APHIDS INFESTING ECONOMIC PLANTS 393 
C.—Cornicle swollen. 
Pale yellow-brown; sensoria numerous and tuberculate on III and IV in 
alata; cornicle about twice as long as hind tarsal II; cauda tapering, 
hardly longer than hind tarsal II, bearing 3 hairs on each side. (p. 213) 
Pe shee esac thet arch ee cce The Honeysuckle and Parsnip Aphid (Rhopalosiphum conii) 
CC.—Cornicle cylindrical. 
D.—Cauda broad, short, .05 long on median line. 
E.—Cornicle imbricated, without definite encircling depression next 
to flange. 
F.—Numerous tuberculate sensoria on III and IV in alata; 
body pale brown to white with dark dorsal patch on abdomen 
of alata. Cauda with 2 hairs on each side. (p. 181)...........:.000020-+- 
atte h ea ha oe eee bey alse ol The Tulip Bulb Aphid (Aphis tulipae) 
FF.—Sensoria not tuberculate, 6 to 8 on III in alata, 4 in 
aptera; dorsal patch absent on abdomen. of alata; cauda with 
about 5 hairs on each: side. (p. 133)iscccc- eee eeeeee nescence Aphis crypta 
EE.—Cornicle smooth, with encircling depression next to flange; 
dorsal dark patch on abdomen of alata; cauda with 2 to 3 hairs on 
each side. (p. 142)................ The Leaf-curl Plum Aphid (Aphis helichrysi) 
DD.—Cauda spoon-shaped longer than .05 on median line. 
E.—Sensoria 7 to 10 on III of alata; cauda bearing 2 to 4 hairs on 
each side; body pale yellow, medium green, or blackish green, 
mixed in same colony. (p. 139)............ The Melon Aphid (Aphis gossypii) 
Sensoria 15 to 32 on III of alata; cauda bearing 4 lateral and 4 
dorsolateral hairs on each side; body yellow-green or yellowish 
BROWN (Dsl 4.3) ie eeecsecesteote sac The Wild Parsnip Aphid (Aphis heraclella) 
AA.—Frontal tubercles exceeding vertex (Fig. 409); antenna at least as long as body. 
B.—Body pale green, with dark dorsal patch or bands in alata; sensoria absent 
on antenna of aptera; cornicle usually swollen (in spring migrants cylindrical), 
not with striae, .45 to .60 long except in fall migrant .30 to .43. (p. 340).............-.. 
POR Ta Sy Be aerate eas el TON a ah eee The Green Peach Aphid (Myzus persicae) 
BB.—Body pale green, immaculate in both alata and aptera, with darker green 
blotch about each cornicle base; sensoria 1 to 6 on III of aptera; cornicle 
always cylindrical, with 2 or 3 cross striae just before large flange, .60 to .75 
long in aptera, .50 to .60 in alata. (p. 342)............ The Foxglove Aphid (Myzus solani) 
Cherry (Prunus cerasus) 
A.—Body shining black; cornicle black, curved outward at tip; hind tarsal II shorter 
than base of VI or rostral IV+V. (p. 335).......... The Black Cherry Aphid (Myzus ceras1) 
AA.—Body pale green with dorsal dark patch, sometimes broken, on abdomen of 
alata; cornicle dusky, not curved; hind tarsal II as long or longer than base of VI 
OrsrostralilV =H Vip. 340) ete ae cree The Green Peach Aphid (Myzus persicae) 
Chokecherry (Prunus virginiana) 
A.—¥Frontal tubercles projecting beyond vertex; dorsal patch or dark bands present 
on abdomen of alata. (p. 340)......-.----.---.cce------eeeeeee The Green Peach Aphid (Myzus persicae) 
AA.—Frontal tubercles not developed beyond vertex; dorsal patch not present on 
abdomen of alata. 
B.—Cornicle present, at least 3 times as long as rostral IV+V and twice as long 
ASH DASETOET Vile Ops bl 2S) ceceecccsetotee se esecrenee cate = The Chokecherry Aphid (Aphis cerasifoliae) 
BIB? —Corniclerapsents) Cp 261) te ote ac cet eee ee taespacecs aeaace Asitphonaphis pruni 
Chrysanthemum (Chrysanthemum sp.) 
A.—Frontal tubercles developed beyond vertex. 
B.—Body amber-brown to black, , shining; cornicle about the same length as 
cauda, thick, tubular, broadened at the base, reticulated over half of the length. 
broader at the base, without reticulation. (p. 340) --.......2...22...c2cceececceeeeseeceneceeceeeeeeneneeees 
Bs eee ie Re EG ome colt water ga teg i Safad reee The Green Peach Aphid (Myzus. persicae) 
AA.—Frontal tubercles not developed beyond vertex. 
B.—Abdomen of alata with dark dorsal patch or bands; -cornicle shorter than 
unguis, not longer than 1.5 times rostral IV+V, cylindrical and smooth. Cauda 
short,and  prOad. (pL 42) tecseeercecnce renee The Leaf-curl Plum Aphid (Aphis helichrysi) 
