Managing attack by bark and ambrosia beetles (Coleoptera: Scolytidae) in fire-damaged Pinus plantations and salvaged logs in Queensland, Australia

Abstract

In late 1994, bushfires in the Beerburrum area north of Brisbane, in Queensland, Australia, damaged 8688 hectares of pine plantations (mostly Pinus elliotlii, P. caribaea and P. taeda). In the 4712 hectares of government-owned plantations affected, large-scale salvage operations were commenced quickly in order to minimise damage by the established exotic bark beetle Ips grandicollis Eichhoff and associated sapstaining fungi. The bark beetle began attacking fire-damaged trees 6 weeks after the fire and was significant in most areas at 10 weeks. Sapstain carried by I. grandicollis became significant at the completion of a life cycle of the insect (about 4 weeks in summer). Losses caused by I. grandicollis and sapstain following the fire were estimated at several million dollars Australian, mostly in privately-owned plantations where salvage was delayed for several months.

Salvaged timber was stored on a 49 hectare site at Beerburrum under water spray to inhibit degrade of logs by insects and fungi. Serious attack of the logs by the ambrosia beetles Xyleborus perforans (Wollaston) and Xyleborus ferrugineus (Fabricius) occurred one year after the storage commenced, and a high incidence of the decay fungus Rigidoporus lineatus (Pers.) Ryvarden was also detected in stored logs at that time. The circumstances associated with the insect attack, management options and implications for contingency planning are discussed in this paper. The main recommendations are to salvage all material within three months and store under water spray for periods no longer than six months.