Leafcutter bees, solitary wasps

Habitat:

Decayed timber, usually out of doors, such as in dead trees and fence posts, but may infest badly rotted exterior building timbers such as window joinery, fascias, cladding, exposed ends of rafters or even wall plates. Some bee species may bore into soft mortar or stone, causing serious weakening over a period of time.

Damage characteristics:

They produce large, circular emergence holes and tunnels, 6-7 mm in diameter, partly plugged with coarse chippings. Tunnels may contain dead leaves formed, with bees, into cells, or with wasps, into membraneous 'cells' and many small metallic-coloured fragmented remains and wings of dead flies.

Insect characteristics and location:

Adults appearance is variable, but all have the general characteristics of wasps and bees.

Larva Both types have legless, non-mobile larvae, reared in the cells in tunnels. Present during springtime.