Insect Pests of Cotton Crop and Management Under Climate Change Scenarios

Abstract

Insects comprise the largest group of animal kingdom and play vital role in providing various ecosystem services. Some of these tiny creatures serve as notorious and serious pests of crops including cotton. Cotton is an important fibre crop which being succulent, is observed to be attacked by various chewing and sucking insects. Due to anthropogenic activities, climate on the earth is being chaged since last century that leads to global warming. Under this situation of climate change, abiotic factors like temperature, humidity, rainfall and atmospheric gases (especially CO2), and biotic factors like parasites, predators, competition are dominant factors that govern population dynamics and proliferation of insect pests of cotton. Insects being poikilothermic in nature have temperature of their bodies is approximately the same as that of the environment. Therefore, the developmental rates of their life stages are strongly dependent on temperature. So with the increase in temperature, almost all insects are affected to some degrees by changes in temperature due to global warming and there may be multiple effects upon insect life histories. These effects exert impact on crop insect pests’ populations in several complex ways like extension of geographical range, increased over-wintering, changes in population growth rate, increased number of generations, extension of developmental season, changes in interspecific interactions, changes in crop pest synchrony, increased risks of invasions by migrant pests, introduction of alternative hosts and over-wintering hosts. The various methods such as culturals, physicals, biologicals, botanicals, entomopathogenic fungi and synthetic chemicals are adopted by farmers and researchers at national and international level to control pest population. Among all above mentioned methods, the main emphasis in insect pest management in cotton crop is use of synthetic pesticieds. These are although cheap, effective and having faster action but have much side effects like environmental pollution and health hazards due to their penetration in food chain. Due to excessive and non-judicious use of these chemicals on high infestation of cotton pests, resistance and resurgence of these pests are now being recorded as more serious. Such situation leads in integration of all possible alternate measures like resistant cultivars, GMOs, genetic controls, use of biocontrol agents, use of biopesticides, use of insect pheromones and many others for effective control. So, effects of climate change on insect pests of cotton crop and management tectics in this scenario are being reviewed in this chapter that will provide a ready reference for policy makers and researchers to improve management practices of cotton pests in various geographical areas, in ecofriendly and efficient way.