History and Habits of Pityogenes. 27 
but at times was still quite restless as if in some pain. At the 
end of an hour he was apparently normal again and was hard 
at work. The following few days he was very active as shown 
by the large quantity of frass he cast out of his burrow. 
Hight days later he seemed especially solicitous in guard- 
ing his burrow, refusing to retreat even when prodded firmly 
with the needle, and considerable poking was necessary to 
make him retreat for even a short distance into his burrow. 
The burrow was therefore opened by turning back a flap of 
the bark and found to consist of a large nuptial chamber from 
which extended four female burrows. Two of them were 
only just begun while the other two were of considerable 
length and contained a number of egg niches. The flap of 
bark was replaced in its natural position without seriously dis- 
turbing either the male or his four mates. This burrow con- 
tained more females than any other in the same breeding jar 
although a greater number often occurs in nature. It is 
possible that the turpentine used in the experiment was re- 
sponsible, it being a well known fact that the odor of turpen- 
tine will attract many species of bark beetles. 
Disposat or Prrcon.— In nature P. hopkinst will often 
attack living white pine which is unhealthy, but which still 
contains a considerable amount of liquid pitch. Several 
young white pine trees about five feet high which were sickly, 
but on which the leaves were still partly green were found 
at Great Bear Springs near Fulton, N. Y., on May Sth. 
These were just being attacked by the beetles and the trunk 
of one of them was brought to the laboratory. The bark on 
one side of this was dead, while that on the other side was 
alive, green and quite pitchy. The dead side contained no 
beetles, but the pitchy side was riddled with their burrows 
in all stages from that in which the beetle had penetrated 
only about one-third of his length into the bark, to burrows 
containing females, ege burrows and eggs. Many of these 
burrows had tapped pitch ducts and typical pitch tubes (Fig. 
24) consisting of frass excrement and pitch had been con- 
structed at the entrance. Several burrows were observed 
which had been carried just the length of the beetle and into 
