The sexual behavior of five eumenid wasp species is described. This behavior differs sharply between species, and there is considerable within-species variation. Pairs of Ancistrocerus antilope remained together for 0.5-4 h and copulated one to four times. Pairs of A. adiabatus, A. catskill, and Euodynerus foraminatus came together, copulated once, and separated within 1-2 min. Pairs of Parancistrocerus pensylvanicus joined, and copulated once within about one min; but remained together for about 12 min and engaged in an elaborate postcopulatory behavior before separating.