132 
light. Later m the season no doubt the proportion of females 
to males would have been greater; but statements made in 
another part of this article, under the head “Life History and 
Habits, show that the disproportion continues throughout the 
season. 
The spraying of trees most resorted to for food is a possible 
measure, since the beetles are killed by arsenical poisons—a fact 
demonstrated by laboratory experiments made by us in 1888 
with oak leaves dipped in Paris green mixture, one ounce to 
twenty gallons of water The expense of a general application 
of such an insecticide will, however, prevent its common use. 
When pigs can be turned, in May and June, into groves 
orchards, or forests infested by the beetles, they cannot fail to 
destroy immense numbers of them, since they eat them eagerly 
and can easily find them, hidden as they commonly are by day 
barely under the surface of the ground. This is a measure 
only occasionally applicable. 
Remedial Measures .-Direct remedies for the attacks of white 
grubs are either inapplicable to the corn field, are of doubtful 
economic value, or are too little understood, as yet, to make 
them worthy of recommendation. For example, kerosene emul¬ 
sion may properly be applied to infested lawns, and, if followed 
by a copious watering, may kill large numbers of the grubs 
but the cost of this material and treatment will preclude its use 
against grubs m corn; and kainit and other potash fertilizers 
(the sulphate especially) will destroy grubs in the earth, but for 
this purpose must be used at a rate inadmissible in farm prac- 
tice more than a ton per acre according to Prof. Perkins (Fifth 
Ann. Rep. Yt. Agr. Exper. Station, p. 152). 
Among remedial measures of uncertain value may be men- 
tioned the cultivation and dissemination of the fungus parasites 
oi the white grub—uncertain because not yet thoroughly tested 
and because such tests as have been made do not demonstrate 
the practical utility of the method. 
These parasitic fungi do, however, sometimes spontaneously 
destroy immense numbers of white grubs in the field, and some 
oi them can be easily cultivated in quantity outside the body 
or the insect almost as easily as mushrooms may be grown for 
e maiket. the subject of the fungous diseases of these insects 
is therefore a very suitable one for investigation, and should 
undoubtedly be most thoroughly studied from every point of 
