Insect and Fungous Enemies of the Grape. 33 
ent insect is a small midge, or gnat, resembling the preceding species, 
and the larva or grub within the gall is pale drange in color. This 
species is not sufficiently abundant to require treatment. 
HAWK MOTHS. 
Several species of insects known in the adult stage as hawk» moths 
and in the larva stage as hornworms attack ‘the grape, cultivated 
and wild, the Virginia creeper, and numerous other plants. As a 
rule the caterpillars occur in small numbers, stripping the foliage 
from parts of the vines, though young plants may be entirely defoli- 
ated by them. There are records, however, of the local occurrence of 
certain species in very large numbers completely defoliating large 
vineyards and requiring prompt action to arrest their ravages. Such 
Fic. 34.—The grape apple gall. 
an outbreak occurred in Tulare County, Calif., in 1919, involving 
some 700 acres of vines. Large-scale spraying operations were su- 
pervised by the bureau, requiring an outlay of about $11,000, but 
resulting in saving the crop, valued at $800,000. 
The life and habits of the hawk moths attacking the grape are 
fairly similar. Eggs are laid by the parent moth, usually singly on 
the leaves, the resulting larve attacking the foliage and eating the 
leaves more or less completely. The young larvee bear on the caudal 
end of the body a conspicuous horn-like process which may persist in 
the full-grown caterpillar, or be replaced by an eye spot, according 
to species. When mature, the larve go to the soil, change to brown 
pupee, and pass the winter in this condition. In the case of some 
species the moths appear again the same season and deposit eggs for 
an additional generation or generations. 
48533°—21—Bull. 1220 5 
