New Delhi: Spiders and their webs have long been considered a harbinger of debt for farmers, who waste no time evicting them from their houses, sometimes with the use
of pesticides, but ICAR scientists claim the misunderstood arachnids should be considered well-wishers instead.
The Indian Council of Agricultural Research (ICAR) based the assertion on experiments conducted by scientists from the National Centre for Integrated Pest Management (NCIPM) with spiders in nine villages -- three in Uttar Pradesh, four in Haryana and two in Uttrakhand.
The study was a part of the NCIPM`s initiative to devise an economically viable and sustainable strategy of integrated pest management. The seeds of the experiment were sown around 10 years back, when the NCIPM was deluged with information about the rejection of several basmati rice export consignments due to high pesticide content.
"Basmati rice varieties like Pusa Basmati-1, Dehraduni Basmati (Type-3) and Taraori Basmati fulfill all the quality norms required for export, but due to high incidence of pests and diseases, farmers use excessive chemical pesticides and fertilisers in their quest for higher yield," said O M Bambawale, the Director of NCIPM, a research institute of the ICAR.
"This aggravates pest problems and leads to the rejection of several export consignments due to high pesticides residue," he said.
In their experiment, the NCIPM scientists introduced certain spider varieties to tackle the pest menace.
"The introduction of spiders along with other IPM techniques substantially reduced the incidence of insect pest and diseases. The results of IPM were so encouraging that farmers of all the nine villages stopped using hazardous pesticides such phorate," Bambawale said.
The farmers in the villages where the experiment was conducted were overwhelmed to find they were able to garner an additional profit of 19.70 per cent to 21.65 per cent through successful implementation of the NCIPM`s integrated pest management strategy. They have now started rearing spiders in their fields and imparting knowledge to eager farmers of nearby villages, Bambawale said.
The scientists have also developed a novel technique involving the use of straw bundles to enhance and conserve the population of spiders. This has quite effective in increasing the population of the insects.
"Earlier, farmers of these villages used to spray pesticides indiscriminately on spiders and kill them like harmful insects. But now they have been trained to identify between beneficial and harmful pests and judicious application of pesticides and fertilisers," the ICAR director said.
In all eight species of spiders have been identified for control of pests and diseases in rice fields.