Series of Megarhyssa macrurus (?) ovipositing on dead tree. There seemed to be two males and one female - the males primarily black in color, the one female brown and yellow. Males went back and forth, walking over the female. Several occasions of drawing the tail and/or ovipostior into the bubble, from both sexes. Wondering if the reproduction is separate, i.e., males deposit, then females deposit or vice versa.