THE COLORADO POTATO BEETLE IN VIRGINIA. 6 
coming after this time to the surface, where the third generation of 
eggs was deposited three days later. Owing to a scarcity of proper 
food at this time this third generation was not well cared for, and as 
only three mutilated specimens reached maturity the experiment 
was closed. This record, however, verified the existence of a third 
generation, concerning which there has been some doubt. 
The beetles issue from hibernation in the soil, where they pass the 
winter in the adult stage, some time during the first two weeks of 
April, as the earliest. potato plants begin to appear above the soil, 
and begin to feed upon these young shoots before producing eggs, 
which, however, are soon deposited. In many cases from six to 
twelve beetles may be seen on a single plant, which is likely to be 
completely defoliated if not entirely destroyed. As many as 20 
beetles are sometimes seen on a single shoot, and where they occur 
in such numbers the plant is very apt to be eaten off close to the 
ground if, indeed, the beetles do not follow the stem into the earth. 
It is at this time that the attack of the adults is most severe and the 
plant is greatly weakened by such injury. (See PL I.) 
After the plants reach a considerable size the damage done by the 
larvae becomes most apparent, large plants being defoliated. At 
this time the poison is usually applied to the plants showing the 
greatest injury and a majority of the larvae are destroyed. 
The beetles which pass through the winter are usually those of the 
third generation. These seem to do very little injury to the second 
crop of potatoes, which is generally quite free from damage and 
rarely needs treatment for insect attack. It would thus appear that 
the beetles coming from this generation hibernate after the first crop 
with but few exceptions and remain in hibernation until the following 
year. A few of the beetles may be seen occasionally upon second- 
crop and volunteer potatoes, but no eggs are deposited, the entire 
injury being accomplished by the adults. Unquestionably many of 
these perish during the long period of hibernation and, on warm 
spring days with an offshore wind, great numbers of the hibernated 
individuals are blown or carried out to sea, where they perish, the 
beach after such a time being frequently covered with windrows of 
the dead beetles. Notwithstanding these facts, a sufficient number 
survives to make the insect the pest that it is, although the destruction 
in this manner must serve as a temporary check to the increase 
of the species. 
INSECT ENEMIES. 
The insect enemies of the potato beetle were very little in evidence 
in tidewater Virginia during the season of 1908. Podisus maculi- 
ventris Say was noted and the usual tachinid parasitization was 
o This statement is substantiated by similar observations by Dr. A. D. Hopkins 
and Mr. E. A. Schwarz, of the Bureau of Entomology. 
