PINK-BOLLWORM (LEPIDOPTERA, GELECHIIDAE) - EFFECT OF STEINERNEMATID NEMATODES ON LARVAL MORTALITY

Pink bollworm (PBW), Pectinophora gossypiella (Saunders), second, thir d and last stage larvae were susceptible to infection by infective juv enile nematodes, Steinernema riobravis Cabanillas, Poinar and Raulston and the Kapow nematode strain of S. carpocapsae (Weiser). Third and l ast stage PBW larvae were more susceptible than second stage larvae. T he LC(50) (1.84) for last stage PBW larvae treated with S. riobravis w as significantly less than the LC(50) (3.07) for PBW larvae with S. ca rpocapsae. S. riobravis induced higher percentages of larval mortality than S. carpocapsae in bioassay containers with 10, 50, or 100 nemato des per 10 PBW larvae and in each case at densities of 1, 5, and 10 PB W larvae per bioassay container. Small percentages (4-23) of PBW larva e were found containing infective juvenile nematodes after 1 h exposur e to either species.