Megarhyssa nortoni, commonly known as the giant ichneumon wasp, is a species of parasitic wasp found in North America. The females of this species can grow up to 4 inches long, making them one of the largest wasps in the region. They have a long, slender body with a black and yellow coloration, and their ovipositor, used for laying eggs, can be as long as their body. These wasps are known for their unique reproductive behavior, as they lay their eggs inside the larvae of wood-boring insects, providing a natural control for these pests.