68 College of Forestry 
also in the Catskills the senior author has most often taken 
it from balsam fir. There can be no doubt, as is indicated 
by its distribution, that a large number of conifers may serve 
as host. In larch this beetle was bred only from the trunk 
region, but doubtless also occurs in the tops and larger limbs. 
In other hosts it occurs most often in regions haying com- 
paratively thin bark. Thus in white pine it is most usually 
found in the tops and limbs, while the two sister species 
M. confusor and M. titillator are more common in the trunk. 
In spruce this is true to a lesser extent, due to the thinner. 
bark, and in balsam any part of the trunk and the hmbs 
down to a diameter of less than an inch are likely to contain 
larvae, although they are here perhaps more common in the 
trunk. 
The eggs are laid in material in a variety of different 
conditions. Eggs still unhatched and newly hatched larvee 
have been taken from a balsam tree which was still entirely 
alive and green but slightly injured by lumbering operations. 
On the other hand, living, callow adults have been taken 
from their transformation chambers in balsam which had 
been down and dead at least four years. The larch from 
which specimens were bred was in similar condition when 
brought to the laboratory, the bark being loose and the tree 
having been dead three or four years. However, in other 
recently killed larches the larvee have been found and burrows 
in such material from which the larvee have been removed by 
woodpeckers are numerous. 
The adults of this beetle are abroad throughout most of 
the summer and may oviposit at any time between the first 
of June and the first of September. However, the height of 
the breeding season is during July and August. On July 8, 
1914, the senior author took twenty-one specimens of this 
insect in a few minutes while eating his lunch in a small, 
recently-made clearing near the summit of Twin Mountain, 
Greene Co., N. Y. These beetles were at the time creeping 
over the bark of recently felled balsam and spruce. Several 
pairs were taken in copulation, and in one case the female 
was ovipositing although still attended by a male. 
