The Development of Blepharipa pratensis and Its Histopathological Effects on the Gypsy Moth, Lymantria dispar

The growth and development of Blepharipa pratensis (Meigen) and its histopathological effects on its host, the gypsy moth, were studied. B. pratensis eggs, consumed by gypsy moth larvae, hatched by the time they entered the midgut. Maggots penetrated the gut into the hemocoel and 20 h after ingestion were established within an intersegmental muscle of the gypsy moth larva. Histological sections made at various stages of infection showed a gradual transition in the muscle, characterized by cell proliferation and nuclear and cellular hypertrophy. Maggots spent their 1st stage in the muscle, growing very slowly until the host neared pupation. They then rapidly completed their development. There were no significant differences between mean weights of maggots in ♂ and ♀ hosts of the same developmental age.