CONVERGENCE OF COLORATION BETWEEN AMERICAN PILOSE FLIES AND BUMBLEBEES (BO MB US). E. GABRITSCHEVSKY, RESEARCH FELLOW OF THE INTERNATIONAL EDUCATION BOARD, COLUMBIA UNIVERSITY, NEW YORK. THE EUROPEAN AND ASIATIC GROUP OF Vohicella Bombylans. In a previous paper, in which the heredity of color variations in the European fly Vohicella Bombylans has been described, an attempt has been made to show the striking resemblance in coloration between various flies of the families Syrphidae, Asilidse, Tabanidae, (Estridx and Bombylidx with various bumblebee species which inhabit the same geographical regions. The study of those analogous color patterns which appear both amongst flies and bumblebees is interesting from a genetic point of view and bears on the problem of mimicry in animals. The black V. Bombylans (PI. L, Figs, i, d\ 9 ; 2, 9 ; 3, 9 ) with its fulvous bands on the last abdominal segments has exactly the same coloration as the common European Bombus lapidarius, B. confusus, B. rajellus, B. mastrucatus, etc. The other variety, V. hxmoroidalis (PI. L, Figs. 4, 5), is almost indistinguishable from many other Bombus species, as for example B. agrorum, B. vorticosus. The third variety of the V. Bombylans, the V. B. var. plumata (PL L, Figs. 6, 6 , 9 ; 7, 9 ) with its characteristic white hairs on the last abdominal rings, is extremely like B. hortorum, B. lucorum. Vohicella bombylans (and its varieties), if really pro-tected by her mimetic coloration, may be supposed to creep unobserved into a Bombus nest to lay her eggs there on the wax-combs. More often however the fly puts her eggs on the grass and moss, which covers the Bombus nest. This of course can only be performed with a Bombus species which builds its nest on the ground, not under the ground. In localities where many Bombus colonies of this kind are present the Vohicella flies are also found in large quantities. The larvae of Volucella feed on wax, 269
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