1910] Key to the Genera of Aphidinae 319 



Gen. Idiopterus Davis 



type nephrelepidis Davis. 

 Antennae about one and a half times as long as the body and 

 placed on prominent tubercles; segments one and two large, 

 the remaining segments long and slender, spur of sixth segment 

 longer than the third. Antennal tubercles much larger than 

 the second segment and with the upper inner side sharply 

 angled. Body elongated, wings with the stigmal vein deeply 

 rounded almost touching the discoidal and both lying in a 

 broad dusky band. This gives the wing the appearance of 

 having a closed triangular cell. Nectaries about one fifth the 

 length of the body, straight and cylindrical. Cauda nearly as 

 long as the nectaries and tapering. 



Gen. Microparsus Patch 



type variabilis Patch. 

 Antennae longer than the body and placed on prominent 

 tubercles, spur of sixth segment longer than the third. First 

 segment large and gibbous on the inner side. Antennal tuber- 

 cles close together, head fiat in front and merging into the 

 tubercles. Wings long, cross veins heavy and cubitus usually 

 with a single fork; stigma long and slender, hind wing with but 

 a single cross vein. Nectaries about one fifth the length of the 

 body and tapering. Cauda as long as the nectaries and broadly 

 tapering. Anal plate slightly broader than the base of the 

 Cauda and triangular. 



Gen. Pentalonia Coquerel 



type nigronervosa Coq. 

 Antennae slender, longer than the body and placed on promi- 

 nent tubercles; spur of sixth segment longer than the third, 

 first segment strongly gibbous. Antennal tubercles gibbous 

 at the upper inner edge. Body short and robust, wings long 

 and with the oblique veins nearly at right angles to the costa; 

 cubitus twice forked and at or slightly beyond the second fork 

 combines with the radial sector, thus forming a closed cell; 

 veins dark, hind wing with but a single cross vein. Nectaries 

 about one-fifth the length of the body, and constricted in the 

 middle and just behind the tip. Cauda but a knob situated on 

 a broad base as in CaUipterini . Anal plate broad with apex 

 parallel to the base. 



