60 NEW YORK STATE MUSEUM 
approach of cold weather and remain until the following spring. 
In July of the third summer they construct oval cells and change 
to pupae, the latter transforming to beetles the following August 
or September and the perfect insects appearing during May and 
June of the next year. 
Natural enemies. White grubs are. most acceptable prey to 
pigs and also that much avoided and generally abused animal 
known as the skunk. Both dig in badly infested fields and swine 
are generally credited with being exceedingly efficient destroyers 
of these pests. They will frequently root up and devour prac- 
tically all the grubs in badly infested areas to which they have 
access. 
Crows are well-known enemies of the white grub. Mr William 
H. Wanzer of Slingerlands reported that in his locality these birds 
had discovered the infested areas and were digging out and de- 
vouring the grubs in grass and potato fields. Similar operations 
have been observed in Illinois, while studies by Dr F. E. L. Beal 
in 1894 showed that crows ate either beetles or grubs in every 
month from March to October inclusive. Blackbirds are also re- 
ported as feeding upon the grubs. 
A common parasite of the white grub in Illinois is known as 
Tiphia inornata Say. The cocoon of this species is oval, 
brown and about three-quarters of an inch long. It is easily recog- 
nized by the slight neck or constriction at one extremity. These 
cocoons were found in small numbers in one infested field in 
Schodack. Another large parasite known as Myzine sex- 
cinecta Fabr. also preys upon the white grubs and forms a co- 
coon similar to that of the Tiphia noted above, though differing 
in their greater smoothness and lacking the loose, fluffy coating of 
silk. This species, according to recent investigations, appears to 
be fully as efficient a parasite as the Tiphia. Another parasitic 
Hymenopteron which has been reared from white grubs is 
Ophion bifoveolatum Brulle. The genus Ophion is 
rather common in New York State and there is no reason for think- 
ing that other species may not prey at least occasionally upon the 
white grub. 
A number of parasitic flies also depend in considerable measure 
for sustenance upon white grubs. A bee fly, Sparnopolius 
fulvus Wied. has been reared in Illinois from white grubs, and 
the same is true of the peculiar Pyrgota undata Wied. a 
species which unfortunately seems to be not very abundant in New 
