New YorK AGRICULTURAL EXPERIMENT STATION. 209 
of which were badly infested with this beetle, a lantern trap was 
placed on the nights of October 4th and 5th, 1905, and again 
for eleven nights during August, 1906. The catch of insects in 
each instance was large, both in variety and numbers, but included 
no C. lapathi. Some observations that are of interest in this con- 
nection were made in one of the nurseries belonging to Mr. H. E. 
Merrill of Geneva. There are four blocks of poplars in a line. 
east and west, each about one hundred yards apart. The west and 
east blocks are the youngest, one being one year old, and the other, 
cuttings ; and though frequently inspected no beetles were found 
on either. But the central blocks, one two years old and the other 
three years old, were each badly infested. 
During the summer of 1906, in order to learn more of the migra- 
tory habits of the beetle, thirty-five specimens were caught in a nur- 
sery poplar block and marked so that they could be recognized. 
These marked beetles were then liberated at a distance of fifty 
yards from the block in which they were captured. At intervals 
of several days all the neighboring poplars were carefully examined, 
and more than four times the original number of beetles were 
captured, but none of the marked beetles were collected. 
While these observations are not conclusive, yet it is believed 
from the behavior of the beetles that they do not naturally travel 
far and that they rarely migrate from an abundant food supply. 
EXPERIMENTS WITH POISON SPRAYS FOR THE CON- 
TROL OF CHE PEST. 
The adult is an external feeder and obtains subsistence by 
puncturing the bark.—The great number of punctures made in 
the bark by the adult while feeding at once suggested the possi- 
bility of using arsenical sprays as a means for the control of the 
pest in the nursery. In order to learn the effect of these sprays 
upon the beetles, a number of experiments ware made, as follows: 
SPRAYING TESTS OF I905. 
Experwmment No. 1.— On August 26, 1905, the branch.of a poplar 
tree was sprayed with paris green at the rate of one pound to 
fifty gallons of water. Three pairs of beetles were then put on 
the branch, which was covered by means of strong mosquito netting. 
Four days later some of the beetles were apparently dead and the 
others were ailing. On September 1, six days later, all the beetles 
_were dead, The bark showed no evidences of injury by the beetles. 
