78 College of Forestry 
much longer than usual, varying in cases observed from 45 
mm, to 120 mm. This pupation chamber is solidly packed 
with fine frass for the greater part of its length — only from 
20-30 mm. being free of this material — and in spite of its 
excessive length it usually does not lhe more than half an 
inch from the surface of the bark, although it may lie deeper. 
On emerging the adult gnaws through the surface and leaves 
the wood through a nearly circular hole slightly more than 
2 mm. in diameter. 
Larch is attact by N. longipes the same season that it is 
attact by P. rufipennis and EF. picew, and thus the larve are 
often associated with the brood of these scolytids through- 
out their first year of life. It was also associated with the 
following insects emerging at about the same time: Lep- 
tostylus sea-quttatus, Pogonocherus mixtus, Chrysobothris 
dentipes, C. sex-signata, C. blanchardi, Melanophila fulvo- 
guttata and Anthaxia quercata. In the material studied 
these forms were never so numerous that the burrows inter- 
fered with each other seriously, and therefore the inter- 
relations were probably not at all important im an adverse 
way. However, in dying or sappy bark presence of a greater 
number of specimens, up to a number where additional ones 
would interfere with the available supply of food, is of a 
distinct advantage in overcoming the resistance of the tree. 
So long as these all worked in a similar region it would 
make no difference whether the larvee represented a number 
of species or were all of one species. 
Phyllobaenus dislocatus was the only predator derived 
from material containing N. longipes. It is probable that 
this is more usually dependent upon the associated scolytids 
for its food, but it is by no means improbable that it will 
attack the larve of any of these smaller round-headed and 
flat-headed borers whenever it can gain access to their bur- 
rows. The same three parasites were associated with 
NV. longipes as with L. sex-quttatus. 
