296 
JOURNAL OF ECONOMIC ENTOMOLOGY 
[Vol. 17 
The injury is very conspicuous, since the insect causes the formation 
of a leaf gall, frequently spoken of as the witch’s broom. The galls are 
composed of many small, stunted, tightly curled leaves and may vary 
in size from one-fourth of an inch to two or three inches in diameter, 
depending upon various conditions, chief of which are weather and 
abundance of individuals. The curling of the leaves is so pronounced that 
it is very difficult to make life cycle observations, since the insects are so 
completely secluded. The first seasonal galls are produced by the first 
nymphs hatching in the spring and each generation continues to produce 
new galls throughout the summer. After the formation of the galls, 
the leaves are soon killed, turn brown and remain on the plant for seme 
time. The last galls formed in the autumn usually remain on the 
plant during the dormant season. During the development and growth 
of the gall this portion of the plant is apparently stimulated to produce 
certain definite types of growth. As has been mentioned previously, 
the first conspicuous change from a normal growth condition, is the 
formation of a large number of stunted curled leaves. The next con¬ 
dition following the leaf gall is the formation of the witch’s broom 
which is caused by the gall giving rise to a large number of new shoots. 
Thus wherever there is a gall, a large number of unhealthy dwarfed 
shoots are formed which produce only a small amount of inferior fruit, 
instead of the normal condition of each branch producing a few healthy 
shoots. The vines are injured in this way very noticeably because of 
insufficient numbers of normal healthy canes and normal leaves, and the 
fruit production is decidedly reduced because of the condition of the 
shoots that form the fruit buds. This loss is more apparent when it is 
known that sixty-five or seventy galls may occur on a single plant. 
Life History Notes 
Many details of the life cycle cannot be given at this time, but con¬ 
tinued observations have shown certain definite relationships with the 
host throughout the season. 
The aphid overwinters as a shining black egg about 1 mm. long which 
is deposited near the ground on the lower limbs and canes. They may 
be placed on the bark, buds, old leaves or thorns but are usually on 
the lower portion of the canes. As many as ten or twelve eggs are fre¬ 
quently placed inside the bud scales and form the galls on the new 
leaves as they push out from the bud. During the past season the eggs 
began hatching at Columbus about April 10th when the buds were burst¬ 
ing, and galls were formed from the first opening leaves before they 
