Pest profile

Blue-Winged Wasp

Scolia dubia · Hymenoptera: Scoliidae[4]

The blue-winged wasp is a large, gentle scoliid wasp often seen hovering a few inches over lawns in late summer; females hunt beetle grubs in the soil, so it is a beneficial insect that rarely, if ever, stings people.[1][2][3]

Blue-winged scoliid wasp on goldenrod, showing blue-black wings, two yellow spots and a reddish rear abdomen
Blue-winged scoliid wasp on goldenrod, showing blue-black wings, two yellow spots and a reddish rear abdomen. (c) Linda Watson, some rights reserved (CC BY) — via iNaturalist, CC BY 4.0

How to identify it

  • Adults are over 1/2 inch long (about 5/8 inch) with a shiny black head and thorax, black antennae and blue-black wings.[1][2]
  • About midway along the abdomen are two yellow spots, one on each side; in flight they can look like a band.[1][2]
  • The rear part of the abdomen is reddish brown and fuzzy.[1][2]

Where it lives

It is the most common scoliid wasp in North Carolina and is seen in Maryland and South Carolina lawns and gardens; adults are active from June to October.[1][2][3]

US map: public records from 33 states since 1990 (GBIF).

Biology and life cycle

Adults are present from June to October and are most abundant in August, often flying in large numbers over lawns during the day.[1][2]

A female digs through the soil or follows grub tunnels, stings and paralyzes a grub, and lays an egg on it; the wasp larva eats the grub in about two weeks.[1][3]

The larva spins a cocoon and spends fall and winter in the soil, and a new generation of adults appears the following summer.[1][3]

Adults feed on nectar and are often seen on goldenrod, mountain mint and other flowers in late summer.[1][2][3]

Damage and signs

  • None; the wasps help control green June beetle, Japanese beetle and other white grubs in lawns.[1][3]

Health risk

They are not aggressive and generally do not attack people; only females can sting, and they rarely if ever do.[1][2][3]

Control

Prevention

No control is needed or recommended; many wasps over a lawn usually mean it has grubs.[1][2]

Biological control

Their presence is a sign that natural grub control is already at work.[3]

Common questions

Why are wasps flying low over my lawn?
In late summer they are often blue-winged scoliid wasps searching for beetle grubs in the soil, or males looking for females.[1][3]
Do blue-winged wasps sting?
Rarely, if ever. They are not aggressive, and control isn't recommended.[1][2]
Should I spray them?
No. They help control June beetle and Japanese beetle grubs and pollinate flowers.[1][2][3]

Sources

  1. NC State Extension, “Blue-winged Wasp (PDIC Factsheet).” content.ces.ncsu.edu/blue-winged-wasp (accessed 2026-10-15)
  2. University of Maryland Extension, “Scoliid Wasp.” extension.umd.edu/resource/scoliid-wasp (accessed 2026-10-15)
  3. Clemson Cooperative Extension, Home & Garden Information Center, “Two-Spotted Scoliid Wasp: A Gentle and Valuable Garden Visitor.” hgic.clemson.edu/two-spotted-scoliid-wasp-a-gentle-and-valuable-garden-visitor/ (accessed 2026-10-15)
  4. iNaturalist, “Scolia dubia taxon page (order and family).” www.inaturalist.org/taxa/1129479 (accessed 2026-10-06)

Updated 2026-10-15. Built from sourced records. Spot an error? Tell us.