Thread-waisted Wasps

Sphecidae

Classification

Phylum: Arthropoda
Subphylum: Hexapoda
Class: Insecta
Order: Hymenoptera
Family: Sphecidae

Pronunciation

How to pronounce Sphecidae: /ˈsfɛsɪˌdiː/

These audio files are automatically generated. While they are not always 100% accurate, they are a good starting point.

Images

Eucerceris melanosa by the Smithsonian. Used under a CC0 license.

Trypoxylon sarum by the Smithsonian. Used under a CC0 license.

Trypoxylon atkinsoni by the Smithsonian. Used under a CC0 license.

Cerceris inselita atrafemori by the Smithsonian. Used under a CC0 license.

Cerceris queretaro by the Smithsonian. Used under a CC0 license.

Summary

The Sphecidae, or thread-waisted wasps, are a diverse family of predatory wasps found worldwide, characterized by their elongated bodies and behaviors related to nesting and feeding. They play a vital ecological role as predators of various arthropods.

Physical Characteristics

Body length ranges from 10 to 30 mm; abdomen long and stalked (petiolate), giving a 'thread-waisted' appearance. Body colors vary and may be all black, sometimes with a metallic blue or green tint, black and red, yellow and black, or white and black. Males have no tarsal rake, 11 flagellomeres, and 7 gastral segments; females have a tarsal rake, 10 flagellomeres, and 6 gastral segments.

Identification Tips

Look for the distinctive long and slender waist (petiolate abdomen) characteristic of thread-waisted wasps, along with the number of flagellomeres and gastral segments which are different between males and females.

Habitat

Many species nest in the ground, typically in areas with sparse or no vegetation, while some build aerial nests of mud. Others may nest in hollow stems or abandoned bee burrows in logs.

Distribution

Approximately 127 species in 11 genera in the specified area, about 800 species in 18 genera worldwide. 21 species are found in Canada, and 44 in the eastern United States.

Diet

Larvae feed on paralyzed arthropods provided by adults; common prey includes spiders, grasshoppers, and caterpillars. Adults feed on nectar from flowers and various fluids of their prey.

Life Cycle

Most Sphecidae are solitary nesters, although some are kleptoparasitic, utilizing prey caught by other wasps for their larvae. The vast majority practice mass provisioning by providing all the prey items before laying their eggs.

Reproduction

Females lay eggs in burrows filled with paralyzed prey, ensuring the larvae have ample food when they hatch.

Ecosystem Role

Predatory and parasitoidal role in the ecosystem, controlling populations of various arthropods.

Evolution

The family Sphecidae is a monophyletic clade that diverged from the former Crabronidae, with phylogenomic studies indicating the need for a reevaluation of wasp family classifications.

Similar Taxa

Misconceptions

Some may confuse Sphecidae with other types of wasps or bees due to their similar appearances or behaviors; however, their unique nesting behaviors and body structure (e.g., thread-waisted appearance) distinguish them.