VISAKHAPATNAM: A report by the Intergovernmental Panel on Climate Change (IPCC) indicated that global warming and rising temperatures could cause an increase in the population of insects around the world. Temperature is crucial in regulating insects’ physiology and metabolic rates. As temperatures rise, the physiological activity of insects increases, and they need to consume more food to survive. This is expected to lead to an increase in the growth rate of insect herbivores, which could cause more crop damage. Additionally, because insects that grow faster tend to reproduce more, their population is likely to multiply rapidly.
Addressing this, L Rajesh Chowdary, a scientist in entomology at the Agricultural Research Station in Darsi, in a conversation with TNIE, said, “It is worth noting that the relationship between temperature and the insect population is complex and not entirely predictable. Some species of insects may be negatively affected by rising temperatures, while others may benefit from the changes. Furthermore, the impact of climate change on the insect population is likely to vary depending on the region and ecosystem in question. But the concern is that usage of pesticides will increase if the pest population keeps increasing, keeping product quality and health at stake.”
Being the major crops sown in Andhra Pradesh, paddy, cotton and chilli have been attacked by pests a lot in the last few years. Despite this, farmers have shown little concern about these pests. They traditionally only sprayed insecticides on significant pests such as the brown planthopper and rice stem borer, which substantially threaten paddy. However, recently, farmers have started showing concern about the gall midge and leaf folder, as they have become more prevalent and are now a significant threat to the crop.
Pink bollworm has significantly threatened cotton fields since 2014-15. “Despite farmers’ efforts to control the pest using several pesticides, the frequency of its attacks remains unchanged. This could be attributed to increased cotton cultivation even during non-seasons like summer (February, March, April), when it was only grown earlier during the kharif season (June, July, August). The pests that survive in the kharif season crop continue to multiply during the non-season crop. Thus, we often advise farmers not to cultivate cotton during summer,” Rajesh explained.
“One of the primary reasons for the insect and pest population surge is farmers’ failure to follow the recommended intervals between pesticide applications. Ideally, a minimum of 7-8 days must pass between pesticide sprays. New-generation pesticide molecules can control the pest population for 8-10 days, so adhering to the recommended interval is crucial. However, farmers often expect immediate results and reduce the application interval, causing insects to develop resistance. As a result, even new-generation molecule pesticides available on the market may not be effective on crops,” he added.