THE DIPTEROUS GENUS DRAPETIS MEIGEN 

 (Family Empididae).* 



By A. L. Melander, 

 Pullman, Washington. 



The species of Drapetis are to be distinguished from the 

 remainder of the Empididae by the following summarized com- 

 bination of characters. Thorax robust, the humeri not swollen 

 and constricted. Eyes closely approximate on the face, but on 

 the front diverging above; palpi broad, incumbent on the 

 very short proboscis; antennas three-jointed, with terminal or 

 subterminal arista ; one pair each of vertical and ocellar bristles. 

 Legs hairy and often furnished with bristles or setae, the middle 

 femora however rarely armed and not thicker than the front 

 pair. First basal cell of the wings shorter than the second which 

 is united with the discal cell, anal cell completely wanting, only 

 two posterior cells before the anal area. 



The genus Drapetis includes very small flies, among the 

 smallest of all the Diptera, which are found during the spring 

 and summer, sometimes swarming about flowers like wild 

 cherry and plum, and sometimes running about singly over 

 grass and low shrubbery. Their early stages are quite unknown. 

 In the tropics slender yellow-colored species predominate but 

 in the Temperate Zone the general species are black and more 

 robust. 



In the following pages are given a detailed discussion of the 

 external morphology of the drapetine flies, a synoptic table to 



* Contribution from the entomological laboratories of the Bussey Institution 

 for Applied Biology, Harvard University. No. 149. 



During the year 1899, while- a student at the University of Texas the writer 

 began a study of the Empididae, a family of predatory dipterous flies. Since that 

 time several papers dealing with the taxonomy of the family have appeared from 

 his pen, notably a review of the North American species known up to 1902, which 

 was published as a thesis for the master's degree. The accumulation of a wealth of 

 material in this family, especially from the rich collecting fields of the Pacific 

 North-west, led to the preparation of an exhaustive review of the group which 

 was accepted by Harvard University in 1914 as the thesis requirement for the 

 degree of Doctor of Science. It was the writer's intention to issue this manuscript 

 of quite one thousand page5 in the Genera Insectorum, but the outbreak and 

 centralization of the war in Belgium entirely precluded this possibility. Since 

 many of the new species have been distributed among museums and individual 

 collections it seems desirable to have their names published. The following pages, 

 dealing with the single genus Drapetis, have been excerpted as the first presenta- 

 tion of the dismembered dissertation. 



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