Biological Control of Lepidopteran Pests in Rice: A Multi-Nation Case Study From Asia

Abstract

Abstract We provide a case study where Integrated Pest Management (IPM) for rice production systems has been introduced to the Greater Mekong Subregion (GMS). Funded by the European Union (EU), this IPM initiative brought together local and international partners to develop an environmentally friendly and economically sustainable rice pest management strategy for southwestern China, Laos, and Myanmar. A key component of the strategy was to establish 12 Trichogramma spp. rearing facilities (TRFs) that mainly targeted rice stem borers. Four TRFs were established in each of the participating countries. The most promising strains of Trichogramma chilonis (Ishii) and T. japonicus (Ashmead) were selected for production in the TRFs based on extensive field surveys as well as laboratory and field release studies. The project also considered the potential for Trichogramma spp. of each strain to withstand the high temperatures expected under a changing climate. Implementation of the IPM strategy resulted in higher rice yields (2–10%), an increase in natural enemy abundance (e.g., twice as many spiders), and a reduction in insecticide applications (1.5 fewer applications). During a capacity-building program, IPM practices with strong cultural and biological control-based components were promoted among ca 50 IPM trainers and ca 6,400 rice farmers. This case study indicates the potential successes of advanced biological control-based IPM systems. We believe that these systems merit wider consideration, including adaptations for other regions and crops.