Vol. XI] COLE AND LOVETT—L1ST OF OREGON D1PTERA 261 



Family DOLICHOPODID^ 



Fig. 23. Argyra nigripes Locw. 



These flies are small and usually shining green in color 

 but occasionally black or yellow. The tarsi are long and 

 often ornamented in the males; these and the curiously modi- 

 fied claspers of the male genitalia furnish some of the best 

 specific characters. The adults are slender and delicate and 

 many are found about damp places in rank growth. They 

 are predatory, darting over leaves or the surface of water 

 in search of their prey. 



Little is known of the early stages of American species. 

 The larvae have been recorded as predaceous on other larvae 

 and also as feeding in plant tissues. A great majority are 

 aquatic, such as Dolichopus, Hydrophorus, and Campsic- 

 nemis. 



361. Sciapus pilicornis (Aldr.) 

 Hood River, VI-2 and 20. (Cole). M. C. Van Duzee 

 det. 1904, Trans. Amer. Ent. Soc, XXX, p. 282 (Psilopo- 

 dinus.) 



362. Chrysotus choricus Wheeler 

 Forest Grove, VI-2 (Cole). 



363. Chrysotus discolor Loew 

 Narrows, VII-1. 



December 14, 1921 



