Effect of climate change on arthropod and impact on crop production

INTRODUCTION: Effect of climate change is not confined to arthropod pests and their outbreaks; beneficial arthropods are also affected. Therefore, an attempt has been made to include effect of global warming on four beneficial arthropods viz., insects, mites, ticks and, spiders. Global warming is a great concern throughout the world. The ill effects of global warming like change in climate, temperature, rainfall, humidity, level of carbon dioxide have been found to have both positive and negative effects on insects, which in turn reduces the effectiveness of crop protection measures. Effect on human animal health is no exception. This creates the need for global warming to be taken as an important criterion in Entomology. Being poikilothermic in nature insects are greatly affected by changing temperature.

The major cause of climate change is the increase in the concentration of greenhouse gases (GHG) viz., carbon dioxide (CO2), methane (CH4) and nitrous oxide (NO2) as a result of human activities from pre-industrial era. These gases keep the earth warm and cause global warming or greenhouse effect. Global warming is caused by natural factors as well as human activities. There are number of natural factors responsible for climate change. Some of the most prominent are volcanoes, ocean currents, forest fire etc. Among human activities, emissions of greenhouse gases, industrialization, deforestation, fuel burning, etc. are the most important factors contributing to global warming. It is not new that global warming can affect agriculture through their direct and indirect effects on crops, soils, pests, livestock and fish. Changes in climatic factors affect crops in various ways through ineffective pollination, salinity, drought, crop sterility, submergence, flash floods, plant mortality through inappropriate temperature level, hot air flush, cyclone, hailstorm etc. Climate change affects the biology of insects, spiders and mites.

Global climate changes have significant impacts on agriculture and also on agricultural insect pests. Agricultural crops and their corresponding pests are irectly and indirectly affected by climate change. Direct impacts are on pests’ reproduction, development, survival and dispersal, whereas indirectly the climate change affects the relationships between pests, their environment and other insect species such as natural enemies, competitors, vectors and mutualisms. Insects are poikilothermic organisms; the temperature of their body depends on the temperature of the environment. Thus, temperature is probably the most important environmental factor affecting insect behavior, distribution, development and reproduction.

Therefore, farmers can expect to face new and intense pest problems in the coming years due to the changing climate. The spread of crop pests across physical and political boundaries threatens food security which is a global problem common to all countries and regions. Effects of different climatic factor on several aspects of insects, their natural enemies, insecticides, biopesticides and overall impact on crop production and food security are described here starting with effects on some beneficial and commonly known arthropods.