Sphecius speciosus (Drury, 1773)

Cicada killer wasp

A huge black-and-yellow wasp that hunts cicadas; rarely stings people.

Order: Hymenoptera
Family: Crabronidae
Group: Wasps, hornets & bees
Ontario status: Present in southern Ontario, common digger wasp across the eastern US

Why it matters

Looks terrifying, acts harmlessly, the single most misunderstood wasp in Ontario. Females reserve their sting for cicadas and sting people only if grabbed; males cannot sting, period. The complaint is burrow mounds in lawns and fear, not stings.

Origin

Native to eastern North America, a long-standing Ontarian, doing exactly what its name says every summer.

Behavior

Solitary, each female digs her own burrow, then hunts cicadas one by one, paralyzing each with a sting and dragging it underground as living food for one larva. Males patrol territories and grapple intruders but cannot sting at all. Active July, August.

Living conditions

Sunny, sandy, well-drained soil for burrowing: lawn edges, gardens, playgrounds, and bare patches. Needs annual cicadas nearby as prey, where cicadas sing, cicada killers dig.

Signs of presence

U-shaped mounds of excavated sand ~10 cm across on lawns and paths in midsummer
Huge wasps hovering low over lawns, carrying cicadas in flight
Burrow entrances ~15 mm wide in bare sandy patches
Males dogfighting in the air over territories, noisy but harmless

Weaknesses

One generation per year, the whole season is a few summer weeks
Needs bare sandy soil; thick turf and mulch block burrowing
Each burrow provisions only a handful of cells, low reproductive output per female
Males are all bluff: no stinger, no venom, just grappling

Myths and facts

Myth They're aggressive and will chase you.
Reality Males chase each other, not people, and they can't sting. Females are too busy hunting cicadas to care about you.
Myth A big wasp means a dangerous wasp.
Reality Size and danger are unrelated here. This is a solitary hunter, not a colony defender, it has no nest full of sisters to protect, which is why it doesn't attack.

Research notes

Morphology

Females 30-50 mm, males 25-35 mm, among the largest wasps in Ontario. Black abdomen with yellow bands, reddish-brown thorax, amber wings. Females have a functional stinger (modified ovipositor); males lack one entirely.

Diagnostics

Confirm by: very large size + reddish thorax + yellow-banded black abdomen + sandy burrow mounds in midsummer. European hornets are social, nest in cavities, and lack the burrow-mound association.

Easily confused with

European hornet, Vespa crabro European hornet is social (colony, paper nest in cavities) and active at dusk; the cicada killer is solitary, nests in ground burrows, and active by day.

Life cycle

Egg: Single egg laid on a paralyzed cicada sealed in an underground cell
Nymph or larva: Larva consumes the living-but-paralyzed cicada over ~2 weeks, then spins a cocoon
Adult: Lives 2-4 weeks in the midsummer; males emerge first and patrol
Egg to adult: ~11 months including overwintering as a prepupa in the soil
Generations per year: 1 per year

Development

Complete metamorphosis: egg → larva (feeding on the paralyzed cicada) → pupa (overwintering in a soil cocoon) → adult.

Reproduction

Each female provisions ~6-15 cells per burrow, one cicada (male offspring) or 2-3 cicadas (female offspring) per cell, prey number sets the sex of the offspring.

Distribution

Native range: Eastern North America
Ontario: Present in southern Ontario; common where sandy soils meet cicada populations
Global: Eastern North America; related Sphecius species across the Americas

Ecology

Obligate cicada predator; females paralyze (not kill) prey with venom, preserving it fresh for the larva. Males hold small mating territories and grapple rivals mid-air. Adults feed on nectar. Peak activity tracks annual cicada emergence.

Resistance

Unknown, not a pesticide target species.

IPM implications

First-line response is education: the risk profile does not justify intervention in nearly all cases. Monitoring: midsummer burrow-mound mapping. Lawns are made unattractive by thick turf and mulch over sandy patches; burrows in high-traffic areas are best tolerated for the few weeks of activity. No colony exists to 'remove', each burrow is one female's work.

Chemical ecology

Venom is a prey-paralysis formulation tuned to cicada nervous systems, defensive use against vertebrates is essentially absent. Males mark territories; cuticular hydrocarbons mediate mate recognition.

Genetics and DNA

No reference genome published as of 2026.

Taxonomy

Hymenoptera: Crabronidae. Sphecius speciosus (Drury, 1773), a solitary digger wasp, not a social wasp; the 'killer' hunts cicadas, not people.

Open questions

Venom composition specificity across cicada prey species; range dynamics at the northern edge in Ontario.

References

Evans, H.E. (1966) The Comparative Ethology and Evolution of the Sand Wasps, Harvard Univ. Press
BugGuide.net, Sphecius speciosus species account