Papers on Aphididae

MISSING IMAGE

Material Information

Title:
Papers on Aphididae
Physical Description:
Serial
Language:
English
Creator:
Phillips, W. J
Davis, John J ( John June ), 1885-1965
Publisher:
Government Printing Office. ( Washington, D.C )
Publication Date:

Subjects

Genre:
serial   ( sobekcm )

Record Information

Rights Management:
All applicable rights reserved by the source institution and holding location.
Resource Identifier:
aleph - 029622135
oclc - 27899811
System ID:
AA00017574:00003

Table of Contents
    Front Cover
        Page i
        Page ii
    Table of Contents
        Page iii
    List of Illustrations
        Page iv
    Introduction and synonymy
        Page 17
    Distribution
        Page 18
    Food plants
        Page 19
    Descriptions
        Page 20
        Page 21
        Page 22
        Page 23
        Page 24
        Page 24a
        Page 24b
        Page 25
    Life history and habits
        Page 26
        Page 27
        Page 28
        Page 29
        Page 30
        Page 31
        Page 32
        Page 33
        Page 34
        Page 35
        Page 36
        Page 37
        Page 38
    Natural enemies
        Page 39
    Bibliography
        Page 40
Full Text




TECHNICAL SERIES No. 25, PART 11. TATEL1BfR B AR
U. S. DEPARTMENT OF AGRICULTURE,
BUITEATU OF IN'I'OMOLO(Y.
L. 0. HOWARD, Entomologist and Chief of Bureau.



PAPERS ON APHIDIDE.







THE YELLOW CLOVER APHIS.





BY


J. J. DAVIS,

Entomological Assistant, Cereal and Forage Insect Investigations.






ISSUED NOVEMBER 12, 1914.





















WASHINGTON:
GOVERNMENT PRINTING OFFICE.
1914.





















B UREA U OF ENTOMOLOGY.

L. O. HOWARD, Entomologist and Chief of Bureau.
C. L. MARLATT, Entomologist and Acting Chief in Absence of Chief.
R. S. CLIFTON, Chief Clerk and Executive Assistant.
F. H. CHITTENDEN, in charge of truck crop and stored product insect investigation. A. D. HOPKINS, in charge of forest insect investigations. W. D. HUNTER, in charge of southern field crop insect investigations. F. M. WEBSTER, in charge of cereal and forage insect investigations. A. L. QUAINTANCE, in charge of deciduous fruit insect investigations. E. F. PHILLIPS, in charge of bee culture. A. F. BURGESS, in charge of gip:y moth and brown-tail vmoth investigations. ROLLA P. CURRIE, in charge of editorial work. MABEL COLCORD, in charge of library.

CEREAL AND FORAGE INSECT INVESTIGATIONS.
F. M. WEBSTER, in charge.

G. I. REEVES, W. J. PHILLIPS, E. O. G. KELLY, J. A. HYSLOP, J. J. DAVIS, C. N.
AINSLIE, W. R. WALTON, A. B. GAHAN, J. M. ALDRICH, V. L. WILDERMUTH, W.R.
MCCONNELL, T. D. URBAHNS, R. A. VICKERY, PHILIP LUGINBILL, C. W. CREEL, HENRY Fox, GEO. G. AINSLIE, HARRISON E. SMITH, P. H. TIMBERLAKE, R. N.
WILSON, VERNON KING, E. H. GIBSON, L. P. ROCKWOOD, F. H. GATES, PHILIP B.
MILES, T. R. CHAMBERLIN, A. F. SATTERTHWAIT, T. ScoTT WILSON, D. J. CAFFREY, W. H. LARRIMER, L. J. BOWER, C. M. PACKARD, ADOLPH H. BEYER, CLAUDE L. SCOTT, S. J. SNow, DESLA BENNION, R. J. KEWLEY, GEO. W. BARBER.
C. F. TURNER, Jos. S. WADE, W. E. PENNINGTON, W. T. EMERY, D. G. TOWER.
P. R. MYERS, E. L. BARRETT, entomological assistants. W. B. HALL, J. T. MONELL, collaborators.
II
























C 0 NTE N T S.

Page.
Introductiou ---------------------------------- -_ -------------_ ------- 17
Synonym y ---------------------------------------------------------------- 17
G eneric positioii ------------------------------------------------------ 18
D istribution -------------------------------------------------------------- 18
In A m erica- -------------------------------------------------------- 18
In A sia --------------------------------------------------------------- 19
Food plants -------------------------------------------------------------- 19
D escriptions ------------------------------------------------------------- 20
W ingless stem-mother ------------------------------------------------- 20
W inged viviparous female ---------------------------------------------- 21
W ingless viviparous female --------------------------------------------- 23
W inged m ale --------------------------------------------------------- 23
W ingless oviparous female --------------------------------------------- 25
E gg ----------------------------------------------------------------- 2 6
Life history and habits ----------------------------------------------------- 26
M ethods of study ------------------------------------- : --------------- 26
Generation experim ents ------------------------------------------------ 27
Uolting --------------------------------------------------------------- 38
Fecundity in relation to other species ----------------------------------- 38
N atural enem ies ---------------------------------------------------------- 39
Bibliography ------------------------------------------------------------- 40
III

























ILLUSTRAT IONS.


PLATE.
Page.
PLATE II. Outdoor rearing shelters used in life-history studies on the yellow
clover aphi --------------------------------------------- 4

TEXT FIGURES.
F. 1.0. Map showing distribution of the yellow clover aphis (Callipterus trifolii) in the United States-- ..---. ----------------------------- 19
1 1. The yellow clover aphis (Callipterus trIfolii): Winged viviparous fem ale and details ............................................... 11
12. The yellow clover aphis: Wingless viviparous female and details..... 23 13. The yellow clover aphis: Winged male and antenna ................. 24
14. The yellow clover aphis: Wingless oviparous female and details ..... 25
15. Diagram showing periods and succession of generations in the yellow
clover aphis, La Fayette, Ind., 1913 ----------------------------- 34
IV







U. S. D. A., B. E. Tech. Ser. 25, Pt. II. Issued November 12, 1914.

PAPERS ON APHIDID4.


THE YELLOW CLOVER APHIS.
(('allipterus trifolii lonell.)
By .J. J. DAVIS,
Entomological Assistant, Cereal and Forage Insect In restigations.
INTRODUCTION.
The yellow clover aphis, or plant louse (Callipterus trifolii Monell), is common and oftentimes abundant throughout the eastern half of the United States, although it has never been considered a pest in this country and consequently little of its life history and habits has been studied. The author takes this opportunity of gratefully acknowledging the assistance of Mr. Alfred F. Satterthwait and Dr. Henry Fox, both of the Bureau of Entomology, who continued the experiments during the writer's absence.
SYNONYMY.
Gallipterus trifolii was first described by Mr. J. T. Monell (1882) 2 from specimens collected at Washington, D. C., and forwarded to him by Mr. Theodore Pergande. Buckton (1899) described this species under the name Chaitophorus maculatus from specimens collected in India on lucern, or what is known in America as alfalfa (Medicago sativa). Dr. Bashambar Das, of the Government college, Lahore, India, has very kindly sent us specimens of maculatus Buckton, collected on the type host plant (Medicago sativa), and a careful examination has shown no characters distinguishing it from Monell's trifolii. Dr. Das writes that to his knowledge the species has not been collected on Trifolium in India.
What will probably prove to be identical with the species under discussion was described by Kaltenbach 3 in 1846 as Aphis ononidis. We have not as yet had an opportunity to examine the European material relating to this species, however, and thus prefer to leave this question undecided until a comparison can be made. Should it prove identical, it will naturally have priority over both trifolii and maculatus.
I Synonym: Chaitophorus maculatus Buckton.
2 Dates in parenthesis refer to Bibliography, p. 40.
3 Kaltenbach, J. H. Entomologische Zeitung, Stettin, Jahrgang 7, pp. 173-174, June, 1846.
17





18 PAPERS ON APHIDID1E.
GENERIC POSITION.
Whether or not Kaltenbach's ononidis is specifically synonymous with trifolii, it can still be definitely placed in the same genus. Aphis ononidis was described first by Kaltenbach, and the species has since been placed in the genus chaitophorus by Koch, Myzocallis by Passerini, and Therioaphis by Walker. As Wilson 1 has pointed out, Therioaphis seems hardly sufficiently distinct to be placed as a separate genus. Buckton described the species maculatus, which is now considered a synonym of trifolii, in the genus Chaitophorus, but it is universally considered as not a member of this genus. The species trifolii was placed in the genus Callipterus by Monell, who described the species, and it has since been placed in the genus Myzocallis by some authors. This species can not be placed in Mordwilko's generic table,2 but can be run down in Wilson's table 3 to the genus Callipterus, although in the list of species Wilson places trifolii Monell under the genus Myzocallis. Likewise in studying Wilson's synopsis of characters of the genera this species can best be placed in the genus Callipterus. All of the characters given for the genus Callipterus agree reasonably well for trifolii, while this is not the case with the characters given for the genus Myzocallis.
We must therefore conclude that trifolii should be placed in Gallipterus, although it is recognized as an intermediate species and not a typical member of the genus.
DISTRIBUTION.
IN AMERICA.
In America Callipterus trifolii is generally distributed throughout the eastern half of the United States, except possibly in the extreme southern portions. The species was originally described from Washington, D. C., and has since been reported in literature from Iowa (Osborn and Sirrine); Delaware (Sanderson); Illinois, Minnesota, Kansas, North Dakota, Virginia, Missouri, and New York (Davis); Michigan and New York (Gillette); New Jersey (Smith); Indiana (Morrison); and Nebraska (Williams). In addition to these States Mr. R. A. Vickery has taken it in North Carolina, Mr. George G. Ainslie in South Carolina, Tennessee, and Kentucky, and Messrs. E. O. G. Kelly and Paul Hayhurst in Maryland. Prof. F. M. Webster found it in Indiana as early as 1887, our first record of its capture after the original collections were made in 1880. The accompanying
SWilson, H. F. Can. Ent., vol. 42, no. 8, pp. 253 -259, Aug., 1910.
SMordwilko, A. Ann. RItept. Zool. Mus. Imperial Acad. Sei., vol. 13, pp. 353-384, Sept. 17, 1908.
SLoc. cit.





THE YELLOW CLOVER APHIS. 19

map (fig. 10) shows the present known distribution of the species in the United States, compiled largely from records in this office made by various members of the staff.
IN ASIA.
In Asia the species under consideration was first reported from Jodhpur, India, by Buckton (1899), and the writer has received specimens from Dr. Das, presumably collected at Lahore, India.

FOOD PLANTS.
In America the universal food plant of this species is red clover (Thfolium pratense), on which it is usually to be found on the underside of the leaves, living more or less solitary. We have reared it also on white clover (Trifolium repens).
In 1909 Mr. T. H. Parks, at that time connected with the Bureau of Entomology, conducted a series of experiments in testing
the ability of Callipterus trifolii to live on various plants. The -.'
plants used in these experiments ... v
were white clover sweet clover. .* .
(Melilotus spp.), timothy, spring *' .. ,
vetch, Japan clover (Lespedeza -,. .- ,
spp.), sanfoin (Unobrychis sa- ------
tiva), alfalfa, bur clover (Medi- ..----.-cago maculata), alsike clover, "....
English clover, and mammoth -clover (Trifolium medium perenne). The aphis would not breed on the first seven plants in these tests. On bur clover FIG. 10.-Map showing distribution of the yellow
it lived for a number of days clover aphis (Callipterus trifolii) in the United
States. (Original.)
and then disappeared, the re- tates. (Original.)
sults in this case being inconclusive. On alsike, English, and mammoth clovers (all species of Trifolium) they bred without difficulty.
In India the species lives on lucern (Medicago sativa)-indeed Buckton received reports that it was destructive to this plant-and, as already stated, Dr. Das reports that it has never been found in that country on Trifolium. We are as yet unable to explain why this species lives on Trifolium and not alfalfa in America, while in India it is found on alfalfa but apparently not on Trifolium.





20 PAPERS ON APHIDIDY.
DESCRIPTIONS.
WINGLESS STEM-MOTHER.

General color gamboge. Head and body bearing numerous tuberculate capitate hairs or spinelike hairs in a more or less regular order, as follows: Head with three in a row on each side of the dorsal median line; two pairs, one not always conspicuous, projecting from the front, and a single one on each side near the posterior border; prothorax with two near anterior border and six along the posterior border; remainder of body bearing two rows of capitate hairs on each side of the dorsal median line, the tubercles bearing these two rows being confluent, so as to present the appearance of a single row on each side, with two hairs to each tubercle; laterad of these are two distinct rows of tuberculate hairs on each side. The tubercles on the head and prothorax are dusky at their apices and the capitate hairs are black; other tubercles are rimmed at base with a blackish line, the apices and hairs being black.
Eyes red. Antenna reaching about to the cornicles; segment III longest, it being more than one-third longer than VI (base + filament), the base and filament of VI subequal; segment III with 7 to 10, usually 8, oval sensoria in a row, V and base VI with the usual distal ones; segments I and II concolorous with body; III and IV pale, but slightly darker than body color and with a faint brownish tint; V becoming blackish towards tip, and VI black. Beak not quite reaching coxv of second pair of legs. Legs paler than body color, the tip of tarsus black. Cornicles as long as width at the base, being about as long as antennal segment I, concolorous with body, the basal rim and tip with a narrow blackish line, on border. Cauda globular, concolorous with body, bearing a number of moderately long unknobbed hairs. Anal plate conspicuously bilobed.
Measurements made from two individuals, May 5, 1913, at La Fayette, Ind., immediately upon placing in balsam and before any change of form occurred, are as follows: Length of body, 1.55 mm.; width, 0.77 and 0.81 mm., respectively; length of spines, 0.078 mim.; of tubercles, 0.05 mm.; length of cornicles, 0.061 mm.; width at tip,
0.035 mm.; antennal measureIuients as follows:

VI VI Ttl
I. II. IIl. IV. V. bsae. fia nt.l.

Mm. Mfm. Mm. Mmn. Min. Ill. Mm. Mill.
0. Cwl 0. 052 0.435 0. 261 0. 234 0. 148 0. 139 1.330
.................... 417 .243 .252 .148 .148 ..........
1 .052 .495 .2s7 .2i1 1 56 .139 1.451
S .0-52 .487 .278 .243 .148 .139 1. 416





THE YELLOW CLOVER %PHIS. 21

WINGED VINVIIAROUTS FEMALE.
(I [i. 11.)
General color of body pale yellowish green, with dusky tuberculate areas more or less uniformly placed on the dorsum. Capitate hairs and tubercles not so prominent tts in the apterous forms. Head bearing three capitate hairs, more or less in a row on each side of the median dorsum, an additional one on each side, near the posterior margin, and a pair projecting from the front, one on each side of the median ocellus. Prothorax with two similar hairs near the posterior margin and an additional one on each side. The thoracic plate













/_1/




FIG. It.-The yellow clover aphis (Callipterus trifolii): Wingud viviparous female, much enlarged a, Antenna of same; b, cornicle of same; c, end of abdomen and cauda of same, lateral view; d, cauda and anal plate of same in natural position; e, cauda of same, depressed, showing its full length. a-e, Greatly enlarged. (Original.)
bears numerous minute pits or clear circular areas, some of which bear hairs. Abdomen with a row of coalesced tuberculate dusky areas, each area usually bearing two capitate hairs, as described for the stem-mother, and a longitudinal row of dusky tuberculate areas, each area smaller than those just mentioned and each bearing but a single hair. On the margins, and often projecting from its body, thus giving the border the appearance of being coarsely dentate, are rows of setm bearing tuberculate areas, one row on each side. Although there is some slight variation in the position of the hairs and maculations, and the maculations on the abdomen also vary more or less in shape and size, the foregoing is the usual arrangement.
483060-14- 2






22 PAPERS ON APHIDIDE.

Eyes dark red to brown. Antennze about as long as the body; relative lengths of segments as for stem-mother; segment III bearing 9 to 12 oval sensoria in a row, and the usual ones at apex of V and of base VI; concolorous with body at base, gradually darkeni ag towards apex (fig. 11, a). Beak not reaching coxo of second pair of
legs. Wings hyaline, veins dark brown to blackish, with a very narrow brownish border, and small brownish areas at their apices; basal half of radial sector (stigmal veins) obsolescent toward basal half; terminal forks of the median (discoidal vein) branching at a point slightly less than one-half the distance from the tip of wing to where the media first branches; width almost one-half its length. Legs concolorous with body, excepting tarsi, which are nearly black. Cornicles dusky and about as long as the width at base (fig. 11, b). Cauda globular and constricted at middle; a lateral view (fig. 11, c) shows it to be decidedly upturned so that a dorsal view usually shows it to be globular (fig. 11, d), although when pressed down, as is usually the case in mounted specimens, it appears more or less oval and pointed from tip from above (fig. 11, e). Anal plate dusky and bilobed and described for the stem-mother.
Measurements: Length of body, 1.345-1.564, average, 1.454 mm.; width, 0.582-0.691, average, 0.642 mm.; expanse of wings, 4.654 mm.; length of wing, 2.0 mm., width, 0.80 mm.; cornicles, 0.066 mm.; cauda, 0.139 mm.; hind tarsus, 0.129 mm.; antennal measurements as follows:

I. III. IV. V. VI bse.
men t.

Mm. Mm. Mm. Mm. IMm Mm Mm.
0.0815 0.057 0.522 0.391 .......... .. ...............I
.0733 .057 .505 .383 0.359 0.179 0.179 .0733 .049 .513 .375 .326 .163 .163
.0733 .057 .538 .359 .350 .179 .179 .0733 .057 .513 .379 .310 .179 .179 .0815 .057 .538 .375 .326 .147 .147 049 .522 .375 .310 .163 .163 ...........057 .522 .342 .318 .179 .163
.0815 .057 .513 .375 .310
.057 .522 .359 .310 .163 155 .0815 .057 .497 .359 .310 .163 .146 .0815 .057 .489 .359 .301 .155 .155 2 .07 .043 .514 .271 .243 .143 .143
(2) .057 .471 .313 .2S5 .143 .157
(3) 428 .285 .285 .157 .143
(3) .414 .328 .271 .157 .143
(3 .042 .428 .285 .285 .143 .143
(3) .042 .414 .271 ..
499 .342 .299 .IS 28
(3 ...... 485 .357 .............................
3.043 .043 .428 .314 .271 .157 12S
3.071 .057 .485 .314 .314 .128 .128
I From specimens collected at T'rbana, Ill., except is poted.
2 Measurements by 3. T. Monell from specimens collected by Paul Hayhurst, at Washington D. C.
3 Measurements by J. T. Monell from type specimens, which were collected at Washington, D. C.





THE YELLOW CLOVER AP1IIS. 23

WINGLESS VIVIPAROUS FEMALE.
(Fig. 12.)

General color pale yellowish green, with dusky tuberculate areas bearing capitate seto on the dorsum, arranged as described for the stem-mother and as shown in figure 12. Both the tubercles and capitate hairs (fig. 12, a) are more prominent in this form than in the winged female.
Eyes (lark red. Antenne almost as long as the body; relative lengths of segments as in other forms; segment III with 7 to 12, usually 9 or 10, oval sensoria in a row and the usual distal ones on V and base of VI; basal segments pale, the remaining ones gradually darkening toward the tip. Beak scarcely reaching coxve of second pair of legs. Legs pale, excepting the joints, which are dusky, and the tarsi, which are black. Cornicles (fig. 12, b) and cauda as in winged female.
Measurements (from speci- P
mens mounted in balsam): Length of body, average, 1.60 mm.; width, average, 0.76 mm.; antenna, averages, segment I, 0.076 mm.; II, 0.053 F~G. 12.-The yellow clover aphis: Wingless viviparous female, much enlarged. a, Lateral capitate hair of same; mm.; III, 0.517 mm.; IV, b, cornicleof ame. a, b, Greatly enlarged. (Original.)
0.347 mm.; V, 0.316 mm.; VI base, 0.156 am.; VI filament, 0.162 mm.; total, average, 1.627 mm.; cornicles, 0.062 mm.; cauda, 0.171 mm.; hind tarsus, 0.130 mm.
WINGED MALE.
(Fig. 13.)
Wingless males unknown. Head and thorax light olive-green; abdomen pale yellowish green, with rather conspicuous black markings. Similar to the winged female but smaller, with more slender body (the illustration, fig. 13, shows the abdomen too robust), and the dusky tubercular areas on the dorsum of abdomen smaller. Head and thorax bearing a number of hairs in a more or less regular order as shown in the illustration. As stated, the abdominal markings are reduced in comparison to those on other forms. The areas of the two median rows are larger than those of the lateral rows, but they vary



B




24 PAPERS ON APHIDIDX.


more or less in the number of hairs borne on each, some having two and others but one. The cephalic and thoracic hairs are unknobbed or but inconspicuously capitate,fand those on the abdomen may also be capitate or not, usually inconspicuously knobbed.
Eyes dark red to blackish. AntennT, dusky to black, reaching a little beyond tip of abdomen; relative lengths of segments as in the other forms; segment III with 13 to 16 oval sensoria more or less in a row; IV with 3 to 5; V with 3 to 5, not including the usual distal one; and VI base with 1 sensorium surrounded by several smaller ones at the tip (fig. 13, a). Beak not reaching coxve of Second pair of legs. Venation as described for the female. Cornicles and cauda dusky, the latter edged with black; in form they agree with those of the viviparous generations.
















Fu. 13.-The yellow clover aphis: Winged male, much enlarged. a, Antenna of same ,greatly enlarged.
(Original.)
Measurements (averages): Length of body, 1.3 mm.; width, 0.53 mm.; expanse of wings, 4.1 mm.; length of wing, 1.8 mm.; cornicles, 0.049 mm.; hind tarsus, 0.130 mm. Antennal measurements as
follows:

1. ll. Ill. IV7. V. VI VI otl
base. filament. rol
Mm. Mm. Mm. Mm. Mm. Mm. Mm. Mm.
0.065 0.053 0.473 0.277 0.261 0.147 0.163 1.439 .065 .057 .473 .277 .277 .147 .163 1. 459
.065 .057 .522 .277 .293
.0s .065 .546 .293 .309 .171 .15. 5 1. 620
'.065 .049 .505 .326 .309 .163 .163 1.580 '.073 .049 .522 .326 .318 .155 .155 1.598 1 .05 .049 .530 .342 .293 .147 .147 1.573 .: .049 .554 .359 .277 .139 ,139 1.582 ..
Measurements made immediately upon mounting in balsam; other antennal measurements are fro balsam mounts after standing and clearing.













Tech. Series 25, Part 11, Bureau of Entomology, U. S Dept. of Agriculture. PLATE 11.




























































OUTDOOR REARING SHELTERS USED IN LIFE-HISTORY STUDIES ON THE YELLOW CLOVER APH IS.








THE YELLOW CLOVER APHIS. 5

WINGLESS OVIPAROUS FEMALE.
(Fig. 14.)

General color yellowish orange to orange when fully mature. The body is usually yellowish when the female first reaches maturity, but as the eggs, which are of an orange color, begin to develop within the body they show through the semitransparent skin, giving the conspicuous orange color to the body. Head and prothorax pale yellow, mesothorax and metathorax varying from yellow to orange according to age since maturity. Dusky tuberculate areas conspicuous. These and the black capitate hairs arranged as on the stem-mother.
Eyes blackish or brownish black. Antennoe not reaching to base of cornicles; relative lengths of segments as in other forms; segment III bearing 7 to 10 oval sensoria in a row, and segments V and base of VI with the usual distal areas; basal segments concolorous with head, others gradually darkening toward apex. Legs pale yellowish except tarsi; proximal halves of hind tibiav swollen and bearing 25 to 40 inconspicuous, irregularly placed, circular sensoria (fig. 14, a). Cornicles and cauda concolorous with abdomen, often dusky at 50A
margins. Cauda knobbed as in other forms, but the anal plate is rou nd e d a t the tip and does not have the slightest emargination (fig. 14, b). FIG. 14.-The yellow clover aphis: Wingless oviparous
Measurements: Length female, much enlarged. a, Hind tibia of same;
b, cauda and anal plate of same. a, b, Greatly enof body (average), 1.8 mm.; larged. (Original.)
width, 0.86 mm.; cornicles, 0.061 mm.; hind tarsus, 0.134 mm.;
antennal measurements as follows:
Il IV VI VI Total.
I. II. III. IV. V. base. filament.

Mm. Mm. Mm. Mm. Mm. Mm. Mm. Mm.
0.082 0.057 0.473 0.236 0.228 0.139 0.139 1.354 .065 .057 .434 .204 .204 .122 .139 1.225 .065 .057 .407 .204 .204 .147 .139 1.223 .065 .057 .391 .196 .212 .130 .147 1.198 .065 .065 .399 .196 .212 .130 .147 1.214 .082 .065 .434 .196 .212 .139 .147 1.275 .073 .057 .407 .196 .212 .130 .147 1.222 .065 .065 .399 .196 .212 .130 .147 1.214 .065 .057 .383 .196 .212 .139 .139 1.191 .073 .065 .391 .179 .179 .130 .139 1.156 .073 .057 .359 .179 .196 .122 .139 1.125





26 PAPERS ON APHIDID.

EGG.
The egg is elliptical, bright orange when first laid, gradually changing to shining jet black, and measures 0.575 mm. in length by 0.248 mm. in width.
LIFE HISTORY AND HABITS.
With Callipterus trifolii, as with most other plant-lice, a number of generations of winged and wingless viviparous females are produced during the summer, and the true sexes, consisting of winged males and wingless oviparous females, appear in the fall; these females in turn laying eggs on the stems and leaves of clover to carry the species over the winter months. This species does not have an alternate host, nor does it ever pass the winter, in the latitude of La Fayette, Ind., as viviparous females. However, in the Southern States it probably does winter as viviparous females, for Mr. Geo. G. Ainslie found the viviparous forms not uncommon at Clemson College, S. C., in December (Dec. 3, 1908), whereas a careful search for sexual individuals proved fruitless. Similar observations were made by Mr. R. A. Vickery at Salisbury, N. C., November 11, 1909.
As is characteristic of this tribe of plant-lice (Callipterini) the species under discussion is sporadic in habit and is very easily roused, the least disturbance causing it to jump from its host. This habit is much to its advantage, for it seems to render the species almost immune from predaceous and parasitic enemies.
METHODS OF STUDY.
The life-history studies here recorded were made in outdoor shelters, and the vivaria used were chimney cages such as had previously been used and described by the writer for other species of aphides.' The outdoor shelter consisted of frame benches, placed under a canvas canopy (P1. II) to protect the cages and shelters from the intense midsummer sun. This was necessary, for while the aphides might live out of doors without special protection from the sun, there they have the advantage of a constant circulation of air which is not possible within the glass chimney cages.
The generation series were begun with the stem-mother hatching from the winter egg, and the first and last born generation series continued to the true sexual forms in the fall. In this way the maximum and minimum number of generations annually was obtained under what might be considered optimum conditions, at least from the standpoint of natural enemies and harmful climatic conditions. U. S. Dept. Agr., Bur. Ent., Tech. Ser. No. 12, Pt. VIII, p. 159. (See also Bul. 25, Pt. I. of the same
series.)





THE YELLOW CLOVER APlIS. 27

GENERATION EXPERIMENTS.
Eggs which were laid on the stems andI leaves of red clover plain in the fall of 1912 were kept out of doors under natural conditions throughout the winter, and these began to hatch (luring the latter half of April, 1913. The young which were used to begin the continuous-generation experiments hatched April 22, and it is worthy of note that this was almost a month af ter the eggs of Macrosiphum pisi, kept under identical conditions, hatched this same year. This is all the more unusual since trifolii invariably produces the sexual forms and deposits its eggs noticeably earlier in the fall than does pisit.
The young stem-mother-the aphis hatching from the egg being so called-which hatched April 22 and was placed on a red clover. plant gave birth to her first young on May 4 and her last young on May 30. In the first-born generation series, that is, taking the first young of the first young in each new generation, 17 generations Were obtained, counting the oviparous generation as the last. On the other hand, in the last-born generation series, beginning with the last to be borne by the individual which hatched from the egg April 22 and following the series of the last born of each "last-born" generation, there wore in all only 8 generations. In other words, there was a maximum of 17 generations and a mini-Mum of 8, from which we may reckon that the approximate average number of yearly generations is 12~ (Tables I and II).









28 PAPEIR6 ON APHIDID.E.


to 00 cla m 00 1-4 Vt 00 "!r = t- to to = "ll to eq N N Cq m M M t4 C4 M
79
C14
ca



m m CR N N clt -.4 N N N C4-4 N

tk t c

o 0
*.;.

w m t- -"M t- w cc m to w r- :,X.c ac m r- tc AP
go

C3 04


uj
+ + + + ++ + +
0 0 > 1-4 Cq 00 LO x
4w LO I-i C06 CIS .1; k6 ci cli 1; M. m I-i vi t1i ci C4 ci -1: vs ci
> O 03
>


UID = to -"4 '"q LO to I"- N -4 C C m UID 00 -4
m t- M N,.rr Cq N -t* Cc r 00 C9 00'"4 ko


Z.

C) C> eq
1-41-4





C4 ko Cc Lr) -4 N 10 N to "'t cp
N M C14 C4 C4 t4 cq N

r-h



(M to 00 1-4"W to t, C> to vz (M C'D U-., m CIA C4 Cq N N C4 m N C,4 C4
co
04
> to bc "4.; >
:3 > 0
:3 5 5 A 3 9

10
cq to m m m 0 m t- t- t- 1- 0 t- cc O cc -,r : 't 4
C13



w 0
k* r-4 I- -!V N =to 00 in f- 1-4 IW cl
1-4 Cq m V-4 N -4-4 C4 C14
4J
cc o (D v >, >, 4i 4-: 4.;
>) U U bt
z ZIA"" >
rn


te
=
C, 0 '0
_4 C-4 C4 0 C4 o, 4m 'j,
00
bc bb
2F .
ch

>1









to


WD L,



00
C4 m -W U.) rz t .-0 C% "r to 0 t 00 M


L. 0
'4 (P
4< to t



44

toolp
tk CD
(p
: >1









THE YELLOW CLOVER APHIS. 29



U011S.IquaW qllqlla


U011131OU02 qjuaAas
..........

-UO141310ua qjxjs


*U01 1131OU02 iqljlf


U01 1131;DU02 qjln0a


ulaua2 pj!qj,


U01 VIOUaAl PU039S


U01julaU32 Ism


*U011VIOU02 qjU0.nU0A0S ---------- I


U01116JOU02 TPU004xis .


.U011161OU02 lqjua njla .


*U014-claua2 iqluaa4jnoj


-u0ljvlaua2 qluaNllql MOT 131OU02 lqljla&,L


-U0IjVJ0Ua q4U0A8ja
a
U01 101guas qju0j,
.4 C3
I .. .... . . .

-U0lj'8J;DU02 lq4UIX


-U011161mas I[Iqjla
. .

U01 VJOUO l tjJU;aA9S : : : : : : : : : : : *1 : : : : : : : : :
. .

U01 IOU02 I[IXIS
. .
0



-tiollwauaS q4moa .00


*u0ljvlaua2 p4ql


*U0pvl;aua2 PU03as
Z en


U014VIOU02 Isild 0 0 0 0 0 0-4 M-4 M-4 M 00

r- c0c, C4 r- x CID x cq ac cq" m cq XO m C4 ^t D C4 m c)
-uinuiiuiw .'r "'D -,r -t tf to X -0
0
"c,
I'D '::I
t- lZ U- 00 00 00 00 x t r- .1, G 00 x t'- 9.

>


P4
W







. . S m
m c w cq Mr Lo 2 c; c
N cq N C14.M V-4 4 -1 Q V-4 -4 -4-4








30 PAPERS 0 N APHIDIDJE.



uonujau92 tuOia .trOjjvj;aua2 lqluoAaS


tim s . . .




-uoij-ulaua2,qjmod
. . .

-uopluoua2 pjlqL . .
0 0 0 0 0 0 0 O r UOTIl6JOUa2 1DUO30S .


-uOljujaUa2 Is.4a ... . .

'U011WOU02 qJU004MAOS
. . .

-UOIjUJOU9A
Its
. .




UOT .1qua I[JUONMOA



.. .... . . .
-umejaua qluanqqj,


UOII'6,10UOA OAA J, I.Q

-uOlj,6laua2 iqjuaAala

0 U014,81OU92 iqluoL


U014VIOU02 q4ulx


-U014,01OU02 lqlq2la 'UOI SIOU02 qlUOAOS



.. . .. .

-uoijciaua2 qljlj . .
*:,o 0 0 0 0 0 0 0 0 0 OQ Oto c
-uoijviaua2 qjanoa :.Coco 00 0 0 0 0 0 0 U011101OU02 pilill

0 C4 m C4 m C4 cq ce cq m ko .r t- co m m ul ult-4 4-4 cq V-4 N C4 U-) tU01113JOU02 PUODOS




C4 eq w 0 tl N C t- Cq 'r m .4 utw t- u-) U-j u-, cq;% U-j
-uinuiluTW o r, to O to Ir Nr ko WD lr,N Ir U") cz to lf" O to to to

N c N kf* r- 0 t'4 C 4 ta t- 00 N Ct Z c kf* to N t21-4 to, f
-mnmixuN 00 00 t- 00 1 t'- t- m to t- t- W m m












14 M,01,0 to t. 00 41












THE YELLOW CLOVER APHIS. 31



















































..0 0 0~ c q 1-........... ......


... ........c;a- o ........ ...



.~ 00000 0... .... .. ............ ...





















~O 0 cO'0 C~~ ~ _O 0 0 0' .0 CO 1- C.Z 0q M Cq 0l C4 0C4 -a Z~0~ ~0~' 0t ~C ~0- ~ ~ ~ ~ ~ ~ ~ ~ -- --q -- -----4'4,- i4iI


.









3 2 PAPERS 0 X APHIDIDIE.



moll-caqua-2 ..........

'UOII131@Ua lqjUaAGS

:,a 0 0 0 0 UO1413.iaua qjxls


MOT IOU02'qljla


uo1 IOU02 q4lno,4 . . ...

uoplGIOU02 PqT4,L
--------U014131OU02 puoaos


-U01413JOU02 JSJTJ .. .

*U014UJOU02 qjU'Oi4U;DAOS
. . .

-uoTjBjaUa2 qluoa4xls


luol Jauo2,q4uoa4jjj . .
0 0 0 0 0 0 0 0,rcq,,rmo
*uoljvlaua2 q4uao4jnoa

. .
UO14.8,10ua qJU001 qq'L

. .
0 0 0 0 O=q.CkooctQ omcli .
U01110JOU02 T44JIOA&J, . .
Nr C4,.4 0
-UO14UIOU02 q4UOA0ja

m ko 1-41-4 cli 11.4 Uopv.Iqua2 I[JUOL


-uolT8.Iqua2 lqjul, ,T . .. .
. .
-uoljlGjaua2 t[4112la .. .... . .. . ..

*U011-6JOU02 I[JUgAOIS


-110pulaU02 qlxis


-uoljulauq2 T4jj!,j . .

Z *UO14-ujaua2 tilatiod . .

00
t UO14-03OU02 pilill
Cl


*uol4-ujqua2 pu0jas . .

-uojjelaUO2 4S.11A . . .

r !2::o :2 t"D 8 It z 1 8 2 .13 G G s G 6
mntuxuln

0 to x N
-UltiluIXUA s t.- C, =1 m C l )o 00 m m












. .
vkx o

bo










THE YELLOW CLOVER APHIS. 33


















._ .C





. .
0 IfD C-flcl -i V, c C4 t N m0 0m 0


"4 t to -i r4 t- c mm x q .


_______________ ._________ .

















. .I to






._____ .. .

11



... --- -Ito
1



M M C: f-r-4NOMOMOOO t- MN OO to N-tto o1*k ct n oc oII o mt to__ __ ____ -4i H =


to~ ka L










c c 0 c 10
N C4 -4 N





34 PAPERS ON APHIDID.

As will be noticed by referring to figure 15 the first generation extended over a period of 39 days, from April 22 to May 31; the second, 60 days; the third, 54 days, etc.; and the eighth generation, which includes the last generation of the last-born series, being the longest, a period of 128 days. It is interesting to note that on May 4 individuals of the first 2 generations coexisted in the insectary; on June 4, 3 generations; on July 4, 5 generations; on August 4, 8 generations, or from the fourth to the eleventh; on September 4, 10 generations, or from the sixth to the fifteenth; and on October 4, 11 generations, or from the seventh to the seventeenth. Also, it will be observed that sexual generations occurred in the last 10 generations, from the eighth to the seventeenth inclusive, thus, with the additional data previously reported by Webster and Phillips, and by the writer, thoroughly disC~ 9pr// /1yy olive e/l4' qaeor 60vom-?k CAh6e Alavea'M'___=......






lO P-,?" ----"--14 .............. ...,
4 ...... ..
/4 ____-- __ _----O _.........___ .. A

I3 /8- 2 .............
/0 /4........,..-.. ...
/0 x-----.- 4
1.5 6 .


FI;. 15.-Diagram showing periods and succession of generations in the yellow clover aphis, La Fayette, Ind., 1913. (Original.)

proving the theory held by some that the sexual forms appear necessarily in a certain definite generation.
Our records show that the first oviparous females were observed in the experimental cages early in October, they having been born September 25, and our field records prove that the sexual forms may be produced even earlier than this. As has been inferred, the sexual forms seem to appear after the earliest weather conditions indicative of winter, although occasionally viviparous females have been observed until killed by cold weather. It was a usual occurrence for the same female to produce young part of which were viviparous and part oviparous.
Again referring to Tables I and II it will be seen that the immature stage varied from 6 to 16 days, depending on the temperature; the average for the year, in the 1913 series, being 9.1 days. The productive period, from birth of first young to birth of last young, like-





THE YEIIA)W CLOVER APHIS. 35

wise varied considerably, covering from 4 to 32 days, with an average of 15.4 +days. The largest number of young produced by an individual female was 99 and the average of the 22 regular generations in the series was 50, averaging 3.2 + young per day per femle throughout the entire season, the largest number of young produced in a single day by one female being 9.
With only an occasional exception the aphides in these experiments were wingless. Crowded conditions, predicative of a shortage of food, always resulted in a large percentage of winged forms.
Messrs. W. J. Phillips and T. I. Parks followed this species through two series of generations in 1909 at La Fayette, Ind., beginning with young found in the field May 13, and a synopsis of their experiments is here given in Tables III and IV. In general the results they obtained agree with our own studies in 1913.









36 PAPEM 0 N APHIDIM.


C
O'D O cc -j ". Cw C4 :,=,4
m eq M cq,-4 M V-4,CA C041 CR4






C4 kt 0; 4 06 4 C4
CD 1-4 C,4 04 -4 Cla
4-D -,-,A P, C14

7 75 75 (v Q c-) a)O :75 75
-1 0 OD Z
Go
1 bjD I- AO LO kfl to Itz V: ",x -,,r t- t, to 00 to
'n mv
0 0 cs
>1
0

t'O ++ ++++
0 > Cq
)144 --0 7 I . .
0 M M C4 C4 Cl Cq M C4 M 04-4 N N N r N
>-, iv

zz 00 N C4 00 00 -.14 00 00 M Cc to r COD t- COD M (M eq
C: I- OC 04 Cc C"D IV t l M -r -q IV q 00 -4 q to C14 C14 M ci
4 sw


z C3

C'4 r 0 0 Cq W M 1-4 0
4z,
w ; Ia
ca >

C44

m tfl C4 OD ICD m x U13 to .1. 10 A
eq eq -4 N 04 N -4 C4 N C*4 4) w







-4 -4
C4 Cq N
11 >, a C3
>, ho bk bC bC 41 .
4-4 04 0.4.> > > bi
75 7Ei -5 (1) v C-1 C-1 0 0
0

%-4 (m 00 cq t- m to Oc C> 03
0
at be

4) W .0



4-4 .
0 lmmcq ca 'D
Cq
cq M C4 C4 Cq C14 14 eq
bc
04 0
75 l 04) ce 1-4


4-4 .
0 '.4 :C; (=; Cm ., (=> I .
I= C4 C4 04 C', C4 t5
CIO C4 4 C14 C4 1-4
zz g 0 '.
> > u bf
-5 7
0
>-. boo

C>

00
0 0 0r r 08 0;,.::4 N = 20 12 C .4 'i




4-









THE YELLOW CLOVER APHIS. 37












t- CVD C14 4 C4 C-4 C4 C4
"V14











+++,D+++++ ++++ ++
ho
.4z
.> 1 -4 vi ci vi -4 ,. C'i ci "i C'i 4 C'i ci "i :c'i C'i
:z
OD Ov
41Q,
bB t- C) C C14 C 00 4 C11 "'r 00
C4 t- tIM
P4
Z"


4a ft




ko -4 1- 1- q N C14 tc 4 0 r CA m :0 C Do
cq C14 Cq ",I N 1-4 C11 4 N M -r cq C-1 cql



P
00 b.0

P4 C'i Cq m 144 q.- m cq -4 C,4
Cq C14 Cq 4Z .4 rv
0 CD t L > u u u
A 4-4
-14 0 0

0 C> t- 00 IrD C t- N (M z 10 C
ho





4-4 .
t":
C4 M r-4 C11 C4 C', 4; CD Q) to, blo b.'O b'D t o
;s 0 z = C-,Q
-F t 5


W too C; I I :> ;4 W C*
-W 0;,.z $..
Cq m "'4 C4 (m C,4 m C4 m 64 to:z
03-
cd cd

C,4 ..a

cd

p

4 C64 0 0 00 0
C3
rp
> CS PT4 w 0 1.4 C4 ft




1= C', M (:z t
1-4 -4 1.4 C tr








tt
$.


to





38 PAPERS ON APHIDIDI.

Mr. R. L. Webster has followed the successive generations of this species in the insectary of the Illinois State Entomologist from the eggs which hatched March 27 through nineteen generations to October 18. The nineteenth generation disappeared before maturing an4 the oviparous generation was not obtained. In his experiments,reported by Dr. J. W. Folsom (1909), he found that the length of time from birth to maturity varied from 5 to 24 days, with an average for the season of 10 days, and the length of life of an individual varied from 9 to 43 days, with an average of 22. The largest number of young produced in one day by a single female was 13. with a yearly average of 3.7 young per day; the maximum number of young born of a female was 75, the average for the series being 34.8 young per female.
MOLTING.

So far as our observations extend, the yellow clover aphis invariably molts but four times. Table V records the molting records of six individuals from data obtained by Mr. Parks in 1909 at La Fayette, Ind.
TABLE V.-Periods of molts of Callipterus trifolii, viriparous generation.

Age at Age at Age at Age at Age at first molt, second third molt, fourth birth of Date of birth, second molt, third fourth molt, fifth first
instar. instar. instar. instar. young.
19. Days. Days. Days. Days. Days.
M ay 15 ------------------------------------ 2 3 6 9 10
M ay 20 ------------------------------------ 2 6 8 11 11
Do .................................... 2 5 8 10 11
May 31 .................................... 2 4 6 8 9
Do .................................... 2 5 7 8 8
June 8 ..................................... 2 4 6 9 10

FECUNDITY IN RELATION TO OTHER SPECIES.
In comparison with its associate on clover, Ma crosipk urn pisi Kalt.. Cahipterus trifolii is quite noticeably less prolific. While pisi, according to our 1913 experiments, produces an average of about 65 young and a maximum number per female of 124 young, trifolii, on the other hand, averages 50 young and produced a maximum of 99 young per female. Likewise a single pisi has produced as high as 13 young in one day while the maximum number of young per (lay borne by a female trifolii was 9, and this was an unusual number.
From dissections made in Illinois several years ago the writer found that the oviparous females contained an average of 10 eggs per individual. The past fall (1913) 8 oviparous females were examined and found to contain the following numbers of apparently fully developed eggs each, respectively: 13, 13, 14, 10, 12, 13, 14, 16an average of 13.1 + eggs per female. In the latter counts only females





THE YELLOW CLOVER APHIIS. 39

which had not previously lai( eggs were used, while in the earlier counts no choice was made, which probably accounts for the differences in the average. Similar egg counts for Macrosiplu pisi show it to be much more prolific in egg production; in fact the courts for pisi were nearly twice those for trifolii.
Although we find both species attacking red clover, the one (pisi) is often quite abundant and destructive to clover, while the other (trifolii) is seldom if ever injurious. One of the principal causes of this difference will be readily understood from what has just been noted, namely, the great difference in fecundity of both viviparous and oviparous females. Other habits which doubtless have an influence in making trifolii less abundant are its sporadic mode of living, the comparatively late date of hatching from the egg, and the additional fact that it always winters in the egg stage while in pisi the eggs hatch earlier in spring and many individuals winter as viviparous females, thus giving it the advantage of an early start. Further, pisi has a variety of hosts, which is not true of trifolii in America; and, finally, the latter species requires a much smaller quantity of sap for becoming mature than does pisi, and as a result it is individually less harmful to the plant.
NATURAL ENEMIES.
Doubtless the most important checks on the yellow clover aphis are the weather conditions, more especially heavy rains. The aphis fungus, Empusa aphidis, is likewise quite an important factor in holding this plant-louse in check.
On account of its habits of living singly and jumping from the leaf at the least disturbance, this species is seldom attacked by internal parasites. Mr. Paul Hayhurst noticed a few parasitized specimens of this species at Chevy Chase Lake, Md., July 9, 1907, but apparently no parasites issued. The writer has likewise found occasional specimens parasitized, but has never reared the parasites.
Of the coccinellids, three species, Megilla maculata DeG., Hippodamia convergens Guer., and Coccinella 9-notata Herbst, were reared to the adult stage in the insectary at Washington, from larvx which were feeding on Callipterus trifolii on material received from Cadet, Mo., June 19, 1889.
The writer observed the 9-spotted ladybird (Coccinella 9-notata Herbst) attacking the yellow clover aphis at Urbana, Ill., September 18, 1913, and larvve of what were considered the same species were not uncommon on the badly infested clover plants, devouring the aphides.
At La Fayette, Ind., we have reared a species of Aphidoletes from larvea feeding on this aphis in chimney cages, although it has never been found attacking it in the field.






40 PAPERS ON APHIDID.E.

BIBLIOGRAPHY.

trifolii Monell.

1882. MONELL, J. T.-Can. Ent., vol. 14, p. 14, Jan. Original description of Callipterus trifolii. 1891. WILLIAMS. T. A.-Spec. Bul. 1, Univ. Nebr.. Dept. Ent., p. 8, July 8.
Lists Callipterus trifolii from Trifolium praten e. 1892. OSBORN, H.-Proc. Ia. Acad. Sci., vol. 1, pt. 2, p. 129.
Reports this species as Callipterus sp., from Iowa. 1893. OSBORN, 11.. AND F. A. SIRRINE.-Proc. Ia. Acad. Sci., vol. 1, pt. 3, p. 98.
Reports Callipterus trifolii abundant in Trifolium pratense in autumn. 1901. SANDERSON, E. D.-Twelfth Ann. Rept. Del. Agr. Exp. Sta., 1900 (1901),
p. 207.
Reports occurrence of Callipterus trifolii on clover in Delaware. 1906. SANBORN, C. E.-Kansas Univ. Sci. Bul., vol. 3, no. 8, pp. 251, 252, and 262,
April.
Lists Callipterus trifolii from Trifolmura sp. and T. pratense. 1908. DAvis, J. J.-Ann. Ent. Soc. Amer., vol. 1, p. 256, figs., Dec.
History of Callipterus trifolii, its distribution, and description of various stages. 1909. FOLSOM, J. W.-Bul. 134, Ill. Agr. Exp. Sta., p. 175, figs. (Also in 25th Rept.
Ill. State Ent., p. 103, figs.)
Treats Callipterus t olii under the following headings: Distribution, description, life-history studies, natural enemies, and bibliography. 1910. DAVIs, J. J.-Journ. Econ. Ent., vol. 3, p. 419, Oct. Lists Callipterus trifolii from Illinois. 1910. GILLETTE, C. P.-Journ. Econ. Ent., vol. 3, p. 369, Aag. Lists Myzocallis trifolii from Lansing, Mich., Geneva and Albany, N. Y., and Washington, D1). C. 1910. SMITHrr, J. B.-Ann. Rept. N. J. State Mus., 1909 (1910), p. 116.
Lists Callipterus trifolii from New Jersey. 1911. WILLIAMS, T. A.-Univ. Studies, vol. 10, no. 2, April, 1910 (1911), p. 32. Describes apterous and winged viviparous females of Callipterus trifolii collected at Ashland, Nebr.~ on Trifolium pratense.
1912. MORRION, II.-Fifth Ann. Rept. State Ent. Ind., 1911-1912, p. 216. Reports Callipterus trifolii as common at McCordsville, Ind.
maculatus Buckton.

1899. BUCKTON, G. B.-I11ian Mus. Notes, vol. 4, p. 277. Original description of Chaitophorus maculatus.




ADDITIONAL COPIES OF THIS PUBLICATION MAY BE PROCURED FROM THE SUPERINTENDENT OF DOCUMENTS GOVERNMENT PRINTING OFFICE WASIINGTON, D. C.
AT
5 CENTS PER COPY
V

UNIVERSITY OF FLORIDA


3 1262 09229 6523