58 SOME INSECTS INJURIOUS TO TRUCK CROPS. 
The idea was to distribute them around the field while the beetles are 
still active and collect them as soon as the beetles hibernate. Under 
laboratory conditions beetles entered two sorts of traps very readily. 
The one is made by cutting the old vine stems into 6-inch sections 
and tying 8 or 10 of them into a bundle. The other trap is made of 
corrugated paper, with a plain sheet fastened on each side with 
marine glue. This leaves a row of tubes into which the beetles can 
crawl. Pieces 4 inches square were to be pegged out with slender 
pegs, but since other control measures have proved so effective the 
experiment has never been tried in the field. 
CULTIVATION AND FERTILIZATION. 
The earlier the hops come up in spring, the better chance there will 
be of their reaching the " string " before the beetles attack them. 
When the vines are once on the string they can be protected with 
tanglefoot bands or by the use of tarred boards. 
Inasmuch as cultivation and fertilization tend to bring the vines 
up earlier in the spring they aid in the control of the beetles, and if 
clean cultivation is practiced after the vines are tanglefooted a large 
number of beetles will starve to death. 
RECOMMENDATIONS. 
The first knowledge that the hop growers will probably have of the 
presence of the hop flea -beetle in dangerously large numbers will be 
attack by the beetles upon the vines about the time that they are 
ready to train. The " fleas " at this time may be greatly reduced in 
numbers, so that the vines can reach the strings, by the use of the 
sticky shield (p. 49) or the heavier tarred board (p. 48). 
After the vines are trained the beetles are readily controlled by the 
use of the tanglefoot bands. These bands should be renewed on the 
vines, and the trellis poles should also be banded at the time that the 
vines are tied in and stripped, or just before the appearance of the 
second generation. These tanglefoot bands form a perfect barrier 
to the insects. Even though the beetles are present in very large 
numbers they can not reach the upper parts of the hop vines, which 
can therefore produce a crop without molestation. 
In order to starve the beetles the yards should be well cultivated 
and all suckers cut from the bases of the vines. If this is done the 
emerging insects will find very little to feed upon. In some cases 
the destruction of the beetles which hibernate in the trellis poles, 
string pegs, and vine stubs may be advisable, but if the banding is 
thoroughly done and the yards are kept clean during the growing- 
season, very few beetles will live through the winter to attack the 
vines in the following spring. 
