Saproxylic Bees and Wasps

Abstract

Bees and wasps are usually known to occur in open habitats, with most species recorded from sand, loess, and open rock biotopes. Although most species nest underground (45% of the fauna of the Czech Republic), followed by parasitic species (31%), many species from various groups use dead wood for nesting. Of the group of species nesting in various cavities (21% of all species), one quarter is represented by species highly preferring cavities in dead wood. These species, especially of the families Crabronidae, Vespidae, and Megachilidae, are real saproxyles, as are also many members of the families Chrysididae, Sapygidae, Tiphiidae, and Scoliidae. The European honeybee is also saproxylic, with its preference for cavities in tree trunks for nesting, as well as several species of bumblebees . Dead wood is the most important building material used by many wasps and paper wasps for making nests. Saproxylic bees and wasps are endangered due to the loss of old trees, as well as due to the removal of dead wood. We can support saproxylic hymenopterans in forests by retaining standing dead trees and other forms of sun-exposed dead wood. In urban or residential environments, populations of these insects can be supported using insect hotels and other types of artificial nests.