46 
Journal of Agricultural Research voi. xxvn, no. i 
NOTES ON HABITS AND DEVELOPMENT 
From larvae collected at Arlington, Va., June 20, 1919, and later, 
the first adults began to emerge June 29, continuing to emerge until 
July 3. In outdoor rearing cages emergence was from September 10 
to the first week of October. Adults observed on sweet potato all 
developed within 7 to 10 days of each other. Individuals collected by 
Miss Marion T. Van Horn on wild bindweed {Convolvulus sp.) that grew 
in a shady location in the District of Columbia were, evidently as a 
result of not being exposed to direct sunlight, over two weeks late in 
development, while larvae one-third to two-thirds grown were observed 
after the Arlington material, which was almost constantly exposed to 
sunlight, had all transformed to pupae. 
In 1919, 50 reared beetles were under observation during July. Of 
this number 20 were placed on growing sweet potato plants and covered 
with a large cloth-covered rearing cage, but they did not thrive, some 
individuals dying, and no eggs could be found up to the end of the 
month, although in a second lot kept in the insectary eggs were observed 
August 3. Finally the cage was removed and the beetles allowed to 
shift for themselves. September 2 an egg mass was found on the same 
plat where the beetles had been feeding. 
The experience of two years shows definitely that the second genera¬ 
tion is only a partial one, since only three egg masses of this generation 
were found and at intervals of a month, indicating that the majority of 
the beetles of the first new generation hibernate, in this respect agreeing 
with some other insects. 
Of the second generation, the eggs of which hatched during August, 
several pupae were formed a month later, showing a larval period of 
about three weeks in rather cool summer weather. 
In its apparently irregular development, Chelymorpha cassidea re¬ 
sembles to some extent the Colorado potato beetle. The overwintered 
beetles first occur some time in May—in 1920, May 17, in an exception- 
