ESSIG. APHIDIDAE OF SOUTHERN CALIFORNIA 9 



small tubercles. Cornicles — wanting. Legs — short, hairy, without sensoria. 

 Wings — sub-hyaline, the veins lightly pigmented along margins. Primary — 

 length 1.9 mm., width 0.67 mm. Cubitus — well defined. Stigma — short and 

 broad, nearly trapezoidal in shape. Radius — curved. The third oblique pre- 

 sents but two straight remnants near the margin. A slight vein-trace shows 

 a connection to form the forks. The first and second obliques arise from the 

 tame point near the cubitus and fork towards the margin. Secondary — length 

 1.5 mm., width 0.47 mm., with two discoidals. The first and second discoidals 

 arise from the same point on the sub-costal about one-third its length from 

 the wing base and extend nearly to the margin. The first curv.es away from 

 the base while the second oblique curves towards the base of the wing. Cauda 

 — rounded and hairy. Style — wanting. 



Figure 7. Pemphigus radicicola 



Apterous Vivip.\rous Female. — Length 1.42 mm., width 1.19 mm. 

 Differs from the winged form as follows : Prevailing color — mealy-white, 

 sometimes shading oilf into a gray. The eyes are very dark. 



Head — Without bisecting suture, nearly straight across frontal margin. 

 Compound eyes — round, very small antennae (Figure 5, G) — lengths of the 

 articles as follows: I 0.06 mm., II 0.13 mm.. Ill 0.16 mm., IV 0.09 mm., 

 V 0.18 mm. — total length 0.62 mm. The sensoria are distributed as follows: 

 I, II and III none, IV one large circular near distal end, V one large cup- 



