14 BULLETIN NOU. 4, DIVISION OF ENTOMOLOGY. 
the larva as soon as it breaks the shell, or, indeed, in the egg. As the 
surface water is always warmest, it should be retained as long as pos- 
sible and the cooler water drawn off from beneath. This can be easily 
done by building a second gate, not reaching to the bottom, outside the 
main gate, at a distance of about one foot from it. The water will rush 
in from below, rise to the level of the inside gate, and overflow with- 
out materially disturbing the surface water. This plan has been pur- 
sued by Dr. Brakeley, and on his bogs I had a chance to test it. May. 
22, the water had been about half drawn off, it having reached a tem- 
perature of 80° two inches from the surface. On that day I examined 
for eggs and larve in various portions of the bog. Where the water 
had not touched, the larvee were abundant and half grown; where the 
water had covered, but had been off a week, no larve were found, and 
but few perfect eggs; while, on the contrary, many eggs in which were 
fully developed aud defunct larve were found. Still there were eggs 
enough left to furnish a very respectable lot of larvee, as will hereafter 
appear. Going down close to the water line many eggs were found 
largely containing fully developed but dead larvae, but some also liv- 
ing; a few instances were seen where the larva had hatched beneath 
the water, had lived and eaten between the surfaces of the leaf for a 
day or two, and had then succumbed. One instance was noted where 
the larva was yet alive, and in the cavity in the leaf. This use of the 
water is not of course as successful as the first plan suggested, for 
while it destroys a large number of insects in embryo, a large number 
escape, owing to the difficulty of raising the water on an unequal bog 
to a sufficiently high temperature. Many bogs have 10 to 12 feet ot 
water at the gates, and the vines at the edges scarcely covered; of 
course the deeper parts of the bog will not be warmed for a long enough 
time to force the development of the larvz beneath the water far enough 
to destrey them, and many will thus escape. Ona level bog, where the 
water covers the vines but a few inches, there is much greater hope of 
complete success. 
On June 6,1 again visited the bogs, and for several days experi- 
mented with insecticides. I found on those portions of the bog which 
had not been flowed full-grown larve, some pup, and a few imagos; 
on the portions which had been flowed, larvee in all stages of growth; 
and on the portion tirst laid dry, some pup. The dates here given refer 
to the appearance and development of the insect on one particular bog 
only; the dates vary according to circumstances on other bogs. 
White hellebore had been used by Dr. Brakeley in previous seasons 
with good success, and as soon as the larve became dangerous he 
turned his attention to them. On the part not flowed larvze were abun- 
dant in May, and they were given a dose of hellebore; to ascertain 
what effect it had I covered aspace of about three square feet, and this 
was thereafter not dosed. 
The hellebore was applied in the form of powder, with a bellows con- 
