iQog] Studies on Aphididae II 39 



ln-o\vnish. Wings hyaline, with ])ro\vnish veins, the first and second discoidals 

 branching at one halt" or less the distance from the margin to where the third 

 discoidal branches. (PI. Vll, fig. 31.) Legs pale green to the distal portion ol" 

 femur, which is blackish, tibia pale brownish excepting the black apical end, 

 tarsus black. Abdomen entirely pale bright greenish. Cornicles pale greenish, 

 white at basal half, the distal portion changing to blackish; reaching beyond 

 the tip of the abdoinen and more than three times the length of the hind tarsus; 

 cjdindrical and slightly dilated at distal one third. (PI. VI, fig. 28.) vStyle 

 concolorous with abdonien, ensiform, and slightly less than one-half the length 

 of the cornicles. (PI. VI, fig. 29.) 



Measurements [from alcoholic and balsam mounts, collected in Chicago, 

 September 3 and 10, 1 008] : — Length of body, L65 mm. ; width, 0.61 mm, ; length 

 of wing, 2. Go mm.; width, 0.91 mm.; expanse, approx. 0.00 mm,; antenna, I, 

 0.08; II, 0.07; III, 0.55-0.77, av. 0.65; IV, 0.32-0.42, av. 0.35; V, 0.29-0.36, av. 

 0.32; VI, base, 0.08-0.09, av. 0.085; VI, filament, 0.83-1.09; av. 0.95; average 

 total, 2.505 mm. ; cornicles, 0.48 mm. ; style, 0.20 mm. ; hind tarsus, 0.14 mm. 



Wingless viviparous female : — Head with about six subcapitate hairs pro- 

 jecting cephalad from the front. (PI. VII, fig. 32.) Antenna; borne on the 

 usual frontal tubercles; pale excepting segment VI and the distal portion of V; 

 usually 15 to 26 circular sensoria, unequal in size and irregularly placed on III 

 (this is a very uncertain character in this form, some antenme bearing only 7 

 sensoria on III), and the usual ones at apical ends of V and base VI ; longer than 

 body, the comparative lengths of the separate segments as given for the winged 

 viviparous female. (PI. VII, fig. 33.) Eyes dark red. Beak reaching or 

 extending slightly beyond the coxas of the third pair of legs. Legs pale, except- 

 ing the distal ends of the tibicC, and at the joints of the tibiie and femora, which 

 are dusky, and the tarsi which are black. Abdomen bright green. Cornicles 

 pale excepting the tips, which are slightly dusky, and about four times the 

 length of the hind tarsi. Style pale with a slight greenish tint, and about two 

 fifths the length of the cornicles. 



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

 1.90 mm.; width, 0.88 mm.; antenna, I, 0.095; II, 0.08; III, 0.61; IV, 0.35; V, 

 0.35; VI, base, 0.095; VI, filament, 0.89; average total, 2.47 mm.; cornicles, 

 0.61 mm. ; style, 0.23 mm. ; hind tarsus, 0.15 mm. 



Wingless oviparous female: — Head pale yellowish or greenish yellow, bear- 

 ing about six subcapitate hairs which project cephalad from the fore margin. 

 Antennal segments I and II concolorous with the head or slightly dusky, the re- 

 maining segments dark to black; subcapitate hairs sparsely placed on all seg- 

 ments; 13 to 23 circular sensoria irregularly placed on III, and the usual ones 

 at the apical ends of V and base VI : subequal to or slightly longer than the 

 body. III one third longer than IV, IV and V subequal, VI the longest, being 

 about three times V, the base VI about subequal to I. (PI. VII, fig. 34.) Eyes 

 dark red. Thorax pale yellowish. Legs pale excepting the distal ends of the 

 tibiae and femora, also the tarsi, which are blackish; the basal one third of the 

 hind tibiae swollen and bearing 30 or 40 irregularh' arranged circular sensoria. 

 placed on the inner surface. (PI. VII, fig. 35.) Abdomen pale orange and 

 usually with two or three yellowish spots which are the eggs showing through 

 the semi-transparent body tissue. Cornicles pale excepting at tips, which are 

 dusky, cylindrical, and sometimes slightly dilated at the distal third, subequal 

 in length to segment III of the antenna. Style pale and about two fifths the 

 length of the cornicles. 



Maesurements [specimens mounted in balsam] — Length of bodv, 2.09 mm. ; 

 width, 0.92 mm. ; antenna, I, 0.11; II, O.OS; III, 0.60; IV, 0.37; V, 0."33; VI, base 

 0.11; VI, filament, 0.88; average total, 2.48 mm. (An exceptional specimen 

 had the following antennal measurements: III, 0.39; IV, 0.26; V, 0.20; VI, 

 base, 0.08; VI, filament, 0.61 mm.); cornicles, 0.56 mm.; style, 0.23 mm.; hind 

 tarsus, 0.15 mm. 



Winged male: — Head brownish and with very small subcapitate hairs 

 arranged as on wingless oviparous female. Antenna dark brown at the base, 

 darkening to black at the apical portion; bearing subcapitate hairs which are 

 less conspicuous than those on the antenna of the above described female; 20 to 



