The management of diamondback moth and other crucifer pests Proceedings of the 4th International Workshop, Nov. 2001, Melbourne, Australia 381 Ecological impact of Brassica IPM implementation in Indonesia S. Sastrosiswojo, W. Setiawati, L. Prabaningrum, T.K. Moekasan, I. Sulastrini, R.E. Soeriaatmadja and Z. Abidin Research Institute for Vegetables (RIV), Jl. Tangkuban Perahu No. 517, Lembang, Bandung 40391, Indonesia Abstract In Indonesia, Brassica vegetables such as cabbage and Chinese cabbage are heavily infested with diamondback moth (DBM), Plutella xylostella (L.) and sometimes with cabbage head caterpillar (CHC), Crocidolomia binotalis (Zeller). Diadegma semiclausum Hellén is the most important larval parasitoid of DBM and becomes a key component of IPM programs on DBM. In 1999, studies were conducted at Lembang (RIV) and at Pangalengan in West Java to observe the ecological impact of IPM implementation versus a conventional pest management system on cabbage, using a paired treatment comparison. The faunal diversity in sweep net samples was higher in the IPM system compared with the conventional system (expressed by D values: 0.83 at Lembang and 0.59 at Pangalengan). The population of D. semiclausum increased in the IPM system by 34% at Lembang and 53% at Pangalengan. The abundance of soil dwelling predators (Coleoptera, Araneida, Hemiptera and Orthoptera) in the IPM system at Lembang and Pangalengan, increased by 84% and 68% respectively. Two species of soil microorganisms known as important biological control agents, namely Trichoderma sp. and Bacillus sp., were higher in the IPM system. IPM implementation on cabbage was superior to the conventional system in terms of (i) reduction of costs for insecticide usage by 79% at Lembang and 64% at Pangalengan and (ii) increase in marketable yield by 57% at Lembang and 19% at Pangalengan in the IPM system. Keywords cabbage, faunal diversity, Plutella xylostella, Crocidolomia pavonana, Diadegma semiclausum Introduction The Food and Agriculture Organization of the United Nations (FAO) (1989) defines sustainable agriculture and rural development as: “The management and conservation of the natural resource base, and the orientation of technological and institutional change in such a manner as to ensure the attainment and continued satisfaction of human needs for present and future generations. Such sustainable development conserves land, water, plant and animal genetic resources, in an environmentally, non-degrading, technically appropriate, economically viable and socially acceptable manner.” The definition stresses that management of resources can meet the human needs without destroying environment and should enhance the quality of the environment. “Sustainable farming system” has become a popular term and is a most important issue in the field of agriculture to those people who have an interest in agricultural sustainability and who are concerned about conventional farming systems that rely heavily on synthetic chemicals and other off-farm inputs (Untung 1995). The problems associated with conventional farming practices are now widely recognised and include pest resistance to pesticides, the problem of pesticide residues in food, human and environmental hazards and harmful side effects for beneficial insects (Sastrosiswojo 1996b). Arthropod biodiversity is an important component in the development of sustainable agriculture because of its role in maintaining soil fertility, crop pollination and control of arthropod pests (Sosromarsono & Untung 2001). Biodiversity forms an important part of an agroecosystem that includes both the living organisms and non-living components that interact within cultivated fields (Ooi 1997). Overcoming the problems created by conventional farming systems has been by the implementation of integrated pest management (IPM), which is also considered as part of a sustainable farming system (Untung 1995). The general objective of IPM programs has been the development of improved ecologically- oriented pest management systems that optimise, on a long term basis, costs and benefits of crop protection (Huffaker & Smith 1980).