‘Beneficial insects such as the spider, ground beetle, wasp, destroy pests’.
Want to get rid of pests from crops without using pesticides? Don’t kill beneficial insects — even though you may find them scary or repulsive — because they are actually your crop’s best friends.
This is the new thinking that the state government is now promoting among farmers across the State, training them in as many as 150 villages under the Integrated Pest Management (IPM) programme originally conceived by Food and Agriculture Organisation (FAO). The logic is simple: pests feeds only on plants, whereas the beneficial insects — such as the spider, ground beetle, wasp, assassin bug and damsel bug — destroy the pests. By using pesticides, you only end up killing the enemies of the pest.
“Under IPM, a farmer can harvest, say, six quintal of cotton from one acre. This yield may double if pesticides and fertilisers are used, but when you take into account the input cost, the six quintals achieved through IPM is not only profitable but also environment friendly,” explained N. Selvam, a senior agriculture officer and entomologist who is training the farmers.
“The beneficial insects either feed on the pest or lay eggs in the body of larvae or eggs of pests and in the process break their life cycle,” he said pointing out that though cotton was cultivated only five percent of the total cultivable land in the country, 50 per cent of pesticides manufactured in the country was used to control pest in the crop.
“Many farmers are not aware that pests have four cycles — egg, larvae, pupa and adult — and pesticides mainly target adult and larvae and the insect in other two stages. It results in a virulent pest that is resistant to pesticides,” he said. Mr. Selvam, who has written and lectured extensively on IPM and has visited China, Malaysia, Philippines, Tajikistan, Mozambique and Tanzania in connection with his training programme, said pesticides should be the last resort as they proved extremely harmful to humans.
“Paul Muller invented mosquito repellent in 1939 and it has not eradicated mosquitoes. On the other hand the insect has developed resistance to 250 insecticides over the years,” he said.
As part of IPM, farmers are encouraged to plant inter-crops, border crops and trap plants. “They attract beneficial insects. We can gradually reduce pesticides and switch over to natural farming in five years,” Mr. Selvam said.