86 
Journal of Agricultural Research 
VoL XI, No. 3 
SUMMER WINGLESS VIVIPAROUS FEMALE 
The summer wingless forms (PI. 9, B, C) occur very abundantly 
throughout the summer. They reproduce very quickly during the early 
summer, so that seven generations have often reached maturity by the 
1st of July. The wingless forms reach maturity a day or two before the 
winged forms of the same generation, so that during the season many more 
wingless generations are produced upon grape than there are of winged 
generations. The wingless insects vary considerably in size and color, 
sometimes being a distinct brown, while other specimens are deep hl gn k 
They also vary considerably in size, the darker, smaller individuals 
occurring later in the summer. The number of young produced daily 
ranges from 6 to 10, and the insects live for three weeks or more. 
The summer wingless and winged forms do considerable damage to the 
vines in some sections. They attack the growing clusters, sometimes 
thickly covering them, and the feeding of the insects causes the berries 
to drop. Some vines at Vienna, Va., which the writer had under obser¬ 
vation produced scarcely any fruit owing to the attacks of the aphids. 
The berries dropped while still green and ranging in size from that of a 
pea to that of a small cherry. The fruit stems in nearly every case had 
become somewhat withered owing to the continued feeding of the insects. 
The young growing shoots and leaves are also very abundantly attacked, 
and when the aphids are numerous growth is more or less retarded. The 
most important injury, however, appears to be that caused to the fruit 
clusters. 
Fifth instar (adult) (PI. 9, C).—General color a deep reddish brown. Antennae 
with the basal two segments and the distal segment dusky, the remaining segments 
yellowish brown, dusky at the joints; eyes black; hind legs and cornicles black, femora 
of the middle and fore legs and a band about their tibiae yellowish brown, remainder 
black, cauda dusky. Length from vertex to tip of cauda, 1.272 mm. Measurements 
of the antennae and cornicles as follows (Table II): 
Table II. Lengths (in millimeters) of the antennal segments and cornicles of the 
summer wingless vivipara of Macro sip hum illinoisensis 
Generation. 
Segment 
III. 
Segment 
IV. 
Segment 
V. 
Segment VI. 
Cornicles. 
Third. 
Sixth. 
Seventh. 
Eighth. 
0.4 
. 416 
. 416 
.464 
0. 32 
•32 
.288 
. 368 
O. 256 
. 272 
. 272 
. 224 
O. 096+0. 256 
. 112+ .336 
• 112+ .336 
• ° 9 6 + • 352 
0. 48 
.496 
. 48 
• 5<5 
INTERMEDIATE 
Intermediates between the summer winged and the summer wingless 
forms have been found upon grape. These resemble more closely the 
winged form than they do the wingless one. 
Thorax partially developed, some of the large wing muscles remaining. Wings 
represented by small pad-like structures about 0.4 mm. long. Antennae and cornicles 
