GENERIC CLASSIFICATION OF APHIDIDAE. 13 



ed with hairs. t Soine specialized forms have srnall cornicles or none 

 at all. Wax-secreting structures, but no distinct gland areas, are 

 present in this tribe and a coating of fine wax is often found over the 

 entire insect, including the appendages. This is true of the oviparous 

 forms, as well as of the viviparous ones. 



The cauda and anal plate are here rounded, never developed into 

 elongate structures as in some of the other tribes of the subfamily. 

 The sexual forms are nearly as unspecialized as the viviparous ones. 

 Both sexes possess a distinct rostrum and take food. The males in 

 the typical subtribes are winged. The females are apterous, but the 

 ovaries are developed and several eggs are laid by each individual. 



Key to the Subtribes of the Lachnini. 



1. Radial sector of fore wings curved, and of moderate length 2. 



Radial sector of fore wings short and straight, situated near the tip of the 



wing 4. 



2. Hind tarsi extremely elongate, head divided, wing venation usually faint. 



Tramina. 

 Hind tarsi normal 3. 



3. Stigma short and thick, sexes both apterous Anoecina. 



Stigma elongate, males often winged Pterochlorina. 



4. Form elongate and very narrow; antennas with bristles, cornicles not hairy; 



eyes without ocular tubercles Eulachnina. 



Form not elongate ; cornicles on hairy cones; eyes with ocular tubercles. . Lachnin a. 



Subtribe ANOECINA. 



The subtribe Anoecina is suggestive of the Tramina, but none of 

 the forms are as specialized as some of the genera of that subtribe. 

 The typical genus is quite distinctive in the short rounded stigma 

 and in the sexual forms. The genus Nippolachnus, however, has 

 a stigma quite Lachnus-like in appearance. Only two genera are 

 known at present. 



Key to the Genera of the Anoecina. 



1. Head not divided; eyes with prominent ocular tubercles; stigma of wing 



short and rounded Anoecia. 



2. Head divided; eyes without ocular tubercles; stigma long and straight. 



Nippolachnus. 

 Genus ANOECIA Koch. 



Plate 1, A-F, I. 

 1857. A noecia Koch, Die Pflanzenlaiise Aphiden, p. 275. 

 Characters. — Head not divided, front somewhat rounded. Eyes prominent but not 

 distinctly set off from the head. Antennae of six segments, armed with subcircular or 

 oval or elongate sensoria and covered with hairs. Fore wings with the media once 

 branched. Stigma short and thick. Hind wings with both media and cubitus 

 present. Cornicles situated on broad hairy cones. Cauda and anal plate somewhat 

 rounded. 



Spring forms free, living in colonies; summer forms often subterranean. Sexes 

 small and apterous, possessing beaks and feeding. Oviparous female laying one or 

 more than one egg. 



Type (mono typical), Aphis corni Fab. 



