ie 
mometer ranged near 100° F. During the intense heat that prevailed 
during the summer of 1896 the writer noticed the same conditions in 
and near the District of Columbia, the eggs and larve being literally 
dried up on the potato plants, and, the species temporarily disap- 
pearing altogether. 
Northward the Colorado potato beetle is practically limited to 
the Transition zone, although it occasionally invades the Boreal 
zone, as, for example, in Colorado, where it has been found 8,000 
or more feet above sea level. Severe winter weather alone probably 
has little effect upon the insect, since it hibernates, as a rule, exclu- 
sively in the beetle state and deep in the ground. It is, moreover, 
one of our most hardy species, ranking with the hard-shelled snout- 
beetles in its resistance to cold and frost. Cold snaps, however, over- 
take the insect before it has sought out proper hibernating quarters, 
and when these occur it is doubtless killed off in great numbers. As 
was predicted years ago, the Rocky Mountains have proved an 
impassable barrier for this species, and the insect has not been able to 
reach the Pacific coast or neighboring States west of such barrier. 
INJURIES, LIFE HISTORY, AND HABITS. 
NATURE OF INJURY. 
A few remarks in regard to the nature of the injury inflicted by 
this insect are pertinent. Beetles and larve are destructive in nearly 
equal proportions. In times of its early occurrence east of its origi- 
nal limit this insect not only caused the entire loss of crops, but some- 
times destroyed the potato yield of whole counties and of large por- 
tions of some States. Indeed, at one time it materially affected the 
market price of potatoes, not alone by reason of its direct depreda- 
tions, but in discouraging farmers from the cultivation of the potato 
on an extensive scale. Thus in 1873 the price per bushel at whole- 
sale in the St. Louis market reached the high figure of $2. At the 
present time, fortunately, every progressive grower recognizes the 
fact that the control of this species is a part of the necessary routine 
connected with the culture of this tuber. 
It was early recognized that the depredations of this insect ma- 
terially affected the quality of the tuber through the defoliation to 
which the vines were subjected, and it was at one time difficult to 
obtain potatoes that were not watery when cooked. This raises the 
question whether the very marked decrease in quality of potatoes in 
general at the present day is not due directly to the many years in 
which the tubers have been deprived of due nourishment by more or 
less defoliation of the plant itself; for, despite all the remedial 
measures that are usually practiced, such as the liberal use of arsen- 
icals and “ bugging” or jarring, a certain amount of injury nearly 
[Cir. 87] 
