Since the gypsy moth,Porthetria dispar(L.), is spreading southwestward into new environments, substantial numbers of exotic parasites of the gypsy moth are being laboratory reared for field colonization and manipulation.Rearing techniques and biology of 5 species, 1 established and 4 not yet established in the United States, are being studied at the Plant Protection Division's Methods Development Laboratory, Otis Air Force Base, Mass.