This wasp’s ovipositor, the structure at the tip of the abdomen used for laying eggs, is impressive—about two times its body length. How she wields it is quite extraordinary… after locating horntail larvae, a type of wasp larvae that bores in wood, she positions herself with back legs extended and ovipositor perpendicular to the bark, and drills into the tree to deposit an egg on or near a horntail larva within its burrow. (If you have a few minutes, we highly recommend watching the process in action.) When the egg hatches it becomes an external parasite, completely consuming the larva. It pupates within the burrow and emerges in the summer. As you can imagine, the mother is vulnerable to predation by birds while drilling and ovipositing. Long “hairs” embedded in wood tell of doomed adults. The western giant ichneumon can be found in forested regions from Newfoundland south to northern Georgia, west to Alaska & California (also introduced in Australia and New Zealand).

Photo by: Kyle Rholl on 7/18/21 Arlee, MT