98 a 
that it cannot keep itself erect or recover itself after prostration by a 
windy summer storm. 
In any case where the plant is yellowed, or dwarfed, or killed out- 
right,—especially if these appearances be most marked on the higher, 
lighter parts of the field,—the presence of white grubs may be sus- 
pected. 
As the roots of an infested plant are evidently eaten away, injury 
by the white grub is not easily mistaken for any other, and the presence 
of the conspicuous insects themselves, in the earth among or beneath the 
roots, will commonly confirm the diagnosis. If they are not thus found 
where other evidence points to them as the cause of the injury, they may 
frequently be discovered by digging down a foot or two in the worst- 
injured tracts. 
As a fair illustration of the extent and general effect of a severe 
attack on corn, our observations of their work in a twenty-acre field near 
Champaign, Illinois, are worthy of detailed report. This field of rich, 
black land had been heavily fertilized with straw-pile manure and 
seeded to timothy in 1884. It was pastured continuously until 1888, 
when it was left for hay, yielding a good crop of clean timothy that year. 
The sod was broken in the spring of 1889, and planted to corn May 10, 
immediately after breaking. This first planting was taken by web 
worms and cutworms, but the second grew well, and promised an excel- 
lent crop until about tasseling time, when the owner noticed that much 
of the corn had a yellowish and unhealthy appearance, and that it blew 
down readily when the ground was wet. These fallen hills pulled up 
easily, and the roots had a stubbed appearance, as if cut off near their 
origin. A search in the earth where the corn had stood commonly 
yielded six to twelve white grubs to a hill. The crop on two or three 
acres of the highest land was a total failure, and the yield was light on 
the lower ground. 
The followi ing year (1890) the field was plowed April 28 and 
planted again to corn, although an abundance of grubs were noticed when 
the plowing was done. Several hundred were, in fact, collected by us 
April 28 for breeding-cage experiments, nearly all belonging to the s species 
L. rugosa. An estimate based at this time on a count of the grubs found 
within the length of a rod in a fourteen-inch furrow, gave between six 
and seven hundred to the square rod, or at the rate of two hundred and 
eighty-eight pounds per acre. By the time the young corn was six inches 
high about two thirds of it had been destroyed by the erubs. The field 
was not replanted, but about the 10th of June it was vide harrowed. and 
sown to hemp. On account of the lateness of the season and a mid- 
summer drouth the hemp did not grow well, and about a hundred bush- 
els of corn were finally taken from this twenty-acre field. July 26, in 
the part of the field which had been worst infested, but three grubs and a 
single pupa were found in digging with a spade twenty holes, ranging 
in depth from a foot to twenty-six inches. On the 1st of September a 
trench four feet long, three feet wide, and two feet deep was dug in 
this same part with the result that only one adult June beetle and two 
long-dead larvee were found. In another space eight feet long by three 
