Bug FAQHornworm Parasitoid Wasp Complex
Cotesia congregata · Order: Hymenoptera · Family: Braconidae
Also called: Hornworm Parasitoid Wasp, Tomato Hornworm Parasite Wasp, Tomato Hornworm Parasitoid Wasp
Cotesia congregata is a parasitoid wasp in the genus Cotesia, which uses polydnaviruses to help its offspring develop. Females lay eggs inside tobacco and tomato hornworm caterpillars; the larvae grow inside the host and later emerge to spin cocoons, with adults appearing a few days after.
Source: Wikipedia
How to recognize it
Cotesia congregata belongs to the wasp genus Cotesia, a group noted for employing polydnaviruses.
Source: Wikipedia
Does it bite or sting?
Parasitoids ultimately kill or sterilize their hosts.
Source: Wikipedia
Where it lives
These wasps live where their host caterpillars occur and they inject venom together with eggs and virus particles into the host.
Source: Wikipedia
Life cycle
After hatching inside the caterpillar, the wasp larvae molt twice, emerge after 12 to 16 days, spin cocoons, and the adult wasps emerge four to eight days later.
Source: Wikipedia
Lookalikes
Other species in the genus Cotesia also rely on polydnaviruses.
Source: Wikipedia
Where it is found in the US
Recorded in 40 of 51 states and DC. Most records: Virginia, North Carolina, Pennsylvania, Illinois, Maryland, Ohio, Missouri, Kansas.
Darker = more records. Counts are museum and citizen-science records, not population size.
Source: GBIF
Months it is reported in the US
Source: GBIF
More photos
Questions people ask
What caterpillars does Cotesia congregata parasitize?
It targets tobacco hornworm and tomato hornworm larvae, laying its eggs inside them during their second or third instar.
Source: Wikipedia
How does the wasp develop inside its host?
The larvae develop inside the caterpillar’s hemocoel, molt twice, emerge after about two weeks, spin cocoons, and the adults emerge a few days later.
Source: Wikipedia
Same family (Braconidae)
Sources
- Wikipedia: https://en.wikipedia.org/wiki/Cotesia_congregata
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 2026-10-23.