No. 34-] HEMIPTERA OF CONNECTICUT: APHIDIDAE. 255 



Body, antennae and legs with long slender lash-like hairs; cauda 

 broad or pointed, rarely enlarged at apex ; the parthenogeneti- 

 cally reproducing summer generations in part apterous and in part 

 alate. Partial to Aceraceae and Salicaceac 17 



Hairs of antennae and legs stiff and very short (not lash-like) ; 

 bodies of nymphs and apterous forms often conspicuously set 

 with capitate hairs (suggesting pins in a cushion) ; cauda 

 globate (knobbed) and anal plate notched or bilobed. No New 



England species on Aceraceae or Salicaccae 



CALLIPTERINA, p. 274 



17. New England species only on Aceraceae, producing small summer 



dimorphs Periphyllus CHAITOPHORINA, p. 283 



New England species only on Salicaceae, with no summer dimorphs 

 Chaitophorus and Neothomasia CHAITOPHORINA, pp. 281, 283 



18. Antenna not situated on conspicuous frontal tubercle, though there 



is often a produced inner margin making a broad and shallow 

 concavity at frontal margin. Cornicle without a definite distal 

 area of imbricated or reticulated sculpturing, sometimes nearly 

 smooth, usually fairly evenly beset with faint or definite curves 

 with sometimes wavy and sometimes sharply serrate edges. Fila- 

 ment of antennal segment vi short or long 21 



Frontal tubercle distinctly swollen on inner margin, converging 

 strongly. Filament of vi never short 20 



Frontal tubercle distinctly produced on both inner and outer 

 margin. Frontal concavity broad and deep. Cornicle always 

 long and often with distinct distal area of imbricated or reticu- 

 lated sculpturing. Filament of vi never short 19 



Frontal tubercle short but definite on both margins in apterous 

 female. In alate female frontal tubercle only slightly if at all 

 evident on outer margin. Present on inner margin, wedge-shaped. 

 Cornicle conspicuously swollen. Filament of vi never short .... 



Amphorophora MACROSIPHINI, p. 301 



Aphids which are not in full accordance with any of the fore- 

 going specifications 



Macrosiphum illinoiensis and Aphis nerii, pp. 308, 295 



19. Cornicle cvlindrical. Never with more than a slight swelling as in 



Uriodcndri Macrosiphum MACROSIPHINI, p. 304 



Cornicle conspicuously swollen 



Nectarosiphon MACROSIPHINI, p. 310 



20. Frontal tubercle and first antennal segment with prominent pro- 



jections on the inner margin, especially conspicuous in the apter- 

 ous female and larvae Phorodon MACROSIPHINI, p. 304 



Frontal tubercle or first antennal segment swollen to gibbous but 

 without tooth-like projections ...Myzus MACROSIPHINI, p. 302 



21. Cornicle swollen, long or short 22 



Cornicle straight, cylindrical or tapering 25 



22. Cornicle short (not longer than in Aphis) 23 



Cornicle longer than in Brevicoryne 24 



23. Cauda short and abruptly conical ...Brevicoryne APHIDINI, p. 298 

 Cauda elongate Hyalopterus APHIDINI, p. 299 



24. Rhopalosiphum, Siphocoryne, Hyadaphis and Liosomaphis 



APHIDINI, p. 299 



25. Cauda broad at base, very short to moderately long, abruptly or 



evenly conical — without constriction near middle 



Anuraphis APHIDINI, p. 298 

 Cauda narrower and more elongate usually with constriction near 

 middle Aphis APHIDINI, p. 293 



