Pair of Megarhyssa atrata ovipositing in the trunk of a dead boxelder tree. Several (4 to 6) wasps were ovipositing on the same tree. The week before I had witnessed one "hatching," but I did not realize what I was seeing at the time, and I failed to take a picture. Does anyone know how long the gestation period is? Perhaps I can catch the new batch when they hatch.