A SYNOPSIS OF THE APHIDIDAE 59 



2. Ill without or at most with only a few secondary sensoria (0-12) 11 



Ill with several (over 12) secondary sensoria scattered along the greater part 



of its length 3 



3. Cornicles short and tapering, being somewhat bottle-shaped and not distinctly 



longer than the cauda sanborni Gillette* 



Cornicles normal, being cylindrical and considerably longer than the cauda 4 



4. Ill and IV with secondary sensoria heucherae (Oestlund) 



IV without secondary sensoria 5 



5. General body color dark, being red, wine, brown or black 6 



General color lighter, usually being a shade of green 8 



6. Cauda black. Legs black, except the bases of the femora taraxici (Kalt.) 



Cauda pale. Legs with at least the bases of the femora and tibiae not black 7 



7. Legs green, except tarsi and apices of femora and tibiae. Cauda not more than 



half the length of the cornicles. Not more than ten to twelve sensoria on 

 the basal one-third of III rosae (Linn.)* 



Legs black, except bases of femora and tibiae, which are light brown. Cauda 



more than half the length of the cornicles. A considerable number of 

 sensoria scattered over more than the basal one-half of III. 



rudbeckiae (Fitch)* 



8. Cornicles subequal to or shorter than III. Body covered with a whitish pul- 



verulence 9 



Cornicles distinctly longer than III. Body without whitish pulverulence .... 10 



9. Cornicles, except tip, and cauda green; the former subequal in length to III 



and about twice as long as cauda albifrons Essig* 



Cornicles black, cauda yellow or light brown; the former considerably shorter 



than III and not twice as long as cauda ludovicianae (Oestlund)* 



10. Cauda quite broad and blunt at end. Cornicles with not more than apical one- 



sixth reticulated rosae (Linn.) * 



Cauda slender and pointed. Cornicles with apical one-fourth reticulated. 



rudbeckiae (Fitch) n.var. madia* 



11. Body covered with capitate or fan-shaped setae 12 



Body without specialized setae 14 



12. Setae with fan-shaped tips and thickly covering the body. Cornicles slender 



and imbricated for their entire length artemisicola (Williams)* 



Setae capitate and only sparsely covering body 13 



13. Cornicles fairly stout, with tips reticulated, and about twice as long as cauda. 



artemisiae (Fonsc.) 



Cornicles slender, with no reticulations, and considerably more than twice the 



length of the cauda pteridis Wilson 



14. Cornicles with tips at least reticulated 16 



Cornicles with no reticulations 15 



15. Cornicles very long and slender. Antennae considerably longer than body. 



pisi (Kalt.)* 



Cornicles shorter and heavier. Antennae at most but slightly longer than 



body dirhodum (Walker)* 



16. Cornicles for the most part dusky or black 17 



Cornicles mostly pale or green 19 



17. Cornicles and III subequal. Body not pulverulent 18 



Cornicles considerably shorter than III. Body more or less pulverulent. 



ludovicianae (Oestlund)* 



