Pomona College Journal of Entomology 529 



marginal and transverse dorsal markings, one pair of small lateral tubercles near 

 the base of tlie abdomen and a second pair just behind the cornicles, genital plate 

 dusky. Cornicles — (Figure 171 D). Cylindrical, imbricated, wider at base and 

 gradually narrowing to apex, black, three times as long as style, length 0.36 mm., 

 widtli at base 0.07 nun. Lcgx — Moderately long and hairy, coxa' dark; femora 

 lemon yellow with apical halves dusky; tibw lemon yellow with extreme bases and 

 tips dusky; tarsi dusky. Wings — Hyaline, normal. Primary — Length 3.4 mm., 

 widtli 1.2,') mm., costal and subcostal veins and the stigma dark brown, remaining 

 veins light yellow. Secondari/ — Length 2.1 mm., width 0.65 mm., veins light 

 yellow. Style — (Figure 171 E). Conical, black, nearly as long as tarsi. 



APTEROUS VIVIPAROUS FEMALE (Figure 171 B) 



Length l.f) mm., greatest width of abdomen 1.2 mm., small robust species. 



Prevailing color — Dull green or black with often a shade of maroon, many 

 individuals slightly covered witli fine white powder, others shiny black. Head — 

 Dull reddish-green or black. Ei/es — Dark red. Antennae — (Figure 171 G). Not 

 half as long as the body, on slight frontal tubercles, articles I and II color of head, 

 III, IV, and V lemon yellow — the latter with apical one-half dusky, VI dark, 

 lengths of the articles: I, 0.0.5 mm.; II, 0.06 mm.; Ill, 0.14 mm.; IV, 0.13 mm.; 

 V, 0.12 mm.; VI, 0.3 mm. (spur 0.2 mm.); total 0.7 mm. Rostrum — I-emon 

 yellow with dark base and tip, reaches to third coxae. Thorax — Dark green, 

 maroon, or black, ligliter ventrally. Abdomen — Somewhat globular, smooth, shiny 

 or dull, varying from dark green or maroon to black, ventral surface lighter in 

 color, genital plate dusky. Cornicles — (Figure 171 F). Cylindrical, black, shorter 

 than in winged specimens, imbricated, wider at base than at apex, length 0.21 mm. 

 Legs — Same as in winged specimens. Style — (Figure 171 H). Conical, dark with 

 black spot at the ventral base, the distance across the base equals the length. 



Hosts — This species was obtained in rather limited numbers from the floweriu'r 

 shoots of the native Rattle Weed or Loco Weed (Astragalus leucopis Torr). It 

 also feeds upon Medicago falcata, Carngana arhorescens, Robinia riscosa, Meli- 

 lotus italica, Wild Licorice {Glycyrrliiza lepidota) . Artemisia catifornica Less., 

 and Clovers. 



Locality — Along the foothills of the Upper Ojai Valley, two miles from 

 Nordhoff, at an altitude of 1,000 feet. Date of collection — May 1.5, ipil. Serial 

 number 35. 



The species, as it occurs here, conforms remarkably well with the original 

 description given by Koch, and there can be little doubt regarding its identity. In 

 the descri))tion by Williams (Aphid, of Nebr. pp .50-1) the following differences 

 are noted : 



Species Described by Williams Species as Found at Nordhoff 



Cornicles of the apterous female Cornicles of the apterous females 



longer than those of the winged females. shorter than those of the winged 



Antennal article III of the apterous females, 

 forms longest. Article VI and the spur of it (which 



is commonly termed VII) is always 

 longest. 



However, in spite of these rather indefinite differences, I believe this to be 

 the true Aphis medicaginis Koch. 



