Invertebrates
Ichneumon Wasp
Ichneumonidae · also called ichneumon wasps, ichneumonid
A female ichneumon wasp lands on a dead tree trunk, unfurls an ovipositor several times longer than her own body, and drills precisely down to a beetle larva hidden deep inside the wood, guided by vibrations most creatures could never detect.
Overview
The ichneumon wasp, family Ichneumonidae, is an enormously diverse parasitoid wasp found in forest and grassland habitat across nearly every region of the world. Its extraordinarily long egg-laying ovipositor, precise host-detection ability, and status as one of the largest insect families on Earth make it one of the more remarkable and ecologically important groups of insects most people rarely notice.
A drill built for finding hidden prey
What looks like a fearsome stinger is actually a precision egg-laying tool, letting the ichneumon wasp reach hosts that would otherwise be completely safe, buried deep inside solid wood.
Status
Least Concern — widespread and abundant across suitable habitat worldwide, given the family’s enormous diversity and broad ecological tolerance.
Ichneumon Wasp: common questions
Can an ichneumon wasp sting people with its long ovipositor?
No, despite an ovipositor that can look alarmingly like an oversized stinger and sometimes reaches several times the length of the wasp's own body, the structure is used purely for laying eggs inside a hidden host insect and poses no danger to people at all.
How does a female ichneumon wasp find a host hidden inside wood?
She can detect a host insect larva buried deep inside wood by sensing vibrations or chemical cues given off by the larva, then drills precisely down to that exact location using her long, needle-like ovipositor, an impressively accurate feat of remote detection.
What happens to the host insect after an ichneumon wasp lays its egg?
The ichneumon wasp larva develops inside or attached to the host insect, gradually consuming it over time and eventually killing it, a strategy known as parasitoidism that distinguishes true parasitoids from parasites, which typically do not kill their host.
How many species of ichneumon wasp are there?
The ichneumon wasp family may include well over 100,000 species worldwide, making it one of the largest and most diverse insect families known to science, with researchers believing many additional species remain formally undescribed.