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BULLETIN 124, U. S. DEPARTMENT OF AGRICULTURE. 



DIPTEROUS PARASITES. 



Fig. 14. — Pliorocera daripennis, a parasite of the 

 alfalfa caterpillar. Adult and enlarged antenna of 

 same; puparium. Enlarged. (From Howard.) 



Three tachinid flies, determined by Mr. W. E. Walton, of this 

 bureau, have been reared from the larvae and pupae of this caterpil- 

 lar. Phorocera daripennis 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 Centro, 

 Cal., the writer observed 

 as many as 15 per cent 

 of Eurymus larvae 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 larvae 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. daripennis has been reared from 

 this species at the following 

 other places: Salt Lake City, 

 Utah (E. J. Vosler and L. P. 

 Eockwood) ; Wellington, Kans. 

 (H. T. Osborn) ; Greenwood, 

 Miss. (E. H. Gibson) ; Nash- 

 ville, Tenn. (W. H. Larrimer). 

 Three specimens of Frontina 

 archippivora Will, were reared 

 from a larva and pupa collected 

 at El Centro, Cal., by Mr. E. 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 pupae. This 

 Avas a small brown phorid (fig. 15) which has been determined by 

 Mr. J. E. Malloch as ApJiiockmta perdita, a species recently de- 



Fig. 15. — Aphiochwta perdita, a pborid 

 parasite of the pupa of the alfalfa cater- 

 pillar. Greatly enlarged. (Original, i 



