Insect Identification logo

Giant Ichneumon Wasp (Megarhyssa spp)

Detailing the identifying qualities of the Giant Ichneumon Wasp, including physical features and territorial reach.

 Updated: 1/27/2018; Authored By Staff Writer; Content ¬©

  Giant Ichneumon Wasp  
Picture of Ichneumon-Wasp

The intimidating female Ichneumon Wasp has a tremendously long ovipositor that is used for egg-laying, not for stinging.

There are several different species of Ichneumon Wasp, each with its own color variations. Some are black and yellow, others reddish and striped. All have the Ichneumon Wasp body shape: a thin waist and an abdomen longer than the rest of the body. Members of the family Ophion have abdomens that are shorter than Megarhyssa, but they are still long in comparison to more familiar wasps.

Females may have a long, needle-like ovipositor which is often mistaken as a stinger. The sturdy ovipositor acts like a syringe, injecting eggs deep into wood (live trees, or logs) where the larvae will feed on any other insect larvae already deposited there. It is not uncommon to see females poking around wood in an attempt to find a good place to deposit her eggs. Males do not have the ovipositor so their abdomen ('tails') are shorter. Both genders are still wasps, however, and capable of stinging if threatened.

See a female in motion here:

Giant Ichneumons tend to live in wooded areas and throughout all of North America, though they do stay away from the arid and hot desert regions and featureless plain states.

Ichneumon adults do not eat at all. Larvae are parasites of Pigeon Horntail larvae, another type of wasp that deposits eggs in wood. The Ichneumon larvae will hatch and feed on the Horntail Wasp larvae.

Variations of the Ichneumon include the Eastern Giant Ichneumon, the Lunar Giant Ichneumon and the Western Giant Ichneumon. These can all be found in their respective habitats consisting of Canada, the United States of America and Mexico. This is truly a North American insect!

Picture of the Giant Ichneumon Wasp
Picture of the Giant Ichneumon Wasp

Giant Ichneumon Wasp Information

Category: Bee, Ant, Wasp and Similar
Common Name: Giant Ichneumon Wasp
Scientific Name: Megarhyssa spp

Taxonomy Hierarchy

 Arrow graphic Kingdom: Animalia
  Arrow graphic Phylum: Arthropoda
   Arrow graphic Class: Insecta
    Arrow graphic Order: Hymenoptera
     Arrow graphic Family: Ichneumonidae
      Arrow graphic Genus: Megarhyssa
       Arrow graphic Species: spp

Size, Identifying Tags and Territorial Reach

Size (Adult, Length): Size (Adult, Length): 10 mm to 19 mm (0.39 inches to 0.741 inches)
Identifying Colors: brown; yellow; black; orange; red, white
Additional Descriptors: long, tail, stinger, stinging

North American Territorial Reach (Though Not Limited To): Alabama; Alaska; Arizona; Arkansas; California; Colorado; Connecticut; Delaware; Florida; Georgia; Hawaii; Idaho; Illinois; Indiana; Iowa; Kansas; Kentucky; Louisiana; Maine; Maryland; Massachusetts; Michigan; Minnesota; Mississippi; Missouri; Montana; Nebraska; Nevada; New Hampshire; New Jersey; New Mexico; New York; North Carolina; North Dakota; Ohio; Oklahoma; Oregon; Pennsylvania; Rhode Island; South Carolina; South Dakota; Tennessee; Texas; Utah; Vermont; Virginia; Washington; West Virginia; Wisconsin; Wyoming; Alberta; British Columbia; Manitoba; New Brunswick; Newfoundland and Labrador; Nova Scotia; Ontario; Prince Edward Island; Quebec; Sasketchewan; Mexico

A Note About Territorial Reach: Keep in mind that an insect's reach is not limited by lines drawn on a map and therefore species may appear in areas, regions and/or states beyond those listed above. Insects are driven by environmental factors, food supplies and mating patterns and do not nescessarily work within hard-and-fast territorial lines like we humans do.

Images Gallery


BugFinder: What is it?