1908] Studies on Aphididae 253 



Antennae not more than one half the length of body; borne on gibbous tubercles; 

 the first segment gibbous and with a single capitate hair projecting from the 

 prominence; the articulation between the third and fourth .segments absent 

 or indistinct in the specimens reared in the insectary. (PI. XXI, fig. 5.) Eyes 

 dark red. Beak not reaching beyond the coxaj of the middle pair of legs. Color- 

 ation of legs as follows: femora light green, tibi;B pale greenish, excepting the 

 tip, which is slightly dusky ; tarsi black. The last two segments of the abdo- 

 men with a number of capitate hairs projecting caudad. Cornicles almost 

 transparent and with a faint greenish tint, incrassate, and reaching to the tip 

 of the abdomen. Style pale green, and ensiform in shape. (PI. XXI, fig. 7.) 



Measurements. — (Averages.) Length of body, 1.6119 inm.; width, 0.7898 

 mm.; antenna, I, 0.06)31; II, 0.0368; III and IV, 0.3:390; V, 0.1450; VI, basal, 

 0.0896; VI, filament, 0.2445; total, 0.9180 mm.; cornicles, 0.3912 mm.; style, 

 0.1630 mm.; tarsus, 0.0978 mm. 



Immature. — The young when first hatched from the eggs are brown, with 

 a slight tint of dull orange, and they very closely resemble the rusty leaf 

 patches, present, at this stage of development, on the Elasagnus leaves. The 

 young of the second instar of this fundatrix generation are pale yellowish green, 

 and of about the same color as the leaves, the latter by this time having lost 

 most of the brownish patches and become more of a solid pale green color. This 

 would appear to be a case of protective resemblance. 



Wingless oviparous female. — Head pale green, and bearing a few capitate 

 hairs on the front. Antennas borne on gibbous tubercles, and the first segments 

 likewise gibbous; dusky, excepting the first two segments and the basal portion 

 of the third, which are pale green; usually reaching to the bases of the cornicles; 

 the usual circular sensorium at the distal end of V, and several at the apex of the 

 basal portion of VI ; the articulations of the third and fourth segments indistinct, 

 and sometimes invisible. (PI. XXI, fig. 4.) Eyes dark red. Abdomen and thorax 

 of the general dark coloration, having a mottled appearance and consisting of 

 greens, reds, and blacks; and bearing a few capitate hairs. Under inagnification 

 there appear three more or less distinct longitudinal lines of this dark color 

 mixture on the dorsum, one on the median line and one on either side; also, the 

 last few segments are solidly of this color. Legs pale green, excepting the 

 articulations and the tarsi, which are dark to black; the basal two thirds of the 

 hind tibiae swollen and bearing numerous circular sensoria. (PI. XXI, fig. 9.) Cor- 

 nicles incrassate, and reaching to tip of abdomen; pale green, and darkening at 

 tips. Style ensiform and of a pale dirty-green color. 



Measurements. — (Averages.) Length of bodv, 1.6726 mm.; width, 0.8363 

 mm.; antenna, I, 0.0652; II, 0.0489; III, 0.2445; IV, 0.1483; V, 0.1597; VI, basal, 

 0.0880; VI, filament, 0.49:39; total, 1.2405 mm.; cornicles, 0.3830 mm.; style, 

 0.1711; min. tarsus, 0.0978 mm. 



Young of the first three instars are light green in color, but the imma- 

 ture aphids of the fourth instar are pale yellow with bright green spots 

 scattered over the body in longitudinal rows, as are the dark markings in the 

 adult. 



Eggs. — Elliptical oval, greenish-yellow when first deposited and later 

 changing to jet-black, and measuring 0.2443 by 0.5216 mm. 



Winged male. — (No color notes were made and the following description is 

 taken froin specimens mounted in balsam.) Antenna? longer than body; borne 

 on gibbous tubercles; the first seginents likewise gibbous; irregularly placed 

 circular sensoria as follows: 24-27 on III, 9-14 on IV, 2-4 on V, and several 

 at the distal end of the basal portion of VI. (PI. XXI, fig. 2.) Wings hyaline, 

 the first and second discoidals branching about one third, or slightly more than 

 one third, the distance from the margin of the wing to the third discoidal. 

 Cornicles incrassate, and reaching beyond the tip of the abdomen. Style 

 ensiform. 



Measurements. — (Average.) Length of bodv, 1.2089 mm.; w^dth, 0.6045 

 mm.; antenna, I, 0.0652; II, 0.0571; III, 0.4401; IV, 0.3097; V. 0.2553; VI, basal, 

 0.0978; VI, filament, 0.8150; total, 2.0402 mm.; cornicle, 0.;3830 mm.; style, 

 0.1630 mm.; hind tarsus, 0.1141 mm. 



