LIFE HISTORY AND CONTROL OF HOP FLEA-BEETLE. 39 
were brought into the laboratory died within a week. Another lot, 
brought in May 11 and placed in a lamp chimney, lived well into 
July, the last individual surviving until August 22. This was an 
exceptional case, the average length of life being between three and 
six weeks. 
HABITS. 
THE LARVA. 
Where found.—Most of the larve were observed to be within 18 
inches of the base of the vine, the number increasing as the vine was 
approached. A_ few, 
however, were taken 
between the rows, 
among the roots of 
chickweed and lambs- 
quarters, and even in 
well cultivated parts 
where no weeds were 
growing. The surface 
soil of the hopyards is 
filled with delicate 
rootlets (fig. 12) and 
the larvee find sufficient 
food almost anywhere. 
Depth in soil—In 
order to determine the 
average depth at which 
the younger stages may 
be found, the earth 
was taken up around 
the base of a Vine in Fle. 12.—Filamentous roots of hop vine on which the 
hop flea-beetle larve feed. (Original.) 
3-inch layers, and the 
larve in each layer counted. The results are as follows: 
No. of laryze 
Depth ot soil. found. 
U8). MGT. ee se 2h eg Oe Os Ske ROR Pee cD 6 
SOM ChCGEte. ee kitee Skew ee). 2 el ie eee 21 
GO SIN CIC Sie eh eee Sa a ge TF 
a NT AT Ch CS ees ee mee DA REE BLE a as SE te Se ey 1 
Although some few may be found above and some below, from 2 
to 7 inches is the depth at which one may expect to find the majority 
of the larve. 
Conditions favorable——The soil in which the larve were found 
varied from a light sandy loam to a very heavy, almost adobe condi- 
tion. 
82 
