894 Th American Naturalist. [October, 
New Use for Bisulphide of Carbon.—Professor J. B Smith 
acting on the suggestion of Professor H. Garman finds by experiment 
that bisulphide of carbon can be used to advantage against aphides on 
plants above ground. By covering infested melon vines with a tub or . 
other closed vessel, and allowing a drachm of bisulphide to evaporate 
in a shallow dish beneath it, the pests were killed at the end of one 
hour. The coverings were then removed. 
Mimicry in Diptera.—Mr. C. J. Wainwright reports‘ interesting 
observations ou mimicry of Diptera flying in England in early spring. 
Two species of the Syrphid genus Cheilosia so resembled bees of the 
genus Andrena as to make it very difficult to distinguish them. “They 
particularly resembled Andrena fulva, and we netted far more of the . 
bee than of the Dipteron in our efforts to get the latter. The resem- 
blance is very strong, color, size, and (to a considerable extent) shape 
being much the same; when at rest on a flower the Dipteron curls its 
body under a little as the bee does, and folds its wings over its back in 
the same manner." 
There was also present a species of Echinomyia of the family Tach- 
inide, which had a bee-like appearance, differing in this respect from 
other members of its genus. “It, however, resembled no species in 
particular ; it bore a general resemblance to Bombus muscorum in size, 
shape and color, but it was not so hairy and did not fold its wings bee 
fashion.” 
In commenting on these observations Mr. Wainwright says: “There 
is very little doubt that in the spring, when insects are not very num- 
erous, and when, therefore, we may reasonably infer that their enemies 
are unusually alert in discovering and capturing them, that it must 
even more necessary than during the summer, for those insects 
which do appear, to be well protected.in some way from their foes, and 
especially if they happen to be species which, through feeble reproduc- 
‘tive powers or other similar causes, are limited in numbers to commence 
with. Now, the two Cheilosiae are distinctly species which are limited 
in numbers, in fact, they are somewhat rare species, and may be de- 
scribed as occurring singly ; they are not robust species, in fact, rather 
the reverse, and, therefore, they are just such species one would expect 
to find protected by mimetic resemblances. In every way they may be 
said to present all requirements of an ordinary case of mimicry. 
“The Echinomyia, however, does not present so ordinary a case. It 
isa wonderfully strong and robust species, belonging to a group of 
*Ent. Monthly Magazine. 
