just in front of the slight basal collar, this least width 0.9
the greatest width; dorsum of head somewhat elevated and arched as seen
from the side, with heavy dark lines of reticulation which give the cheeks a
tuberculated appearance, and with a number of short, stout, pale sete (many,
perhaps all, of them rounded at tip) which arise from tubercles situated fre-
quently in the middle of reticles, the reticles themselves often more or less
subdivided by dark incomplete ruge and decidedly smaller along median line
of head; postocular sete very short (about 13 w) and stout, curved and broad-
ened distally; vertex rounded and slightly overhanging, bearing the forwardly-
directed median ocellus at its extremity, without strong sete but with a number
of short curved ones; ocelli about 13 » in diameter, the: posterior pair 43 py
apart, the median one with its posterior margin on a line with anterior margin
of eyes. Eyes small, just one-fourth the length of head, a little longer than
wide, and about two-thirds as wide as their interval, composed of relatively few
facets, extending onto ventral surface of head in a forward, rather than lateral,
direction and thus occupying the front, instead of the sides, of head. Antenne
(Pl. 18, fig. 2) about 1.33 times as long as head, segment VIII completely fused
with VII to form a large lanceolate and pedicellate segment which is the longest
in the entire antenna, no trace of a transverse suture even on ventral surface;
segment III particularly small and weak; II especially large, roughened, and
with subcircular sensorium elevated; III-VI with prominent transverse lines
of sculpture on dorsal surface; sense-cones absent (!) from III, IV with a large
one arising on outer surface of apex and extending beneath the succeeding seg-
ment and a smaller one arising ventrally on inner surface, V and VI each with
a much slenderer cone on each surface and an additional minute one on outer
surface, morphological seventh segment with the usual dorsal one.
Prothorax (Pl. 18, fig. 1) along median line of pronotum nearly 0.6 as long
as head and (inclusive of cox) about 2.3 times as wide as long, without median
thickening, but with a shallow curved impression across middle and a shallow
fovea on each side between midlateral seta and the roundly emarginate anterior
margin, the posterior margin curved; epimeron distinct; surface reticulated
like that of head, with numerous short curved pale sete arising from tubercles,
posterior margin with numerous minute non-setigerous tubercles; major sete
all present, very short (13-20 u), broadly expanded from base and hence some-
what fan-shaped, all arising from slight eminences, epimerals longest (20 yu);
metanotum and posterior part of mesonotum heavily reticulated like pronotum,
the anterior part of mesonotum with asperate anastomosing lines. Legs short
and stout, roughened by numerous low anastomosing rug and setigerous
tubercles; fore tarsus unarmed and without a downwardly-directed claw on
outer surface at apex of first segment. /Vings curving posteriorly in basal third,
then recurving and continuing in the original direction, this distal portion of
wing somewhat more than half the total length of wing and slightly widening
to apex; basal third of fore wing closely tuberculate along anterior margin and
with four or five widely separated sete which are similar to anterior marginals,
equal to them in length, and which arise from tubercles; recurved portion of
wing with a median vein-like thickening, distal portion roughened but scarcely
reticulated; no accessory setz.
Abdomen broadest at segment ITI, distinctly wider than either the pterothorax
PROC. ENT. SOC. WASH., VOL. 36, NO. 5, MAY, 1934 117
or prothorax, with a longitudinal furrow for the reception of the wings, this
furrow at sides in each of terga II-VII with two pairs of conspicuous dark brown
wing-retaining sete, of which the posterior pair is in every case longer, broader,
flatter, and more recurved at base; posterior margins of these same terga each
with three pairs of major set, all of which arise from tubercles and are stout,
pale yellow, and divided at apex, the inner pair longest, the middle pair much
the shortest and fan-shaped, the outer pair similar to the inner but smaller
(on tergum V these sete measure respectively 50 u, 20 wu, and 32 uw); tergum VIII
(Pl. 18, fig. 3) with these sete more slender than on VII, the outer pair longer
than its homologue on VII, the inner pair shorter than its, the middle pair
pointed and with a companion midway between it and outer seta, one pair only
of wing-retaining sete, two pores and five (six normally?) smaller setee between
them (these forming a broad arc), and four pairs of sete in lateral portions of
tergum, the stigmata borne on low tubercles; tergum IX (PI. 18, fig. 3) with the
dorsal pair of major sete stout and 40 uw long, the others slender and pointed;
tergum I much broader than long, trapezoidal, and distinctly polygonally
reticulate with dark lines; tube three-fourths as long as head, slender, formed
as shown in Pl. 18, fig. 3, and three times as long as greatest subbasal width,
its longest terminal sete 133 uw; entire dorsum of abdomen in segments I-VIII
and in basal portion of IX sculptured with anastomosing lines which are much
weaker than those on head and prothorax, but thoroughly distinct even in the
dorsal furrow, heavier, more raised and prolonged into dark aspere at sides of
segments, some of these sharp points projecting beyond posterior margins of
terga II-VII.
Measurements of holotype ( 2 ): Length about 1.3 mm. (distended, 1.62 mm.);
head, length 0.212 mm., greatest width (across eyes) 0.180, least width (near
base) 0.163 mm.; eyes, length 0.053 mm., width 0.046 mm., interval 0.071 mm.;
prothorax, median length of pronotum 0.126 mm., width (inclusive of coxe)
0.293 mm.; pterothorax, greatest width 0.307 mm.; abdomen, greatest width
0.323 mm.; tube (length of segment X only) 0.157, width near base 0.053 mm.,
width at apex 0.025 mm.
Antennal segments: bere 2 eg lh OU Sa ee Se by a
henge thr (2) ee se eee es Dye EXO) SiS} 400) SEB. SVT
Wichita (2) een eee = eo D5 S6) Qihkis8, Sle 28a 28
Total length of antenna, 0.281 mm.
Described from one female taken at Amani, Tanganyika
Territory (East Africa), January 27, 1928, by Dr. C. B. Williams,
from a dead branch [Hood No. 460].
PLATE 17 PROC. ENT. SOC. WASH., VOL. 36
FULT RR
[118 |
PLATE 18
PROC. ENT. SOC. WASH., VOL. 36
[119 }
120 PROC. ENT. SOC. WASH., VOL. 36, NO. 5, MAY, 1934
=) J
EXPLANATION OF PLATES.
(Drawn by Miss Helen E. Rearwin; camera lucida.)
Brare al 7
Stegothrips barronis gen. et sp. nov.; holotype, @.
Fig. 1. Head and prothorax; all sete omitted from legs and antenne; sculpture
of posterior part of cheeks not shown,
Fig. 2. Right antenna.
Fig. 3. Abdominal segments VIII-XI.
Fig. 4. Head and prothorax; perspective view (freehand drawing).
Fig. 5. Right fore wing.
PraTeE 18.
Arcyothrips africanus gen. et sp. nov.; holotype, @.
Fig. 1. Head and prothorax; all setee omitted from legs and antenne.
Fig. 2. Right antenna.
Fig. 3. Abdominal segments VIII-XI.
Fig. 4. Left fore wing.
NOTES ON MOSQUITOES FROM SOUTH AMERICA, WITH A
DESCRIPTION OF A NEW SPECIES
(DIPTERA, CULICIDAE).
By Roperr MarHEson.
In several small collections of mosquitoes made by Dr. J. C.
Bradley, Dr. Babiy and Dr. Forbes in various parts of South
America I find some interesting records of distribution. In
addition I find one quite distinct form not hitherto described.
Aedes albifasciatus Macquart.
Two males fron Ancud, Chiloe Island, Chile. One female
from Butalcura, Chiloe Island, Chile. April 2—7, 1920.
Aedes fulvus Wied.
One female from El Encanto, Putumayo River, near Peru,
Aug. 21, 1920; one female from Iquitos, Peru, Aug. 1, 1920.
Aedeomyia squamipennis L. Arrib.
Putumayo River, Peru, Aug. 7, 1920; Amazon River, near
Peru, Aug. 9, 1920.
Culex taeniopus Dyar & Knab.
Two females, Amazon River, near Peru, Aug. 9, 1920; one
male, Putumayo River, Peru, Aug. 14, 1920.
PROC. ENT. SOC. WASH., VOL. 36, NO. 5, MAY, 1934 121
Culex putumayensis, new species.
Male.—Proboscis slender, black; palpi slender, black, the last two segments
upturned, longer than the proboscis by the last two segments; last two seg-
ments not enlarged and clothed with sparse, fine, blackish hairs. Antennae
almost black, each segment except the last two clothed with dense whorls of
black hairs; last two segments elongate with numerous short hairs. Occiput
brownish with numerous narrow, curved, yellowish scales and erect, forked,
yellowish scales; sides with broad, flat, whitish scales. Prothoracic lobes widely
separated with a few scales and hairs. Mesonotum brownish-yellow, clothed
with very small hair-like, golden yellowish scales with bronzy reflections and
scattered black setae. Scutellum trilobed with long, black hairs and golden
yellow scales on the lobes. Postnotum nude, dark brown. Abdomen densely
clothed with black scales which give a bluish reflection in certain lights; basal
white bands distinct and prominent except on the first and second and the last
two segments; last two segments with prominent white lateral spots; venter
brownish scaled with distinct basal whitish bands on the last four segments.
Legs entirely black, the scales giving a metallic bluish reflection in certain
lights. Wings with broadly ovate and narrow, brownish scales. Halteres with
dark brown knobs, yellowish on basal part.
Hypopygium (Figure 1).—Side-piece somewhat longer than wide, stout,
clothed with scales and long spines; shorter spines on the lower surface. Apical
lobe divided; base of inner lobe columnar, not divided and bears two elongate,
parallel distorted filaments,—one hooked and the other sharply pointed; outer
division columnar and bears a broad, angularly hooked filament, a stout spine,
two peculiar spatulate structures supported on their outer sides by thickened
borders, and a single short spine. Clasper a little more than one-half as long as
Figure 1. Hypopygium of Culex putumayensis. Only
the apical portion of the 10th sternite is shown.
122 PROC. ENT. SOC. WASH., VOL. 36, NO. 5, MAY, 1934
the side-piece, thickly snout-shaped, the snout strongly crested, two setae
below the groove, terminal horn and stout appendiculate spine. Tenth sternites
slender, comb-shaped, each with about seven teeth. Mesosome consists of
two narrow, elongate plates, expanded laterally near the middle but without
teeth. Ninth tergites large, broadly elliptical, approximate, slightly oblique,
and clothed with fine setae on their posterior half.
Female and larva unknown.
Type.—One male from the Amazon River, collected by
Dr. J. C. Bradley, Aug. 7, 1920. Hypopygium mounted on a
slide. U.S. National Museum No. 50353.
Paratypes—TYwo males, Putumayo River, Peru, Aug. 10,
1920. Hypopygia mounted on slides; five males taken on the
Amazon River, near Peru, Aug. 7, 1920. Two paratypes in the
collection of the U. S. National Museum; the others in the
collection of Cornell University.
Mansonia amazonensis Theo.
One male from Bella Horizonte, Minas Gerais, Brazil, Nov.,
1919; one female from Porto America, Putumayo River,
Brazil, Sept., 1920.
Mansonia humeralis Dyar & Knab.
Ucayali River, Peru, July, 1925; Sint Barbara Plantation,
Surinam River, Surinam, Apr. 15, 1927; Kwakoegron and
Ongelijk, Surinam, June 1 and May 1, 1927. Dyar (1928)
records this species from Colombia, Venezuela, British Guiana
and Brazil. Bonne and Bonne-Wepster (1925) record taking
only a single specimen in Surinam.
Trichoprosopon (Joblotia) splendens Lutz.
One female from McKenzie River, British Guiana, June 23,
1927. This species has hitherto been recorded only from Brazil.
A NEW SPECIES OF CIRROSPILUS WESTWOOD
(CHALCIDOIDEA).
By A. B. GaHan,
Bureau of Entomology, U. 8. Department of Agriculture.
The following description is published at this time in order
to make the name available for use by Mr. Frank L. Marsh,
to whom the writer is indebted for the material.
i)
o>)
PROC. ENT. SOC. WASH., VOL. 36, NO. 5, MAY, 1934 1
Cirrospilus inimicus, new species.
This species can be distinguished from others of the genus
only by differences in the details of coloration.
Female.—Length 2.4 mm. Head, except occiput, pale yellow, occiput black;
mandibles reddish at apex; palpi and rest of mouthparts yellow; antennal
scape yellow with a broad black longitudinal stripe on inner side; pedicel and
flagellum black above, more or less yellowish beneath; prothorax black above
and below, the prosternum narrowly bordered with yellow, and the pronotum
with a broad oblong yellow spot at each lateral posterior angle, these spots
broadly separated: mesoscutum yellow except for a large, irregularly semicircular
area at the anterior margin of the median lobe; axillae yellow; scutellum and
postscutellum bronzy black, propodeum entirely black; dorsum of metathorax
black but with two transversely elongate yellow spots which are separated by
the postscutellum; meso- and metathorax entirely black laterally and beneath;
anterior coxae yellow, median and posterior pairs yellow at apex; all trochanters,
all femora and the posterior tibiae yellow; anterior tibiae yellow but with a
blackish posterior margin; median tibiae yellow with a broad, usually in-
complete, black band near the middle; anterior tarsi fuscous, the median and
posterior pairs, except apical joint, yellow; tegulae yellow; wings hyaline, the
venation yellowish; abdomen black above and below, but with the apical half
or more of first tergite and the lateral margins of tergites 2 to 5 yellow, the
black area at base of first tergite triangularly produced caudad at the middle;
ovipositor sheaths black.
Both funicle joints longer than broad, subequal; head without distinct
sculpture; thorax dorsally and ventrally with distinct shallow reticulate punc-
tate sculpture, the axillae smooth and scapulae less distinctly sculptured than
median lobe of mesoscutum; propodeum weakly reticulated, shining, with a
distinct median carina but without lateral folds; abdomen about as long as
head and thorax, with weak reticulate sculpture, the first tergite and yellow
portions of following tergites apparently smooth.
Male.—Length 1.75 mm. Color variable. The allotype specimen largely
yellow with the following black markings. Antennal pedicel above, a large,
semicircular area at base of prescutum, scutellum on apical two-thirds, propo-
deum except for a small spot near each lateral posterior angle and one in the
middle, sutures between mesopleura and metapleura, a moderately broad
submedian band on each middle tibia, a broad apical band on dorsum of
third tergite, all of fourth tergite dorsally and all of fifth tergite dorsally except
for a large rounded spot at each anterior lateral angle. Wings hyaline; venation
pale yellow. Eyes slightly reddish.
The color in both sexes is variable but distinctly more so in
the male than in the female. Some female paratypes have the
head mostly black with only the frons and face yellow. The
prothorax is sometimes entirely black, the coxae of at least
one female are all blackish, and in several specimens the yellow
area on abdomen is greatly reduced. The great majority of the
females, however, agree with the type. Males may have the
124 PROC. ENT. SOC. WASH., VOL. 36, NO. 5, MAY, 1934
head entirely yellow or yellow with a narrow transverse streak
of blackish on the occiput, the prothorax mostly yellow with
the anterior margin black, the scutellum entirely yellow to
entirely black, the propodeum mostly yellow to entirely black,
and the black area on abdomen slightly variable in extent.
Among the females examined length varied from 1.5 to 2.5 mm.
and among the males from 1.4 to 1.9 mm.
Type locality.—Hinsdale, Ill.
Type.—Cat. No. 50149 U. S. N. M:
Described from 23 females and 6 males said to have been
reared from Spilocryptus extrematis (Cresson) infesting Cecropia
at Hinsdale, IIl., August 30, 1933, by Frank L. Marsh.
MINUTES OF THE 455TH REGULAR MEETING OF THE ENTO-
MOLOGICAL SOCIETY OF WASHINGTON, APRIL 5, 1934.
The 455th regular meeting of the Entomological Society of Washington was
held at 8 p. M., Thursday, April 5, 1934, in Room 43 of the new building of the
National Museum. Mr. J. S. Wade, president, presided. There were present
38 members and 37 visitors.
Under notes and exhibition of specimens, Mr. John Smith of New Jersey
discussed the mouthparts of the dragon fly and exhibited a mechanical model
to show how they functioned.
H. H. Richardson discussed briefly some phases of his work on the Phlox
plant bug, Lopidea davisi Knight, and showed lantern slides of nymphs hatching.
Among those present were Dr. J. Chester Bradley, Dr. V. S. L. Pate, and
Major J. A. LePrince. Dr. Bradley, upon invitation, greeted the Society.
Mr. A. B. Gahan presented a note on the identity of two Chalcidoid tick
parasites of the family Encyrtidae, [xodiphagus texanus Howard and Hunterellus
hookeri Howard, stating that at present these were the only known parasites
of the tick.
Dr. S. B. Fracker discussed the influence of the weather during the past
winter on entomological work in various portions of the United States.
The first communication on the regular program was by W. D. Reed of the
Tobacco Insect Laboratory, Richmond, Virginia, and entitled “Infestation of
Turkish Type Tobaccos.”’ Before proceeding with his discussion, Mr. Reed
conveyed to the society the greetings of the following European entomologists:
Dr. C. A. Isaakides, Director of the Benaki Institute, and Technical Advisor
of the Minister of Agriculture of Greece; Nesip Bey, Director of the Scientific
Section, Turkish Tobacco Monopoly, Instabul; Prof. F. Silvestri, Portici,
Italy; Dr. Paul Marchal, Paris, France; and Prof. J. W. Munro and Mr. G. V. B.
Hereford, Imperial College of Science and Technology, London.
During the period July 29 to October 16, 1933, Mr. Reed made a survey of
tobacco districts in Greece and Turkey. This survey was made in order to
determine the distribution and abundance of cured tobacco insects in the Near
East and to cooperate with the importers of Turkish tobacco in working out
satisfactory control measures. The principal insects attacking cured tobacco
PROC. ENT. SOC. WASH., VOL. 36, NO. 5, MAY, 1934 [25
are the cigarette beetle (Lasioderma serricorne Fab.) and the moth (Ephestia
elutella Ubn.).
A short account was given of visits made to various tobacco districts in Greece
and Turkey and lantern slides of the cultivating, curing, and storing of Turkish
tobacco were shown.
A total of 68 tobacco warehouses were inspected for insect infestation. The
warehouses were the property of American tobacco companies, Greek tobacco
merchants, and the Turkish Monopoly.
Infestation was found to be most severe where large stocks of old tobaccos
were stored or where accumulations of scrap tobacco were allowed to remain in
the building. This scrap is a by-product of the manipulation of Turkish tobacco
into the various grades which meet trade requirements.
The warehouses visited were divided into Groups A and B on the basis of the
amount of old-crop tobacco and scrap in the building. Those in Group A, 30
in number, contained none or very small amounts of old tobacco and scrap,
while the 38 in Group B contained large quantities of these tobaccos. In Group
A 235 bales of tobacco were examined and in Group B 188 bales. The data
obtained from these inspections showed the following per cent of the bales
infested:
Group A. Group B.
Ep pe StvGNCIUECL ake) @ Tks eee ees SP) 90.4
Lastoderma serricorne Fab... 26.4 35.6
IMGCTOUAZCOM: HECELOTA (Say) eee 28.1 61.2
Aplastomorpha calendrae (How.)......... re ene 4 5.8
INemeritis canescens (Grav) = 0 5.8
Tenebroides mauritanicus VW. 0 8.0
Pediculoides ventricosus Newp....-------------- 0 2.0
The old tobacco and scrap stored in the warehouses support heavy infestations
of insects and it is likely that this factor is responsible for the heavier infestation
in the storage of Group A.
Microbracon hebetor (Say) and Nemeritis canescens (Grav.) were parasitizing
the larvae of Ephestia, and Aplastomorpha calendrae (How.), the larvae of the
cigarette beetle. Tenebroides mauritanicus L. and the mite, Pediculoides ventri-
cosus Newp., were preying on the larvae of the cigarette beetle. (Author’s
abstract.)
This paper was discussed by Dr. MeIndoo.
The second communication on the regular program was by Dr. F. C. Bishopp,
entitled ““Combating Mosquitoes with an Army of 25,000 Unemployed Work-
ers.” Dr. Bishopp showed numerous lantern slides illustrating the type of
work being done and told some of the difficulties encountered in its execution.
An interesting discussion of this paper was given by Major J. A. LePrince.
Meeting adjourned at 10.25 p. M.
P. W. Oman,
Acting Recording Secretary.
Actual date of publication, May 25, 1934.
VOL. 36 JUNE, 1934 No. 6
PROCEEDINGS
OF THE
ENTOMOLOGICAL SOCIETY
OF WASHINGTON
CONTENTS
GREENE, CHARLES T.——A REVISION OF THE GENUS ANASTREPHA BASED ON
A STUDY OF THE WINGS AND ON THE LENGTH OF THE OVIPOSITOR
SHEA THs (DIPTERA RRVBETUDA'E) 0 aj va say wet as. Ges sR eT ioe IT
WALTON, Ws R.JOHN MERTON ALDRICH, PH.D. 4.4 2s «4 a ms. 0 80
AASOMAN LASTS
A\\WOt AN IAS 7/77 5S
\\ : Tig
193 fl
JO 4 Y
Pus.isHep Montruty Except Jury, Aucust anpD SEP BER) z ~ oF .
‘inner arm of V Numbers 1to6 - longitudinal veins
Anastrepha wing hypothetical )
Fig. 1.—Wing of an Anastrepha, showing characters.
Main pattern: Includes all the color pattern on the basal two
thirds of the wing. There is usually a definite line marking the
outer limits of this pattern, extending diagonally across the
wing just beyond the anterior crossvein.
Stigmal area: This is the space along the costal or anterior
margin of the wing extending from the tip of the auxiliary vein
to the tip of the first longitudinal vein and limited posteriorly
by this latter vein.
Hyaline costal area: This space begins at the tip of the first
longitudinal vein and extends posteriorly across the wing at least
to the second and usually to the third longitudinal vein. In
some species this area continues beyond the third vein and is
continuous with the hyaline area which includes: the second
basal cell. It is absent in a few species.
Interruption on third vein: This term means that the hyaline
costal area is not continuous to the base of the wing to include
the second basal cell. The yellow or brown pattern extends
across the third longitudinal vein, causing an interruption of the
hyaline space at this vein. When the hyaline costal area
extends posteriorly from the costal margin to include the second
basal cell it is then called ‘‘ continuous.”
PROC. ENT. SOC. WASH., VOL. 36, NO. 6, JUNE, 1934 129
Anterior crossvein: A small crossvein near the middle of the
wing, on the upper side of the discal cell, connecting the third
and fourth longitudinal veins.
Apical crossband: Yhe narrow portion of the color pattern
along the apical costal portion of the wing. It is really a con-
tinuation of the main pattern and terminates at the margin of
the wing between the apices of the third and fourth longitudinal
veins.
Curvature of the fourth vein: The apical tip of the fourth
longitudinal vein curves upward to the margin of the wing and
unites with the tip of the costal vein.
Inverted V: This portion of the pattern is shaped like the
letter V inverted. The tips of the arms reach the posterior
margin of the wing. The point at which the two arms join is
called the apex and is usually at the third longitudinal vein or
slightly anterior to this vein. The narrow arm, nearer the tip
of the wing, is called the “outer arm”; the broad arm is called
the “inner arm.”
When the apex of the V is prolonged beyond the third longi-
tudinal vein and connects with the main pattern it is termed
“connected”? (dotted lines in figure 1 show it connected).
When the apex of the V stops at the third longitudinal vein it
is termed “disconnected” because a broad hyaline area separates
it from the main pattern.
For additional information on characters used in this paper
see text figures | to 4, inclusive.
Anas trepha acidusa Walker
_- scute/llum
_dorsocentrals
a
_ecrostichals
~ pos talar
hae Female Abdomen
/ateral view
Thoracic bristles
dorsal view
Fig. 2.—Dorsal view of thorax of adult Anastrepha acidusa, showing bristles.
Fig. 3.—Lateral view of thorax of adult Anastrepha acidusa, showing bristle,
scutellum, postscutellum, and metanotum.
Fig. 4.—Sheath of ovipositor of a female Anastrepha.
130 PROC. ENT. SOC. WASH., VOL. 36, NO. 6, JUNE, 1934
Genus ANASTREPHA Schiner.
Anastrepha was described by Schiner in 1868 (28, p. 263) in
his Reise Novara, page 263. The genotype is Dacus serpentina
Wied.
Head hemispherical; eyes bare; front broad, slightly longer than wide;
surface of front with numerous very short black setae; a vertical row of large
bristles on each side; face vertically impressed on each side beneath the antenna;
epistoma somewhat prominent, no vibrissae, mouth opening large; proboscis
with large labellae; palpi rather broad; antenna with basal joints short, third
joint slender, a little longer than first two together; arista long and slender,
microscopically pubescent. Mesonotum slightly convex, with large bristles
at the sides and a transverse row anterior to the scutellum; scutellum with four
large bristles. Abdomen not much longer than thorax, with five segments;
male genitalia somewhat prominent; abdomen of female projecting style-like;
this projection or ovipositor ranges in length from two-thirds the length of the
abdomen to a length slightly longer than head, thorax, and abdomen together.
Legs rather long; front femora bristled below; middle tibiae with apical bristles;
metatarsi not shortened. Wings large as a rule, with brown bands; apical
portion of auxiliary vein bent forward almost at a right angle, into the costal
vein; first and third longitudinal veins setulose; apical portion of fourth longi-
tudinal vein curved up toward the third and joining with the tip of the costal
vein; small crossvein beyond the middle of the discal cell; anal cell drawn out
to a point on the posterior edge.
This genus is most closely related to 4cidia and Hexachaeta.
The scutellum has four large macrochaetae like the former,
whereas the latter has six macrochaetae. It differs from both
genera in having the apical portion of the fourth longitudinal
vein curved forward to unite with the tip of the costal vein.
This genus is found only in the western hemisphere and occupies
the same position there as the genus Dacus occupies in the
eastern hemisphere.
For students interested in the genus A4nastrepha papers by
Crawford (7), Dampf (8, 9), Darby and Kapp (/0), Greene
(73), Isaac (75), Lima (/8), Mackie (22), McPhail and Bliss
(27), Silvestri (30), and Wille (35) are included in the literature
list, although having more of a biological or economic than a
taxonomic bearing.
The Aldrich Catalog (/) is listed because the genus Avastrepha
is mentioned, although at the time this catalog was published
there were no species known from the United States.
The article by Bezzi (4) was included but the writer was:
unable definitely to place the species mentioned.
é
i)
PROC. ENT. SOC. WASH., VOL. 36, NO. 6, JUNE, 1934 131
TABLE OF SPECIES.
Females.
», [Denis lopetoniiat tele) Soveeaellsy; LoVe, GOONS a ee ee cat te eceeeeccencenecene 2
Naello was PECtes eA ee ah al Fe eS SAE IN ot, a ee ee 5
Hyaline costal area present
Hyaline costal area absent
. Hyaline costal area interrupted just before the third vein; only the
inner arm of the V present, beginning near apex of sixth vein,
extending upward along the posterior crossvein and ending at
the third vein. Ovipositor sheath 3 mm. long. (West Indies,
Trinidad, Mexico, Central America, Peru, Brazil, Ecuador).
serpentina Wied., p. 142
Hyaline costal area continuous to the base of the second basal cell;
only the inner arm of the V present, connected with the main
pattern along the posterior margin of the wing and extending
upward along, and ending just beyond the tip of, the posterior
crossvein. Ovipositor sheath 3 mm. long. (Ecuador).
ornata Aldrich, p. 143
. Wing mostly hyaline; a dark brown band along the costa to the tip
of the fourth longitudinal vein; a dark brown band from the
posterior border following the posterior crossvein to slightly
beyond its tip; a dark band from the base of the wing extending
to the tip of the sixth vein. Ovipositor sheath 2 mm. long.
(BrazileiParaouciy) ee eee cose oe si Ne eR daciformis Bezzi, p. 143
Wing entirely infuscated, much darker in front of the third longi-
tudinal vein; a darkened area at the base of the wing between
the fifth and sixth veins, fading out just beyond the crossvein.
Ovipositor sheath 5.5 mm. long. (Paraguay) _macrura Hendel, p. 143
» Dorsum) offthorax with) onelormore black markings= ses 6
Dorsumiof thorass with omtsrcaniyalolac kementskttn one ey eee 26
Dorsal markings im) the rosmuotia band on stripes =. es ee 7
Dorsal markings in the formyof ajspotor spotss. = 10
With a broad, transverse, dark brown band on the posterior margin
of the thorax. Hyaline costal area broadly interrupted on third
vein; V complete, its apex connected with the main pattern.
Ovipositor sheath robust, three-fourths as long as the abdomen.
(Mexico, Guatemala, Venezuela)... robusta, n. sp., p. 144
Withaventicaladankabrowinns thi cs seen note ees eens See 8
. Four vertical black stripes, the outer ones interrupted at the trans-
verse suture and connected transversely on posterior edge of
thorax. Abdomen with three transverse dark brown bands; last
segment with two large brown spots. Inner arm of V very con-
spicuously large and dark brown; outer arm very narrow, pale
yellow. Ovipositor sheath as long as thorax and abdomen together
(British#londunas) paar ee cordata Aldrich, p. 144
Two vertical black stripes interrupted at transverse suture
132 PROC. ENT. SOC. WASH., VOL. 36, NO. 6, JUNE, 1934
9. Wing pattern dark yellow; inverted V with only the inner arm pres-
10.
11.
12"
3s
14.
iNSe
16.
17.
ent, located on posterior crossvein, extending from the fourth
longitudinal vein to the posterior margin. Ovipositor sheath
robust, one and one-fourth times as long as the abdomen. (Brazil,
Peru, ‘Pataguay kee ie: = cent ood ee ee grandis, Macq., p. 145
Wing pattern yellow with some ae near base of wing; inverted V
with both arms present, mostly brown, disconnected from main
pattern. Ovipositor sheath robust, almost as long as the abdomen.
(Mexico, Central America, Trinidad, West Indies, Bolivia)...
striata Schiner, p. 145
With one spot at middle of posterior edge of thorax... 11
With two or three spots on posterior edge of thorax.........................---.----..-23
Hyaline costal area absent; inner arm of V connected at its apex
and on the fourth longitudinal vein with the main pattern; outer
arm absent. Ovipositor slightly longer than the abdomen.
(Surinam Brazil) eee oe eee eee atrigona Hend., p. 146
Etyaline’costall area. presents. tec ee eee 12
Hyaline area interrupted on third jesewaninel Vell ssn 13
Hyaline area continuous to include second basal cell. 22
Abdominal segments 2, 3, and 4 each with a transverse black band.
Inner arm of V usually extending to third vein; outer arm short,
extending slightly beyond fourth vein. Ovipositor sheath half as
long as head, thorax, and abdomen together. (Cuba, Isle of Pines)
tricincta Loew, p. 146
Abdominal segments without black markings
Costa with a broad, very dark brown band from base of wing to tip
of first vein. Ovipositor sheath as long as last three abdominal
segments combined. (Jamaica)... longimacula, n. sp., p. 146
Gostabnot’as above: 2 te eee ee ee eee
Ovipositor sheath shorter than the abdomen... ---e i enecenenenceeeeeeee
Ovipositor sheath as long as or longer than the abdomen
V connected with main pattern; species of a more golden brown
color; hyaline costal area usually interrupted on third vein.
Ovipositor sheath as long as last three abdominal segments com-
bined. (Puerto Rico, Cuba, Florida) ................. suspensa Loew, p. 147
V not connected with main pattern; species paler yellow... 7
Black spot on dorsum of thorax always present. Hyaline costal
area interrupted on third vein; width of apical crossband never
more than half the length of anterior crossvein; stigmal area with
a brownish tinge. ‘Ovipositor sheath as long as last three abdomi-
nal segments combined. (Peru, Chili)..__.peruviana Towns, p. 148
Black spot on dorsum of thorax usually absent. Hyaline costal area
interrupted on third vein; width of apical crossband about three-
fourths the length of anterior crossvein; stigmal area dark brown
and a little longer than in peruviana. Ovipositor sheath as long
as last three abdominal segments combined. (Brazil, Uruguay,
Petia) fics 7 07 Mie OT peeimee Me ee RO ON, ee tee meee distans Hend., p. 149
18.
19.
i
nN
23.
PROC. ENT. SOC. WASH., VOL. 36, NO. 6, JUNE, 1934
Ovipositor sheath not longer than the abdomen. Interruption on
third vein not more than one half the length of anterior crossvein;
V not connected with the main pattern. Metanotum with a black
sétipe on each side (Pera)... iy pilates net distincta, n. sp., p.
Ovipositor sheath longer than the abdomen...
Ovipositor sheath only a little longer than the abdomen _.
Ovipositor sheath at least as long as thorax and abdomen...
. Ovipositor sheath only slightly longer than abdomen. V not con-
nected with the main pattern; interruption on third vein as long
as anterior crossvein. Metanotum entirely yellow. (Panama)...
panamensis, n. sp., p.
Ovipositor sheath one and one third times as long as the abdomen.
V not connected with the main pattern; interruption on third vein
not more than half as long as anterior crossvein. Metanotum with
a black mark on each side. (Mexico, Texas) .__/udens, Loew, p.
. Ovipositor sheath slender, about as long as the thorax and abdomen
together. Interruption on third vein about as long as anterior
crossvein; V usually connected with the main pattern; inner arm
of V mostly dark brown. (Canal Zone). passiflorae, n. sp., p.
Ovipositor sheath very slender, slightly longer than head, thorax,
and abdomen together. Interruption on third vein nearly equal
in length to anterior crossvein; V not connected with the main
jOMaterea ((Ceyneall 7Aoyate)) ts zeteki, n. Sp., Pp.
. Inverted V incomplete; inner arm dark brown, not connected with
main pattern; outer arm absent or at most represented by only a
brown spot on or near fourth vein. Ovipositor sheath almost as
long as the abdomen. (Guatemala, Honduras, Trinidad)...
leptozona Hend., p.
Inverted V complete, both arms complete, not connected with main
pattern. Ovipositor sheath very slightly longer than the abdo-
mens (Brazil Panama) Oooh 1214 ED similis, n. sp., p.
With two black spots on posterior edge of thorax
With three (rarely two) somewhat elongated black spots on posterior
edge; scutellum with a black latero-basal spot on each side; basal
third of scutellum reddish brown, apical portion pale yellow.
Wing pattern pale yellow; hyaline costal area continuous to include
second basal cell; inner arm of V broadly connected at its apex
with the main pattern; outer arm absent. Ovipositor sheath
slender, half as long as head, thorax, and abdomen together.
(liexa’s, Melon ras) eee Be Biot hh sen bil Sl pallens Coq., p.
133
150
151
151
152
153
154
24. Bristles of thorax reddish; thoracic spots large, rounded. 25
25:
Bristles of thorax black; thoracic spots small, not definitely rounded.
Wing pattern mostly dark brown, sharply defined; hyaline costal
area continuous; VY dark brown, arms narrow, usually not con-
nected. Ovipositor sheath slightly longer than last three abdomi-
naliseo ments (bhai) pean eee hens 2 brazilensis, n. sp., p-
Abdominal segments 3 to 5 each with two dorsal brown spots.
Hyaline costal area continuous to second basal cell; inverted V
154
134 PROC. ENT. SOC. WASH., VOL. 36, NO. 6, JUNE, 1934
30.
Silk
34.
with both arms complete, narrow, reaching to the third vein but
not connected together. Ovipositor sheath slender, almost as long
as abdomen. (Brazil, Paraguay)... _.punctata Hend., p. 155
Abdominal segments without spots. Otherwise like punctata.
(Brazil). eee oe ie henge ano sp pales
Palpi broadly black tans anil care Ovipositor half as long as
head, thorax, and abdomen together. (Bolivia)...
veeeie Hen - PSEUDOPARALLELA
5 | FRATERCULUS ¢ | 10 — townsenpr ¢
PROC. ENT. SOC. WASH., VOL. 36 PLATE 23
1 PALLIDIPENNIS 9 6 SOLUTA ¢
9 scuausi ¢
a CONCAVA ¢
7
=
,
%
@ 7 7
‘ om
ae
ae
=
_—
*
~ |
a’ tS
‘ '-
~ -
omer
at i ‘
Pet Bb
vill
—
PROC. ENT. SOC. WASH., VOL. 36, NO. 6, JUNE, 1934 179
Plate 21.
il. OUEST: hendeli Greene, female (type) (Sao Paulo, Brazil).
We obscura Aldrich, male (paratype) (Trinidad).
3 hamata Loew, male (Brazil).
tripunctata Van der Wulp, female (type) (Mexico).
sylvicola Knab, female (paratype) (Trinidad).
nigripalpis Hendel, female (type) (Bolivia).
bivittata Macquart, female (locality unknown).
ocresia Walker, female (type) (Jamaica).
cry ptostrepha Hendel, female (type) (Peru).
Plate 22.
Anastrepha urichi Greene, female (type) (Trinidad).
oe trinidadensis Greene, female (type) (Tabaquite, Trinidad).
s acidusa Walker, female (type) (Castries, St. Lucia, B. W. I.).
es lambda Hendel, female (type) (Peru).
fraterculus Wiedemann, male (type) (Sao Paulo, Brazil).
flavipennis Greene, female (type) (Boa Vista, Brazil).
ethalea Walker, female (type) (Hermitage, Trinidad).
obliqua Macquart, female (Barro Colorado Isl., C. Z.).
pseudoparallela Loew, female (Trinidad).
tawnsendi Greene, female (type) (Boa Vista, Brazil).
SOR CO IONE ta aaa
SSCS I Loa eS Sh
Plate 23
Anastrepha pallidipennis Greene, female (type) (Medellin, Colombia).
ee barnesi Aldrich, female (type) (Cayuga, Guatemala).
chiclayae Greene, male (type) (Chiclaya, Peru).
integra Loew, female (Trinidad).
concava Greene, male (type) (Cano Saddle, Canal Zone).
soluta Bezzi, male (Sao Paulo, Brazil).
consobrina Loew, female (Brazil).
parallela Loew, male (Sao Paulo, Brazil).
schausi Aldrich, male (type) (Juan Vinas, Costa Rica).
SOM oe ST oe ae co)
180 PROC. ENT. SOC. WASH., VOL. 36, NO. 6, JUNE, 1934
JOHN MERTON ALDRICH, PH. D.
At the 457th meeting of the Entomological Society of Wash-
ington, June 7, 1934, the following announcement was made by
W. R. Walton:
“Mr. President, fellow members, ladies and gentlemen:
It becomes my sad duty to announce to the Entomological
Society of Washington the death of one of its most valued and
beloved members, Dr. John Merton Aldrich, who passed away
on May 27th, at Georgetown Hospital, Washington, D. C.,
after an illness of about three weeks, at the age of 68 years and
4 months.
I shall omit for the present the details regarding his early life
which I feel sure will be carefully collated and recorded by the
Society subsequently, and speak now of Dr. Aldrich principally
as a member of the Federal Bureau of Entomology and of the
Entomological Society of Washington as we knew him.
In 1913, immediately following his separation from the .
University of Idaho, Dr. Aldrich accepted appointment as
Entomological Assistant in the Division of Cereal and Forage
Insect Investigations of the Federal Bureau of Entomology
under the immediate leadership of the late F. M. Webster. He
was assigned to a field station at West Lafayette, Indiana, where,
at the request of Webster, he began in December of that year, a
revision of the North American Sarcophagidae. This work
finally culminated in 1916, in the publication, under the auspices
of the Thomas Say Foundation, of the well-known volume
entitled ‘Sarcophaga and Allies in North America.’ At the
inception of this task Aldrich states in his Introduction to the
book: ‘In the United States since the beginning of any in-
digenous dipterology, about 1880, there has been a virtual
blockade in this group, due to the vast number of old unrecog-
nizable descriptions, of which the types were scattered in
European museums or lost.’
When Aldrich’s ‘Catalog of the North American Diptera’
was published in 1905, ‘it included 106 nominal species of
Sarcophaga of which hardly more than half a dozen were ever
recognizably described.” In the absence of any clear under-
standing of the specific characters in this group, Aldrich truly
PROC. ENT. SOC. WASH., VOL. 36, NO. 6, JUNE, 1934 181
says that ‘this looked like the most hopeless field imaginable.’
However, the completion of his work saw the intricacies of the
complex resolved most satisfactorily into 145 species and
varieties, belonging to 16 genera, in a volume containing some
300 pages and 170 figures, which undoubtedly will stand as a
model of taxonomic excellence for all time to come.
During his service at Lafayette, Aldrich also conducted a
series of biological experiments with several nominal species of
Oscinis affecting small grains which resulted in the revelation
of the presence in America of the European fruit fly Oscinis
frit (Fab.) which had been masquerading under various specific
names for many years although, curiously enough, it has never
become of more than occasional economic importance here.
It was during this period that I first became well acquainted
with Dr. Aldrich although, in common with all students of the
American Diptera, I had known him through his writings and
especially through his monumental and indispensable catalog
of the order. Upon the death of Webster in 1916, when the
administration of the Division passed into my hands, I had
frequent contact with Aldrich, both personally and through
correspondence, as he was then making all routine identifications
of the Diptera for us. In these circumstances, it was not only
astonishing to observe the celerity with which Dr. Aldrich
determined practically all of this material, but I was deeply
impressed by his ever-present desire to furnish his correspon-
dents, many of them personally unknown to him, with all
information that could possibly prove pertinent to their work.
No pains were too great, or no research of the literature so
tedious, as to prevent the transmittal of whatever information
Aldrich considered appropriate to the needs of the case. This
admirable trait of the man persisted with the passage of the
years, as I have within the last few months had occasion to
remark its exercise in the case of a peculiarly involved taxonomic
tangle in the tachinid parasites of the European corn borer. In
this case Aldrich had not only resolved the snarl to its last
convolution but, in the written discussion of it, he had even sent
to our field men copies of his correspondence with European
authorities in the group in order that no vestige of doubt should
remain regarding the matter.
I well remember my feeling of extreme gratification when, in
182 PROC. ENT. SOC. WASH., VOL. 36, NO. 6, JUNE, 1934
the early months of 1919, Dr. L. O. Howard told me in private
that he was seriously considering the nomination of Dr. Aldrich
for the position of Associate Curator of Insects in the U. S.
National Museum and I then expressed the opinion that none
could fill the position with greater ability and honor than he.
Shortly after his arrival in Washington that year, Aldrich
began to interest himself in the affairs of our Society and very
soon to publish in our Proceedings. His longer papers were, of
course, included in the regular series issued by the Museum but
those of lesser length usually came to us. Thus no less than 25
such articles have been contributed to the Society during the
past 14 years. In addition to these generous contributions,
Dr. Aldrich served the Society as its First Vice President in
1925, and in 1926 was elected President, filling the office with
his usual efficiency and kindliness. He was a constant and most
welcome contributor to the informal discussion of many papers
presented before the Society as well as to our program; in point
of fact, he was to have had a place on it this very evening.
As a taxonomist in the American Diptera Dr. Aldrich was the
peer of any who had preceded him, and I feel confident in saying
that none survives who possesses his breadth of knowledge of
this complex. In his work he had accepted Osten Sacken and
Williston as his models and in this choice he could not have done
better. His descriptive work possesses a quality that is ex-
ceptional and his command of good English was indeed re-
markable. All who knew him well will remember with wonder
his amazing ability to converse on his beloved order almost
‘ad infinitum’ and at great speed, without faltering an instant
for a shade of expression or a technical name. Dr. Aldrich, to
the end, maintained his boyish enthusiasm and I can not refrain
from quoting as an illustration of this a note received from him
in 1931 which then impressed me as so characteristic that it
was preserved. It was as follows:
‘Dear Walton: I seized the opportunity to send over a
page of manuscript by Joe [Wade] yesterday, but it was a
little premature, as, in the first draft, I found I had not
covered the ground properly. So now I shall have to ask
you to substitute the two pages enclosed for the one page
sent yesterday. J feel quite jubilant to have at last found out
what Eurycephalomyia is, it having been an enigma since
88/1!’ (The italics are mine.)
PROC. ENT. SOC. WASH., VOL. 36, NO. 6, JUNE, 1934 183
Although he was then 65, and had been working continuously
with the Diptera for at least 40 years, he still found delight in
adding another morsel of knowledge to his already plethoric
store. What further proof is wanting that Aldrich had indeed
found his exact vocation in life?
The sound quality of Dr. Aldrich’s work is universally ac-
knowledged and, although always in a conservative vein, it 1s
never reactionary. He kept abreast of the times in taxonomic
advance, and, especially in recent years, when he devoted a
large part of his attention to the taxonomy of the muscoidean
flies, he provided a stabilizing influence which not only was
greatly needed in this field but which will now be sorely missed.
In addition to a vast store of knowledge of the Diptera and their
literature, Dr. Aldrich possessed that rare and most desirable
quality in taxonomic work, the judicial mind. This enabled
him to view his problems uncolored by personal feeling, and in a
detached and dispassionate manner that was ever admirable.
Thus, even in the heat of argument, so inseparable from this
type of research, we find him scrupulously courteous and polite
toward his opponents.
Although we, who mourn his loss, can not refrain from feeling
that his end was both premature and untimely, John Merton
Aldrich bequeathed to us a great work well done, and a scientific
heritage of which entomology may well feel proud.”
A more extended biography, together with a portrait of the
late Dr. Aldrich, will appear in a subsequent issue of these
Proceedings.
184 PROC. ENT. SOC. WASH., VOL. 36, NO. 6, JUNE, 1934
MINUTES OF THE 456th REGULAR MEETING OF THE ENTO-
MOLOGICAL SOCIETY OF WASHINGTON, MAY 3, 1934.
The 456th regular meeting of the Entomological Society of Washington was
held at 8 p. m., Thursday, May 3, 1934, in room 43 of the new building of the
National Museum. Mr. J. S. Wade, president, presided. There were present
28 members and 10 visitors. The minutes of the previous meeting were read
and approved.
Under “Notes,” Dr. J. M. Aldrich read a letter from E. P. Van Duzee, of the
California Academy of Science, calling attention to the recent death of M. C.
Van Duzee, one of the leading authorities on Dolochopodidae. Van Duzee’s
collection of flies of that family has been purchased by the California Academy
of Science.
Dr. Aldrich also called attention to the report of the committee on graduate
instruction of the American Council on Education, and read the list of institu-
tions considered by the council as being qualified to give doctorate degrees in
Entomology.
This note was discussed by Ewing.
The first communication on the regular program was by Dr. F. W. Poos, and
entitled “Notes on the genus Empoasca.” Dr. Poos gave a brief review of the
more common species of the genus and the plants which they affect. He also
showed slides with drawings illustrating the structures by which the species
are separated taxonomically, charts giving a comparison of the life histories of
some of the species, and pictures of the disease-like injury to legumes that is
caused by Empoasca fabae.
This paper was discussed by Cushman and MclIndoo.
The second communication on the regular program was by W. B. Wood,
entitled “Plant Inspection.” Mr. Wood limited his remarks to the inspection
of introduced plants, most of which come into the country for propagation in
nurseries or for experimental work by the Department of Agriculture. Most
of the stock for propagation comes from European nurseries and because of
the money invested it must be handled with extreme care during inspection
and treatment. Treatment most frequently consists of fumigation with cyanide
gas or carbondisulphide, often in connection with vacuum. Heat, hot water,
and moist air are also used, depending upon the nature of the infestation or
disease and the plants involved.
This paper was discussed by Cushman.
The third communication on the regular program was a paper by N. E. Good,
entitled ‘‘ Biology of the flour beetles of the genus Tribolium.” Mr. Good gave
a comprehensive discussion of the seven species of this interesting genus, three
of which occur in the United States and two of which are almost cosmopolitan.
The most widely distributed species are practically omnivorous, living on all
kinds of seeds if the hull is broken. The genus is of particular importance as a
pest of stored grains.
This paper was discussed by Hyslop.
Meeting adjourned at 10:05 p. m.
P. W. Oman,
Recording Secretary.
Actual date of publication, Fuly 9, 1934.
VOL. 36 OCTOBER, 1934 No. 7
PROCEEDINGS
OF THE
ENTOMOLOGICAL SOCIETY
OF WASHINGTON
CONTENTS
SHANNON, RAYMOND C. AND PUTNAM, PERSIS—-THE BIOLOGY OF STEGO-
MYIA UNDER LABORATORY CONDITIONS: I. THE ANALYSIS OF FACTORS
WHICH INFLUENCE LARVAL DEVELOPMENT Alaa. EE Re ALO
PUTNAM, PERSIS, AND SHANNON, RAYMOND C.—_THE BIOLOGY OF STEGO-
MYIA UNDER LABORATORY CONDITIONS: II. EGG-LAYING CAPACITY
AD) HOGI AGSE Oly NDING) og a! no wigs Gb e ow sc pesca 7
PusiisHED Montuiy Except Jury, AucusT AND SEPTEMBER
BY THE
ENTOMOLOGICAL SOCIETY OF WASHINGTON
U. S. NATIONAL MUSEUM
WASHINGTON, D. C.
Entered as second-class matter March 10, 1919, at the Post Office at Washington, D. C., under
Act of August 24, 1912.
Accepted for mailing at the special rate of postage provided for in Section 1103, Act of October
3, 1917, authorized July 3, 1918.
THE
ENTOMOLOGICAL SOCIETY
OF WASHINGTON
Orcanizep Marcu 12, 1884.
The regular meetings of the Society are held in the National Museum on the
first Thursday of each month, from October to June, inclusive, at 8 P. M.
Annual dues for members are $3.00; initiation fee $1.00. Members are
entitled to the ProcEEDINGSs and any manuscript submitted by them is given
precedence over any submitted by non-members.
OFFICERS FOR THE YEAR 1933.
FAGHOLGHY EV ESAGCHT. oe ccy cys, Peer eae eee .. -L.'O. HOWARD
Presidents se du Bo Miele) 6 La en ee ee J. S. WADE
JE AGS VAG Ba 2 6 4 0 8 - toe ke os ee ee os De ee a
Seconda ice-Presiacnt ©. 8. 53 oe io ee ee ee S. B. FRACKER
Recording Secrelary /.. a. e's a eee ay © ee P. W. OMAN
Corresponding Secretary-Treasurer. . . 1... +24 S. A. ROHWER
Bureau of Entomology, Washington, D. C.
PDRLOP aoc ebteyoy te eee) oe Ae hein Eee ae W. R. WALTON
Bureau of Entomology, Washington, D. C.
Executive Committee: Tue Orricers and W. H. Larrimer, H. E. Ewine,
F. L. CampseE-t.
Representing the Society as Vice-President of the Washington Academy of
SCLCHNCES RA Pn ete ES? cate Pn cr ar eaten amt a anes H. MORRISON
PROCEEDINGS
ENTOMOLOGICAL SOCIETY OF WASHINGTON.
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PROCEEDINGS OF THE
ENTOMOLOGICAL SOCIETY OF WASHINGTON
SJ
VOL 536 OCTOBER, 1934 No.
THE BIOLOGY OF STEGOMYIA UNDER LABORATORY
CONDITIONS. !
By Raymonp C. SHANNON AND PeErsis PuTNnam.
I THE ANALYSIS OF FACTORS WHICH INFLUENCE LARVAL
DEVELOPMENT.
The main features relating to the life history of 4edes (Stego-
myia) aegypti are well known. When we attempt to define
conditions of nurture, however, we find that a state of confusion
exists. Buxton and Hopkins (1927) have said: “‘One frequently
wants a number of larvae for experimental purposes, all of
precisely the same age. In our present state of ignorance one
can only secure these accidentally by putting a lot of eggs
into suitable water; three-quarters may hatch in an hour, or
none may hatch in the first week.”
The contradictions in the results of laboratory work may have
resulted from different environmental conditions or from the
fact that the cultural methods practiced did not give uniform
and favorable results. Some of the difficulties may have arisen
from the use of different strains. The material, for example,
that Roubaud (1927-29) used in his experiments may belong
to a different strain than the Brazilian material used by us,
which may account for the different rate of hatching he obtained.
Preliminary experiments (R. C. S.) which are being made on
the Greek strain indicate that its incubation requirements differ
from those of the Brazilian strain.
In the course of two years in the Yellow Fever Laboratory
in Bahia, Brazil, some of the causes of variation have been
determined, and through their elimination a standard method
of breeding has been devised, especially adapted to the normal
conditions prevailing in tropical laboratories. This method
must of necessity differ from those in practice in temperate
climates, e. g., at the Wellcome Entomological Field Laboratory
(MacGregor, 1931) and at the London School of Tropical
Medicine (Lesson, 1932).
The method devised has been thoroughly tested through two
1The studies and observations on which this paper is based were conducted
at the Yellow Fever Laboratory, Bahia, Brazil, with the support and under the
auspices of the International Health Pivision of The Rockefeller Foundation.
186 PROC. ENT. SOC. WASH., VOL. 36, NO. 7, OCT., 1934
years of daily routine breeding during which several hundred
thousand mosquitoes have been reared, constituting the type
of material referred to as “standard stock” in various papers
published from this laboratory. The individuals reared by this
formula maintained a uniform rate of development in all stages.
Mortality was low, and the adults attained what appeared to
be maximum size and vigor for the species. Excellent material
of known age in desired quantity was thus easily available.
The detailed observations of large numbers of specimens
made routinely throughout the period of development furnished
excellent data for statistical analysis. We are able, conse-
quently, not only to discuss the basis and technic of the method
and its application, but also to describe the results biometrically
and to evaluate some of the factors which influence them.
The literature dealing with the biology of stegomyia is very
extensive and scattered. Reference here will be limited to a
few of the earlier and a few of the later papers. It may be
stated, however, that most of the experiments to be described
have been covered by others in the papers cited.
The essential phases of the biology were worked out by the
American Yellow Fever Commission in Cuba (Reed and Carroll,
1911). The minimum duration of the early stages of develop-
ment, as indicated by Reed and Carroll, was nine and one-half
days: incubation, two days; larval stage, six days; pupal, 36
hours. Goeldi (1905) obtained a minimum of four days for the
larval stage, with males emerging on the fifth day. The duration
of*egg and pupal stages as given by Reed and Carroll, and of
the larval stage as given Pek Goeldi represent the minimum
obtained by us.
MacGregor (1931) states that the strain of aegypti used at
the Wellcome Entomological Field Laboratory, when kept at
30° C. produces successive generations on the average of every
10 to 15 days throughout the year. He does not mention egg-
production, larval mortality, or size and longevity of adults.
Martini (1924) observed that mosquito larvae when subjected
to warm temperatures produced smaller sized adults than those
kept at cooler temperatures. It is probable, therefore, that
MacGregor’s strain was rather dwarfed.
The development and behavior of stegomyia under laboratory
conditions will be discussed from two points of view: as observed
under normal or standard conditions, and when subjected to
special influences which may materially retard or alter their
course. A third point to be mentioned will be the appearance ,
of a natural phenomenon of unknown origin adversely affecting
development.
PROC. ENT. SOC. WASH., VOL. 36, NO. 7, OCT., 1934 187
STANDARD DEVELOPMENT.
Equipment.
All equipment is of a very simple nature and was originally
installed by Bauer and Davis in August, 1928.
1. Breeding cages Screened cages of about one-half cubic meter capacity
will readily accommodate from 100 to 250 female mosquitoes and an equal
number of males. This number of females will supply from 500 to 1,000 eggs
daily. Fresh adults are added once a month. An immobilized guinea pig is
supplied every third or fourth day, and a dish with raisins is kept in the cage
continuously. Receptacles for the eggs consist of flat pans containing a layer
about one inch thick of wet cotton covered with filter paper.
2. Larval rearing jars—Any type of uncovered dish or jar with a capacity
of one liter suffices.
3. Pupal tubes —Wassermann tubes are used to isolate the pupae. These
are plugged with cotton and stored in wire racks.
4, Experimental cages for adult females.—These are 12 by 12 by 16 inches,
with screened sides and an attached cloth sleeve.
Procedure.
Conditioning of the eggs.—At the time of oviposition the embryo has not as
yet begun to form. The eggs are, therefore, kept im situ on the egg pans and
placed in the open air to dry slowly. It requires from two to three days at
temperatures from 25° to 27° C. for the embryo to form and to reach a state
for immediate hatching. Below 25° the time is longer, and at 23.5° the eggs
should be allowed to stand for at least four or five days. After eggs have been
kept on moist filter paper for several days they may be dried and, if used within
a month, serve as well as freshly conditioned eggs for routine rearing.
For hatching the eggs—Properly conditioned moist eggs, when submerged
in water with food, will hatch within 10 minutes’ time. If floated, eclosion is
irregular, requiring one to five days or more.
Rearing of the larvae—I\t was found that minimal larval development and
mortality were obtained when lots were limited to 150 eggs or less. Conse-
quently, our practice is to use 100 eggs per jar although the number may be
increased to 150 or 200 without adverse results.
Ordinary tap water and about 2 cc. of dried bread may be used exclusively.
Dried blood serum in place of bread or a combination of both will also serve.
Bacteria quickly develop in the water, and the larvae appear to be fully nour-
ished.
Care of the pupae-——Each morning the pupae are removed by means of a
large-bore pipette and isolated in individual Wassermann tubes.
Care of the adults —The tubes are examined daily for adults. The males are
discarded and the females placed in the experimental cages. These are provided
with two petri dishes, one containing wet cotton, the other honey overlaid with
filter paper.
Laboratory labor required.—One well-trained laboratory assistant can perform
all the routine work, handling as many as 200 pupae and an equal number of
188 PROC. ENT. SOC. WASH., VOL. 36, NO. 7, OCT., 1934
adults in four to five hours. Occasionally the assistant has handled fully a
thousand of each in a day.
Two experiments will now be described and their results
analyzed to illustrate what may be expected through the
application of the standard method. The first was carried out
under routine laboratory conditions, and the second under
what might be considered optimum conditions.
Development of Stegomyia Larvae under Routine Laboratory Conditions.
In this experiment a lot of 100 properly conditioned eggs in
a rearing jar was set aside each day for 61 consecutive days.
Daily records of pupation and emergence were kept for each
jar. Temperature was recorded at 8:00 a. m. and 4:30 p. M., and
a mean was computed for each day. No record was made of
eggs that did not hatch, so that larval mortality as recorded
includes that for both eggs and larvae. Time was counted
from the day on which the eggs were placed in the jar. Table 1
contains the daily pupation records for each jar and the mean
pupation day for each lot. It also contains a seven-day average
temperature, which will be described here.
TABLeE 1.
DEVELOPMENT OF STEGOMYIA LARVAE UNDER RourTINnE LaBorATORY CONDITIONS.
Daity Pupation Recorps or Lots or 100 Ova.
NUMBER OF PUPAE ON
MEAN PUPA-|MEAN TEMPERA-
SUBSEQUENT DAYS TION DAY | TURE (Cc) FOR
one OF __—————|roral] or tor | 7-DAY PeRie
See eS aPl bali clic vin S.2 NASI aL aE fg Gas
1930
Sept. 13 TN EZ A 5s. | 90 9.57 23.8
14 4 OF G25 2S ales 7 2 83 10.23 23.6
15 DW lL es} 1 99 7.80 23.6
16 Ll) AU) PB SO Nh Ve! 2 2 89 Qe 23.6
itd 8 5206 76 HAS 23.4
18 14 | 66 9) 2 91 7.49 2383
19 39 | 49 1 89 70% 23.4
20 129) 384) 33 83 Galle 23e5
21 P| 58h |) 2 5 91 Foil 23,
22 O) || Ssh) 240) |) se. |] ala 2 92 Y) 33s) 23)
ws ANY | US || 5 68 6.87 2889
24 10 2 OR AS ana 4 1 98 8.66 He) se)
25 SON 255 8 4 1 98 8.39 Whe
26 56 |) Sa] S 1 95 6.99 PST)
2 (Os) || 32 1 98 6.85 23.7
28 1/959) 6 1 1 94 7.56 23.6
29 10 | 40 | 28 4 2 84 7.88 230
30 SPN SI) jf hy alk 95 7.01 23.6
[TasLe 1 continued on next page.|
PROC. ENT. SOC, WASH., VOL. 36, NO. 7, OCT., 1934
TaBLe 1—continued.
DEVELOPMENT OF STEGOMYIA LARVAE Unper Routine LABORATORY
Datty Pupation Recorps oF Lots or 100 Ova.
189
ConDITIONS,
MEAN TEMPERA-
TURE (C) FOR
7-DAY PERIOD
NUMBER OF PUPAE ON
MEAN PUPA-
SUBSEQUENT DAYS ‘4
pare of] —_—___ en ———Jrorai| or tot
i Berkel Se eS leon ete tao! LS
Oct. 1 57a tou) a Teh 677
D DONCotulioy | I 96 7.42
3 36) 500 7 3 96 7.29
4 ia Ale eee S 94 OD
ESP heal sil ad Nee 91 6.98
Gimplsles7 | 328) 2 1 93 6.92
FN s3NeG6. | 20 89 6.69
Simo shoal 4) 9 57 Pails.
9 Sar sieh3 87 6.93
10 BB i35/ 1 2 90 6.93
11 18 (637/830) 12 100 9.89
12 10050! he Glad 1 68 WB
13 FON) 1 od 1 85 6.76
1432 || 48.1 3 83 6.15
15127 | 69 13 99 6.26
1G S71 35-| 7 79 6.12
17) 3156 | 29 | 4 1 93 6.91
18| 21 | 62 | 11 94 6.39
19) 99)| 51 | 413 86 6.40
D0 1269) || D4 D 97 6.79
21 Bil 44 | 29") 12 93 7.98
22 Goel ooalesall 2 99 6.94
23| 40/10] 1 51 5.74
24| 53 | 34 87 5.89
25 40° | °42"|) f0-| 3 95 TNs
26 61) 3924 Onl e2ei te| A 83 8.14
Si Saale alle EU) eas 84 7.05
28| 14 | 67 | 6 87 6.41
59 ti’ | 67 | 4 82 6.41
BOO) 47 Vat | 78 6.42
Ses SR ease |e 91 7.09
Non IN) al Shi 2Ysy |] a3} 1 91 Wohl
DS! VSIA Sule 89 6.62
BSH (248 le oGalecd 92 6.18
4| 26 | 46 72 6.14
SS os) 82 6.09
Pel e210) 66.4) eT A. 95 6.37
Te 56 (16 || 14 86 6.01
Cll Ge MeO S| 96 5.92
lieteiea e591") 20 Dia) 95 6.69
LOSS AT AL Suk 1 90 6.26
Malte) 50m) Sel.) 2 716 6.58
TOD 7 52 Ves 2 89 6.33
Total | 629 |2237/1508] 542|} 242/120] 49 | 14] 2 | 5343 7.16
in) i)
Os Nn He
BOIAMANNAN HOW WOOO 0 C00 OND DAD NUNN WOOD HANWN HOW DWDYIIDNW OS
N
Nn
Oo
190 PROC. ENT. SOC. WASH., VOL. 36, NO. 7, OCT., 1934
The mean pupation period or duration of larval stage, for all
individuals in the 61 lots was 7.16 + .0O1 days. It seems de-
sirable, therefore, to convert the daily temperature averages
into a mean for a period that would approximate the interval
required for the pupation of the individual lots. The seven-
day moving average computed for any date in the table is the
mean of the temperatures on seven days beginning with the
date indicated.
28
27
26
25
Mean = 25.02° + 0,09° c,
24
Temperature in Degrees Centigrade
23
22
13 20 27 4 Uy 18 25 1 8
Sept. Oct. Nov.
First Day of the Week for which the Average Temperature was Computed
Figure 1.—Development of Stegomyia Larvae under Routine Laboratory Conditions.
Seven-day Average Temperature, September 13-November 13, 1930.
Figure 1 shows the time trend of these moving averages.
It is evident that there was a steady rise in temperature during
the period of the experiment, with relatively slight deviation
from a straight line course. We may now compare the mean
pupation period, or duration of larval stage, for each lot with
its corresponding temperature average. This has been done in .
Figure 2.
PROC. ENT. SOC. WASH., VOL. 36, NO. 7, OCT., 1934 191
15
14
13
al
alt
10
9
8
te
b
4 6
=|
ed 5
ne]
°
od
o
Ay a
§
3 Rate of decrease in mean pupation period per Ono KCe
8 3 rise in temperature = 0.76 + 0.08% days
a
:
a
23 24 25 26 27
Temperature Centigrade (Seven-day moving average)
Figure 2.—Decrease in Pupation Period with Rise in Temperature in Routine Labora-
tory Studies of Stegomyia Development.
(Each symbol represents the pupation period for a lot of 100 stegomyia ova.)
It was found that if the mean pupation periods were plotted
on a logarithmic scale against the temperature on an arithmetic
scale, a definite decrease in larval stage with rise in temperature
appeared. Figure 2 shows the character of the relationship
with the aid of the fitted regression line. From the equation
2 The equation for the line was:
Log (mean pupation period in days) = log 8.1247 + log 0.9924 . temperature.
(Temperature was expressed in units of one for each 0.1° from 23.2° C. as origin.)
192 PROC. ENT. SOC. WASH., VOL. 36, NO. 7, OCT., 1934
for the line we obtain the mean rate of decrease in pupation
period per rise of 0.1° in seven-day temperature average. The
rate was 0.76 + 0.08 per cent days which, though slight, was
nearly ten times its probable error and hence statistically sig-
nificant.
By means of the equation for the line it is possible to compute
an expected mean pupation period for a given seven-day temper-
ature average. For example, at 27° C., when temperature is
considered more favorable for rearing, the computed duration
of larval life would be 6.08 + 0.07 days. We shall see presently
how well this period compares with actual results of rearing at
this temperature.
Table 2 contains the mean number of days to emergence of
adult stegomyia males and females from these 61 lots. The
decrease in these averages with rise in temperature is shown in
Figures 3 and 4. The rate of decrease was the same in each
case: 0.74 + 0.07 per cent days per 0.1° rise in average tempera-
ture. The important difference here was the higher level of the
emergence periods for females. Means for all individuals
were as follows:
Mean Emergence Periods.
emval ese. -se2 9.64 + 0.02 days
Mirai estan eee 9.05 = 0.02 days
Difference... 0.59 + 0.03 days
The emergence period of females was approximately 14 hours
longer than that for males.
’ Regression equations:
Log (male emergence period in days) log 10.2412 + log 0.9926 . temperature
Log (female emergence period in days) log 10.8176 + log 0.9926 . temperature
(Temperature was expressed in units of one for each 0.1° C. from 23.2° C. as
origin.)
PROC. ENT. SOC. WASH., VOL. 36, NO. 7, OCT., 1934 193
TABLE 2.
DEVELOPMENT OF STEGOMYIA LARVAE UNDER RourINE LABORATORY CONDITIONS.
Mean Day or EMERGENCE OF MALES AND FEMALES.
MEAN DAY OF |MEAN TEMPER- MEAN DAY OF |MEAN TEMPER-
DATE OF EMERGENCE ATURE (C) ||DATE OF EMERGENCE ATURE (c)
SD AY |= ee |) EORISEVEN=«|\ST DAY =-scan cel Ge | EORESE VEN
MALES |FEMALES| DAY PERIOD MALES |FEMALES| DAY PERIOD
1930 1930
Sept. 13} 11.68 12.46 23.8 Oct 15) 78.38 8.67 25.6
14, 12.03 | 13.48 2376 IG) Wore 8.50 D558
15]) 1O07 |) 10.88 23.6 7 SoS 9.48 25.8
1G) Wiss |) Aoi 23.6 1S}, Booz 8.84 DSI)
U7) Dots |) 10.08) 23.4 ID) Basil 8.59 D5
18} 9.84 9.98 WBi8) 20} 8.57 9.17 Dot
UH Passi ORS 23.4 21) 10.04 10.14 DSi.
DO |i GE6S | Ong 2855) 22} 8.87 8.99 DS 6
pA ees} 10.46 Wah 28 750 8.50 2526
DP WSS. |) PAS Whe Tl DAS e9 8.29 DS ol
PEM QO 9.17 2379 25] 9.05 9.70 25R8
24; 10.72 | 11.44 IBY) 26} 9.98 10.32 25.8
25\) 1Oe55 11.04 23.8 D7) Bots! 9.30 25.8
26) Ges 9.68 Die Hl 28) 8.01 hs 5 25.9
DT eis) 9.46 23m) 29) 827 8.61 25.9
28) 9.48 ORS2 23.6 SO} thasia/ 8.61 25n9
DS), O63) || IOLeY 23.6 31} 8.84 ©) 118) 25n9
30} 8.76 32 23.6 Nov. 1] 9.06 9.65 259
Oi, i), Boz 9.09 24.0 Dl 322 9.03 25.9
AN 28} 9.63 24.3 3) 7296 8.55 25.9
SH 92) 9°76 24.5 4) 7.67 8.08 26.1
re 0) 9.87 24.6 a fold 8.01 26.2
5 2) 9.39 24.7 6) 7.88 8.50 2665
6) 8.74 9.38 24.7 MW Boll 8.77 26.6
MN B.a9 ells 24.8 8] 7.60 8.26 26n5
8} 9.08 9.37 24.8 9} 8.40 9.01 26.6
D800 8) 3Y) 24.8 IQ) oa? 8.57 26m
10| 8.74 9.26 24.9 if 8 Seon, 26.5
Hilf TSS Po 533) Doh 1A 727 8.78 26.4
12 OE 24 9.81 DSP
13} 8.40 9.01 2553 Toll || O05 9.64 25.0
14, 7.79 8.67 2555
194 PROC. ENT. SOC. WASH., VOL. 36, NO. 7, OCT., 1934
15
14
13
12
11
10
¢)
1
”
£6
q
of 5
a]
°
od
o
4
8 Rate of decrease in mean emergence period per O21 7 7G
a rise in temperature = 0.74 + 0.07% days
: 3
Fi
i)
=a
23 24 25 26 27
Temperature Centigrade (Seven-day moving average)
Figure 3.—Decrease in Emergence Period for Males with Rise in Temperature in
Routine Laboratory Studies of Stegomyia Development.
(Each symbol represents the emergence period for a lot of 100 stegomyia ova.)
PROC. ENT. SOC. WASH., VOL. 36, NO. 7, OCT., 1934 195
. fC)
Rate of decrease in mean emergence period per Ol C.
rise in temperature = 0.74 + 0.07% days
Mean Emergence Period in Days
23 24 25 26 27
Temperature Centigrade (Seven-day moving average )
Figure 4.—Decrease in Emergence Period for Females with Rise in Temperature in
Routine Laboratory Studies of Stegomyia Development.
(Each symbol represents the emergence period for a lot of 100 stegomyia ova.)
The interval between mean pupation and emergence periods
for males and females was as follows:
Males. Females.
Bimergence=. 9.05 + 0.02 days Emergence............9.64 + 0.02 days
Rupation 7.16 + 0.01 days Pupation == 7.16 + 0.01 days
Difterencele. = 1.89 = 0.02 days Pe Ditterences =a 2.48 + 0.02 days
196 PROC. ENT. SOC. WASH., VOL. 36, NO. 7, OCT., 1934
Under routine conditions, therefore, the interval from pupation
to emergence of males was approximately 45 hours and for
females 60 hours.
The frequency distributions of individuals in all lots according
to day of pupation and of emergence are shown in Figures
5 and 6. These figures show more scattering of the observations
to the right of the means than to the left.
2500
2000
oO
& 1500
é Mean = 7.16 + 0.01 deys
a
° Standard deviation
1.218 + 0.008 days
E
Zi 1000
500
“YY
(0) Le L, Yi // EID. —
TOF Sai ae 13
Figure 5.—Development of Stegomyia Larvae under Routine Laboratory Conditions.
Period from Eclosion to Pupation.
PROC. ENT. SOC. WASH., VOL. 36, NO. 7, OCT., 1934 197
1500 Males
a”
2 1000
s
Hw
° Mean = 9.05 + 0.02 days
u
oO
F Y Standard deviation
Z 500 Yj; g 1.254 + 0.012 days
GY Z Y
YY —Y
y Hj
0 J U4 V4 y YY YEE Zo
lo} ub CO 4 5 6 lg 43) 4
Vs]
© 1000 Females
a
Oo
fe
9
‘ Mean = 9.64 + 0.02 days
2 500
g Standard deviation
a 1.308 + 0.013 days
Days from Eclosion to Adult Emergence
Figure 6.—Development of Stegomyia Larvae under Routine Laboratory Conditions.
Period from Eclosion to Emergence.
Ege and larval mortality in the 61 lots was 12.41 + 0.29
per cent, since 757 individuals failed to pupate from the 6100
eggs set aside. Among pupae 364, or 6.81 + 0.23 per cent,
died before emerging.
The mean temperature for the entire period computed from
the seven-day averages was 25.02 + 0.09° C.
Development of Stegomyia Larvae under Optimum Laboratory Conditions.
In this experiment five lots of 100 eggs each were bred under
optimum laboratory conditions. These were the most favorable
conditions existing in the Bahia laboratory and were doubtless
as favorable as any occurring in nature in Brazil. The eggs
had been kept eight days on damp filter paper, and eclosion
198 PROC. ENT. SOC. WASH., VOL. 36, NO. 7, OCT., 1934
was effected in from 10 seconds to 10 minutes. All but about
five per cent hatched. This experiment was carried out at
midsummer temperatures averaging 27° C.
Table 3 contains the pupation and emergence records for
this experiment, and Figures 6 and 7 show the frequency poly-
gons. The mean period of pupation for these lots was 6.40
+ (.02 days, which was 18 hours less time than that required
for the 61 lots reared under routine conditions. Furthermore,
pupation was completed on the ninth day, and was limited
almost wholly to the fifth to seventh days.
TABLE 3.
DEVELOPMENT OF STEGOMYIA LARVAE UNDER Optimum LABORATORY
ConDITIONS.
Lots or 100 Ova at 27° C.
DAILY PUPATION RECORDS (NUMBER OF PUPAE)
DAYS SINCE ECLOSION
LOT MEAN INTERVAL
5 6 7 8 9 LOM 1 TOTAL IN DAYS
1 Gl: (eee 96
2 11 | 59 (eo, | 4 95
3 aa: | 47 We Gialon 90
4 2 | 69 | 24 2 97
5 a7|52 Wabash o 89
Moral 134,054: Neallnan lesen 467 6.40 +0.02
MALE EMERGENCE RECORDS.
1 Deedee | Sesion 52
2 {9 it] Sel 58
3 34| 8 | 2 44
4 31481 7 58
5 25 | 22 47
Total 2 |118/124| 14| 1 259 8.09 +£0.03
FEMALE EMERGENCE RECORDS.
|
1 ile oa ees 42
3 Bete teal et 37
3 Fa ec a 44
4 16 | 20 36
5 Silkae 7 luge) 40
Total 241116| 53| 412 | 199 8.72 £0.03
PROC. ENT. SOC. WASH., VOL. 36, NO. 7, OCT., 1934 199
Mean = 6.40 + 0.02 days
aera ord iatio
0.740 + a 016 eae ays
160
Oo
a
Qa
3
Ay
w
°
= 220
oO
E
80
40
)
(e) al 2 3 4 5 6 if 8 9
Days from: Eclosion to Pupation
Figure 7.—Development of eae Larvae under Optimum Laboratory Con-
ditions. Period from Eclosion to Pupation.
Emergence of adults was also highly concentrated, particu-
larly among males. e mean interval for males was 8.09 + 0. ce
days and for females 8.72 + 0.03 days. This was ar rece tio
from the time required in the first experiment of 23 hours = or
males and 22 for females. The observations were Hie more
concentrated than they were in the previous experiment. These
differences are all significant.
200 PROC. ENT. SOC. WASH., VOL. 36, NO. 7, OCT., 1934
Mean = 8.09 + 0.03 days
Number of Males
Standard deviation
0.623 + 0.018 days
Mean = 8.72 + 0.03 days
Y y as cy deviatio
ty
Y 3 715 + 0.024 riage
Number of Females
rs fon}
fo ro)
Days from Eclosion to Adult Emergence
Figure 8.—Development of Stegomyia Larvae Under Optimum Laboratory Con-
ditions Period from Eclosion to Emergence.
The interval between pupation and emergence was shorter in
the experiment under optimum temperature conditions. For
males it was reduced from 45 to 40 hours, and for females from
60 to 56. The emergence of females still required 15 more
hours than that of males.
Mortality was less for individuals in this experiment than
for those in the previous one. For eggs and larvae it was
6.67 + 0.75 per cent and for pupae it was 1.93 += 0.43 per cent.
The developmental process was accelerated in this experiment,
and the hazards to survival were fewer. The question arises,
to what extent was the difference in the mean temperature of
the two experiments responsible. The regression equations,
expressing the relation between pupation period and tempera-
ture and emergence period and temperature, enable us to
PROC. ENT. SOC. WASH., VOL. 36, NO. 7, OCT., 1934 201
compute expected pupation and emergence intervals for a
seven-day average temperature of 27° C. These expected
intervals are in the form of geometric means since the regression
was based on the logarithms of the original means. Conse-
quently, they must be compared with geometric means of
observations in the second experiment, although the arithmetic
means that we have been discussing are not significantly higher.
The following comparisons may be made:
Comparison of Expected with Observed Results.
Geometric mean Observed at Computed for Difference
period in days Die TENG:
Pupation period._............- 6.35 + .02 6.08 + .07 86) S= 107
Emergence period
MEI eos. ieee 8.07 = .03 Tofil 2S Os 36 + .08
emaless.= 2 -- 8269) == 03 8.27 = .08 42 + .08
The results of this comparison are most interesting. The
means computed on the basis of the experience with the 61
lots were significantly lower in every case than those actually
observed under similar temperatures. That is to say, if the
routine experiments had been continued until midsummer the
results might have been as good as or better than those attained
in this special experiment.
Obviously, we cannot assume that the relationship between
pupation and emergence periods and rise in temperature from
23.3° to 26.7° C. would necessarily continue for all higher
temperatures. The justification for making the assumption in
this case was the fact that the observed averages in the earlier
experiment extended to within 0.3° of the desired point. In
this connection MacGregor’s (1931) statement that at 30° C.
only 10 to 15 days are required from egg stage to egg stage is of
interest.
In each of these experiments a larger number of males than of
females was obtained. The proportion was 56.55 + 1.56
per cent males in the experiment under optimum temperature.
In the routine experiment the proportion of males was 52.10 +
0.48 per cent. In each case the difference was significant.
Owing to the fact that a significantly larger proportion of males
was obtained under optimum conditions, the possibility of a
correlation with temperature was investigated, but none that
was significant was found.
DEVELOPMENT UNDER ADVERSE CONDITIONS.
In nature the development of the stegomyia is subjected to
many influences favorable and unfavorable to its progress.
In the experiments just described optimum conditions were
202 PROC. ENT. SOC. WASH., VOL. 36, NO. 7, OCT., 1934
provided, the only variant being the temperature. Before the
standard method was adopted, certain experiments were per-
formed under adverse or suboptimum conditions of known
character in order to measure their effect upon development.
Many of these adverse factors are present in nature and affect
development. The adaptablity of the species enables it to
survive often in spite of most unfavorable conditions, as the
following experiments will show:
Ege Stage.
The egg stage is the most resistant of the four major stages of
stegomyia. The small size and black color of the eggs prevent
detection—except where ants are concerned—and their ability
to withstand desiccation after the full development of the
enclosed larvae for from six to twelve months renders this stage
the strongest link in the life of the species. In the egg stage
the species are transported great distances (in water Jars, etc.)
and no doubt this is one of the chief means of distribution.
Reed and Carroll (1911) called attention to the fact that the
eggs of stegomyia were remarkably resistant to drying, and
that even though the adults could not survive a winter lasting
three months, it would be entirely possible for the eggs to do so,
especially since they are also resistant to freezing.
Reports of investigators on ges teiiie for this stage give varying
results. Bacot (1916), Young (1922-23), Buxton and Hopkins
(1927), and Roubaud (1927-29), although fully aware that
some time was required for incubation before the eggs woud
hatch, state that frequently numbers of matured eggs would
resist hatching indefinitely. These investigators are all agreed
that the presence of organic matter, especially bacteria or
yeast, stimulates hatching. Buxton and Hopkins and Roubaud
have also shown that a variety of chemicals will produce a
similar result although some of the substances used are lethal
for the larvae. Preliminary experiments on the Greek strain
(R. C. S.) suggest that this resistance may be peculiar to certain
strains of stegomyia.
Four classes of eggs will now be discussed, divided according
to initial treatment:
Class I.—Properly conditioned eggs are those that have been
kept in the open air on moist filter paper until the enclosed
larvae are fully developed and then placed in water containing
food. _ The process was discussed under “Standard Develop-
ment.” Approximately 95 per cent of the moist eggs properly
conditioned will hatch within 10 minutes when submerged in
water with food.
Class II. These consist of freshly oviposited eggs less than
twelve hours old. If placed immediately into water containing
food, these eggs do not undergo as rapid or uniform a period of
PROC. ENT. SOC. WASH., VOL. 36, NO. 7, OCT., 1934 203
development as the eggs that are air conditioned according to
the method followed in Class I. The rate of hatching at 24° C.
of six lots of 100 eggs each according to the period of air con-
ditioning given them is shown in Table 4.
TABLE 4.
Ectoston Pertop or S1x Lots or 100 Eces Eacu AccorpincG To PERIOD OF
Arr Conpitioninc (Att Eces Oviposirep Less THAn 24 Hours Berore
THE BEGINNING OF THE EXPERIMENT). TEMPERATURE 24° C.
pees aoe
HOURS AIR HOURS REQUIRED FOR
CONDITIONED FIRST HATCHING HOURS TOTAL
LOT r REQUIRED FOR | PERIOD
RANCE | MEAN | ADDITIONAL | CUMULATED | FINAL HATCH |IN HOURS
HOURS HOURS
Q)} (2) (3) (4) (5) (6) (7)
1 0-24 nl; 144 156 216 372
A || WARS 24 52 76 2 148
3) || SIES7/ 45 31 76 54 130
4 | 40-64 52 18 70 48 118
5 | 60-81 70 8 min. 70 24 94
|| tai 99 2 min. 99 10 min. 29
There are several points of interest in this table. The interval,
following that of air conditioning, which elapsed before hatching
began was less for each lot given a longer period of conditioning.
Hatching time was also less, decreasing from nine days for the
first lot to 10 minutes for lot 6.
From the biological point of view, there is another aspect of
this table to be considered, and that is the variation in the
complete interval from the time the lots were started (1) to the
beginning of hatching, and (2) to the completion of hatching.
These intervals are given in columns 5 and 7 of Table 5. Here
we find that the interval to the beginning of hatching was
approximately the same for lots 2 to 5. It was slightly longer
for lot 6 and very much longer for lot 1. The time required
for complete hatching was also much longer for lot | than for
any of the others. The interval decreased with the longer period
of conditioning for lots 2 to 5, and rose slightly for lot 6.
What apparently happened was this: the eggs in lot | were
not fully mature when they were placed in water, and their
subsequent development was retarded. In lots 2 to 5 the
increased interval of air conditioning did not affect the time
required for the beginning of hatching, but the lots with the
204 PROC. ENT. SOC. WASH., VOL. 36, NO. 7, OCT., 1934
longer preliminary treatment completed the process somewhat
earlier. Lot 5 completed the entire process in the minimum time
of 94 hours, conditioned for 70 hours and hatching in 24 hours.
The entire interval required by lot 6 was covered by the con-
ditioning process of 99 hours, since hatching was completed in
10 minutes.
Class III.—Eggs in this class were air dried while less than
24 hours old and kept in this state a week or longer. When
placed in water these eggs exhibited a high mortality. Many of
our early routine breeding records for the summer of 1928-1929
show a mortality of 50 to 80 per cent, which we attribute to the
fact that the eggs were dried before they were fully mature.
Table 5 shows the results of experiments at 24° C. in which the
eggs were dried shortly after oviposition and kept in this state
for varying lengths of time.
TABLE 5.
Morratiry Due to Dryine FresHty Oviposirep Eaes, 100 Eces Per Lor,
aT 24° C,
DATE SUB- |
DATE OF | DAYS KEPT |MERGED IN| EN VAL | INTERVAL | DER CENT
LOT | OVIPOSI- Baie amma. |,TOLSERST || TO ENAILO| e ee
TION HATCHING | HATCHING
WITH FOOD
1 July 14 1 July 16 | 3 days 4 days 8
|
2 July 14 Zi July 22 | ¥% hour 1 hour 20
3 July 14 LW Aug. | 1 hour 8-16 hours 38
Although humid atmospheric conditions prevailed when
these experiments were made, mortality was fairly high, par-
ticularly when we consider that lot 6 in Table 4 of eggs air
conditioned for 99 hours at the same temperature before being
submerged had a mortality of only 3 per cent.
Class IV.—These are eggs ripened on moist filter paper
and then dried. Treated in this way the eggs may be stored
for a period of six months without showing a high mortality.
About 5 per cent will survive a year or more.
Our experience with thousands of eggs which were dried
within four weeks and then used in routine rearings gave such
uniform results that it is possible to formulate the following
rule for our Brazilian strain:
Conditioned eggs, air dried from one to four weeks, begin to hatch within 30
minutes when submerged in water to which food has been freshly added; and when
placed in water which has contained food 12 hours or more, they begin to hatch
in about seven minutes.
PROC. ENT. SOC. WASH., VOL. 36, NO. 7, OCT., 1934 205
A large proportion will even hatch in distilled water. Better
results in general may be obtained by using eggs less than
10 days old, or by moistening the older eggs several hours
before submerging them in water.
A small percentage of eggs which have been dried a month
or more may resist hatching. If these are removed and re-dried,
additional ones will hatch when again placed in water. If
this process is repeated several times, all viable eggs will even-
tually hatch. We have not observed such striking cases of
resistance to hatching as recorded by Roubaud (1927-29),
Buxton (1927), and others.
Only one experiment with 5,000 eggs, which had been kept
dry five to six weeks, is given below, but others also numbering
thousands of eggs have given similar results.
TABLE 6.
Errecr Upon Eciosion or IMMERSING AND ReE-pryING Ecos PREVIOUSLY
CoNnDITIONED AND DrieD For A Pertop or 5 ro 6 WeEEKs; 5,000 Eccs Usep.
DATE IMMERSED NUMBER DATE UNHATCHED
IN WATER WITH LARVAE EGGS REMOVED FOR
FOOD HATCHED FURTHER DRYING
March 2 4,500 + March 6
March 18 170 March 19
March 28 19 March 29
April 4 0 April 10
Total hatch 4,689 =
These methods of treating newly oviposited eggs of stegomyia
were designed to reproduce various events that may occur in
nature so that their results might be evaluated. The wild
female stegomyia lays her eggs preferably on the side of the
water jar just above the water line, where the film ordinarily
keeps the eggs moist until the enclosed larvae are mature.
Some of the eggs may be laid on the surface of the water and
maturation in this case must take place there. The laboratory
experiments indicate that the moist side of the jar is more
favorable to rapid development of the eggs than the water
surface, but that sufficient water must be added to cover the
eggs before they will hatch. The speed of hatching when water
is added depends on the length of time the eggs had remained
on the moist side of the jar. Eggs laid on the surface of the
water develop more slowly, and the hatching process is longer
206 PROC. ENT. SOC. WASH., VOL. 36, NO. 7, OCT. 1934
than those ripened on the side of the jar. If water is removed
and the eggs dry before they are ripe, mortality is doubtless
high, but if they remain moist until thoroughly mature, they
can withstand drying for some time. When water is added to
the jar, they will begin to hatch, and repeated drying and sub-
mergence will facilitate almost a complete hatch.
Larval and Pupal Stages.
These are the most critical stages in the life cycle of the
stegomyia. Inasmuch as the female stegomyia prefers the
domestic water container for oviposition, there is always the
danger that the water may evaporate or be drawn off before
the larvae have completed their development. Experiments
in this laboratory show that larvae can survive at least 18 hours -
on the damp sides of the container. Half-developed pupae
when placed on a damp surface are still capable of producing
adults. Young (1922) states that pupae kept dry 24 hours
were able to produce adults.
The strictly domestic habitats of stegomyia larvae are
practically free from predatory enemies, and it may be for this
reason that these larvae are more susceptible to predators
added to their breeding jars than are the larvae of other species.
This was discussed in detail in a former paper (Shannon, 1931).
The following experiments describe the effect upon stegomyia
larvae of (1) starvation, and (2) overcrowding.
Starvation—In the first experiment 20 larvae were allowed
to hatch in distilled water and were then transferred to
isolation tubes containing distilled water. Another 20 larvae
were given plenty of food until the third stage was attained.
They were then thoroughly washed in distilled water and
placed in isolation tubes with distilled water. Mean tempera-
ture during this period was 23.5° C. Table 7 shows the number
of days survived by the individuals in each group.
a ae
207
PROC. ENT. SOC. WASH., VOL. 36, NO. 7, OCT., 1934
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208 PROC. ENT. SOC. WASH., VOL. 36, NO. 7, OCT., 1934
It is of interest to note that the survival period was no
longer for larvae fed up to the time of reaching the third stage
than for those starved from the time of hatching. Three weeks
was the survival period for at least one individual in each group.
Table 8 shows the effect upon survival when only a very
small amount of food was present. The small pinch of dried
beef serum was sufficient to stimulate hatching but not enough
to enable the larvae to complete development. In this experi-
ment the feeding jar was kept covered.
TABLE 8.
RESISTANCE OF 50 LarvaE TO ALMost CoMPLETE STARVATION.
TEMPERATURE APPROXIMATELY 27° C.
peeeeiok |) sicrvinell| sukien en REMARKS
Dec. 1 50 Number eggs hatched
Jan. 6 15 36 About one-third grown
Jan. 11 iil 41 About one-half grown
March 25 1 114 Very small, died pupating
Although the survivors fed upon those which died, none of
the 50 larvae in this experiment lived to complete pupation
in spite of the fact that approximately one-third lived 36 days.
This experiment was run during the summer, and experience
with normal rearings at midsummer temperature under stand-
ard development gave a mean pupation period of 6.40 + 0.02
days and a maximum interval of nine days. The effect of lack
of food is therefore apparent. The maximum survival period
in this experiment was 114 days.
The ability of stegomyia larvae to withstand semistarvation
and even to develop when there is but a minimum of food
present is well shown in the following experiment in which
Culex quinquefasciatus was included. In this experiment
100 stegomyia eggs and an equal number of culex eggs were
put in a large pan of tap water, which was placed in a fairly
dusty room. The only food available consisted of the dust and
small insects settling on the water, any microorganisms which
may have been in the water originally, and the larvae which
died during the experiment. The results are given in Table 9.
PROC. ENT. SOC. WASH., VOL. 36, NO. 7, OCT., 1934 209
TABLE 9.
Errect oF SEMISTARVATION ON 100 SrEGomy1a AnD 100 Culex quinquefasciatus LARVAE
(Eces Piacep 1n A Larce Open Pan or Tap Water JUNE 19 1n A Fatrty Dusty Room.
No Foop AppDED).
PUPATION EMERGENCE MORTALITY
SPECIES FIRST LAST
Mates | FemaLes |=CC* #5? ip
INTERVAL INTERVAL LARVABM |
DATE IN DAYS DATE IN DAYS
Stegomyia| July 18 29 Sept. 24 gy 43 28 17 12
Culex Aug. 11 53 Aug. 23 65 2 i 94 3
The differences are striking. Mortality was 29 per cent for
stegomyia and 97 per cent for culex. Adult emergence for
stegomyia was 71 per cent and for culex 3 per cent. Actually
very few of the culex larvae had advanced beyond the second
stage at the time of death, and one of the striking results of
this experiment was that within four days the stegomyia larvae
could be instantly distinguished from those of culex by their
noticeably larger size.
It is well known that stegomyia breeds preferably in fresh
water supplies while Culex guinquefasciatus shows an equal
preference for waste waters.’ The reason why stegomyia larvae
can develop in a medium with but a small amount of surface
food while nearly all of the culex larvae die in such a medium,
apparently lies in the differences in behavior of the two species.
The chief characteristic of stegomyia larvae, aside from their
negative phototropic tendencies, is their extreme restlessness
and their ability to feed from all parts of the body of water.
They feed chiefly around the sides and bottom of the container,
but are able to feed on suspended particles and from the surface
of the water as well. The larva possesses two methods of feeding
at the surface film. By means of the first, the body is raised
and twisted so that the mouth parts are brought into contact
with the surface. By retaining hold on the surface film with
its respiratory tube, the larva is able to propel itself about in a
circle by the movement of its mouth brushes, feeding as it
goes. By the second method, the larva may feed on the lower
side of the surface film by turning its body completely over,
with the respiratory tube pointed downward, and by gliding
along with the aid of the mouth brush movements.
Culex larvae are also able to feed from the sides and bottom
of the container and to pivot in a circle at the surface film, but
they prefer to hang suspended from the surface film, feeding
210 PROC. ENT. SOC. WASH., VOL. 36, NO. 7, OCT., 1934
upon the suspended particles within their reach. It may well
be that culex larvae require a richer type of food than stegomyia.
Certainly the experiment indicated that the stegomyia larvae
were better able to find and utilize what food was present than
were the culex larvae.
This difference in the behavior of the two species suggests
that in experiments dealing with the food of mosquito larvae,
behavior as well as type of food should be studied. Christophers
and Puri (1929) have shown the importance of this for anophe-
line larvae. They speak of the tendency for particles of living
and dead matter to accumulate just under the surface of the
water without coming into contact with the surface film, and
suggest that the horizontal position of anopheline larvae
enable them to tap this special food supply.
MacGregor (1929) has noted a phase of suspended develop-
ment among tree-hold breeding species which he attributes to
the temporary or complete disappearance of microorganisms
from their breeding sources. He suggests that these micro-
organisms help to convert organic particles in the water into
suitable form for larval food.
Hinman (1930) met with a type of development similar to
that in the experiment described above when he attempted to
rear stegomyia in water obtained from tubs previously used for
breeding larvae in large numbers and which had been passed
through a Berkefeld filter. All solid material and organisms
were thus removed and only the organic and inorganic sub-
stances in solution and colloids in suspension remained. He
was successful, however, in rearing a few adults in from 9 to 17
days, while similar experiments with culex and anopheles were
unsuccessful. His experiments also indicate a greater efficiency
in searching for food on the part of the stegomyia larvae as
compared with those of culex.
Overcrowding—Table 10 gives mortality and the time re-
quired for pupation at 27° C. of lots of stegomyia larvae
according to their density in the rearing jar.
PROC. ENT. SOC. WASH., VOL. 36, NO. 7, OCT., 1934 211
TaB_Le 10.
Errecr oF OVERCROWDING ON PupatTion PERIopD AND MorrALiry OF STEGOMYIA
LARVAE AT 27° C.
NUMBER DAYS TO DAYS TO NUMBER Peace
OF EGGS FIRST FINAL OF EGG ped
PER LOT PUPATION PUPATION PUPAE LARVAE
MORTALITY
ee 5 7 95 5.00 + 1.47
400 5 10 10 5550) Se DY
1000 ii 16 790 2000) == 0587
4000 10 60 2096 47.60 = 0.53
These results should be compared with those obtained at
27° C. under standard development. There we found a pupation
period extending from the fourth through the ninth day and
an egg and larval mortality of 6.67 + 0.75 per cent. These are
virtually the same as the results in Table 10 for the lot of 100
larvae. Although the pupation interval for the lot of 400
larvae was not appreciably longer, mortality was nearly three
times as high, 15.50 + 1.22 per cent. In lots of 1,000 eggs and
more, both pupation interval and mortality were increased.
One might be inclined to attribute the slow development and
high mortality in the overcrowded jars to toxic action exerted
by waste products in the water. It was found, however, that
25 larvae when placed in water that had been fouled by 2,000
larvae during two weeks’ time—the pH had dropped from 8.0
to less than 5.2—developed normally, completing pupation on
the fifth day and producing large sized adults.
The behavior of the stegomyia larvae may offer an explana-
tion for this. Their sensitiveness to light and vibration is
well known. Owing to their negative phototaxis, the larvae
seek the darker side of the container. Their massing together
and extreme restlessness may prevent them from feeding
normally even when an abundance of food is present. De Buck,
Schoute, and Swellengrebel! (1932) claim that it is necessary for
anopheline larvae to maintain a constant stream of food passing
through the body in order to develop normally, and that when
they live in overcrowded conditions food may remain undigested
in the alimentary tract from 12 to 24 hours.
Apparently, too, when once growth has been arrested it is
likely to continue so. The larvae remaining in a jar that was
formerly overcrowded continued to develop slowly. Figure 9
shows the relative difference in size of the cephalothorax of a
female stegomyia pupa developed under uncrowded conditions
and that of one from an overcrowded Jar.
212 PROC. ENT. SOC. WASH., VOL. 36, NO. 7, OCT., 1934
Stegomyia
A. Opened cephalothorax of a
Female pupa developed under
uncrowded conditions.
B. Same, but from a larva in an
overcrowded yar.
Magnification X 50
Figure 9.
An ADVERSE PHENOMENON oF UNKNowN ORIGIN.
In routine laboratory procedure an average of five larval
jars were started daily. It was observed that once or twice
a month from 50 to 75 per cent of the adults, usually from one
jar, died shortly after emerging. Equal numbers of males and
females were usually affected. Similarly full grown larvae in a
single jar would die just before pupating. Instances of this may
be found in Table 1. It is highly probable that a disease is the
cause of this remarkable phenomenon, although as yet the
laboratory staff has been unable to discover the cause. Neither
has it been possible to propagate the cause in fresh jars.
The fact is of interest in that it suggests the existence of a dis-
PROC. ENT. SOC. WASH., VOL. 36, NO. 7, OCT., 1934 213
ease which attacks stegomyia larvae, which may kill them while
they are still in the larval stage or which may not become
effective until the adults have emerged.
ACKNOWLEDGMENTS.
The authors are indebted to Drs. J. H. Bauer and N. C.
Davis, who installed the equipment for rearing stegomyia in
the laboratory at Bahia and who began the routine breeding.
Dr. Davis in his capacity as director of the laboratory con-
tributed materially in practical and advisory ways. Dr. Hugo
Muench in the New York Office assisted with the statistical
analysis.
SUMMARY.
In this paper a technic for rearing stegomyia larvae has been described which
was evolved in the Yellow Fever Laboratory, Bahia, Brazil. The method was
found to give highly uniform results, with a minimum mortality and maximum
development for the species, indicating most favorable conditions of nurture.
A statistical analysis of records of two series of observations defined relationships
and set up norms for comparison with results of subsequent experiments under
similarly favorable or unfavorable conditions. Since stegomyia is essentially
a domestic species, the laboratory affords an environment not unlike that
encountered in nature.
The standard method adopted was based on results obtained in experiments
similar to those described under “Development under Adverse Conditions.”
In summarizing, therefore, these results will be discussed in their relation to the
technic adopted.
This paper is concerned with egg and larval stages of stegomyia development.
Egg laying capacity and longevity of adults will be discussed later.
Egg stage-——The most rapid and complete hatching of stegomyia eggs was
secured when they were allowed to ripen on moist filter paper from two to five
days before being submerged in water. The time required depended upon the
temperature. Although the total number of hours in the egg stage did not
decrease materially for eggs conditioned more than 24 hours, the hatching
process was accelerated by a longer period. In the experiment reported, eggs
conditioned four days completed hatching in ten minutes when submerged in
water containing food.
Freshly oviposited eggs if placed immediately in water require a much longer
interval for complete eclosion, possibly because the eggs are not ripe when
placed in water. On the other hand, eggs that are dried before they mature
show a high mortality. If conditioned first, they may be dried and kept six
months without losing their viability. Some may survive for more than a year,
The egg stage of the stegomyia is doubtless the most resistant period in the
life cycle of the species owing to the ability of the egg to withstand drying and
adverse temperature.
Larval stage—The most favorable conditions for rearing larvae require an
adequate food supply consisting of 2 to 3 cc. of dry bread, temperature ranging
214 PROC. ENT. SOC. WASH., VOL. 36, NO. 7, OCT., 1934
from 23° to 27° C., and a maximum of 100 larvae per jar. In such an environ-
ment pupation will occur in an average of 6 to 7 days, mortality will be low, and
the size of the individuals will be large.
It was found that stegomyia larvae were able to complete development on
an amount of food wholly inadequate for Culex quinquefasciatus larvae. Mor-
tality was 29 per cent among stegomyia and 97 per cent among culex larvae in
this experiment. Difference in larval behavior and feeding habits may account
for this. Although stegomyia may survive for a considerable period on a
minute quantity of food, pupation does not necessarily occur.
Experiments in overcrowding indicated that mortality was significantly
higher when 400 or more larvae were placed in the same jar. With 1000 or
more larvae, the pupation period was also increased and the ultimate size of the
individual larva was smaller. Improper nourishment due to massing habits of
the larvae may account for this rather than an excess of toxic substances, since
it was found that small numbers of larvae passed through a normal cycle when
placed in water previously fouled by the presence of large numbers of larvae.
An apparently natural phenomenon of unknown origin was also observed in
the course of routine rearings which caused severe mortality among full-grown
larvae and newly emerged adults.
To illustrate the type of results attained in rearing stegomyia larvae according
to the standard method, two series of observations were analyzed. The first
applied to pupation and emergence periods for 61 lots of 100 eggs each, one
started on each of 61 succeeding days. Daily mean temperature records were
available for this series. The second series of observations were from five lots
of 100 eggs each reared at an average temperature of 27° C. The results were
analyzed statistically, and the findings will now be summarized:
1. A definite relationship was found to exist between the mean pupation
periods of the 61 individual lots and rise in temperature. The decrease in mean
pupation period was 0.76 + 0.08 per cent days per 0.1° C. rise in temperature.
In computing this relationship the temperature records were converted into
seven-day averages to correspond to the mean pupation period for all individuals
in the 61 lots found to be 7.16 + 0.01 days.
2. A similar relationship was found between rise in temperature and emer-
gence periods.
3. The average emergence period of females in the 61 lots was 14 hours longer
than that of males.
4, Mean temperature for the entire rearing period of the 61 lots was 25° C.
5. Rearing at 27° C. was more rapid and the process more concentrated.
6. By means of the regression equations expressing the relation between
pupation and temperature, and emergence and temperature, it was possible to
estimate the mean pupation and emergence periods at an average temperature
of 27° C. for comparison with the observed results at this temperature. This
was done and the results agreed very well.
7. Mortality was less for lots raised under optimum temperature conditions.
8. In each series a larger number of adult males than females emerged.
9. The important statistical measures of larval development given by the
two series of observations follow:
PROC. ENT. SOC. WASH., VOL. 36, NO. 7; OCT., 1934 215
61 lots at 5 lots at
Phas ee DIONE:
Egg and larval mortality... 12.41 = .29% 6.67 = .75%
Bipalemogtalityee ee Oil Ss WI, 1.93 = 43%
Mean pupation period... 7.16 = .01 days 6.40 = .02 days
Mean emergence period P
Male samen es bes Men rE 9.05 + .02 days 8.09 + .03 days
emialeoesers mere. Skee as Ree 9.74 + .02 days 8.72 + .03 days
Males per 100 pupae... 2... 52.10 + .48 S6r5 5° Ie
10. In a later paper it will be shown that at 27° C. the female can not produce
eggs until six to seven days after emergence. Therefore, at this temperature
and with the foregoing data at hand it can be stated that the interval from egg
stage to egg stage averaged about 15 days.
References.
Bacor (A. W.), 1916
Report of the Entomological Investigation Undertaken for the Commis-
sion for the Year, August 1914 to July 1915. Yellow Fever Commission
(West Africa) Investigators’ Report. London, 3: 1-191.
Bacor (A. W.), 1917-1918
A Note on the Period during Which the Eggs of Stegomyia fasciata (Aedes
calopus) from Sierra Leone Stock Retain Their Vitality in a Humid
Atmosphere. Parasitology, Cambridge, 10 : 280-283.
Buxton (P. A.) and G. H. E. Hopkins, 1927
Researches in Polynesia and Melanesia, Parts I-IV (Medical Ento-
mology) London, 260 p.
CuristoPHers (S. R.) and IJ. M. Puri, 1929
Why Do Anopheles Larvae Feed at the Surface, and How? Transactions
of the Far Eastern Association of Tropical Medicine, Seventh Congress
Held in India, Dec. 1927; 2 : 736-739.
Goetpi (E. A.), 1905
Os mosquitoes no Para. Memorias do Museu Goeldi (Museu Paraense)
No. 4, 154 p.
Hinman (E. H.), 1930
A Study of the Food of Mosquito Larvae (Culicidae). American Journal
of Hygiene, 12 : 238-270.
Ieessons (HE Ss) eal932
Methods of Rearing and Maintaining Large Stocks of Fleas and Mos-
quitoes for Experimental Purposes. Bulletin of Entomological Research,
23) 25-318
MacGrecor (M. E.), 1929
Significance of pH in the Development of Mosquito Larvae. Parasitol-
ogy, Cambridge, 21 : 132-157.
MacGrecor (M. E.), 1931
The Nutrition of Adult Mosquitoes: Preliminary Contribution. Trans-
actions of the Royal Society of Tropical Medicine and Hygiene 24 : 465-
472.
216 PROC. ENT. SOC. WASH., VOL. 36, NO. 7, OCT., 1934
Martini (E.), 1924 :
Ueber jugoslavische anophelen mit besonderer Beriicksichtigung der
Frage der misanthropen Rassen. Arch. fiir Schiffs-u. Tropenhyg.
28 (6) : 254-265.
Reep (WaLrTerR) and James Carrot, 1911
The Prevention of Yellow Fever. Reprinted in “Yellow Fever. A
Compilation of Various Publications. Results of the Work of Maj.
Walter Reed, Medical Corps, United States Army, and the Yellow Fever
Commission, Senate Documents.” (Washington, Gov’t Printing Office,
D. C.) 61 : 131-148.
Rovusaup (E.) and J. Coras-Betcour, 1927
Action des diastases dans le déterminisme d’éclosion de |’oeuf chez le
moustique de la fiévre jaune (Stegomyia fasciata). Comptes Rendus _
Hebdomadaires des Séances de |’Académie des Sciences, Paris, 184 : 248.
Rovusaup (E.), 1929 4
Recherches biologiques sur le moustique de la fiévre jaune. édes
argenteus Poiret. Facteurs d’inertie et influences réactivantes du dé-
veloppement. Les oeufs durable et leur importance dans le rajeunisse-
ment du cycle évolutif. Annales de |’Institut Pasteur, 43 : 1093-1209.
SHannon (R. C.), 1931
The Environment and Behavior of Some Brazilian Mosquitoes. Pro-
ceedings of the Entomological Society of Washington, 33 : 1-27.
Youne (C2 Jy 1922-1923
Notes on the Bionomics of Stegomyia calops in Brazil. Part I. Annals
of Tropical Medicine and Parasitology, 16 : 389.
ee
PROC. ENT. SOC. WASH., VOL. 36, NO. 7, OCT., 1934 2nF
THE BIOLOGY OF STEGOMYIA UNDER LABORATORY
CONDITIONS.!
By Persts Purnam AND RaymonpD C. SHANNON.
II]. EGG-LAYING CAPACITY AND LONGEVITY OF ADULTS.
The preceding paper contains an experimental and statistical
analysis of various factors which influence the development of
stegomyia eggs and larvae under laboratory conditions.
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Before actual variability can be compared, the standard
deviations must be reduced to a comparable base, and this may
be done by computing coefficients of variation from the formula:
Coefficient of variation = 100 (Standard deviation)
Mean
These are given below:
Attribute observed. Coefficient of variations.
DD ays iliviectemen rere ee 45.21 = 6.03
Blood units consumed_..._... 82.07 = 14.13
Oviposition periods. See SPY yey ear Gils!
Eeecidepostted =a 84.96 += 14.93
These coefficients indicate that the females varied most with
respect to the number of oviposition periods and least with
respect to the number of days lived. The differences between
the coefficients were none of them as much as three times their
probable errors, and so were not significant. They are given to
show how the relative variability in performance of the indi-
viduals in the group may be found.
The purpose of varying the frequency of feeding was to see
what the effect would be on blood consumption, oviposition,
and the number of eggs deposited. Table 4 contains the means
of the observations for each of the three groups.* Although
these means differed considerably, none of the differences was
statistically significant. It was possible, therefore, to proceed
to the analysis of the data for all the specimens as a single group.
The question next to be considered was what effect length of
life, amount of blood consumed, and the number of oviposition
periods had, severally and collectively, upon the egg-laying
capacity. The correlation method was used for this analysis.
In its simplest form this is illustrated in Figure 2 in which each
individual was plotted according to the number of days lived
and the number of eggs deposited in the course of its life. Each
of the scales is arithmetic, and the straight line was fitted to
the observations. This line shows graphically what the average
increase in egg component was per unit increase in days lived.
It was plotted from the equation:
Mean eggs deposited during lifetime = 4.88 (days lived) — 90.19.
4 In computing probable errors the standard deviations applying to all twenty
specimens were used, on the assumption that variability of the means of the
subdivisions would be similar to that of the whole group.
225
PROC. ENT. SOC. WASH., VOL. 36, NO. 7, OCT., 1934
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# 300
200
100
0
0) 20 40 60 80 100 120
Age on Day of Death
Figure 2,—The Regression of Eggs Deposited on the Number of Days Lived for
Twenty Stegomyia Females.
From this equation we may estimate the average egg com-
ponent of individual specimens living a specified number of
days, but we also want to know how blood consumption and
frequency of oviposition affected egg production. Table 5
contains the correlation coefficients giving the amount of
association between attributes of various pairs of biologic
functions and between pairs of functions with the effect of a
third or a third and fourth held constant.
226 PROC. ENT. SOC. WASH., VOL. 36, NO. 7, OCT., 1934
TaBLe 5.
Ecc-Layinc Capacity or Twenty Srecomyi1A FEMALES. CoRRELATION
BETWEEN (z) Eccs Deposirep, (x) AcE 1n Days, (y) BLoop Units Con-
SUMED, AND (uz) OviposiT1on PERIODs.
Coefficients of Correlation.*
ZERO ORDER FIRST ORDER SECOND ORDER
SUBSCRIPT ip SUBSCRIPT r SUBSCRIPT r
Pa ap of IESE. KON/T/ || Bauer + .832 = .050'| zv.uy -- 50/7 = 21125
xy + .682 + .085 | zu.x + .943 + .018 | zuxny + .803 + .060
xu + .623 + .097 | yun + .862 = .042 | xuzy — Al4 = .140
ay + .913 + .026 | 2x.y +" .323 = .147)| zy.na 4-112) 22 Bley
Zu + .960 = .012 | xuy + O11 = .164 | yuzx + 421 = 139
yu + .918 = .025 | zu.y too = 070
ZX.U =o Poe == alll} |
ZV.U + .284 += .150
ne, “iE ol ano
xy. + .090 + .162
yuz + 361 + .142
*N-2 was used to compute probable errors of zero order coefficients;
N-3 for probable errors of first order coefficients; and
N-4 for probable errors of second order coefficients.
It may be well to state briefly how these coefficients should
be interpreted. If for every increase of one unit in either of the
two attributes compared there is a definite and proportional
rise in the other, the correlation coefficient will be + 1. If
the attribute of either function decreases while the other
rises in a definite manner, the correlation coefficient will be — 1.
In either case the correlation is said to be perfect. Conse-
quently, coefficients in the neighborhood of + 1 or — 1 indicate
a high degree of association. If the attributes are unrelated
the correlation coefficient will be in the neighborhood of zero.
If we examine the zero order coefficients in Table 5, we find
good positive correlation between the attributes compared.
This means that as one of the attributes increased the other
rose in a definite fashion. The two most closely associated were
the number cf eggs deposited and oviposition periods, r,,, =
+ 0.960 + 0.012. Egg components and blood units were also
highly correlated, ‘zy = + 0.913 + 0.026, and so were oviposi-
tion periods and blood units, 7,, = 0.918 + 0.025. Actual
length of life apparently affected the number of eggs deposited
less than either of the other two functions.
From these zero order coefficients it is possible to set up
regression equations from which mean egg-laying capacity
<<
PROC. ENT. SOC. WASH., VOL. 36, NO. 7, OCT., 1934 227.
may be computed in terms of each of the other attributes.
This was done in Figure 2 for eggs deposited and length of life.
To determine the effect upon egg components of two of the
other functions, partial correlation coefficients of the first
order were computed. These indicate the association between
the attributes of two of the functions for a constant value of a
third. For example, the correlation between eggs deposited and
oviposition periods with blood units constant, 7, = + 0.756
+ (.07G, represents the amount of correlation we should find
if we compared the egg production and oviposition periods of
those individuals only whose total blood consumption was the
same.
Actually, we are dealing with attributes of four interdepend-
ent biologic functions, and holding one or another constant
would necessarily decrease the amount of correlation between
the two compared. Table 5 shows that the least reduction
between zero order and first order coefficients occurred when
length of life was held constant, ~,, = + 0.943 + 0.018.
When either oviposition periods or blood units were held con-
stant the correlation was considerably less.
To express the association between egg-laying capacity and
all three other functions the second order correlation coefficients
in Table 5 were computed. These indicate the relation between
attributes of two functions with the other two held constant.
This step reduced the coefficients stiJl further. The largest one
remaining was that between eggs deposited and oviposition
periods with length of life and blood units held constant,
y + 0.803 += 0.060.
~ BUX
We find from this analysis that the number of eggs deposited
was most closely associated with oviposition periods. Blood
units were highly correlated with oviposition periods also, and
when they were held constant the correlation between eggs
deposited and oviposition periods were considerably reduced.
It still persisted, however, even to the second order coefficient
when length of life and blood units were both held constant.
Regression equations from which egg-laying capacity may be
computed from attributes of two and finally of three other
functions have been set up and are given in Table 6. Since the
correlation between eggs deposited and oviposition periods
was highest, the equations in terms of oviposition periods give
the best estimates.
228 PROC. ENT. SOC. WASH., VOL. 36, NO. 7, OCT., 1934
TABLE 6.
EQUuATIONS FOR THE ReEGREssION oF Ecos DeEposirED oN AGE IN Days, BLoop
Unirs ConsuMED, AND Oviposirion PeErrops, IN StuDIES oF EGG-LAYING
Capacity oF Twenty STEGOMYIA FEMALES.
z = Eggs deposited
x = Age in days
y = Blood units consumed
u = Oviposition periods
Regression of eggs deposited
on: Equation
Age and blood units... z = 1.22% + 10.33y — 39.49
Blood units and oviposition
eniod Soe ee, O32 Oy a eOLos
Age and oviposition periods = 1.34% + 20.82u — 36.02
Age, blood units, and ovi-
position periods...
ll
nQ
Ion = we se a Se i
The significance of these equations may be clearer if we ex-
amine them graphically. The straight line in Figure 2 represents
the regression of egg production on days lived. Points on the
line indicate the average egg component for a given number of
days lived, based on the experience of these twenty females.
When the regression of egg-laying capacity is expressed in
attributes of two other functions, the theoretical egg components
computed from the equation lie in a plane, not on a straight
line, and the graph showing the three variables is in three
dimensions. This is illustrated in Figure 3. Here each of the
twenty females is represented by a black-headed pin, its height
determined by the total number of eggs deposited during life.
The position of the pin on the rectangular base of the drawing
is determined by the observed number of blood units consumed
and the number of oviposition periods for that individual.
The equation for the regression plane indicated is as follows:
Mean egg component = 19.32 (oviposition periods)
+ 2.62 (blood units) -+ 20.58
The little ellipses indicate the points where the pins pierce
the plane or where they would pierce the plane if they were
tall enough to do so. The slope of the edge of the plane above
the y axis shows how egg-laying capacity increases with rise in
blood consumption when oviposition periods are held constant.
The slope of the plane above the uw axis indicates the rise in eggs
deposited with increasing frequency of oviposition when blood
units are held constant. The steeper slope of this line indicates
a greater correlation between these attributes. The maximum
PROC. ENT. SOC. WASH., VOL. 36, NO. 7, OCT., 1934 229
_effect of both functions on egg production is indicated by the
height of the plane with respect to the base of the figure at the
back of the drawing. The diagonal trend and increasing height
of the pins toward the far corner of the picture indicates how
well the slope of the plane follows that of the observations.
Eggs Deposited (z)
Figure 3.—The Regression of Eggs Deposited on Oviposition Periods and Blood
Units Consumed for Twenty Stegomyia Females.
It is possible to illustrate in this way the relationship between
egg-laying capacity and two other functions, but the final
equation in Table 6 can not be graphed since it adds a third
variable to the regression and calls for a figure in four dimen-
sions.
This completes the analysis of the total performance of the
twenty isolated females. The results are highly gratifying.
230 PROC. ENT. SOC. WASH., VOL. 36, NO. 7, OCT., 1934
We have shown that specimens living longer and consuming
more blood will, on the average, have more oviposition periods
and a larger total egg component. Furthermore, we have
expressed this fact mathematically so that we may estimate the
egg component for other specimens reared under similar con-
ditions.
When we consider that there were only twenty individuals,
that the frequency of feeding was predetermined, and that the
terms blood unit and oviposition period were arbitrarily defined,
it 1s surprising that the correlations should be so definite and
that the regressions should fit the observations so well. One
of the requirements of a good fitting regression equation is that
the standard deviation of the observations about the fitted
plane should be appreciably less than that of the observations
about the mean. Table 4 gave the standard deviation of egg
components about the mean as 218.55 += 24.57. That for egg
components about the regression plane shown in Figure 3 was
63.35 + 7.55, or less than one-third. It is true that we are
considering functions obviously highly correlated, but it is
gratifying to be able to give such a satisfactory mathematical
expression to their interrelations.
These regressions are based on completed performance only.
We now come to the question of the activity of these individuals
at stated intervals during their lives.
Table 7 contains the weekly record of survivors, blood units
consumed, oviposition periods, and eggs deposited for sixteen
of these isolated females. The four specimens fed only once
were excluded, since this fact obviously affected their subsequent
activity. From the data in this table weekly rates per survivor
were computed and are included.
eS
231
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289. PROC. ENT. SOC. WASH., VOL. 36, NO. 7, OCT., 1934
The number of individuals was obviously too small to justify
any detailed analysis of these weekly rates. We shall examine
them merely to see whether there were any definite time trends
inactivity. Apparently, weekly blood consumption did not vary
to any extent. The same was true of oviposition periods.
Weekly egg components per individual, however, decreased with
age. Although rates for later weeks varied oreatly, there was a
definite downward trend during the first six weeks when they
were more stable. The same was true of eggs deposited in
terms of oviposition periods. For these few specimens we may
say, therefore, that egg-laying activity was greater early in life,
whereas blood consumption and frequency of oviposition con-
tinued in much the same way until the end. The question of
trend of egg-laying rate with increasing age will now be analyzed
from observations on a larger group of individuals.
The Trend of Egg-laying Capacity with Age.
Egg-laying capacity and longevity were studied from records
of 118 females subdivided into ten lots, half of which were
offered blood meals once a week and the other half every three
days. Daily records were kept of deaths and of the number of
eggs deposited. All 118 individuals emerged on the same day
and comprise Lot 6 of Table 2. Temperature at the beginning
of the experiment was 27° C.
The first question to be investigated was whether the frequency
of feeding affected the longevity or total egg production of
these specimens. Consequently, the mean age at day of death
and the eggs deposited per female were computed from the origi-
nal data. These are given below:
118 Females.
Frequency of | Mean age on day Egg component
blood meal of death per individual
Onceaiweee 64.7 = 2.2 206.4
Everys sudays sn O57 e853 190.2
MiGtallas 3% see. 622) -=S kG 198.3
The difference in length of life between the two groups was
insignificant. Probable errors for the mean egg components
could not be computed since the records applied to lots, not to
individuals, but the two means are so similar that this omission
is unimportant. The two groups may be combined for further
analysis.
The records of eggs deposited by these 118 females were
placed on a weekly basis and rates per survivor at the beginning
of the week were computed and are given in Table 8. They
are plotted in Figure 4.
Eges per Survivor
PROC. ENT. SOC. WASH., VOL. 36, NO. 7, OCT., 1934
TABLE 8.
233
OBSERVED AND Exprcrep EcGc-Ltayinc Rates oF CoNGREGATED STEGOMYIA
FEMALES OFFERED A BLoop Meat Once a WEEK oR Every THREE Days.
EGGS PER EXPECTED EGGS
WEEK SURVIVORS EGGS SURVIVOR AT | PER SURVIVOR
FOLLOWING | AT BEGINNING| DEPOSITED SEES Le Paes
EMERGENCE OF WEEK DURING WEEK Sn iwese am wiSsIe
(1) (2) (3) (4) (5)
@) 118 0 0 0)
1 118 5,306 44.97 41.13
2 115 3,605 Sled 35.44
3 109 3,509 32.19 30.54
4 108 Psy DEES S53
5 98 DESO 26.19 22.67
6 88 1,726 19.61 19.53
7 79 1,220 15.44 16.83
8 67 925 13.81 14.50
9 59 472 8.00 12.50
10 51 458 8.98 10.77
11 39 466 11.95 9.28
12 29 184 6.35 7.99
13) 16 91 5.69 6.89
14 9 65 1622. 5.94
15 4 51 QS 6D
16 1 0 0 4.41
Week following Emergence
of the Week.
Figure 4.—Observed and Expected Egg-laying Rates per Survivor at the Beginning
234 PROC. ENT. SOC. WASH., VOL. 36, NO. 7, OCT., 1934
It is apparent that the first weekly egg-laying rate was the
highest and that later rates decreased more or less continuously.
The actual amount of decrease was greater in earlier weeks,
so we could not use a straight regression line here as we did in
describing the relationship between total egg component and
days lived shown in Figure 2. To obtain a mathematical
expression of this relationship, it was necessary to use an
exponential equation. The one plotted in Figure 4 was:
Mean weekly egg component per survivor = 51.42. 0.1489 (age in weeks)
This equation gives an average weekly rate of decrease in
egg production of 15 per cent, and from ic theoretical egg-laying
rates were computed. These are given in Table 8. They lie
on the fitted curve in Figure 4. With the exception of the last
two observed rates, the curve fits remarkably well, and may be
considered a very satisfactory expression of the trend of these
observations.
From this equation we may also compute the maximum
number of eggs per female by summating the weekly egg com-
ponents throughout life and assuming that life continues
until the ultimate egg-laying capacity is reached. For the
group we are considering this would average 350 eggs per female.
Longevity of Stegomyia Females.
Two series of records formed the basis for the analysis of
longevity, one obtained from the blood-fed lots of 118 speci-
mens just discussed, and the other obtained from 190 specimens
that were fed throughout life on honey and water only. The
blood-fed lots were started in January, 1930, the non-blood-fed
lots in October and December, 1930.
The mortality records for these two series of observations
were placed on a weekly basis and the number of survivors at
the beginning of each week was determined. The results are
given in columns (2) and (3) of Tables 9 and 10. From these
populations and deaths mortality rates were computed and are
given in column (4).
235
PROC, ENT. SOC. WASH., VOL. 36, NO. 7, OCT., 1934
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PROC. ENT. SOC. WASH., VOL. 36, NO. 7, OCT., 1934 237.
To compare longevity in these two groups the distributions
of survivors had to be put on a comparable basis. This was
done by starting each with 1,000 individuals and computing
the number of survivors at the beginning of each successive
week by applying the death rates in column (4) and deducting
the computed deaths. In this way columns (5) and (6) were
obtained for each table. Column (5), indicating the number
of survivors at the beginning of each week out of 1,000 emerging
on the same day, gives the familiar /. curve of the life table
which is plotted for each distribution in Figure 5.
1000 4 ——*— 4 x—_x—_
x
° Shs
a
900
800
700
600
x
500 ~ ny
ae
«——~- Females offered a blood meal once a ‘
week or every three days
x x Females never offered a blood meal
400
300
200
\
100
Week following Emergence
Figure 5.—Survivors at the Beginning of Each Week of Two Groups of 1,000
Stegomyia Females Emerging.
The mean age at death of individuals in the non-blood-fed
group was 82.2 + 0.77, which was twenty days later than that
for the blood-fed group. We must compare columns (3) and (4)
238 PROC. ENT. SOC. WASH., VOL. 36, NO. 7, OCT., 1934
of Tables 9 and 10 and the two curves in Figure 5 to see what
this difference means.
Table 10 indicates that practically no deaths occurred in the
honey-and-water-fed group until the tenth week of life. During
this week 37 specimens died, and mortality continued very
high until all individuals were dead. Deaths among the
individuals in the blood-fed group were scattered throughout
life. Figure 5 shows the difference in the form of the curves
very clearly. Survivors in the blood-fed group began to de-
crease in number after the first week, while the honey-and-
water-fed group remained close to the upper limit until the
tenth week and then dropped precipitously.
The last two columns in Tables 9 and 10 give the average
expectation of life in weeks and in days for survivors at the
beginning of the week. The blood-fed group started at emer-
gence with a mean expectation of 62.2 days or nine weeks, the
non-blood-fed group with 82.2 days or nearly twelve weeks.
Beginning with the tenth week the mean expectation of life
was the same in both groups.
The difference in longevity between these two groups is
clear-cut and unmistakable. The survivorship curve of the
non-blood-fed specimens approaches in form that of the theoret-
ical rectangular curve described by Pearl and Doering (1923)
as approached in Proales decipiens and by Pearl (1928) in the
wild type of Drosophila melanogaster. Individuals in this type of
population nearly all survive to a given age and then die almost
simultaneously.
It is believed that this difference in longevity was probably
due to diet. Howard (1925) pointed out the effect of blood
consumption on the life of the female when he said: “Blood
food, however, in hastening the development of the eggs shortens
the life of the mosquito. A diet of honey, on the other hand,
prevents the development of the eggs and prolongs life.”
There was an interval of nine months between the experiment
with the blood-fed specimens and the other, but both series
were run during summer months when atmospheric conditions
were presumably similar. Beeuwkes ef a/. (1933), found that
humidity had a noticeable effect on the longevity of stegomyia
females. Experiments were run in Yaba (Southern Nigeria)
and Gadau (Northern Nigeria) and from the data given the
following means were computed:
Laboratory Mean tem- Mean relative Mean days
perature, humidity, lived
C. (per cent)
Yaba(Ss Nigeria) ee 26.2 86.9 96.5
Gadau (N. Nigeria)._......-.---..-.- 26.8 49.7 41.7
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