Ichneumon wasp - unnamed 3

This wasp is a parasite of Ermine moths in Britain.

Species introduction

At a glance
Latin name: 
Hepiopelmus variegatorius
Family: 
Ichneumon wasps
Family Latin name: 
ICHNEUMONIDAE
Category: 
Insects other

Species description

Species description

This wasp is a parasite of Ermine moths in Britain. The females do this with their ovipositor, depositing eggs inside their caterpillars. These hatch inside the living host, devouring it until the wasps pupate. Adult wasps of this species are about 14 millimetres long. The arrangement of the yellow and black markings are key to identifying this wasp to the species level, the yellow horseshoe shape behind the creature's head being especially diagnostic. It is not known how widespread this insect is in Britain. The one shown here was photographed in the cemetery in mid-August 2023.

Species photographs

Larger photograph(s) (click to magnify)

Details

Species family information

Ichneumon wasps are a family of 'parasitoids' that usually attack the caterpillars of butterflies and moths (and other insects and spiders). Unlike social wasps, these parasites are solitary. Although they share the characteristic 'wasp waist' with their social wasp cousins, the ichneumons are generally long and thin, having notably long antennae (usually with 16 segments, compared to the 13 or less of other wasps). If you are lucky enough to see these flighty insects, you may notice their antennae moving rapidly from side to side, indicating that they are probably hunting for prey using a 'stereo-smell' function that enables them to locate prey using olfactory information detected by receptor neurons in their antennae.

Category information

Insects evolved in the Ordovician from a crustacean ancestral lineage as terrestrial invertebrates with six legs (the Hexapoda). This was the time when terrestrial plants first appeared. In the Devonian some insects developed wings and flight, the first animals to do so. An early flying group was the Odonata from the Carboniferous, the damselflies and dragonflies, which have densely-veined wings and long, ten-segmented bodies. They are day-flying carnivores, with an aquatic larval stage, so are commonly seen flying near water. The carnivorous larvae are called nymphs. Odonata species are short-lived, damselflies surviving for 2-4 weeks, dragonflies for up to 2 months.

Some insect groups in the Cretaceous co-evolved with the flowering plants, and they have had a close association ever since. These groups are the Hymenoptera (bees, wasps, and ants), the Lepidoptera (butterflies and moths), the Diptera (flies), and the Coleoptera (beetles). The diversity of beetles is astonishing. Of all the known animal species on the planet, one in five is a beetle!