Bug FAQEmerald Cockroach Wasp
Ampulex compressa · Order: Hymenoptera · Family: Ampulicidae
Also called: jewel wasp
The emerald cockroach wasp is a metallic blue-green insect with red thighs on its second and third pairs of legs. Females are about 22 mm long and have a stinger, while males are much smaller and lack a stinger. It lives in tropical Africa, South and Southeast Asia, and Pacific islands, especially during warm seasons.
Source: Wikipedia
How to recognize it
The wasp’s body shines metallic blue-green and the thighs of its second and third leg pairs are red.
Source: Wikipedia
Size
Females reach about 22 mm in length; males are considerably smaller, sometimes less than half the female’s size.
Source: Wikipedia
Does it bite or sting?
Females possess a stinger; males lack one. The wasp’s metallic blue-green body and red thigh markings are distinctive.
Source: Wikipedia
Life cycle
Four larval stages occur: early larvae feed externally on the paralysed roach’s hemolymph, later instars feed internally. When ready to pupate, the larva spins a thick, chocolate-coloured spindle-shaped cocoon inside the dead cockroach.
Source: Wikipedia
When you see it
Flying adults are most abundant in warm seasons, and development proceeds faster when it’s warm.
Source: Wikipedia
Where it comes from
Its native range matches its habitat: tropical Africa, South and Southeast Asia, and Pacific islands.
Source: Wikipedia
Lookalikes
Other Ampulex species show similar cockroach-paralyzing behavior.
Source: Wikipedia
Where it is found in the US
Recorded in 1 of 51 states and DC. Most records: Hawaii.
Darker = more records. Counts are museum and citizen-science records, not population size.
Source: GBIF
Status: introduced in North America; introduced in United States. Source: iNaturalist
Months it is reported in the US
Source: GBIF
More photos
Questions people ask
What does the emerald cockroach wasp look like?
It has a metallic blue-green body and red thighs on the second and third pairs of legs.
Source: Wikipedia
How big are these wasps?
Females are about 22 mm long; males are much smaller, sometimes less than half that size.
Source: Wikipedia
Where can I find them?
They occur in tropical Africa, South and Southeast Asia, and Pacific islands, especially in warm seasons.
Source: Wikipedia
Sources
- Wikipedia: https://en.wikipedia.org/wiki/Emerald_cockroach_wasp
Look it up elsewhere: GBIF · iNaturalist · BugGuide · ITIS · Wikipedia
Text written 2026-10-23 from the sources above and checked sentence by sentence against them. Data fetched 2026-10-22.