Strepsiptera parasites - novel biocontrol tools for oil palm integrated pest management in Papua New Guinea (vol 44, pg 127, 1998)

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 damag e by defoliating the oil palm tree. This defoliation causes reduction in ph otosynthesis and fruit production, resulting in yield losses. Control of th ese 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 chemical s is expensive and environmentally undesirable. This paper decribes the fir st phase of a project to develop the use of the strepsipteran parasitoid, S tichotrema dallatorreanum Hofeneder as a novel tool for use in an integrate d pest management system. This strepsipteran is found parasitizing two spec ies of Tettigoniidae in mainland PNG, but not in West New Britain, where mo st pest damage occurs. Field studies have been conducted in PNG, and labora tory studies in Oxford, to elucidate the nature of the host-parasite relati onship, and particularly to determine whether parasitism reduces the pest s tatus of the host, and to assess the feasibility of introducing this parasi toid into new areas as a biocontrol agent. The preliminary findings of thes e studies are presented in this paper.