Overview
Adult sphecids ( mud-dauber wasps) feed on nectar or honeydew, while females
prey
on a range of insect groups as well as spiders with which they provision their nests. Sceliphrini provision their nests with various spiders (Araneae). The large orange and black common mud-dauber (
Sceliphron laetum
), may be seen at flowers feeding on nectar or buzzing loudly around trees and buildings. A single female builds a multi-tiered nest of many cells covered in extra layers of mud in sheltered places such as rock overhangs or piles, tree trunks or buildings. This wasp can sometimes be seen collecting mud at the edges of streams or dams. As the wasp spreads mud to build the nest it vibrates and the vibrations produced help to distribute the mud evenly. The female stings and paralyses up to 20 spiders that are placed in cells inside the nest. An egg is then laid in each cell and the developing larva feeds on the paralysed spiders. The metallic blue
Chalybion bengalense
found in northern Australia nests in pre-existing cavities. Ammophilini prey on lepidoperan (moth and butterfly) larvae in soil, whereas Sphecini are predators of Orthoptera (grasshoppers and crickets).
Description
Sphecids are medium to large wasps (8 40 mm) and are distinguished by having a very distinctive elongate petiolate waist that comprises only metasomal sternite 2 (S2), and a large jugal lobe on the hind wing. In addition, many species have bright contrasting colours of black and yellow or black and red.
Distribution
As now recognised, this family constitutes only the subfamily Sphecinae of previous authors (e.g. Bohart & Menke 1976; Naumann 1991) following the work of Melo (1999) who divided the Sphecidae
sensu lato
into two families, Sphecidae
sensu sritcto
and Crabronidae, on phylogenetic grounds. Sphecidae
s.tr.
now comprise 20 species in Australia and one in New Zealand (plus several exotic species). Numerous species are also found in New Guinea and throughout the south-west Pacific.
Further information about the Sphecidae can be found in Bohart & Menke 1976, Harris 1994, Melo 1999 and Naumann 1991.