The Ichneumon wasp reference article from the English Wikipedia on 24-Jul-2004
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Ichneumon wasp

Helping orphans the way you would do it

Ichneumon wasps
Ichneumon wasp image
Ichneumon wasp: body size about 20mm
Scientific classification
Kingdom:Animalia
Phylum:Arthropoda
Subphylum:Hexapoda
Class:Insecta
Subclass:Pterygota
Infraclass:Neoptera
Superorder:Endopterygota
Order:Hymenoptera
Suborder:Apocrita
Superfamily:Ichneumonoidea
Families
  Braconidae
  Ichneumonidae


Ref. research.amnh.org 2004-01-15
Ichneumon wasps are insects classified in the parasitica group of the Suborder Apocrita, within the Order Hymenoptera. Sometimes incorrectly called Ichneumon flies, they are solitary insects, most are parasitoids - the larvae feeding on or in another insect which finally dies. As with all hymenopterans, Ichneumons are closely related to ants and bees.

The Superfamily Ichneumonoidea (consisting of two families: The Ichneumonidae and the Braconidae) has been estimated to contain well over 80,000 different species. Some members use many different insects as a host, others are very specific in host choice. Various Ichneumons are used successfully as biological control agents in controlling pests such as flies or beetles.

Ichneumon wasp image

Ichneumon wasp attacking a case moth caterpillar pupa

Ichneumon species are highly diverse - ranging from 1/8-inch to 5 inches long. Most are slender, with many species having an extremely long ovipositor for laying eggs. The female finds a host and lays an egg on, near, or inside of the host's body. Upon hatching, the larval Ichneumon feeds either externally or internally, killing the host when they themselves are ready to pupate.

Members of the (usually larger) Ichneumonidae are distinguished from the Braconidae by observing wing structures.

Ichneumon wasp image
IchneumonWasp: body size about 15mm



References:
http://eny3005.ifas.ufl.edu/lab1/Hymenoptera/Ichneumonid.htm
http://www.inhs.uiuc.edu/chf/outreach/good/card22.htm

See also:

An interesting account of an observer's encounter with Ichneumons.