24 
BULLETIN 124. U. S. DEPARTMENT OE AGBICTTLTXTRB. 
DIPTEROUS PARASITES. 
Fig. 14. — Phorocera claripennis, a parasite of the 
alfalfa caterpillar. Adult and enlarged antenna of 
same; puparium. Enlarged, i From Hovrard. i 
Three tachinid flies, determined by Mr. W. E. Walton, of this 
bureau, have been reared from the larva? and pupa? of this caterpil- 
lar. Phorocera claripennds Macq. (fig. 14) is the most important 
of these, its wide dis- 
tribution and abundance 
of alternate hosts causing 
it to be always on hand. 
In 1910 at El Centre. 
Cal.. the writer observed 
as many as 15 per cent 
of Eurymus larva? with 
eggs of this species at- 
tached to them: while in 
1913 Mr. T. Scott Wilson, 
at Tempe. Ariz., observed 
as many as 50 per cent 
of larva? with eggs upon 
them, and in some cases 
there were as many as 
five or six to one cater- 
pillar. Of course a great many of these eggs are shed in molting, 
but a majority of them hatch, and the maggot, entering the Eurymus 
larva, kills it in a short time. P. claripennis has been reared from 
this species at the following 
other places : Salt Lake City. 
Utah iE. J. Vosler and L. P. 
Roekwood^ : Wellington. Kans. 
i H. T. Osborn I : Greenwood. 
Miss. (E. H. Gibsoni: Nash- 
ville, Tenn. i W. H. Larrimer") . 
Three specimens of Frontina 
archippivora "Will, were reared 
from a larva, and pupa collected 
at El Centro. Cal.. by Mr. R. N. 
Wilson, and a single specimen of 
the same species was reared by 
Mr. Eockwood at Salt Lake City, 
while at El Centro a single speci- 
men of Masicera sp. was reared 
by the writer. 
Besides these tachinid parasites, another small dipteron was dis- 
covered by Mr. T. Scott Wilson to be parasitic upon the pupa?. This 
was a small brown phorid (fig. 15) which has been determined by 
Mr. J. R. Malloch as Aphiochceta perdit a. a species recently de- 
J 
jpr 
15. — ApliiocJuEia penliia, a phorid 
parasite of the pnpa of the alfalfa cater- 
pillar. Greatly enlarged. (Original.) 
