1881.] Larval Habits of Bee-Flies. 439 
the humming which they produce in flight. Nothing had been 
published of their larval habits in this country till last year, 
though an undetermined larva, at first supposed to be Hymenop- 
terous, but which subsequently proved to be that of Systcechus, 
was figured in the writer’s ninth report on the insects of Missouri 
(1877), and copied in his ‘‘ Locust Plague in the United States,” 
and into the First Report of the U. S. Entomological Commission. 
In October, 1879, we obtained from a lot of larve sent us by 
Mr. G. M. Dodge, of Glencoe, Neb., a single pupa which agrees 
with those of Systechus oreas O. S.,1 presently to be described, 
but which, as Baron Osten Sacken writes us, is probably that of 
S. vulgaris, a common species in the Western States, east of the 
mountains, 
During the past two years we have been in correspondence with 
Professor J. G. Lemmon, of Sierra Valley, Cal., who has kindly 
sent us many specimens of locusts occurring there, and especially 
the eggs and early stages of Camuula pellucida. . 
Among such eggs these bee-fly larve were, if anything, more 
common than we had found them among the eggs of the destruc- 
tive locust, Caloptenus spretus, east of the mountains. We here 
quote one letter in illustration: 
poda atrox, by the end of September looked as if scattered with 
loose shells, so thorough was the work of destruction. 
“ A few of them were detected in among the eggs in April, but 
hot generally until August. One individual seems to empty sev- 
eral egg cases before retiring from the feast and coiling himself 
"Pp in a case which he has emptied, or in a nidus of his own 
< moa G. Lemmon, in letter to C. V. Riley, October 12, 
During 1878 and 1879 we failed to rear any of them to the 
Perfect state, but on June 20 of the present year, 1880, we 
obtained from these California larvze the first fly. This proved to 
bea male of Zyiodites mus O. S.2 as kindly identified for us by 
Mr. S. Ww. Williston, of New Haven. We have, during the sum- 
"Western Diptera, p- 254; Bull. Hayden’s Geol. and Geog. Survey, UI, No, 2. 
Ibid, p. 246, 
. 
