Two new Hoplitis species of the subgenus Hoplitis Klug, 1807 (Hymenoptera, Megachilidae) and the nesting biology of H. astragali sp. nov. in Dagestan

Abstract

Hoplitis astragali sp. nov., a member of the H. monstrabilis species group, and H. dagestanica sp. nov., a member of the H. adunca species group, are described. The former species is known from Dagestan in Russia, Azerbaijan, and Turkmenistan, the latter only from Dagestan. Nests of H. astragali are described. Females of this species excavated burrows in a vertical clay cliff, but sometimes chose a horizontal surface for nest excavation, particularly at the entrance of old burrows of Xylocopa olivieri (Apidae). The nest burrows of H. astragali were either sub-vertical or sub-horizontal. The nests were composed of one to three brood cells, an empty vestibule in front of the outermost cell, and a closing plug at the nest entrance made of moistened mud. The inner surface of the cells was covered with a thin wall composed of compact soil, most probably built by the female bee after cell excavation. The pollen loaf was very liquid and had a spherical shape. The egg was deposited on its top. The cocoon consisted of a single thin layer, which uniformly covered the whole inner surface of the cell. There was one generation per year. The prepupae hibernated. Sapyga caucasica (Sapygidae) was recorded in the nests as a kleptoparasite. Both females and males of H. astragali exclusively visited flowers of two species of the genus Astragalus (Fabaceae).