Halictus (Rostrohalictus), Warncke

Pesenko, Yuri A., 2007, Subgeneric classification of the Palaearctic bees of the genus Evylaeus Robertson (Hymenoptera: Halictidae), Zootaxa 1500 (1), pp. 1-54 : 9

20 (19). Both sexes: head very high and narrow (twice as high as wide in male, 1.6 times in female); malar space very long (nearly as long as length of eye in male, 0.3 times as long as length of eye in female); cardo and maxillary palp very long, palp more than half as long as galea; propodeum longer, its dorsal surface usually as long as scutellum. Male: 2nd flagellomere 1.8 times as long as its diameter, metasomal sterna poorly pubescent ........................................ 18. Rostrohalictus Warncke