i APHIDS OF THE ROCKY MOUNTAIN REGION 
EE.—Cauda elongate, tapering; antenna not conspicuously hairy; 
body pale green or pinkish. 
F.—Abdomen with supracaudal process in aptera, median tu- 
bercle on terminal segment in alata; dorsum of aptera rugose; 
sensoria numerous and tuberculate on III of alata. 
G.—Cornicle swollen. 
H.—Supracaudal process knoblike, much shorter than 
cauda; unguis 1.5 times as long as base of VI. (p. 197) 
AS eae a ie ae a Cavariella essigi 
HH.—Supracaudal process in aptera triangular, same 
length as cauda; unguis shorter than 1.5 times length of 
base of Vili (pp. 196) tet eiee eee eee Cavariella aegopodii 
GG.—Cornicle cylindrical’ (pp. 198)e2 eee 
FF.—Without supracaudal process; dorsum of aptera not rugose; 
sensoria not numerous and tuberculate on III of alata. 
G.—Cornicle cylindrical, .50 to .55 long in aptera; .35 to .40 
in alata, longer than IV and 3 to 4 times length of hind 
tarsal. IT. €pin172)2...Aes.2 ee eee 
oeee Weer! The Green and Pink Willow Aphid (Aphis saliceti) 
GG.—Cornicle swollen, .09 to .13 long, hardly longer than 
TVeorthindstarsale lle (pl94) ee ee Brevicoryne fraterna 
AA.—Frontal tubercles exceeding vertex; antenna longer than body; cornicle longer 
than III, reticulated area as long as hind tarsal II; cauda tapering, .35 on median 
line, 2.5 times length of hind tarsal II; sensoria 5 to 10 on III of alata. (p. 296)............ 
Sect i) Raaey i Se eA BOT Bt Bch Sy The California Willow Aphid (Macrosiphum californicum) 
Wolfberry, Western and Snowberry (Symphoricarpos sp.) 
A.—Cornicle cylindrical; cauda rounded, inconspicuous. 
B.—Body sordid brown-green; very pulverulent; frontal tubercles slightly ex- 
ceeding vertex; cornicle transversely wrinkled, shorter than hind tarsal II or 
antennal V; sensoria absent on IV and V. On bark at base of stem. (p. 115)........ 
Pe eee A ee ee The Pulverulent Snowberry Aphid (Amphicercidus pulverulens) 
BB.—Body yellow-green with dark bands; frontal tubercles not exceeding vertex; 
cornicle imbricated, longer than hind tarsal II, not shorter than V; sensoria 
present on IV and V in both alata and aptera. On leaves or roots. (p. 144)............ 
Fn eee eae ep Re arene me MR ae fe nel oer at ele AS OR at ee ee NE a Fe ae Aphis incognita 
AA.—Cornicle swollen; cauda elongate, tapering to a point. On leaves. 
B.—Brownish green with black bands in alata, powdery cross dashes in aptera; 
cornicle shorter than IV; sensoria present on V in alata, absent in aptera. (p. 
195}. Bee See eee ae ee eee se The Snowberry Aphid (Brevicoryne symphoricarpi) 
BB.—Pale yellowish to yellowish brown, immaculate; cornicle longer than IV; 
sensoria absent on V in both alata and aptefa.\p.0213) aun Rhopalosiphum conti 
Yellow Pine—see Pine 
