Feb. si, 1916 
Green Apple Aphis 
975 
inal sutures as in the wingless form. Wing pads prominent, extending somewhat 
caudad of the hind coxae. Cornicles subcylindric, imbricated, slightly flanged; 
length, 0.168 to 0.376 mm. Legs slender, hairy, hind tibiae 0.50410 0.64 mm. long. 
Anal plate rounded, setose and armed with hairs. Cauda (PI. LXXIV, fig. 21) coni¬ 
cal, not as in the adult form, setose, and armed with many long, curved hairs. Length 
from vertex to tip of cauda, about 2.6 mm. 
Color characters: General color greenish; head and thorax orange-yellow with a 
tosy bloom, the reddish appearance of this increasing with age. Abdomen yellow- 
green. Antennae yellowish, with the distal segments dusky. Wing pads brown, 
with black costal margins. Eyes, tip of labium, tarsi, and distal extremities of tibiae 
and tarsi black; cauda lighter than abdomen, not black as in adult. Area between 
cornicles darker green than the rest of the abdomen. In some cases the margins of 
the thorax are light-straw color, almost white, venter usually lighter than dorsum. 
Fifth instar (adult). —There is no distinct spring or fall migrant in this species. 
All the winged individuals occurring throughout the spring, summer, and fall have 
the same characters and are identical, except for variations bearing no relation to 
season. 
Morphological characters: Antennae (PI. LXXIV, fig. 7) as follows: I, 0.064 mm.; 
II, 0.063 mm.; Ill, 0.192 to 0.312 mm.; IV, 0.144 to 0.288 mm.; V, 0.144 to 0.224 mm.; 
VI, base 0.096 to 0.128 mm., unguis 0.288 to 0.344 mm., segments III to VI imbricated 
and armed with a few hairs, III with a row of usually 6 circular sensoria (range 4 to 9). 
These sensoria form an even row along the segment and are of about the same diameter 
as the segment. They have a distinct double rim. Segment IV often without sen¬ 
soria, although on some specimens there are as many as 3 on this segment near its 
distal extremity. Sometimes one antenna has sensoria here and the other none. 
Segment V with a distal sensorium, and VI with the usual group at the base of the 
unguis. Vertex slightly rounded, median ocellus protruding, lateral ocelli very close 
to the compound eyes; these eyes large and showing with distinct tubercles. Tho¬ 
racic and abdominal tubercles as described for the wingless form. Wings with delicate 
veins; fore wing with the media normally twice branched, but not uncommonly 
with it only once branched and in rare cases (approaching the intermediate) this 
represented by one vein only. Cornicles (PI. LXXIV, fig. 11) subcylindric, tapering 
toward the tip, imbricated and slightly flanged; length, o. 192 to 0.3 52 mm. Anal plate 
rounded, setose, and armed with a number of long, curved hairs. Cauda elongate, 
slightly constricted in the middle, rounded at the tip, densely setose, and armed on 
each side with about 5 long, curved hairs. Legs slender; hind tibiae 0.56 to 0.992 
mm. long. Length from vertex to tip of cauda, about 2.5 mm. 
Color characters: Head and thorax shining black, sutures yellowish; antennae straw 
color at base, dark, almost black distad; eyes black; legs yellowish, with the distal 
extremities of the femora, the distal and proximal extremities of the tibiae, and the 
tarsi black. Abdomen yellow-green, with the margins and a longitudinal median 
stripe darker green. Cauda and anal plate black. Labrum straw color, with tip 
dusky or black. Wings hyaline, veins brown, stigma smoky. 
Most of the winged forms had the abdomen uniform green, but with the second 
winged generation another form appeared. The color of this is as follows: Head and 
thorax black, similar to the first winged generation; veins and stigma dark; abdomen 
unlike the uniform pea green of the first winged generation, but much darker, with 
a median longitudinal stripe of still darker green; margin of the abdomen on each side 
with a row of 5 or 6 dark patches; other characters as in first winged generation. 
The color characters of this winged generation may have had something to do with 
the confusion of A . pomi and A . avenae , as the color characters of the two are quite 
similar. 
