No. 34'] HEMIPTERA OF CONNECTICUT: APHIDIDAE. 291 



Cornicle not longer than antennal segment ii. Cauda abbreviated 

 and blunt rumexicolens 



3. Cornicle shorter than or subequal to distal segment of hind tarsus,* 



constricted more or less at base, distinctly tliough slightly swollen 4 

 Cornicle longer than distal segment of hmd tarsus or if not then 

 not swollen and not constricted at base 7 



4. Cauda elongate with constriction near middle 5 



Cauda short and with no constriction 6 



5. Antennal segment v as long as iv ; iv with sensoria atriplicis 



V shorter than iv ; iv with sensoria arundinis 



6. Beak not reaching beyond second coxae brassicae 



Beak reaching third coxae or beyond tulipae 



7. Distal filament distinctly longer than base of vi 8 



Antenna with distal filament not distinctly longer than base of vi 



spiraephila 



8. Spring alate female without noticeable sensoria on hind tibia 9 



Spring alate female with conspicuous sensoria on hind tibia 



viburnicola 



9. Antennal segment iii conspicuously studded with sensoria, appar- 



ently over entire surface 10 



III with sensoria more or less numerous but not thickly studded 



over apparently entire surface and not confined to a row 16 



III with few to several (rarely 20) sensoria in regular or 



irregular row 20 



10. Cornicle shorter than filament of vi 11 



Cornicle as long as filament of antennal segment vi. Prominent 



tubercle dorsad of cauda saliceti 



11. Beak not reaching third coxae 12 



Beak extending easily to third coxae symphoricarpi 



12. Antennal segment v with secondary sensoria 13 



V without secondary sensoria bakeri 



13. Cornicle subequal to v or longer 14 



Cornicle plainly shorter than antennal segment v crataegifoliae 



14. Cauda shorter than one-half cornicle ^ 15 



Cauda longer than one-half cornicle varians 



15. Black aphid on peach persicae-niger 



Rosy aphid on apple roseus 



16. Beak at most not reaching third coxae 17 



Beak easily reaching third coxae cardui 



17. Second fork distinctly nearer to margin than to first fork 18 



Wing with second fork M about midway between first fork and 



margin of wing bakeri 



18. Cauda broadly conical, not with evident constriction near middle . . 19 

 Cauda elongate and usually with constriction near middle 35 



19. Cornicle and antennal segment iv subequal in length. Spring 



forms on Viburmun viburniphila 



Cornicle and v subequal. On Pruniis tuberculata 



20. Cauda broadly conical, not with evident constriction near middle 21 

 Cauda elongate and usually with constriction near middle 22 



21. Cornicle not longer than antennal segment v folsomi 



Cornicle distinctly longer than v forbesi 



22. Distance between second fork of M and margin of wing not more 



than one-third as long as distance between first and second fork 23 

 Distance between second fork of M and margin of wing plainly 

 more than one-third as long as distance between first and second 

 fork 24 



* Measured exclusive of claws. 



