The natural enemies attacking the larvae of Trichoplusia ni (Hb.) on cotton at Urai and Londrina, Parana, Brazil, in 1979 included the fungus Nomuraea rileyi, which killed 76% of the larvae at Urai; a virus disease that killed up to 35-47% of the larvae in 2 localities near Londrina; the parasite Litomastix truncatella (Dalm.), which was reared from about 5% of the larvae at 2 of the 3 sites; Microcharops bimaculata (Ashm.), which was reared from 7.5% of the larvae at 1 site; and Entomophthora sp., which killed 2.5% of the larvae at 1 site. none