GRAPE-BEERY MOTH IN NORTHERN OHIO. 37 
were parasitized. The parasite was not determined but was thought 
to be the same as recorded by Johnson and Hammar 1 at North East, 
Pa., in 1906, Tricliogramma pretiosa Riley. 
SUMMARY. 
The present account of the life history of the grape-berry moth in 
northern Ohio is based upon a series of studies made in 1916, 1917, 
and 1918. 
In the course of a year the grape-berry moth in northern Ohio 
produces one full brood and a partial second, the second brood of 
larvae being much larger and more destructive than the first. 
The grape-berry moth passes the winter in the pupal stage in 
cocoons in old grape leaves under the grape trellis. Under a leaf 
blanket approximating conditions in a protected part of a vineyard 
the mortality among the pupae was 80 per cent during the winter of 
1916-17 and 76 per cent during the winter of 1917-18. 
The first moths emerge in the spring about 10 days before grapes 
begin to bloom but emerge in greatest numbers during and imme- 
diately following the period of grape bloom. In 1917 but 4 per 
cent emerged previous to bloom, 50 per cent during grape bloom, 25 
per cent in the 10-day period following bloom, and the remaining 21 
per cent later in the season. Moths begin ovipositing about 4 days 
after emergence and the eggs hatch in from 3 to 10 days, with 5 days 
as the average length of the egg stage. 
The first-brood larvae feed in the young grapes for a period of from 
14 to 37 days, and the average length of the feeding period was 20.6 
days in 1917. At the end of the feeding period the larvae leave the 
grapes and go to tender grape leaves on the vines in which they spin 
their cocoons. The prepupal period lasted for from 1 to 3 days and 
averaged 1.77 days with the first brood in 1917, and lasted for from 
3 to 7 days and averaged 4.15 days with the second brood in 1916. 
The pupal period varied from 11 to 16 days and averaged 13 days 
for first-brood pupae in 1917. The total period in the cocoon varied 
from 6 to 32 days with an average period of 15 days. 
The life cycle of the first generation in 1917, taken as a total of the 
average length of the separate stages, was 39.79 days. The total of 
the maximums was 76 days and of the minimums 23 days. 
The incubation period of second-brood eggs varied from 4 to 10 
days with 5.1 days as the average period. The feeding period of 
second-brood larvae was from 16 to 36 days and averaged 24.18 days 
in 1916. All other records have given this period as about 40 days 
which is probably nearer the average condition than the figures 
presented here. 
i Johnson, Fred, and Hammar, A. G. The grape-berry moth. U. S. Dept. Agr., Bur. Ent. Bui. 116 ? 
pt. II, p. 39. 1912. 
