40 
but hibernate where the pupa itself was formed. Additional 
observations on this matter are greatly to be desired, especially 
for the extremes of the State, and for seasons of unusual cold. 
LIFE HISTORY OF CYCLOCEPHALA. 
My notes on the dates of transformations of white grubs be¬ 
longing to this genus are but few in number, but as they accord 
with those already given by entomologists, they probably indi¬ 
cate correctly the life history of these beetles. 
Our only species in Illinois is C. immaculata , and its larva 
occur in grass with the other white grubs, and have been found 
infesting corn on sod. Grubs of this species collected in grass 
lands at Urbana, Illinois, April, 1887, had all emerged as adults 
July 19. Others collected from corn fields April 25, 1888, had 
pupated, at least in part, June 20, and afterwards gave tht 
imago,—at what date is not known. In April, 1890, grubs were 
collected from the 6th to the 29th from roots of corn stalks 
from sod plowed in fall, and from a field of young oats. A1 
but one of these had pupated by June 4, some of them recently 
at that date. The first beetle appeared June 16, and all hac 
emerged as adults (five males and eight females) June 192 
A dozen of the beetles bred from this collection were placed ir 
a breeding cage and furnished regularly with fresh sods. B} 
July 2 they had laid numerous eggs among the grass roots 
and five days later one of these had hatched. July 26 severa 
young larvae were living and doing well, but by Aug. 10, througi 
some misadventure or mismanagement, all had died. In electric 
light collections made April 11 and 12, thirteen days in May 
fifteen days in June, and thirteen days in July, 1887, till 
species first appeared June 10, became abundant bv the 17tl 
and 18tli, continued so until the 1st of July, and disappearec 
July 14,—both beginning and continuing decidedly later that 
any of the six species of Lachnosterna collected at the sam< 
time. 
It is quite clear that white grubs of this group have the lit 
history which has been most commonly attributed to the other 
in so far at least as to hibernate in the larval state, to pupatf 
in May and June, and to emerge in June and July,—later oi 
an average than the species of Lachnosterna. Pupation is con 
sequently earlier than that of Lachnosterna and the emergenc 
of the imago occurs later in the season, the essential difference 
being that adults of Cyclocephala escape from the earth one o 
two months after the completion of their larval life, while thos< 
of Lachnosterna continue in the earthen cells as pupae an< 
imagos about ten months. The difference in the economic ap 
plication of these biographies is not however very great, sine 
* By a copyist's error, these two dates were printed July instead of June in "Insec 
Life,” vol. iii, p. 245. 
