90 ‘ College of Forestry 
The presence of S. barbatus and of other wood-horing 
forms in a tree serves to prepare the wood for other insects 
which otherwise could net utilize it, or at least would not be 
likely to utilize it. This was especially noticeable in Tree V, 
which had been partially peeled a number of years before 
its final death. The presence of the burrows in the wood not 
only affords the insects mechanical entrance to the wood, but 
also so promotes decay as to make it fit material for such 
forms as Adelocera brevicornis, Tenebrio tenebriodes, Dry- 
ophthorus americanus and Stenoscelis brevis to inhabit. 
After decay has started any or all of these forms may enter 
the exposed wood and the two latter at least may continue to 
breed in it for several generations. 
Phyllobaenus dislocatus is the only predator bred from the 
same material as S. barbatus. On account of the character 
of the burrows of the latter and because of their being filled 
with fine sawdust it is not likely that any close relation exists 
between these two forms. No evidence of parasites upon 
S. barbatus was found. 
Urocerus albicornis Fabr. 
(Det. by S. A. Rohwer) 
According to Bradley (1913, p. 19) the geographical range 
of Urocerus albicornis extends “ From British Columbia, 
Northern Ontario, Nova Scotia and Newfoundland, south to 
Pennsylvania, Washington and Northern Idaho.” Hopkins 
(1893 a, p. 215) reports it also from West Virginia. This 
species was recorded by Packard (1890, p. 733) as attacking 
pine. Later Hopkins (1893, p. 215) found the larve in the 
sapwood and heartwood of injured and dying hemlocks, 
while Felt (1906, p. 667) mentions spruce and fir as host 
trees. The senior author has taken it from the wood of 
spruce, fir and hemlock in the Adirondacks. 
The adult female of U. albicornis prefers freshly killed 
wood in which to oviposit. This is very apparent in the 
Adirondacks, where females of this horntail are often seen 
about recently felled spruce and fir. On one occasion the 
