The suitability of two forest biotopes (oak and hornbeam-beech forests) for occupation by D. nitedula in Daghestan, Russia is considered. Biotopes have been characterized according to 11 parameters. All 11 vegetation parameters were significantly different between study areas. The indices of D. nitedula success in the studied biotopes demonstrated that numbers were higher in an oak forest than in a hornbeam-beech forest. Estimates of microhabitat distribution showed that D. nitedula individuals prefer to live in shrub associations and in areas with young trees in both biotopes. The body weight of adults and reproduction rate were similar in both biotopes. We concluded that in situation when the body weight and reproduction rates of individual D. nitedula were similar but the numbers of species in the both forest biotopes significantly differ, the structure of woody-shrub vegetation becomes a significant factor.