Anti-insectan compounds from the tropical tree family Dipterocarpaceae : final report

The project concentrated on the search for naturally occurring insecticides and other potentially useful chemicals, from tropical tree resins, as well as including training and institution-building components. Tree resins were collected in forest stands throughout Indonesia, and subjected to preliminary bioassay in the BIOTROP laboratories. Crude resins which killed termites were subjected to further fractionation and bioassay to isolate insecticidal chemicals. Samples of these chemicals were sent to the collaborating lab at Cornell for further purification and structural analysis. The research established that some of the toxic dipterocarp resins possessed known insecticidal chemicals, the most active of which were alloaromadendrene, humulene, and caryophyllene. Field trials were undertaken with a compound used to stimulate latex rubber flow to determine if it might also increase resin yields. Studies conducted in South Sumatera established that this material -- a commercial formulation containing 2- chloroethylphosphonic acid -- doubled resin yields. Studies of a defoliating forest caterpillar, a tussock moth, were carried out in South Sumatera, and in experimental forests in West Java. In addition to gathering baseline data on a potential pest species, this research resulted in the discovery of parasitic wasps which may be useful for biological control. The scientific results have implications for international development and tropical forest conservation. Tree resins may be harvested continuously with little damage to the tree; in any case the tree continues to set seed. It is possible that potentially useful chemicals harvested from tropical forest trees may have more long-term value than the wood extracted from the trees. Sustainable development, based on exploitation of the resins, would thus promote tropical forest conservation. Together with the prospect of identifying useful natural products from plants in developing countries, this idea formed the basis for an agenda for scientific action endorsed by The International Society for Chemical Ecology at its 1989 Annual Meeting in Gothenberg, Sweden. The project contributed to BlOTROP"s institutional development in several ways. First, training opportunities were provided for BIOTROP staff members working with the project. Second, technical skills relating to the laboratory work were taught, and formal instruction in computer use was provided. Indonesian students performed Master"s Degree research on topics related to the project. Fourth, commodities purchased for BIOTROP included laboratory instrumentation and equipment, a field vehicle, and computer equipment. Fifth, experience participating in international collaborations was gained, which will be important as BIOTROP seeks to expand its research activities. Finally, the project demonstrated that novel, topical scientific research can be conducted at a developing country institution working in collaboration with a U.S. university research lab. It also proved that basic scientific research in chemical ecology may stimulate tropical forest conservation. (Author abstract)