Wasp
Wasps first appeared in the fossil record in the Jurassic, and diversified into many surviving superfamilies by the Cretaceous. They are a successful and diverse group of insects with tens of thousands of described species; wasps have spread to all parts of the world except for the polar regions. The largest social wasp is the Asian giant hornet, at up to in length; among the largest solitary wasps is a group of species known as tarantula hawks, along with the giant scoliid of Indonesia ("Megascolia procer"). The smallest wasps are solitary chalcid wasps in the family Mymaridae, including the world's smallest known insect, with a body length of only , and the smallest known flying insect, only long.
Megarhyssa greenei
Megarhyssa greenei is a species of large ichneumon wasps. It is known from the United States and Canada. It is very similar in appearance to "Megarhyssa macrurus", but the latter species has a relatively longer ovipositor (about 2x the total body length, where "greenei" is only slightly greater than 1x), and usually has more extensive dark wing markings. "M. greenei also" lacks the dark striping on the face present on "M. macrurus."