190 
Psyche 
[June 
THE BREMUS RESEMBLING MALLOPHORiE OF THE 
SOUTHEASTERN UNITED STATES (DIPTERA 
ASILIDiE). 
By S. W. Bromley, 
Amherst, Mass. 
The robber-flies of the genus Mallophora are, for the most 
part, rather large and densely-pilose, and are of a more compact 
build than most of the other members of the Asilidse. Nearly 
all of them resemble bees of one kind or another, and the species 
of the particular section of this genus here treated bear a marked 
resemblance to bumble-bees. In some cases the resemblance is 
actually specific. For example, Mallophora or etna (Wied.) is a 
counterpart of the worker of the bumble-bee, Bremus pennsyl- 
vanicus. The resemblance is, of course, most striking in the 
field, particularly if the flight of the asilid is directed away from 
the observer. The illusion is destroyed, however, when the 
flight of the insect is directed toward the observer, as the cons- 
picuous yellow beard and mystax of the fly dispel all doubts as 
to its identity. When the robber-fly is at rest, moreover, the 
posture assumed is entirely different from that of any bumble- 
bee. In fact, it seems to the writer that the mimicry is not 
nearly as striking as in the case of some of the robber-flies of 
the genus Dasyllis , such as D. thoracica, where the imitation of 
a bumble-bee is so exact that even an experienced collector may 
be mislead when the insect is in flight. 
Of the species here considered, M. orcina is the most abun- 
dant and has the widest geographical distribution. I have taken 
this species commonly in Northwestern Missouri, and have 
examined specimens from most of the southern states, including 
Florida and Texas. It is found in southern Ohio and, according 
to Mr. C. T. Greene of the National Museum, is very common 
in the neighborhood of Washington, D. C. The type-locality 
of Wiedeman’s specimen is “Savannah.” In Arizona, a very 
closely related species, Mallophora fulva Banks (Canadian En- 
tomologist vol. 43, no. 4, 1911, p. 130), has been taken. This is 
so close to orcina that it may possibly prove to be a western 
variety. However, until a full series showing the merging of the 
