Aculeate Hymenoptera (Hymenoptera, Aculeata) Inhabiting Trap Nests in Crimea

Trap nests for aculeate Hymenoptera were exposed during 15 years (2002–2016) in 80 localities of Crimea. A total of more than 500 trap nests containing about 25 000 cavities were used. As a result, 6 895 nests of 97 species from 9 families of Hymenoptera were obtained: Pompilidae (5 species / 118 nests), Vespidae (27/1201), Ampulici-dae (1/6), Sphecidae (2/8), Crabronidae (10/591), Colletidae (7/202), Megachilidae (37/4619), Apidae (3/9), and Formicidae (5/141). The rate of trap nest colonization by different species and groups of aculeate Hymenoptera is discussed. Attractiveness of trap nests to these insects is discussed in relation to their bionomics (nest structure, nesting substrate choice, number of generations per year, trophic relations, and philopatry). A strong correlation between the rate of colonization of trap nests and the amount of rains fallen at the beginning of the corresponding season in the given locality was observed. Nests of some unusual inhabitants of the trap nests, including Eumenes papillarius (Christ) and Eumenes sp., are reported. The number of obtained nests of species of the family Megachilidae was compared with the number of museum specimens of the corresponding species; the correlation between these parameters exists but it is relatively low. Two species of wasps and 9 species of bees are considered as suitable for breeding.