1 9 09] Studies on Aphididae II 37 



Wingless viviparous female: — Head pale green and witl: frontal tubercles 

 as on winged. Antenna black excepting segments I and II, and a small basal 

 portion of III, which are pale green or slightly dusky; the usual sensoria on V 

 and VI (one exceptional specimen has 3 and 4 sensoria, respectively, on each 

 antenna near the base of III); total length aV)out one half greater than that of 

 the body, segment III about one fourth longer than IV, IV and V subequal, VI 

 the longest, and slightly less than IV and V together, base VI about one fourth 

 the length of V, iilament VI setaceous and about one half longer than III (a 

 single exception, not recorded in measurements below, has III and filament VI 

 subequal). (PL VI, fig. 24.) Eyes black. Beak reaching to or sligtly bej^ond 

 the coXcX of the second pair of legs. Thorax pale green, with a very slight pul- 

 verulence. Legs pale green except the bases and apices of tibitp, which areas are 

 dusky to black, and the tarsi which are black. Abdomen concolorous with, and 

 bearing a similar pulverulence as, the thorax. Ventral surface of body with the 

 whitish pulverulence or bloom more conspicuous. Cornicles black except the 

 bases, which are pale, similar in shape to those of the winged female, and about 

 two and a half times longer than the style. Style pale green, ensiform, and about 

 twice the length of the hind tarsus. 



Measurements [from specimens mounted in balsam] : — Length of bodv, 

 1.75-2.50 mm.; width, 0.72-1.07 mm.; antenna, I, 0.13; II, 0.07; III, 0.73; IV, 

 0.60; V, 0.61; VI, base, 0.16; VI, filament, 1.07; average total, 3.37 mm.; cor- 

 nicles, 0.71 mm. ; style, 0.29 nim. ; hind tarsus, 0.15 mm. 



Immature: — Dull green with blackish legs, antenn;c, cornicles, and ej^es. ■ 



Wingless viviparous female, variety riifa: — I have found only the wingless 

 forms of this red variety. It is identical in form and measurements with the 

 normal form of the wingless viviparous female, and is only distinguished from 

 the latter by its coloration. 



Head, thorax, and abdomen of a decidedly rosy tint. The ventral surface 

 pale reddish, and covered with a whitish pulverulence or bloom. Antennal seg- 

 ments I and II pale. III pale at base and gradually darkening to black, remain- 

 ing segments black. Eyes black. Coxte pale reddish, otherwise legs as in nor- 

 mal form. Cornicles black, excepting at bases which are pale. Style pale with 

 a reddish tint. 



Wingless oviparous female: — The only structural character distinguishing 

 this form from the wingless viviparous female is the presence of numerous 

 sensoria on the hind tibiae. General color pale greenish, the abdomen with a 

 yellowish tint. Notes of the individual colorations of the body and appendages 

 have been lost or misplaced, but in general they agree with those of the wingless 

 viviparous female. The antenna is a little less than one and one half times the 

 length of the body. III slightly longer than IV, IV and V subequal, VI the long- 

 est, being subequal to IV and V together, base VI about one sixth or less the 

 length of the filament, wdiich is one and one half times III; sensoria absent 

 excepting the usual ones at the distal ends of V and base VI. (PI. VI, fig. 25.) 

 The basal half of the hind tibia^ swollen and bearing 50 to 70 small circular sen- 

 soria. (PI. VI, fig. 20.) 



Measurements [froin specimens in balsam and alcohol]: — Length of body, 

 1.97-2.47 mm.; width, 0.82-1.07 mm.; antenna, I, 0.125; II, 0.065; III, 0.52- 

 0.65, av. 0.59; IV, 0.42-0.59, av. 0.505;V. 0.42-0.59, av. 0.51 ; VI, base, 0.15; VI, 

 filament, 0.92-1.02, av. 0.95; average total, 2.89 mm. ; cornicles, 0.60 mm. ; style, 

 0.22 mm. ; hind tarsus, 0.145 mm. 



Winged male [from specimens in balsam and alcohol]: — Distinguished 

 from the viviparous female by its smaller size and the numerous sensoria on 

 antennal segments III, IV and V. 



Coloration similar to the winged viviparous female, excepting the usual 

 presence of a faint row of dusky to blackish dots on each side of the abdomen. 

 Head and appendages (excepting the antenna;) similar in shape and markings 

 to those of the winged female. Antenna? about one and one half times the length 

 of the body. III about one half VI, IV and V subequal, basal VI about one 

 fourth V, filament VI equal to IV and V combined; 40 to 53 circular sensoria 

 irregularly placed on one side of III, 22-27 more or less in a row on IV, 15--21 



