Changing trends in cotton pest management

The cotton crop sustains more insects than any other crop grown commercially world-wide. Any single insecticidal intervention to control a particular pest invariably sets up a chain reaction causing short-term imbalances in the ecosystem, mostly in favour of the pest in the long run. Thus over the years, insecticide use was establishing undesirable ecological and economic consequences for cotton cultivators and administrators in many countries. Individual insecticide molecules when first introduced have always been impressive in their rapid efficacy in controlling target insect pests. As long the target pests are effectively controlled with the pesticide, cultivators do not care for the naturally occurring predators and parasites in their ecosystems. Unfortunately almost all the insecticides have inadvertent adverse effects on naturally occurring beneficial insects. However, phytophagous target pests usually develop resistance much faster than entomophages, thereby causing pest populations to survive the pesticide, increase in numbers in the absence of natural control, and so generate outbreaks. The cotton crop has been subjected to more pesticide exposure than any other crop, in all cotton growing countries of the world. Intense insecticide use has resulted in insect resistance to insecticides, pesticide residues, and the resurgence of minor pests causing immense problems to cultivators. With the most reliable tools turning redundant, pest management experts started exploring the utility of naturally occurring pest control components as alternatives to replace the chemical insecticides. Thus, Integrated Pest Management (IPM) programs began to take shape as ‘intelligent selection and use of pest management tactics which results in favorable ecological, sociological and environmental consequences’ as defined by Rabb (1972). Insecticide Resistance Management (IRM) strategies have strengthened pest management systems by identifying appropriate insecticides, rates and timings so as to delay resistance, ensure effective control of target pests, and conserve naturally occurring biological control for enhanced sustainability of ecosystems. With the recent introduction of Bt-cotton, novel eco-friendly pesticides and IRM strategies, coupled with the trends in technology dissemination through area-wide farmer participatory approaches and farmer field schools, IPM programs all over the world have improved their sustainability and economic success