Scoliid Wasps Identification Guide
Scoliidae
Scoliid wasps are large, hairy solitary wasps that hunt scarab beetle grubs in the soil. They are often seen hovering low over lawns or visiting flowers in late summer.
Taxonomy
Scoliid Wasps Coloration
Common color patterns to help identify scoliid wasps
Scoliid Wasps
Seasonal Activity
When scoliid wasps are most active throughout the year
Where Scoliid Wasps Are Found
Hover over states to see their names. Green regions indicate where scoliid wasps have been reported.
Scoliid Wasp Identification Guide
Physical Characteristics
Scoliid wasps are large, sturdy wasps with hairy bodies. Adults are 15 to 25 millimeters long, or about 0.6 to 1.0 inch. The fuzzy midsection and smoother abdomen with bright color markings make them stand out.
The blue-winged scoliid wasp (Scolia dubia) is the most common species in North America. It has a black head and midsection with dark blue-black wings that shimmer in the light. The front half of the abdomen is dark. The back half is reddish-brown to orange with two bright yellow spots. This color pattern makes them easy to identify.
Like all wasps, scoliids have a narrow “wasp waist,” six legs, and two antennae. Males are slimmer with longer antennae. Females are a bit larger and more stocky. Their dark wings often show a blue or violet shine in direct sunlight.
Common Species
Several scoliid species are found across North America:
- Blue-winged scoliid wasp (Scolia dubia): The most common species in the eastern United States. Black body with a reddish-orange back end and two yellow spots. Blue-black wings with a metallic shine. Found from New England to Florida and west to the Great Plains.
- Double-banded scoliid wasp (Scolia bicincta): Looks like S. dubia but has two yellow bands across the abdomen. Found in the eastern and central United States.
- Feather-legged scoliid wasp (Dielis plumipes): A slightly larger species with feathery hairs on its legs. More common in the southern states and Mexico.
Scoliid Wasp Behavior and Biology
Scoliid wasps are solitary. Each female works alone rather than living in a colony. Their life cycle centers on hunting scarab beetle grubs that live underground in the soil.
Lifecycle and Reproduction
A female scoliid wasp finds scarab beetle grubs by flying low over turf and garden beds. She can sense grub movement below the surface. When she finds one, she digs into the soil and stings the grub to paralyze it.
She then lays a single egg on the grub. The wasp larva hatches and feeds on the grub over several weeks. When done feeding, the larva spins a cocoon in the soil. In northern areas, the new generation spends winter as pupae and comes out as adults the next summer. Most populations produce one generation per year. Warmer climates may see more.
Diet and Feeding
Adult scoliid wasps feed on flower nectar. They often visit late-summer plants like goldenrod, boneset, and mountain mint. Males can be seen flying in looping patterns over lawns while looking for mates.
The larvae feed only on scarab beetle grubs. Common targets include Japanese beetle grubs (Popillia japonica), June beetle grubs (Phyllophaga spp.), and green June beetle grubs (Cotinis nitida). Where grub numbers are high, scoliid wasps will follow.
Habitat and Nesting
Scoliid wasps do not build visible nests. There is no paper comb, mud structure, or hive to find. Each female searches for grubs on her own and lays eggs underground. They are most common in open, sunny areas with turfgrass or sandy soils where scarab grubs live.
You may see scoliid wasps hovering just inches above the ground in your yard. This low flight is the female hunting for grubs. Males fly in more erratic patterns a bit higher off the ground.
Why Scoliid Wasps Appear in Your Yard
If you see many scoliid wasps hovering over your lawn, it almost always means you have a large scarab grub population in the soil. The wasps come to your yard because their prey is there. A surge in scoliid wasp activity is a strong sign of a grub problem.
Scarab beetle grubs eat grass roots and can cause real turf damage when numbers are high. Brown patches, spongy turf that peels up easily, and birds or skunks digging in the lawn are all signs of grub damage.
Treatment Methods for Scoliid Wasps
Scoliid wasps are solitary and do not build nests, so there is no colony to target directly. The most effective way to reduce their numbers is to treat the grub population that draws them in.
Grub Control Treatments
Reducing the scarab grub population in your soil is the key to lowering scoliid wasp activity:
- Nematode applications: Microscopic organisms like Heterorhabditis bacteriophora can be applied to turf to target grubs in the soil.
- Milky spore products (Paenibacillus popilliae): These target Japanese beetle grubs over the long term. Once they take hold in the soil, they can keep grub numbers down for years.
- Soil insecticide treatments: Properly timed lawn insecticide treatments can reduce grub populations when applied during the right stage of the grub life cycle.
- Lawn care practices: Keeping turf healthy with proper watering and mowing makes lawns less appealing to egg-laying scarab beetles.
Reducing Contact with Scoliid Wasps
If you want to limit encounters with scoliid wasps around your home:
- Do not walk barefoot in areas where wasps are flying low and searching for grubs.
- Move potted flowers away from doorways and patios, since adults visit blooms for nectar.
- Scoliid wasp activity is seasonal and drops off after the first hard frost in fall.
When to Call a Professional
If you see turf damage along with lots of scoliid wasp activity, a pest control professional can assess the grub problem and recommend the right treatment. Treating the grubs will also cut down on wasp activity around your property.
How to Tell Scoliid Wasps Apart from Similar Insects
Scoliid wasps are sometimes confused with other large flying insects:
- Cicada killers: Much larger, up to 2 inches long, with yellow markings on a reddish-brown body. They hunt cicadas and dig large burrows with piles of soil at the entrance.
- Carpenter bees: Stocky and bee-shaped with a shiny, hairless black abdomen. They bore into wood and do not have a narrow wasp waist.
- Bumble bees: Fuzzy all over with a rounded body and pollen baskets on their back legs. Bumble bees nest in cavities, not open soil.
- Digger wasps: Similar ground-searching habits but usually more slender with less hair on the body. Different species hunt different prey.
The best way to tell scoliid wasps apart is by their hairy midsection, bright reddish-orange or yellow markings on the abdomen, shiny blue-black wings, and low-flying behavior over turf.
References
Other Wasps
Explore other species in the wasps family
Commonly Confused With
Scoliid Wasps are often mistaken for these similar pests
Where Scoliid Wasps Are Found
Hover over states to see their names. Green regions indicate where scoliid wasps have been reported.
Common Questions about Scoliid Wasps
Are scoliid wasps dangerous to people?
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Scoliid wasps are not aggressive toward people. Females have a functional stinger but rarely sting unless handled or stepped on. They are solitary wasps that do not build or defend large nests like yellowjackets or hornets.
Why are there so many scoliid wasps in my yard?
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Large numbers of scoliid wasps hovering low over your lawn usually means you have a significant population of scarab beetle grubs (like Japanese beetle or June beetle larvae) in the soil. The wasps are searching for grubs to parasitize.
Do scoliid wasps damage lawns?
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Scoliid wasps do not damage lawns. Females dig shallow burrows in the soil to reach grubs, but this disturbance is minor. The grubs they hunt, however, feed on grass roots and can cause significant turf damage.
How do you get rid of scoliid wasps?
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Scoliid wasps are solitary and do not build nests, so there is no colony to remove. The most effective approach is to treat the scarab grub population in the soil that attracts them. Reducing grub numbers through lawn treatments will reduce wasp activity over time.
How can I tell scoliid wasps apart from yellowjackets?
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Scoliid wasps are larger and hairier than yellowjackets. They have a more robust body with a hairy thorax and often show reddish-brown or orange coloring on their abdomen. Yellowjackets have smooth, shiny bodies with bold yellow and black banding.
What time of year are scoliid wasps most active?
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Scoliid wasps are most active from mid-summer through early fall, typically July through September. This timing matches when scarab beetle grubs are present in the soil and when late-summer wildflowers are in bloom.
Do scoliid wasps build nests?
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Scoliid wasps do not build visible nests like paper wasps or mud daubers. They are solitary ground-nesting wasps. Each female digs into the soil to find a scarab grub, lays a single egg on it, and moves on. There is no communal nest to find or remove.
With five years of hands-on experience in the pest control industry, George Schulz is a registered technician with the Virginia Pest Management Association and a proud third-generation professional in a family business that's been protecting homes for over 57 years. He manages and trains a team of service pros while also leading internal research efforts—recently spearheading a deep-dive review of thousands of documents on pest control materials to hand-pick the most kid and pet friendly, most effective solutions tailored specifically for homes in the DC metro area.