210 REPORT OF THE DEPARTMENT OF ENTOMOLOGY OF THE 
Experiment No. 2.—On August 29, 1905, the tops of two poplars 
in a nursery row were headed in and then sprayed with arsenate 
of lead, using two pounds to fifty gallons of water. Eight pairs 
of beetles were then placed on each tree, being enclosed by means 
of large cheesecloth bags. On September 4, six days later, twenty 
of the thirty-two beetles were dead. The wood had been only 
‘slightly punctured. 
Experiment No. 3.—On September 29, 1905, forty beetles were 
enclosed in a similar manner as in experiment 2 on two trees that 
had been sprayed twenty days previously with arsenate of lead, 
using two pounds to fifty gallons of water. The greater part of 
the spray had apparently washed off during the twenty days. On 
September 29,’ ten days later, some beetles were dead and all ap- 
peared ailing. On October Io, all but one of the forty beetles 
were dead. 
As a check on the preceding experiments, twenty-six beetles, 
divided into five lots, were confined in bags on unsprayed trees 
to determine if the confinement itself affected the insects unfavor- 
ably. ‘The results are as follows: 
TABLE II].— Errects of CONFINEMENT OF BEETLES ON UNSPRAYED TREES. 

Number of Number Number 
Date beetles were confined in bags.| beetles to alive alive 
each lot. Sept, 23. October 13. 
AUPUSE ZO Tsien shieeiuty ote ane 14 11 2) | The spas 
IATIQUSE OG Sho h.7.) RRP ee Oe 2 2 uf in each 
ANA SISTI DS), Leo sts Wee RUN Ee ook 4 4 1 instance 
AUSUSU PED ec Sais Hen kit aaa! 2 2 iH was badly 
Amoust bes oli peice eee ote lhe 4 3 ed Wh punctured 



3 PEAS 
From the above table it will be seen that on September 23, 
twenty-nine days after the beetles were confined in bags, twenty- 
two of the twenty-six beetles were still living. On October 15, 
fifty days after the beetles were confined, six adults were still 
living. From these results it is believed that the-use of bags 
to enclose beetles had no appreciable effect upon the health of the 
insect. 
SPRAYING TESTS OF 1906. 
On August 23, 1906, the following experiments were under- 
taken to corroborate the results of 1905 with the use of poisons _ 
for the control of the beetle. 
