39 
On the 2d April, 1890, thirty-seven specimens of L. inverse 
btained from the earth by following the plow in corn fields 
nd grass lands were confined in a breeding cage with an abun- 
ance of sod. On the 8th May three of these beetles had emerged 
*om the earth in their breeding cage. By the middle of the 
lonth the abdomens of the females were much swollen and full 
f well-developed eggs, and on the 5th June the first eggs were 
lid. They were oblong oval when first deposited, but soon 
welled to a spherical form. They were deposited singly in 
he earth, each in a separate cell barely large enough to con- 
ain it. At this time the males began to die, and by the middle 
f the month the females were also occasionally found dead, 
Iways with spent ovaries. By June 21 the young larvae were 
•ell "developed within the egg, and on the 23d the first one 
atched. On the 28th of the month, besides young grubs, 
he breeding cage contained well-developed eggs apparently 
bout to disclose the young, the beetles having, in fact, not 
et all perished. At this point the record abruptly ceases. 
A similar experiment with adults of L. hirticula was started 
ipril 8, 1899, and here also the first two beetles emerged the 
5th May. On the 25th June no eggs were to be found, but on 
he 28th eggs were first discovered,—of a shape to indicate their 
ecent extrusion. Nine of these were isolated, and from them 
arvae hatched 7th July. 
HIBERNATION. 
The time and place of hibernation have their especial economic 
nterest as related to the time within which the white grubs are 
lear enough the surface to be reached by agricultural opera- 
ions. That these insects hibernate in two stages has been 
ilready shown; the adults in the earthen chambers within 
vhich they have emerged from the pupa, and the larvae at a 
lepth sufficient to protect them from the frost,—a distance in 
his latitude of about a foot and a half, if I may judge from a 
angle observation made November 29,1886, in a badly infested 
vheat fidld in Sangamon county. Here, around the margins of 
lenuded patches—the ground "being frozen some four inches 
l ee p_the white grubs were found repeatedly in numbers aver¬ 
ting four or five to the square foot, and at a depth varying 
rom a foot and a half to two feet. 
The time at which the grubs begin to retreat and the depth 
:o which they go are probably governed largely by the weather, 
in 1890 they had already come up in meadows and pastures 
tom their winter quarters by the 24th March, were still at the 
mrface in their usual number during the latter part of October, 
and had not all withdrawn by November 25,—although at 
this last date most had gone beyond the reach of the plow. 
The imagos, on the other hand, are to be found in winter 
from no more than two or three inches to about ten inches be¬ 
low the surface. They do not lea\e their pupal cells, as a rule, 
