More and more people in Delhi have been discovering the wisdom of the proverb, “A closed mouth swallows no flies”. Only, it’s a different insect that’s flying into people and blanketing lights in their millions here — an immigrant pest called the Brown Plant Hopper from the rice fields of neighbouring Haryana. It’s coming to this city because it has been displaced from there. See video
GT Gujar, head of the Division of Entomology at the Indian Agricultural Research Institute, says the population of this pest has increased “300 to 400 times (higher than previous years) this year”. A single rice plant could have more than a thousand of these insects hidden inside, he says.
It used to be an agricultural menace in the 1990s but was controlled by pesticides, says TP Rajendran, Assistant Director General for Plant Protection at the Indian Council of Agricultural Research. This year, untimely rains began a chain reaction that led the Hopper population to explode.
The rains caused an increase in the population of crop pests, which made farmers use increasing amounts of insecticides like carbaryl, which ended up killing off all the natural predators of the Hopper like spiders and frogs.
The Hopper, meanwhile, turned mutant and developed immunity to the available pesticides. It then went forth and multiplied. When the rice in Rohtak and Panipat was harvested, the Hopper armies began to fly out in search of food and shelter. They rode the wind to reach Delhi.
Rajendran says they will die out in a few days. Their life span is around 30 days, and in the city, where there’s no paddy to be had, they will die sooner from starvation.