Excerpts from Jim Conrad's
Naturalist Newsletter
from the July 19, 2009 Newsletter, issued from the Siskiyou Mountains west of Grants Pass, Oregon:
A REALLY BIG ICHNEUMON WASP
While typing the above a winged insect flew between my face and the laptop's screen. The amazing thing about it was its size -- maybe 4-½ inches (11 cm)! The critter bumped into the window and somehow took up position on the smooth, vertical glass, as shown below:
With the awe-inspiring "stinger" at the end of its abdomen I knew that this was an ichneumon wasp. Of course that's not a stinger at all but rather a female's ovipositor used for laying eggs on, near, or inside a host's body. Upon hatching, the larval ichneumon feeds either externally or internally, eventually killing the host when it pupates.
The wasp flew out the door before I could measure it with certainty but I read that giant ichneumon wasps of the genus Megarhyssa* do reach 11 cm, counting the ovipositor. As usual, I sent the picture off to Bea in Ontario with her insect savvy and fast internet connection. Bea knew enough to be wary about IDing the ichneumon to species level. She wrote back that the superfamily Ichneumonoidea has been estimated to contain over 80,000 different species and that they are highly diverse -- ranging from 3 mm (1/8-inch) to 13 cm (5 inches) long. The best Bea could do was to find someone commenting on a picture like mine, saying "I would only GUESS tribe Ephialtini (i.e, a genus closely related to Ephialtes).