Hispa Beetle runs riot as crop defence weakens

The Hispa Beetles pest has started affecting crops in Srirangapatna, Mandya district, and other places in the state big time in the recent past, say scientists. All this, thanks to global warming.

Due to global warming, many pest species are likely to become more destructive and their status may change to major pest on a particular crop. Scientists said several pests may even move to new areas as invasive ones, posing a major threat to the production of crops, causing greater yield loses in the absence of effective management practices and biocontrol agents.

“Global warming is likely to result in a pest outbreak, especially in the tropics and sub-tropics. Pest outbreaks will occur when crops are under stress with the weak defence system due to climate change. Pests benefit from reduced host defence due to stress caused by global warming,” said A K Chakravarthy, scientist, Society for Science and Technology Applications at a national seminar on climate change.

Major insect pests like fruit bores, sucking pests and pod bores may move to cooler regions, resulting in severe damage to agricultural and horticultural crops.

He said, “The global warming might even change an insect which is not a pest into a pest. Also, there is an immense effect on sex ratio of insects. Females are likely to increase in number more than males.”

The scientists said the environmental degradation led to the emergence of the new disease among monkeys and man - Kyasanur forest disease. They said the causative factors for the first emergence of the disease was attributed to deforestation, inundation of erstwhile forest areas by the construction of the Sharavathy dam and related activities.

“Areas where KFD is newly reported also possess the same perils like large-scale deforestation and conversion into plantations of cashew, coffee, arecanut and paddy fields,” said a scientist.