85 
Pimpla, Cremastus, and Aleiedes, or a closely allied genus. No 
doubt it is to these friendly insects that the sudden decrease in 
the numbers of the leaf-roller larvse so often noticed is to be at¬ 
tributed. 
REMEDIES. 
It is difficult to prevent the depredations of this insect upon 
young apple-trees on account of the concealed position of the 
larva, and its habit of attacking the young terminal leaves. The 
application of the arsenical poisons is probably as promising as 
any general remedy; but I believe that the most effective pre¬ 
ventive of nursery injury is that of hiring boys to crush the 
larvae. This is not such an endless task as would at first appear; 
and if the first brood of larvae are thus destroyed, the outlay will 
be tenfold repaid. That it is eminently practicable on a large 
scale has been demonstrated the past season by a leading Illinois 
nurseryman who found that the expense of once going over a badly 
infested field did not exceed one dollar per acre; and that the out¬ 
lay was abundantly repaid by the continued vigorous growth of 
the trees. In a recent letter the gentleman informs me that he 
intends continuing the practice “more vigorously in the future 
than in the past.” 
Mr. Smith has recommended light traps for attracting the moths 
in cranberry fields; and probably the same means could be em¬ 
ployed to lessen the number of the moths in nurseries, especially 
in early spring, when the hibernating moths are abroad for the 
purpose of depositing their eggs. 
