Impact of Climate Change on Pests and Diseases of Tea

摘要

The global climate has always been subjected to natural changes and plant and animal species had adapted to these changes. But the global warming observed in the latter half of the 20th century is largely due to anthropogenic factors. Crop plants willbe affected by climate change and also the several insect species which have close association with plants as pollinators and pests. While the increase in temperature directly affects the insects' physiology and life history, they are also influenced bythe changes in the quality of their host plants, which again is affected by the climate change. Insects respond to the increase in temperature in different ways. Their reproductive potential, feedings rate, number of annual generations, distribution pattern, duration of developmental stages, migration etc are influenced by temperature. The elevated level of C0_2 will influence the plants' physiology, especially photosynthesis. The plants' carbon to nitrogen ratio will be affected, leading to higher carbon content, compelling the insects to consume more plant material to get sufficient nitrogen! Entomologists have made detailed studies on the impact of weather factors such as rainfall and temperature on the incidence and abundance of several insect pests of crop plants. Obviously, climate change will affect the pest status of many insect species and insects' role as pollinators. Of greater concern is the impact on species like mosquitoes which are vectors of diseases like malaria, filariasis, dengue,chikungunya etc.