28 Farmers’ Bulletin 1220. 
THE GRAPE LEAF SKELETONIZER.” 
The grape leaf skeletonizer is noted usually on vines grown around 
the home. Owing to the general spraying of commercial vineyards, 
it is rarely seen in these and practically never in such abundance as 
to cause serious injury. The insect occurs rather generally from the 
eastern United States west to Missouri and Arizona. The larve in 
their earlier stages feed in a characteristic manner, usually upon the 
upper surface of the leaf. Starting from a common point, the 
larvee feed side by side, soldierlike, retreating as they feed until the 
leaf tissue is destroyed. Young larve 
eat out the parenchyma or soft leaf 
tissue, leaving the skeleton frame- 
work of the leaf intact. Full-grown 
larvee, however, consume the leaf sub- 
stance entirely, leaving only the 
larger veins (fig. 30). The full- 
grown larva is a little more than one- 
half inch in length, sulphur-yellow 
in color, shghtiy hairy, and having 
on each body segment four black 
tubercles, showing above as four dis- 
tinct longitudinal rows. It is native 
to this country, and in addition to 
grape feeds on various wild plants, 
including Virginia creeper. The in- 
sect winters in the pupa condition in 
oblong-ovate cocoons in fallen leaves 
or trash around the vines. Rather 
late in the spring the moths emerge 
and deposit small, lemon-yellow eggs 
in clusters or masses, ranging from a 
few to over 200, usually on the lower 
surface of the leaves. The resulting 
larvee require some 40 days to complete their growth, and the time 
spent in the cocoon during the summer is about 10 days. The complete 
life cycle from egg to the death of moths is about 66 days. Second 
generation larve are present over a considerable period of the summer, 
and this fact led earlier writers to believe there were two generations 
and a partial third each year. 
Fig. 29.—Grape flea-beetle larva and 
its work on grape leaf. 
CONTROL. 
Under ordinary conditions of abundance, hand picking and de- 
struction of infested leaves will be sufficient to keep the insect in 
138 Harrisina americana Guér, 
