Genus Cerceris

Weevil wasps (applies to many but not all species of Cerceris but also applies to additional species)

reviewed in (1)(2)

Cerceris Latreille 1803

86 spp. in our area (of which ~30 reach Canada)(3), 29 in e. US(4), almost 900 worldwide(5)

Abdominal segments are constricted at the margins. Outer veinlet of submarginal cell 3 meeting marginal cell not beyond its outer third. Terga without median or submedian transverse depressions.

The faces of females are modified with unusual projections on the clypeus and clypeal margin.

worldwide(5)

Females excavate cavities in soil as nests

Most species provision nests with adult beetles (weevils, Scarabaeidae, Cerambycidae, Tenebrionidae, Buprestidae, Chrysomelidae...); some, with bees/wasps; C. halone hunt exclusively Curculio nasicus

Females nest in aggregations in firm bare soil and may use old nests of congeners or other wasps, in which case they tend to dig their own tunnel from the old entrance. While burrowing, some soil is pushed in to form a plug. The burrow is a vertical shaft 2.5 cm to 1.3 m deep with horizontal branches or the shaft itself becoming horizontal. After the shaft is completed, females begin hunting. Some species start building cells from the entrance; others, from the bottom. A nest usually have under 10 cells, with up to 15‒20 prey items per cell. Parasitic Mutillidae have been reared from their nests. One species is known to have daughters assist mothers in nest guarding.(6)(7)