Nesting and Biology of italicEustenancistrocerus amadanensis/italic (Hymenoptera, Vespidae, Eumeninae)

摘要

The nest structure of Eustenancistrocerus amadanensis was studied in Crimea. Females nested in the ground, in level or gently sloping spots with sparse vegetation. The soil in which the nests were built varied broadly in granulometric composition, from sandy loams to dense clay loams resembling clay in their properties. Of 11 nests studied, 5 had been abandoned by the females before oviposition, while the remaining 6 nests contained 1–4 cells each. These nests were 5.0–7.5 cm deep; the diameter of the nest burrow was approximately 3 mm. The cells were 9–13 mm long and did not differ in diameter from the remaining parts of the nest burrow. The multicellular nests had a linear-branched structure. The nests also contained empty lateral burrows whose exact function remains obscure. The nests were surmounted by inclined earthen turrets 5–10 mm tall, solid at the base and showing a laced structure at their distal ends. To construct the entrance turret, the females removed small earthen pellets from the nest burrow; having finished the turret, the females continued excavating the nest burrow, but then they removed and threw away larger earthen pellets. Females dismantled the turrets while sealing the nests. The wasps moistened and softened the ground with water, which they took from wet ground along streams and near the sea coast, and also from puddles, landing directly on their surface and floating due to surface tension. Females hunted for larvae of two species of coleophorid moths. The nesting rate was very low, only 1 cell in 2–8 days. Adult feeding was recorded on flowers of 10 plant species from 8 families. The species is bivoltine, with hibernation at the prepupa stage. A cocoon of an unidentified cuckoo wasp was found in one nest. The reproductive success was 81.1%. A male sleeping aggregation was also recorded. The bionomics of the genus Eustenancistrocerus and related genera are discussed.