Climate Change Effects on Insects: Implications for Crop Protection and Food Security

Abstract

Global warming and climate change will trigger major changes in diversity and abundance of arthropods, geographical distribution of insect pests, insect population dynamics, insect biotypes, herbivore-plant interactions, activity and abundance of natural enemies, species extinction, and efficacy of crop protection technologies. Changes in geographical range and insect abundance will increase the extent of crop losses and, thus, will have a major bearing on crop production and food security. Distribution of insect pests will also be influenced by the changes in cropping patterns triggered by climate change. Major insect pests, such as cereal stem borers ( Chilo, Sesamia, and Scirpophaga), pod borers (Helicoverpa, Maruca, and Spodoptera), aphids, and whiteflies may move to temperate regions, leading to greater damage in cereals, grain legumes, vegetables, and fruit crops. Host-plant resistance, biopesticides, natural enemies, and synthetic chemicals are some of the potential options for integrated pest management. However, the relative efficacy of many of these pest control measures is likely to change as a result of global warming. Climate change will also result in increased problems with insect-transmitted diseases. These changes will have major implications for crop protection and food security, particularly in developing countries where the need to increase and sustain food This article was modified and updated from "Climate Change Effects on Insects: Implications for Crop Protection and Food Security" (Chapter 12) in Combating Climate Change: An Agricultural Perspective, edited by Manjit S. Kang and Surinder S. Banga.

Impact of climate change on insect pests, plant chemical ecology, tritrophic interactions and food production

“…Early onset of infestation by H. armigera in cotton and pulses in Northern India is one such example [8,21]. Lower foliar nitrogen due to elevated CO 2 causes an increase in food consumption by the herbivores up to 40 percent, and unusually severe drought appears to cause herbivore populations to explode [43,44].…”

“…The majority of insects are benign to agro-ecosystems, and there is much evidence to suggest that this is due to population control through interspecific interactions among pests and their natural enemies-pathogens, parasites and predators [7,8,35,53]. Oriental armyworm (Mythimna separate Walker) populations increase when extended periods of drought (which is detrimental to the natural enemies) are followed by heavy rainfall [54].…”

“…Plant physiological processes directly respond to the various climatic factors such as air and soil temperature, solar radiation, precipitation, relative humidity and wind speed [2,3]. Climate change exerts maximum influence on pests, diseases and weeds [2,[4][5][6][7][8].…”

“…Climate change can have a remarkable effect on the incidence and intensity of pest populations [8,15]. Climate change can lead to higher densities of Helicoverpa armigera (Hub.)…”

Biological Consequences of Climate Change on Arthropod Biodiversity and Pest Management

“…Global warm ing will lead to earlier infestation by H elicoverpa arm ig era (Hub.) in North India (Sharma 2010), resulting in increased crop loss. An increase of 1 and 2°C in tem perature w ill cause northw ard sh ifts in the potential distribution of the European corn borer, O strinia nubilalis (Hub.)…”