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



Hind tarsus with second joint excessive in length, approximating 

 length of hind tibia, first joint reduced (apparently lacking) . . 



[Trama] LACHNINI, p. 256 



6. Stigma narrow and long. Stigma or stigmal shading extending 



about curve of wing nearly to distal tip of Rs 7 



Stigma not unusual in foregoing respect 8 



7. M once branched. Only on conifers 



Mindarus MINDARINAE, p. 328 



M twice branched. A giant aphid, not on conifers 



Longistigma LACHNINI, p. 251 



8. Stigma short and stubby. Migrating between Cormis and grasses 



Anoecia LACHNINI, p. 258 

 Stigma and habitat not both as in foregoing 9 



9. Eyes without ocular tubercles; head often elongate; feeding on 



sedges or grasses SALTAPHIDINA, p. 273 



Aphids not in accord with foregoing combination 10 



10. Rim-like cornicle, situated on hairy, broadly cone-shaped or 



volcano-shaped tubercle. On conifers, except Nippolachnus 



rosae Remaining genera of LACHNINI, p. 256 



Cornicle various but not on hairy tubercle ; if reduced to ring-like 



or if absent, then M of fore wing is twice branched (except 



sometimes in Tamelia) 11 



Cornicle vestigial (mere pores) or wanting. Fore wing with M 



never more than once forked 26 



ii« Hind wing not unusually small (except in Rhopalosiphum 



serotinae) 12 



Hind wing minute Microparsus MACROSIPHINI, p. 311 



12. Media of fore wing twice forked (except sometimes in Tamelia) 13 

 Media of fore wing once forked. Cornicle cylindrical 



Toxoptera MACROSIPHINI, p. 302 



13. Antennae of alate form six-segmented 14 



Antenna of alate form five-segmented 



Sipha CHAITOPHORINA, p. 285 



14. Cornicle merely ring-like, cauda knobbed or rounded, anal plate 



often bilobed or divided. MonelUa, Phxllaphis, Tamelia 



CALLIPTERINI, pp. 279, 287 



Cornicle distinct, varied in size and shape 15 



Cornicle absent MONAPHIDINA, p. 273 



and FULLAWAYINA, p. 288 



15. Aphids with long, straight hairs on body, legs, and antennae ; 



cornicles large and usually vasiform. Large gregarious species 



on bark of Salix and Populiu PTEROCOMMINA, p. 288 



Cornicle large, at least three times length of hind tarsus, swollen 



in middle. On Acer or Platanus 



Drepanosiphum CALLIPTERINI, p. 286 



Cornicle large, approximately twice or less the length of hind 

 tarsus, thickly swollen at base and suddenly narrowed, rimmed at 

 tip. The only New England species with conspicuous finger-like 



processes on dorsum. On Acer or Aescuhis 



Drepanaphis CALLIPTERINI, p. 286 



Cornicle usually broadest at base, tapering to truncate tip, often 

 hourglass-shaped ; not cylindrical, not club-shaped, not often with 

 definite flange at tip 16 



Cornicle short to long, tapering, cjdindrical, or swollen and club- 

 shaped. Tip of the rimmed and not the truncate type 18 



16. Aphids forming thickset colonies on stem. New England species 



only on birch. Antennae banded and wing veins shadowed. 

 Parthenogenetically reproducing summer generations in part 

 apterous and in part alate . . Symydobius CALLIPTERINA, p. 280 



