Two-toned caterpillar parasite

Appearance

Body length 20mm
Two-toned caterpillar parasite is so-called because of the wasp has the two-toned body colours, black in the head and thorax with orange at the abdomen. The wasp has yellow legs and clear wings.

Naming

Synonyms
Exochilum atrichiosoma Morley, 1913
Exochilum scaposum Morley, 1913

Reproduction

This wasps attack native budworm Helicoverpa and armyworm Spodoptera caterpillars, but their larvae do not complete development until after the host caterpillar has pupated underground.
The wasp stings caterpillars at larger instars stages. After being parasitised, the host caterpillar continues to grow and pupate as normal. However, shortly after pupation, parasitoid feeds and kills the host. After the parasitoid is fully developed, it pupates within the host pupal case. The adult wasp emerges by chewing open the pupal case and exits the pupal chamber by crawling up the emergence tunnel.
In spring, the parasitoid starts developing, the wasps emerging soon after the emergence of the over-wintering Helicoverpa moths.