October, '12] DAVIDSON: APHID NOTES 407 



Pupa of alate female. Pale yellow, with no woolly secretion. Antennal annula- 

 tions and tarsi black. Rest of body pale yellow with the exception of abdominal 

 black spots arranged as follows; two median dorsal and two lateral on segments 1-5 

 and 7, two median dorsal on segment 6 (on which occur the cornicles). The.'ie black 

 spots are tuberculate and bear capitate hairs. 



This species is not uncommon on the under side of the leaves of 

 Alnus rhombifolia Nutt. I have never seen the apterous female nor 

 the sexual forms. Habitat; Santa Clara Co.,, Cal. Spring and Summer. 

 Aphis cardui L. 



Colonies on the j^oung gro\^i;h of several thistles throughout summer. 

 Habitat; San Jose, Cal. 

 Aphis atriplicis L. (Figs. 8, 9). 



Apterous male. Head, thoracic lobes and scuteUum black. Prothorax brown- 

 Eyes dai'k red. Anntenae black, reaching to the cornicles, third joint the longest? 

 fUament next, then fourth, fifth, sixth, first and second in order. Frontal tubercles 

 small, black. Lateral tubercles absent. Legs brown, hind pair darker. Abdomen 

 pale yeUow, with 8 brown dorsal transverse bars, which are often broken up into spots. 

 Cornicles short, black, incrassate, not half as long as the hind tarsi. Cauda black, 

 tapering to a blunt apex, half as long again as the cornicles. Genital segment below 

 Cauda large, black, rounded. Coxae, under side of head and thorax and genital 

 segment black. Rest of lower surface yellow. Beak transparent, its tip black, 

 reaching second coxae. Sensoria on antennal III 18-21; IV 7-9; V 6-8; VI 3-5, 

 small, placed irregularly^ on the much serrated antennae. 

 Measurements; Body, length 1.08mm Antennal joints 



" width .46mm 



Cornicles . 078mm 



Cauda . 086mm 



Oviparous female. Entirely pale greenish-yeUow, with a thin white powdery 

 covering. Eyes red. Antennae seven-jointed, about one-third the length of the 

 body, pale greenish-yellow; the relative size«of the joints as follows: joint III longest; 

 the filament or seventh joint a httle shorter with IV; V and VI sub-equal. Legs 

 pale greenish-yellow, coxae brown. Cornicles pale brown, almost as long as the 

 hind tarsi. Cauda shaped as in the male, pale brown, slightly exceeding the corni- 

 cles in length. Anal segment bro\Mi. Beak not quite reaching second coxae, its 



Apterous viviparous female. Pale green, sUghtly pulverulent. Body more than 

 twace as long as wide. Antennae dusky, a little over one-third the body in length; 



