100 College of Forestry 
mens of U. albicornis were taken there can be little doubt of 
its being parasitic upon this species also. 
In larch the associated insects in addition to Phymatodes 
dimidiatus are, Leptostylus sex-guttatus, Asemum moestum, 
Serropalpus barbatus, Polygraphus rufipennis, Eccoptogaster 
picee, Urocerus albicornis, Sirex abbotu, Phyllobenus dis- 
locatus, Cymtodera bicolor, Pseudorhyssa sp., Doryctes, sp., 
a, b, ec, Hurytoma sp., Spathius tomici, Spathius sp., and an 
undetermined pteromalid. 
Pseudorhyssa sp. 
(Det. by 8. A. Rohwer) 
Four specimens of this new species of Pseudorhyssa were 
bred from the trunk of Tree III from five to seven feet above 
ground. Of these three specimens were retained by Mr. 
Rohwer and one is in our collection. This species also is 
parasitic upon Phymatodes dimidiatus, as was shown by a 
careful study of all of the burrows in the material from 
which it was bred. The adults emerged in the outdoor breed- 
ing cages on May 24 and 25. 
Insects associated with it aside from P. dimidiatus already 
mentioned as its host, include the borers; Leptostylus sea- 
guttatus, Serropalpus barbatus and Polygraphus rufipenms ; 
the predators, Phyllobenus dislocatus and Cymatodera 
bicolor; and the parasites Rhyssa lineolata Hurytoma sp., 
and three species of Doryctes. 
Odontaumerus canadensis Prov. 
(Det. by S. A. Rohwer) 
No references to this ichneumonid were found in the liter- 
ature examined by us. It was bred from Tree III and was 
associated with Phymatodes dimidiatus, Leptostylus sex- 
guttatus, Serropalpus barbatus and Polygraphus rufipenms. 
It is most probably parasitic on P. dimidiatus. This ceram- 
bycid had been very numerous inthe tree trunk, and cocoons 
of a size which would be made by this parasite, were present 
in its burrow and none of a suitable size were found in any 
others in this lot of material. 
