GALL APHIDS OF THE ELM. 209 



Apterous viviparous form, not stem mother. Head and tho- 

 rax white, abdomen greenish. Eyes, antennae and legs dusky. 

 Antenna 6-jointed. I, II about subequal ; III, IV, V about 

 subequal, each being shorter than II ; VI about equal to IV-j-V 

 and longer than II. I, 0.03 mm. ; II, 0.035 J™""^- '> ^^^> 0.029 

 m.m. ; IV, 0.027 mm. ; A', 0.025 mm. ; VI, 0.055 rnm. Beak 

 short, not reaching second coxae. Total length of body, 1.5 

 mm. This form when removed from the gall propelled itself 

 with a humping motion by curling under the tip of the abdo- 

 men and using that as an aid in locomotion. Color description 

 from live mature specimens taken July 14, 1909, measurements 

 from balsam mounts. Habitat, i or 2 frequently found in 

 cockscomb gall on Ulnius amerieana in company with stem 

 mother and pupse of T. colophoidea. 



Described from 6 specimens. Figs. 133, 174. Alaine col- 

 lection number Aphid 65-09. 



Seeond generation, — migrants. Abdomen and ventral body 

 greenish black, abdomen pulverulent, antennae, head, thorax and 

 legs black. Wings as typical for Tetraneura, — M unbranched 

 in fore wing and Cu wanting in the hind wing. Veins and 

 stigma are dark. Wing expanse about 4 mm. Antennae with 

 IV, V, VI approximately subequal. Ill, 0.175-0.195 mm.; IV, 

 0.075-0.085 mm. ; V, 0.065 mm. ; VI, 0.055-0.063 mm. Ill with 

 an average of 12 partial annulations. lY with an average of 

 6 partial annulations. V with an average of 4 partial annu- 

 lations. VI comparatively smooth though with irregular annu- 

 lations frequently present, especially at base of unguis. (Figs. 

 169, 170). 



This generation while in the young nyniphal stage are yellow 

 and colored like stem mother except that the eyes are red. 

 Pupae about read}' to molt have head, prothorax, and abdomen 

 dark bluish black. Antenna^ 6-jointed (Fig. 171). Antennae, 

 legs and thorax are much paler and the wing pads are a trans- 

 lucent snuiky white. E\es black. Color description from live 

 specimens examined July 8, 190<}. Habitat, developing in cocks- 

 comb gall on Ulmus amerieana and migrating from elm upon 

 leaving gall. Maine ccillcction numbers a])]iid 57-00. aphid 

 65-00. 



.'' generation. Larxce. Beak reaching to 2n(l coxae. 



Antennn ^-jointed with \' verv uneven and ragged at tip. See 



