Thread-waisted Wasps: Sphecidae

Familiar to most people as the long, thin wasps that occupy flower tops during the warmer seasons, their sometimes fragile look masks their predatory nature.

Thread-waisted wasps capture and paralyze a variety of insect species and then transport them to their nests as hosts and feed their own larvae.

Nest building techniques account for some diversity within the family. Species from some Sphecidae genera such as the grass carrying wasps, use grass to line the nests. Ammophilia build below ground, predominantly sandy soil nests.

Three common Sphecidae, the Black and Yellow Mud Dauber, (Sceliphron caementarium) pictured above, the Blue Mud Dauber (Chalybion californicum) and the Pipe organ mud dauber (Trypoxylon politum) build mud nests on a variety of substrates, predominantly wood.

Solitary in nature, females build the mud structures, often on the sides of buildings, without the benefit of either workers or drones.

While nests around residential areas can be considered nuisances, their sometimes aggressive nature gets saved for prey rather than humans.

The handful of dark bodied thread waisted wasps can create identification confusions, especially between the Chalybion and Chlorion genera.

A close-up view of the Blue Mud Wasp (Chalybion californicum) in the top picture shows the hairy head and thorax, usually good field identification clues.

Caught in a good lighting condition, their body color has a metallic blue shine. Recent research suggests black widow spiders rank high on their preferred larval food list.

© 2009-2011 Patricia A. Michaels