Parasitic Wasp (Braconid)
Beneficial insect · Parasitoid
Braconid wasps are tiny to medium-sized beneficial wasps that help suppress many garden pests. They do not build attention-grabbing nests in the garden like social wasps. Most species are parasitoids, meaning their young develop on or inside a host insect.
How to identify it
Adults are slender, usually dark or brownish, with narrow waists and clear wings. Many are quite small and easy to miss unless you look closely on flowers or around host insects. Immature stages develop within or on pests such as caterpillars, aphids, or beetle larvae, depending on the species.
How it helps your garden
Braconid wasps attack tomato hornworms, cabbageworms, aphids, borers, and other garden pests. A parasitized caterpillar may carry small white cocoons on its back after the wasp larvae emerge. These wasps help keep pest populations from building unchecked, especially when flowering resources are nearby.
How to attract it
Grow small-flowered plants such as dill family herbs, asters, and other nectar sources that suit short-tongued beneficial insects. Keep blooms available from spring through fall rather than relying on a single flowering period. Leave some garden edges and mixed vegetation so adult wasps can shelter and find hosts. Provide a shallow water source or damp spots without creating standing, stagnant water.
Tips
Do not remove caterpillars covered with white cocoons, since they are already helping the garden by supporting beneficial wasps. Because many braconids are tiny, their work is often noticed before the adults are. A garden with flowers and moderate pest pressure tends to support them best.
General guidance for US gardens. Broad insecticide sprays harm beneficial insects along with pests; for a local pest-management plan, contact your Cooperative Extension office. Page updated Aug 4, 2026.