STUDIES ON PERILLUS BIOCULATUS FAB. 67 
Ordinarily the male does not live as long cs the female but of two 
males which hatched from the same egg mass on July 18, 1921, 
one lived until June 4, 1922, and the second until June 28. In New 
York, among the bugs that matured during September, 1914, at least 
six females were alive in the cages as late as July 8, 1915. One of 
these lived until July 13, and a second until July 15. The longest 
lived individual laid eggs on July 12 (which hatched), was alive on 
July 15, but was found dead on July 18. 
Hibernation 
With the cotaing of cool days in September, and the disappearance 
of the Colorado potato beetle, Perillus bioculatus begins to seek hiber- 
nation quarters for the winter. After the potato vines have been killed 
by frost, many bugs have been found in depressions of the ground 
beneath piles of the dead plants. Others leave the patch entirely and 
fly in search of more suitable hibernation quarters. Individual bugs 
are frequently found entering buildings, and such situations appear 
to be most favorable as places for passing the winter successfully. 
In northern regions, as in Minnesota and New York, a greater relative 
abundance of Perillus may be correlated with nearness to cities and 
villages where large numbers of bugs probably pass the winter safely 
within buildings of various kinds. This statement is borne out by 
the capture of a considerable number of specimens in buildings late 
in the fall and then again in the spring as the bugs become active and 
try to get out by way of windows. One bug has been found in hiberna- 
tion beneath a burlap band which was wound around the trunk of an 
apple tree for the purpose of collecting larvae of the codling moth. 
A survey of potato fields and egg plants at University Farm, St. 
Paul, was made on September 23, 1921, to learn what activities the 
bugs displayed following frost and the drying up of the potato vines. 
On that date the sun was shining and the temperature stood at 75° 
Bugs were scarce in the dead and dried up potato fields, altho six 
specimens of bioculatus were taken from spots where groups of potato 
beetles were feeding on potato tubers. From egg plants which were 
still largely green, 35 bugs were collected, of which two pairs were 
taken in copulation. Bugs were found among the dead leaves at bases 
of plants, others were active in the sunshine on the upper surface of 
leaves. Several of the active specimens were found feeding on potato 
beetles. Of the inactive specimens, five were found in one group 
under dead leaves at the base of an egg plant. Others were found 
two or three in a spot. Judging by these as well as other observations, 
