April. '17] DAVIDSON": WESTERN' PLANT LICE 293 



Oviparous female (Fig. 16, 5). Light reddish-brown : body clothed with numer- 

 ous long non-capitate hairs: head, prothorax and a broad transverse band on each 

 of the remaining body segments dark brown; each of these segments has also a pair 

 of lateral sub-quadrate brown areas, noticeably large on mesothorax, metathorax, 

 and abdominal segment 8: antennae about half as long as the body, dark brown, 

 basal seven-eighths of III and basal half of IV pale yellow; III thickened basally and 

 on this swollen portion are 3 to 5 oval sensoria in a row: legs dark brown, base of 

 femora and middle part of tibiae pale yellowish-brown; legs hairy: under side of 

 abdomen marked with rows of small faint brown spots: beak pale, apex brown; 

 barely reaches second coxae: cornicles dark brown, subquadrate, .093 mm. long, 

 .082 mm. wide at base; cauda pale reddish brown, obtusely conical, .066 mm. long: 

 anal plate rounded: hind tibiae bear on their slightly swollen basal half a great number 

 of small circular sensoria: length of body 2.48 to 2.89 mm. Width of body (fifth 

 abdominal segment) 1.07 to 1.22 mm. Antennae; III .54 mm., IV. 29 mm., V. 21 

 mm., VI .15 mm., filament .27 mm. 



Male (Fig. 16, 6-8). Groundcolor reddish brown. The single specimen I have 

 is almost destitute of hairs except on the legs and at the extremity of the body: 

 brownish transverse bars, not reaching margins, occur on disk of abdomen and spots 

 of similar color occur on lateral margins: abdominal segments 1 to 5 have 2 pairs of 

 small lateral tubercles, the inner pairs the larger: antennae almost as long as body; 

 on both there are 17 circular sensoria on III and these occupy in a row the entire 

 length of the joint; V and VI have each an unusually large apical sensorium and VI 

 has besides about 3 small ones; the sensoriation similar to that of the male of Calaphis 

 betulaecolens Fitch in that the fourth joint is unsensoriated : beak reaches halfway 

 between second and third coxae : veins of, the wings thick and somewhat narrowly 

 clouded; stigmatic vein obsolete for its basal half: legs with short hairs: cornicles 

 dusky brown, subquadrate, .07 mm. long: cauda rounded, .slightly constricted basally, 

 grey: anal plate emarginate: length of body 1.92 mm. Width, maximum .73 mm. 

 Antennae; III .52 mm., IV .29 mm., V .24 mm., VI .12 mm., filament .24 mm. 



Male and apterous female taken the first half of October, 1913, at 

 Oakland, Cal. Oviparous females taken October 23, 1915. at Walnut 

 Creek, Cal. 



Aphis neo-mexicana Ckll. var. pacifica var. nov. Fig. 16, 9 to 14. 



Alate viviparous female (Fig. 16, 9-11). Light green : head and prothorax olive- 

 grey : antennae black : thorax brownish-olive : cornicles and cauda light grey : beak pale, 

 tip black: abdomen light green with lateral rows of circular black spots: veins of 

 wings brown, narrowly clouded ; stigma and insertions greenish : legs yellowish-broAVTi, 

 tibial and femoral apices and tarsi black: sterna black: anal plate grey: eyes dark red. 

 Antennae not on frontal tubercles, reaching to the fifth abdominal segment ; filament 

 longer than III; IV and V sub-equal; sensoria circular, of irregular size and those on 

 III not disposed in a row, 11 to 14 on III, 4 to 6 on IV, usual apical on V and VI 

 except that occasionally on V there are 1 or 2 extra about the middle of the segment : 

 prothorax bears a pair of lateral tubercles: beak reaches to third pair of coxae: second 

 fork of third discoidal vein slightlj- nearer to the wing apex than to the first fork: 

 seventh abdominal segment bears a pair of lateral tubercles: cornicles imbricate, 

 sUghtly enlarged at base, longer than antennal joint IV but not as long as III: cauda 

 of the usual shape of the genus, rather large, two-thirds the cornicles in length, 

 armed with spines. Length of body 1.2 mm. to 1.3 mm. Maximum width .46 mm' 

 to .56 mm. Wing expanse about 5 mm. Beak .46 mm. Cornicles .17 mm. to .2 mm. 



