Ichneumonidae

Ichneumon wasps Temporal range: Early Cretaceous – Recent[1] PreꞒ Ꞓ O S D C P T J K Pg N
Diphyus sp., Rhône (France)
Anomaloninae, (Tanzania)
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Hymenoptera
Suborder:	Apocrita
Superfamily:	Ichneumonoidea
Family:	Ichneumonidae Latreille, 1802
Subfamilies
See below

The Ichneumonidae, also known as ichneumon wasps, ichneumonid wasps, ichneumonids, or Darwin wasps, are a family of parasitoid wasps of the insect order Hymenoptera. They are one of the most diverse groups within the Hymenoptera with roughly 25,000 species described as of 2016^[update].^[2] However, this likely represents less than a quarter of their true richness as reliable estimates are lacking, along with much of the most basic knowledge about their ecology, distribution, and evolution.^[1] It is estimated that there are more species in this family than there are species of birds and mammals combined.^[3] Ichneumonid wasps, with very few exceptions, attack the immature stages of holometabolous insects and spiders, eventually killing their hosts.^[4] They thus fulfill an important role as regulators of insect populations, both in natural and semi-natural systems, making them promising agents for biological control.^[5]

The distribution of the ichneumonids was traditionally considered an exception to the common latitudinal gradient in species diversity, since the family was thought to be at its most species-rich in the temperate zone instead of the tropics, but numerous new tropical species have now been discovered.