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 antennas 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 Genera of the Chaitophorina. 
1 . Cauda quite distinctly knobbed 2. 
Cauda not knobbed but rounded . v 3. 
2. Antennae of five segments Sipha. 
Antennas of six segments Chaitophorus. 
3. Body elongate ; small dimorphic forms developed Periphyllus. 
Body not elongate ; no dimorphic forms developed . 4. 
4. Antennae of five segments Atheroides. 
Antennae of six segments 5 
5. Anal plate entire or slightly indented Neothomasia. 
Anal plate divided into two quite separate parts Patchia. 
Genus ATHEROIDES Haliday. 
1839. Atheroides Haliday, Ann. and Mag. Nat. Hist., a t . 2, p. 189. 
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. — Antennae 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. Tranaphis Walker, The Zoologist, p. 1999. 
1870. Arctaphis Walker, The Zoologist, p. 2000. 
'1912. Eichochaitophorus Essig, Pom. Coll. Journ. Ent., v. 4, p. 721. 
1912. Micrella Essig, Pom. Coll. Journ. Ent., v. 4, p. 716. 
1856. Type fixation, Gerstaecker, Bericht 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 
