740 



Pomona College Journal of Entomology 



AI'TKROVS VIVII'AHOIS FK.MALE ( I'igurt' "iS'l B) 



I.fiifitli of liody I-..") mm., widtli of abdomen '2. 25 mm. A larger form tlian 

 the winged female Mitli more robust body. Body — Smootli, even .shiny, covered 

 with fine soft hairs, often pruinose, especially if found near the surface of the 

 soil — in some cases densely covered with fine white powder, widest at middle and 

 tapering towards both ends. Prevailing color — From a yellowisli white, to flesh, 

 rose, or grayish or even silvery due to the covering. The forms taken from deep 

 under ground are very light and almost colorless and always without the pruinose 

 substance. Head — Gray or dusky, with broad straight front and little or no signs 

 of antennal tubercles, nearly quadrangular in shape, wider than long, with narrow 



Figure 237. Fullawaya sal.ci-radicis Essifr 

 On root of willow. Showing adult apterous viviparous females and a large horny 

 larva of the red syrphid liy. which is the only natural enemy found preying on 

 this aphid. 



lighter band Jicross the base. Kifcs — D.irk nd. r.itlu r laruc with tubercle. 

 Antennae — (Figure 236, 1 and 2). Not h.ilf as long .is the body, usu.illy reach- 

 ing to tlic middle of the second abdominal segment, iiairy. the Ir.m.sition from the 

 article VI to the spur very gradual; articles I .md 11 dark gray, concolorous 

 with head. III ^-ellow with apical one-half amber, tip of segment distinctly con- 

 stricted from last sensoria to the tip. I\', \' and VI dusky amber with slightly 

 darker tips. Lengths of tin' articles: I. 0.07 mm.; II. O.l.S mm.; III. 0. t.) mm.; 

 IV, 0.2<} mm.; V, O..SI) nun.; \I. (l.t!) nnu. (s|)ur 0.29 nnn.) ; total 1.7.! mm. Thus 

 it will be seen that I is siiortcr th.in 11. wliilr in tjie winged form they were sub- 

 .■(jual; 111 is longer tli;ui 1 \' or \ but not so long .-is both tog.-tiier. neitlier is it 



