A further study of the nesting biology of Leptochilus (Neoleptochilus) regulus (de Saussure, 1855) (Hymenoptera, Vespidae, Eumeninae)

Two females of Leptochilus regulus (de Saussure, 1855) were observed nesting in reed stalks a Fabre’s hive serving as block trap nests Crimea, with the timekeeping all their behaviours. The building material used by to separate cavity into cells consisted pellets dry soil, gravel particles, and small fragments tree bark, leaves, thin stems. Females rapidly carried these items collected 1.0–1.5 m from nests. They bonded only last portions each “partition” very amount mud. An additional unbonded was deposited nest after sealing cell. hunted exclusively for larvae an anobiid beetle (Coleoptera, Anobiidae); they stored 19–37 prey per Hunting provisioning occupied largest portion females’ time budget. Duration hunting flights different between females. both contained three brood cells. Cocoons Chrysis ragusae De Stefani, 1888 (Hymenoptera, Chrysididae) found nests; this cuckoo wasp species also recorded entering host at stage provisioning, acting apparently inquilines. cocoon ultrastructure L. is illustrated discussed.