EFFECT OF SIX CHEMICALS ON THE INSECTS, MITES, NEMATODES AND FUNGI ASSOCIATED WITH IPS GRANDICOLLIS (EICHHOFF) (COLEOPTERA: SCOLYTIDAE) IN NORTHEASTERN NEW SOUTH WALES

Thirty‐two species of insects, mites, nematodes and fungi were collected from brood galleries of Ips grandicollis in billets of Pinus elliottii after 30 days exposure to bark beetle infestation in northeastern New South Wales. Spray application of 6 selective biocides (pentabrite, busan 110, busan 30, lindane, dicofol and nilverm plus water as a control treatment) were used to elucidate interactions among the community associates of I. grandicollis. These interactions were: (1) the significant role of mites in spreading the fungal blue‐stain within the billet, and (2) regulatory predation of nematodes by the mite component. The nonfungicidal activity of nilverm and lindane was verified in a bioassay against I. grandicollis fungal associates on P. elliottii sapwood discs.