SUBFAMILY APHINAE 37 
Type. U.S.N.M., No. 43001. Paratypes, Colo. Agr. Exp. Sta. Collection. 
Chief Distinguishing Characters. Long hind tarsal II (.95, nine-tenths of the 
length of tibia), apparent absence of cornicle, and eye of aptera (showing more 
than 15 facets). 
[Genotype Trama troglodytes Heyden] 
Alate Viv. 
AEE 0 OO eI E00 OT EEF 
: IL 
(After 
Fig. 56. Trama troglodytes 
Trama troglodytes Heyden, 1837:293; Buckton, 1881:68; Theobald, 1929:94. 
Apterous Summer Vivipara. Pale yellowish white to pearly white or dull brownish green. 
Body length 2.5-3.5; hind tibia .90; hind tarsal I minute, triangular, II .72; antenna about half 
the length of body, III nearly or quite equal to IV+V, IV less than half of III, much shorter 
than V, V longer than VI, unguis very short and blunt, secondary sensoria absent; cornicle 
apparently absent; eye very small and dark, of a few facets only; rostral IV .20-.25, V .06, 
attaining middle of body or more. Hairs numerous on body and appendages. 
Alate Vivipara. About the same in color and measurements as aptera except as follows: 
Secondary sensoria of various sizes; cornicle present as slightly raised rim. 
Hosts. On the roots of compositae and in nests of ants. (Not taken in region.) 
Data for above description and drawings taken from Theobald (op. cit.) and from ex- 
amples determined by Cholodkovsky. 
Tribe Thelaxini Baker 
Baker, 1920a:17. 
Characters. Frontal tubercles undeveloped. Antenna five-segmented, with 
unguis shorter than base of VI. Cornicle mere ring on more or less elevated 
base. Cauda semicircular or knobbed; anal plate rounded. Hairs simple. 
Key to Genera of Thelaxini 
Ripe oman AIT SEETIONS YP ECINC DDO 5 Cp), SF) oe tas te cst cy ce weet e sens ne Git Houseeeh eo a carne ttc escent eta ase Thelaxes 
Gauda not knobbed, semicircular (Not taken in region) <..2-c:.--.--ccec-seseeseeteeesteects Glyphina 
Genus Thelaxes Westwood 
Westwood 1840:118; Baker 1920a:21. _ 
Characters. Frontal tubercles undeveloped; antenna five-segmented with 
unguis shorter than half of base of segment VI; cornicle mere rim on slightly 
mammiform base. Cauda knobbed; anal plate rounded. Rostrum with segment 
V needlelike, apparently distinct. Hairs simple; some fine, others heavy, spike- 
like. 
Genotype (fixed by Westwood 1840) Thelaxes quercicola Westwood (syn. of 
Aphis dryophila Schrank). 
Thelaxes californica (Davidson) 
The Oak Bud Aphid 
Chaitophorus sp. Davidson, 1914a:128. 
Vacuna dryophila Schrank ? (misidentification), Davidson, 1917b:290. 
Vacuna californica Davidson, 1919b:245. 
Thelaxes californica, Essig, 1926 (1947 ed.) :230. 
Apterous Summer Vivipara. (Mounted in balsam), colorless except often with brownish 
dorsal patch, broken on median line, on abdominal I to V, the brown color in minute spots 
giving reticulated appearance; appendages pale brownish, darker distally. Body length 1.80- 
1.90; across eyes .40; antenna .60-.65; hind tibia .50-.55; rostrum with needlelike tip, attaining 
3d coxa. Hairs on body of two kinds, on dorsum heavy, sharp, spikelike, .03; on venter slender, 
