Insects Bred from American Larch 107 
dislocatus, Cheiropachus sp., and Epicallima argenticinctella, 
a small moth. Insects emerging the following season com- 
prise those borers in larch limbs and tops which require two 
years for their development, and the parasites upon these. 
Medeterus sp. 
(Det. by C. T. Greene) 
A number of specimens of this small fly were bred from 
larch wood from a variety of different sources. However, 
this larch material was all similar in that it was infested 
with Polygraphus rufipennis or with both this bark beetle 
and Hecoptogaster picew. Small larve which may be the 
immature stage of this fly are common in the engravings of 
both these scolytids. Hopkins (1899, pp. 268, 450) con- 
cluded that M. nigripes is a primary parasite of the larvee 
of P. rufipennis. 
Associated insects in addition to the two scolytids already 
mentioned are Phymatodes dimidiatus, Serropalpus bar- 
batus, Urocerus albicornis, Strex abbotu, Phyllobenus dis- 
locatus, Spathius tomict, Spathius sp., Doryctes sp., and 
Ehyssa lineolata. 
Phorbia fusciceps Zett. 
(Det. by C. T. Greene) 
This small anthomyid fly is well known from the habit 
the larvee have of attacking the roots of radishes, cabbages, 
beans, ete. It has also been said to destroy the eggs of 
locusts and has been suspected of being parasitic upon the 
beet web-worm. Howard (1894, p. 272), however, believes 
this latter relation is very doubtful. 
Our specimens of this species were bred June 28 and 
July 6 from an exposed dead root of a living tree. The bark 
of this root was still adherent and was infested with Dryo- 
coetes americanus. ‘The wood was beginning to decay and 
part of it was riddled by the mines of the larve of Leptura 
vittata. Dryophthorus americanus and the larva of an 
unidentified elaterid were present. It is likely that this fly 
