Scenario of climate change impact on insect pests in India

Abstract

The climate change has been intensified the risk of climate dependent crop production. Increase in temperature can reduce crop duration, increase crop respiration rates, alter photosynthesis process and affect the survival and proliferation of pest populations. The importance of climate and weather events to the distribution of insects and their population dynamics has long been recognized. Insects are poikilothermic in nature and are directly under the control of temperature for their growth. The duration of insect life cycle is altered under increased temperature and elevated carbon dioxide concentrations resulting in variable number of generations per year. The elevated carbon dioxide concentrations are mediated through enhanced photosynthesis in plants for phytophagous insects’ growth and development. Several insect pests, that were important in the past or the minor pests are likely to become more devastating with global warming and climate change. Insect pests cause an estimated annual loss of 13.6% globally and 23.3% in India. Losses due to insect pests are likely to increase as a result of change in crop diversity and climate change. An increase of 0.4ºC average surface temperature over past century in India has led to crop insect pests losses increase from 3.0% during the pre-green revolution period to 50% during the post-green revolution period. The changes of insect pests losses has been increased up to 32%. Considerable knowledge is available on the effects of weather and climatic events on insect pests in India. But concerned to the impact of climate change on insect pests studies are in lag phase. A major portion of the cultivated areas of India covered under rainfed. The rainfed agriculture is directly reciprocal to the climate. So, any changes in the state of climate may cause crop failure due to biotic and abiotic stresses of climatic vagaries. Therefore, detailed study of the climate change scenario, its impact on insect pest management and formulation of coping strategies are of paramount importance to reduce the risk of crop failure. This paper attempt to analyse the review of reported studies on the scenario of climate change impact on insect pests in India to reduce the risk of strategy for effective insect pest management.