The Bulletin 
19 
from hibernation in mid-April (April 10th being the earliest date 
recorded). Their numbers seem to increase rather rapidly until late 
May and after that rather slowly until mid-August. This increase is 
perhaps largely due to the fact that new adults are continually emerging 
from pupa whose larva have developed from eggs laid early in the 
spring. After mid-August the numbers of adults diminish rapidly, 
so that in early corn practically all the adults have disappeared by the 
end of August. A few adults remain active to late October. The 
adults commence to lay eggs by early May (May 5th being the earliest 
recorded date). The number of eggs found in the field increases 
rather rapidly until mid-June and then less rapidly until mid-July, 
the number of eggs falling ofi slightly toward mid-August. After 
which the number decreases rather rapidly. The latest date recorded 
Figure 12. Cvperus Grass growing in a swamp to show characteristics. 
for finding eggs in the field is^ September 23d, but as they were still 
rather common at that time, it seems safe to conclude that egg laying 
continues until early October, especially as the adults are active in the 
fields till late October. The distribution of the larvae throughout the 
year seems to coincide rather closely with the distribution of the eggs. 
The earliest larvae have been found in the field in mid-May, but the 
time of greatest abundance seems to be from late July to mid-August. 
After this time their numbers fall off rapidly, the latest larvae being 
found in late October. (Larvae in what appeared to be the fourth molt 
being found on October 27th.) The earliest pupae have been found in 
late June. The number increases rather rapidly till late July and 
seems to remain nearly constant till late September; the latest pupa 
being found on November 9tli. These late maturing pupae seem to all 
change to adults before winter, and these adults seem to remain in the 
