320 CONNECTICUT GEOL. AND NAT. HIST. SURVEY. [Bull. 



2. Alate forms with distinct cornicles. Stem mother with marginal 



wax pore plates only Pachypappella, p. 320 



Alate forms without cornicles. Stem mother without wax pore 

 plates Asiphum, p. 320 



3. Antennal joint iv subequal to or less than one-half the length of iii 4 

 Antennal joint iv distinctly greater than one-half of, usually 



about three-fourths of length of iii Neoprociphilus, p. 323 



4. Stem mother with five-jointed antennae 5 



Stem mother with four-jointed antennae 7 



5. Alate forms with wax pore plates on inner posterior margin of 



lobes of mesothorax 6 



Alate forms without wax pore plates on inner posterior margin of 

 lobes of mesothorax Cornaphis, p. 321 



6. Wax pore plates of thorax approximate. Distance between them 



normally less than greatest diameter of plate. Secondary sen- 



soria with fringe of celia Prociphilus, p. 321 



Wax pore plates of thorax remote. Distance between them greater 

 than greatest diameter of plates. Secondary sensoria without 

 fringe of celia .Thecabius, p. 324 



7. Spur of sixth joint of antennae longer than joint 



Mordwilkoja, p. 325 

 Spur of sixth joint of antennae shorter than joint Pemphigus, p. 326 



Pachypappella Baker. 



Stem mother with five- jointed antennae. Wax pore plates at 

 margin of abdomen only. Cornicles wanting. Rudimentary 

 gonopophyses, three. Young of stem mother all acquiring wings. 

 Third generation apterous. 



Alate viviparous females with six- jointed antennae. M of fore 

 wing once forked. Media and cubitus present in hind wing. 

 Cornicles present ; reduced to slightly raised rings. Sexual forms 

 small, beakless; females laying but one egg. Antennae five- 

 jointed. 



Asiphum Koch. 



Stem mother with five- jointed antennae. Wax pore plates 

 wanting. Body covered with fine hair. Cornicles wanting. 

 Rudimentary gonopophyses, three. Young of stem mother all 

 acquire wings. Third generation apterous. 



Alate viviparous females with six- jointed antennae. Sensoria 

 oval. M of fore wing once forked. Both media and cubitus of 

 hind wing present. 



Inner posterior margin of lobes of mesothorax with or without 

 wax pore plates. Cornicles wanting. Wax pore plates well- 

 developed in pupae. Composed of many several-sided facets of 

 equal size surrounded by a chitinous ring. Sexuals small, beakless. 

 Antennae five- jointed. 



Species living in pseudo galls or folded leaves or in clusters of 

 leaves of winter host, produced by curling of their petioles. 



Winter host Populus species. Summer hosts unknown. 



Key to Species. 

 1. Mesothorax of alate viviparous females with wax pore plates at 



inner posterior margin of lateral lobes 2 



