Reproductive behavior of the egg parasitoidTetrastichus gallerucae(Fonscolombe) is described. Males show the same distinct behavioral pattern before and after copulation. Males were aggressive toward other males on or near parasitized egg masses. No overt female courtship behavior was observed. Males mated more than once, but females were unreceptive after a successful copulation. Oviposition and associated behavior for each female was>8 h on elm leaf beetle,Xanthogaleruca(=Pyrrhalta)luteola(Müller), egg masses of 20 eggs. Females did not show any egg guarding or external marking behavior. Possible costs of female ovipositional behavior and male guarding behavior are discussed.