Adult length about 7 mm.
Fine-art photographic collection
Ischnus inquisitorius
A seven-millimetre parasitoid that drills through a leaf and cocoon to reach a hidden moth pupa it cannot see.
About this species
Ischnus inquisitorius(Müller, 1776)
Information reviewed15 July 2026
Ischnus inquisitorius is an ichneumon wasp that attacks tortricid moth pupae. A female detects a concealed host through plant tissue and inserts an egg through the leaf and cocoon; the larva then develops externally on the pupa inside the shelter.
Taxonomy
Animalia · Arthropoda · Insecta · Hymenoptera · Ichneumonidae · Ischnus
Accepted taxon. · checked 2026-07-15
Europe and temperate western AsiaBroad range and selected reference localities — not a complete occurrence map.
Europe and temperate western Asia
Woodland, hedgerows and other habitats containing leaf-rolling tortricid moths.
Diurnal in the warmer months.
Adults take nectar; larvae are ectoparasitoids of moth pupae.
Solitary.
What makes this species remarkable?
The female can locate a moth pupa hidden inside a rolled leaf, then thread her ovipositor through both leaf and cocoon without seeing the target.
The wasp larva develops as an ectoparasitoid on the outside of the pupa but remains enclosed within the host’s own shelter.
In 2025 the species received a chromosome-level genome assembly, bringing modern genomics to an insect only about seven millimetres long.