GENERIC CLASSIFICATION OF APHIDIDAE. 33 



Subtribe CHAITOPHORINA. 



The subtribe Chaitophorina is composed of aphids which are similar 

 in many ways to the Callipterina. They differ in that they are always 

 armed with long hairs which quite prominently cover the antennae as 

 well as the other parts of the body, Some of the species perhaps are 

 given more to living in colonies than are the Callipterina, but this 

 habit varies in that subtribe as well. 



Key to the Gexeea of the Chaitophorina. 



1 . Cauda quite distinctly knobbed '. 2. 



Cauda not knobbed but rounded 3. 



2. Antennse of five segments Sipha. 



Antennae of six segments Chaitophorus. 



3. Body elongate ; small dimorpbic forms deA' eloped Periphyllus. 



Body not elongate ; no dimorpbic forms developed 4. 



4. Antennae of five segments Atberoides. 



Antennse of six segments 5 



5. Anal plate entire or slightly indented Xeothomasia. 



Anal plate divided into two quite separate parts Patcbia. 



Genus ATHEROIDES Haliday. 

 1839. Alheroides Haliday, Ann. and Mag. Nat. Hist., v. 2, p. 1S9. 



More careful collecting of marsh-inhabiting species may show that 

 this genus is a specialization from the Chaitophorina as is the Saltu- 

 saphidina from the Callipterina, for most specimens falling here seem 

 to lack ocular tubercles. 



Characters. — Antennse of five segments armed with stout spines. Fore wings with 

 media twice branched; hind wings with both media and cubitus present. Cornicles 

 reduced to mere rings. Cauda broadly rounded. Form elongate and flat. Entire 

 insect prominently spined. Species living on sedges and grasses. 



Type ('set by Kirkaldy, 1906), Atheroides serrulatus Haliday. 



Genus CHAITOPHORUS Koch. 



Plate IV, CC 



1854. Chaitophorus Koch, Die Pflanzenlause Aphiden, p. 1. 



1870. Tram-phis Walker, The Zoologist, p. 1999. 



1870. Arctaphis Walker, The Zoologist, p. 2000. 



1912. Fkhochaitophorus Essig, Pom. Coll. Journ. Ent., v. 4, p. 721. 



1912. Micrella Essig, Pom. Coll. Journ. Ent., v. 4, p. 716. 



1856. Type fixation, Gerstaecker, Berieht for 1854, p. 162. 



In 1854 Koch erected the genus Chaitophorus with several species. 

 Aphis populi was made the type by Gerstaecker in 1856. The same 

 species was used by Walker as type of his genus Arctaphis and there- 

 fore this name will become a synonym. The types of both of Essig's 

 genera show that these vary little from populi. The genus Tranaphis 

 was erected with salicivorus Walker as type and this species is similar 

 in general characters to populi. Therefore, Tranaphis will become 

 a synonym. 



141613°— 20— Bull. 826 3 



