186 APHIDS OF THE ROCKY MOUNTAIN REGION 
Aphis vorabonnevilla Knowlton and Smith 
Aphis vorabonnevilla Knowlton and Smith, 1936a:487. 
Alate Fall Vivipara. (Mounted in balsam), dark markings as follows: Abdomen with 
both dorsal and ventral bands and lateral areas on all segments, with dorsal bands coalesced 
on III to VI; antenna, cauda, cornicle and tips of tibiae black or blackish; tibiae dusky. Body 
length about 2; across eyes .45; antenna 1.50; abdomen marked with rows of denticles; hind 
‘tibia .90-1; hind tarsal II .10-.12; rostrum attaining 2d coxa. 
joss 12 zs 
Sen. 19- 2? sen,7-\! sen..o-5 
are Bis 33-40 "43". 
Hd. Tibs 
Fig. 214. Aphis vorabonnevilla 
Collections. On Populus deltoides, P. angustifolia and Salix sp. Utah: Para- 
dise, Salt Lake City and Wellsville. Fall migrants swarming Sept. 20 to Oct. 6, 
fall migrants and alate males in traps in peach trees in Colorado at Paonia in 
October. This species is evidently in migration from its summer host and may 
have been only accidentally resting on the above-mentioned trees. 
Cotypes: Knowlton Collection. 
Chief Distinguishing Characters. Number of sensoria on III in alate vivipara 
(19-27), presence of sensoria on IV and V, caudal hairs fewer than 3-4 lateral 
pairs, length of cornicle (.20-.29, no longer than unguis), slightly swollen shape 
of cornicle, denticulate imbrications of cornicle and rows of denticles on dorsum 
of abdomen, length of rostral IV-+V (.10-.12) and shortness of the antenna. 
Aphis zonassa Knowlton 
Aphis zonassa Knowlton, 1935c:138. 
Apterous Summer Vivipara. Black; with all appendages black. Body length 1.50-1.70; 
across eyes .40; dorsum of abdomen marked with reticulations; hind tibia .95-1; hind tarsal 
II .11-.12; rostrum attaining nearly to 3d coxa, “‘sometimes to abdomen.” 
Alate Vivipara. ‘‘Black.’’ (Mounted in balsam after clearing), dusky on imbricated 
lateral areas on abdomen; appendages, cauda and cornicle, black. Body length 1.2-1.3 (shriv- 
elled probably 1.5 in normal condition) ; across eyes .40; hind tibia .76; hind tarsal II .11-.12; 
rostrum attaining about to 3d coxa. Fore wing with venation normal except media in one 
wing in one example only once-branched. 
as 243% oe 20 »614- ae " 
Seo ~ aoe — 
d Dy aera) waiag yar eae 
aa 200 Te ee 
AB 
Fig. 215. Aphis zonassa 
Collections. On Chrysothamnus parryi and C. sp. Utah: Kanab. Colorado: 
Buckhorn Creek (above Masonville). Apterous and alate viviparae June 26 to 
Aug. 20. 
Type and Paratypes. Knowlton Collection. 
Chief Distinguishing Characters. Number of sensoria (15-21) on III and 
9-11 on IV) of alate vivipara and length of cornicle (in alate vivipara .17-.20, 
in aptera .22-.25). 
A. lugentis comes very close and differs, apparently, only in slightly and 
doubtfully more numerous sensoria (19-24) on III, larger body size (2 or more 
in length) and the different host plant (Senecio sp.) 
