Oil palm is the second most important cash crop in Papua New Guinea, and in 1995 its export value was US$128 million. The principal pests of oil palm in Papua New Guinea (PNG) are Tettigoniidae (Orthoptera), which cause damage by defoliating the oil palm tree. This defoliation causes reduction in photosynthesis and fruit production, resulting in yield losses. Control of these pests is currently reliant upon the use of trunk-injected monocrotophos. Because of difficult application methods, poor monitoring procedures, and environmental constraints, chemical control usually occurs far too late to prevent significant yield losses. Furthermore, the application of chemicals is expensive and environmentally undesirable. This paper decribes the first phase of a project to develop the use of the strepsipteran parasitoid, Stichotrema dallatorreanum Hofeneder as a novel tool for use in an integrated pest management system. This strepsipteran is found parasitizing two species of Tettigoniidae in mainland PNG, but not in West New Britain, where most pest damage occurs. Field studies have been conducted in PNG, and laboratory studies in Oxford, to elucidate the nature of the host-parasite relationship, and particularly to determine whether parasitism reduces the pest status of the host, and to assess the feasibility of introducing this parasitoid into new areas as a biocontrol agent. The preliminary findings of these studies are presented in this paper.
