1910] Chapman — Scolytus multistriatus Marsh 65 
festation of a standing tree until the bark is removed and this was not 
feasible. One could only make an estimate from the ‘‘shot-holes”’ 
that appeared on the external surface. 
While making these observations a native American Scolytid, 
Hylesinus opaculus Leconte, which lives only in dead wood, was also 
found in abundance. Apparently this species has come to assume 
somewhat the same relation to S. multistriatus in this country as S. 
multistriatus does to S. geoffroyi in Europe, the only difference proba- 
bly being that the American species hibernates in the adult beetle 
stage, while S. mudtistriatus hibernates in the larval stage. 
About the middle of November a representative number of trees 
were examined in the College yard for bark-beetles. It was an 
exceedingly difficult task as the trees were large, and the “‘shot-holes”’ 
which the beetles make were difficult to locate. The trunks, large 
lunbs and upper branches of each tree selected were carefully gone 
over. “Shot-holes” of the beetles were found on all of the trees and 
many of the adult beetles of our American species were busy, making 
temporary hibernating burrows. ‘These could easily be located by the 
reddish boring dust which was freshly thrown out. Since these trees 
were selected in different parts of the yard with a view to making an 
estimate, I can say that it is quite likely that every tree in the yard 
harbors some beetles, but just how numerous they are cannot be stated. 
I have not been able to follow the complete normal development of 
these beetles through and therefore do not know positively whether 
there is one or two broods annually. However, from the observations 
I have been able to make I feel quite secure in saying that there is only 
one brood. A number of small limbs which contained adult grubs 
were collected in October. These have been examined from time to 
time and up to date there has been no perceptible change in the larvae. 
The generations of these beetles vary considerably as is seen from the 
European reports. Eichhoff says that the sume species may or may 
not have two broods annually, depending entirely on its geographical 
location. Gillanders reports that some of these bark-beetles have two 
broods in southern and one in northern England. Each of these 
writers mentions the fact that S. multistriatus may have two broods 
annually though this really seems to be an unsettled question. 
Scolytus multistriatus confines itself almost entirely to elm trees, 
and to such a degree that it is known generally as the “smaller elm 
bark-beetle.” Its habit of attacking injured or weakened trees gives 
