Current status and potential of conservation biological control for agriculture in the developing world

Abstract

Conservation biological control (CBC), often described as the field of biological control with the greatest potential for use in developing world agriculture, has received only marginal, scattered research attention outside Western Europe or North America. As a consequence, pesticide overuse remains rampant in many cropping systems, while in others, a complete lack of safe, affordable and effective pest control options leaves farmers vulnerable in face of herbivore attack. In this study, we describe the current status of CBC research in a wide variety of agro-production systems outside North America, Australia, New Zealand, Japan and Western Europe. We summarize information on (1) a variety of CBC themes related to natural enemy biology and ecology, (2) factors that either disrupt or enhance natural enemy efficacy, and (3) field evaluation of CBC schemes. A total of 390 CBC-related literature records from 53 different crops were considered. Most records were from China, Brazil, or Cuba, while no CBC references were found from several developing countries. CBC research primarily focused on habitat management, with 71 records on general habitat manipulation and 80 records on the effects of inter-or cover-crops on natural enemy abundance or efficacy. The effects of deliberate modification of disturbance regimes, through alterations in pesticide use or tillage, on natural enemies were well-characterized in many cropping systems. For each of the CBC themes, research progress was assessed and opportunities were identified to translate current findings into practical solutions. On a crop level, most research was targeted at rice, maize and cotton. No CBC records were found for key staple crops such as yams, taro, sago or breadfruit; fruits such as papaya, pineapple and avocado; or forage crops. Also, millet, lentils, barley and plantain, all crops grown mainly in the developing world, received limited CBC research attention. CBC research has been done on myriad arthropod pests, including species with high levels of insecticide resistance such as Chilo suppressalis (Lepidoptera: Crambidae) and Helicoverpa armigera (Lepidoptera: Noctuidae). However, almost 70% of pests with high incidence of insecticide resistance have been overlooked. Lastly, we contrast country-specific CBC research advances with the national level of insecticide use and importation, and identify lucrative opportunities for countries to save funds through targeted research investment. Based upon our delineation of the current status of CBC, we indicate potential for well-orchestrated regional research projects to pursue higher levels of CBC integration into current pest management schemes. This work constitutes a first step in drawing a roadmap for developing-world research that provides local farmers with safe, low-cost means to control damaging insect pests, safeguard harvests and secure their livelihoods.