none Lepidoptera entomophages were studied in the southwestern USSR in 1982-1984. Dibrachys is the most wide-spread genus. The genus is characterized by a wide variability of many morphological indices. The study of this variability made it possible to evaluate the morphological boundaries between Dibrachys spp. D. boarmiae is a synonym of D. cavus. The latter differs from other palearctic Dibrachys spp. by the absence of a clearly pronounced darkening under the marginal vein. Data were presented on the dimensions of D. cavus obtained from Tortrix viridana, Hyphantria cunea, Archips rosana, Apanteles solitarius and Larvaevoridae.