44 
Winthemia quadripustulata Fabr. 
This, again, is a species of wide distribution, occurring throughout 
the northern portion of the United States and also in Germany. It 
has been reared from twelve species of lepidopterous larve at this 
office, including certain cutworms, the army worm (Leucania unipuneta), 
the grass worm of the South (Laphygma frugiperda), the promethea 
caterpillar (Attacus promethea), and several sphingid larve. Four 
specimens were reared in the Orgyia observations, three issuing in late 
October, 1895, and the fourth April 14, 1896, this latter having evi- 
dently hibernated in the puparium. 
Exorista griseomicans v. d. W. 
This species, which we know only from the District of Columbia and 
Central America, and which has been reared from this host insect alone, 
made its appearance in our experiments only in late July, 1896, when 
four specimens were reared from the mass of Orgyia cocoons under 
observation. 
THE SCAVENGER FLIES. 
Helicobia helicis Towns. Limosina sp. 
Sarcophaga (two species). Homalomyia sealaris Fab. 
Phora nigriceps Loew. Gaurax anchora Loew. 
Phora incisuralis Loew. Neoglaphyroptera bivittata Say. 
Phora fasciata Fallen. Diplosis sp. 
Phora agaraci Lintner. 
It seems hardly worth while to give any detailed consideration to any 
of the above species. All were reared from Orgyia cocoons, and most 
of them from cocoon clusters which had overwintered and were col- 
lected in the spring of 1896 and placed in rearing jars for observation. 
It was especially noticed that nearly all of the scavenger flies, particu- 
larly the Sarcophagids, after issuing, remained among the litter at the 
bottom of the cage, whereas the adults of the parasitic Diptera, and 
Hymenoptera as well, immediately flew to the upper parts and sides of 
the cage, apparently trying to find a way out. 
By far the most abundant of the eleven species was the little Oscinid, 
Gaurax anchora. This little fly, shown at fig. 24, was first reared 
on September 10, 1895. Its larvee and puparia were found abundantly 
in old Orgyia cocoons the larvie of which had been destroyed by Pim- 
pla inquisitor. The larve of the Gaurax were found to feed upon the 
quite dry remains of the caterpillar.! Other larve were found in dead 
pup early in September. Several hundred were reared in all, of 
\Loew, Centur., VII, page 111, mentions the fact that Osten Sacken found the larvee 
of this species in New York feeding gregariously upon the chrysalis of the Cecropia 
moth inclosed within its cocoon. In Osten Sacken’s catalogue the fact is recorded 
simply in the words ‘inquilinous in cocoons of Attacus cecropia.” The same species 
was reared from the cocoons of the gypsy moth (Porthetria dispar) by Professor 
Fernald and his assistants. 
