Propagation of Horogenes molestae, an Asiatic Parasite of the Oriental Fruit Moth, on the Potato Tuberworm

Abstract

.-An attempt was made in 1949 to expedite the propagation of H. molestae. a valuable Japanese parasite of the oriental fruit moth, Grapholitha molesta, by breeding it on an alien host, the potato tuberworm, Gnorimoschema operculella. At first the propagating rate in this host was much too low for practical use. However, the parasite was induced to parasitize tuberworm larvae, first by mixing them with oriental fruit moth larvae along the cut surfaces of halves of apple pinned to halves of potato, then by spraying infested potatoes with extracts of the oriental fruit moth. After breeding continuously about 39 generations on the tuberworm, a strain was segregated which is readily propagated on it without the use of attractants.