270 Report or THE DEPARTMENT OF ENTOMOLOGY OF THE 
as found after the caterpillars leave the trees. Ten days later 
the moths will have escaped, and hence it will not pay to gather 
them after that date. 
As soon as gathered the cocoons should be placeé in a box 
and covered with a coarse wire net to allow the parasites to 
escape. The imprisoned moths will soon die or may be killed 
_ by sprinkling a little kerosene oil in the box. | 
On the whole the season’s experience indicates that except » 
when attacking forest trees, the insect is not more difficult 
to control than many other noxious species. But as with other 
insect pests prompt and thorough treatment is necessary. 
II. THE FRUIT BARK-BEETLE. 
Scolytus rugulosus Ratz. 
Late in July of the past season Mr. F. C. Stewart of the Station 
staff brought into the laboratory several small branches from a 
healthy cherry tree showing the work of some insect. The loca- 
tion and extent of the injury was plainly indicated by the dead 
leaves. On all of the twigs from one-fourth to about three- 
fourths of the leaves were brown and dead—in sharp contrast 
to the remainder which were of normal green color. Plate 
XXX VII, Fig. 1, is from a photograph of one of these branches. 
All of the leaves.on the lower half were dead. An examination 
showed that in each sj#ur bearing the dead leaves a small round 
hole about the size of the head of a pin had been bored as 
shown, enlarged about four times, at Plate XXXVII, Fig. 2. 
In each case the hole opened into a short burrow in the sapwood. 
About forty burrows were examined at this time. All but three 
were empty, and in these the cause of the injury, some fruit 
bark-beetles, Scolytus rugulosus, were found still at work. Later 
investigations in the vicinity of Geneva and in Monroe and 
Niagara Counties showed that this species has caused extensive 
injury during the past season to healthy, vigorous trees. 
Although this species has been long known as an orchard pest” 
it has been supposed to confine its attacks principally to weak, 
