CLIMATE CHANGE/PEST
PESTICIDES OF THE LAST RESORT
Organophosphates used by states to kill locusts are known to leech into waterbodies and harm the ecosystem
Organophosphates,such as chlorpyrifos,malathion and fenitrothion,are a group of chemicals developed as human nerve agents by the Nazis and were later adapted as insecticides.These are known to leech into waterbodies close to agricultural fields. This varied exposure from different sources leads to bio accumulation in our bodies too.
“It is inevitable that migratory birds arriving in Rajasthan will die in the coming season because these organophosphates would have leeched into water bodies,”says Madan Mohan, associate professor at Agriculture University, Jodhpur.
The Food and Agriculture Organization recommends 10 types of chemicals (divided into three categories) to be used for controlling locust.Of these,organophosphates are pesticides of the last resort. The first category is of mycoinsecticides, such as metarhizium acridum.These have low risk for non-target organisms,such as birds and reptiles which ingest the treated locusts.The second priority category is Insect Growth Regulators,such as diflubenzuron,teflubenzuron and triflumuron.These have very low human toxicity and are less hazardous in comparison to neurotoxic insecticides.They do have some adverse effects on certain non-target organisms,especially aquatic arthropods.“The first two categories would be effective if we have early locust infestations detection in place.But this time we acted late and ended up using these hazardous but effective organophosphates,”says Chandrashekhar Sharma,a Jodhpur-based scientist trained in controlling locusts.Chlorpyrifos,he explains,kills 50 per cent of its targeted pest within three hours. The remaining get paralysed or unconscious and die within the hour.
say media reports. Pakistan farmers’ advocacy organisation Sindh Abadgar Board has urged the government to ask for international help because they are unable to meet this crisis.
In India, officials and leaders have blamed Pakistan for the attacks. On January 7, the Union agriculture state minister Kailash Choudhary, who represents the Barmer-Jaisalmer constituency, visited Rajasthan and accused Pakistan for the locusts. “Locusts attack our side because the people on the other side of the border do not handle them properly,” agrees J P Singh, joint director, LWO.
The swarms that had crossed the Persian Gulf to reach Africa caused damage in Eritrea, Ethiopia, Somalia, Sudan from October to December 2019. On December
2, Djibouti received two years’ rain in a day, further providing suitable breeding conditions. In January 2020, swarms also attacked Kenya.
COUNTER MEASURES
Since swarms move across borders, they cannot be dealt with without international cooperation. For instance, before the Iran Revolution in 1979, Pakistan and Iran took joint actions against locusts in April, but the practice ended. It was revived in mid 1990s with the help of FAO, says Keith Cressman, senior locust forecasting officer with FAO. “There should be a meeting between India and Pakistan every month to manage locust attacks,” agrees Jat.
But even after there is information, dealing with locusts is difficult because they move with the wind and there is no certainty where they will attack. What can be done is to monitor the possible regions and spray pesticides if there is a known swarm resting at night. Locusts only fly and eat during the day. Since they lay eggs in moist soil at a depth of 10 cm, the areas where they were seen but have moved on must also be sprayed on as soon as possible.
“In September and October, Rajasthan asked the Centre to undertake aerial sprays to check locust attacks, but we advised the government against the move because the people are no longer living in clusters, and have spread out, even living in fields,” Gujjar told DTE. “The spray could have harmed them.”
During a tour to Jaisalmer on January 5, Rajasthan’s revenue minister, Harish Chaudhary, accepted that the Centre and state governments had failed in their duty, but farmers had saved the day by dealing with the raiders. Still Rajasthan has lost 60 per cent of its cumin, estimates Dilip Singh, who works with a Barmerbased spice manufacturing company. Rajasthan produces almost 44 per cent of the country’s cumin and the market rate has already gone up by about 10 per cent.
Moreover, the threat is not over yet. The swarms have started moving towards the Iran-Pakistan border. An unusual rain spell in south-east Iran in the first week of January, during which the country received an year’s worth of rain, has ensured that a treat awaits the locusts there. They will breed in Iran and if India has an early monsoon, they will return in larger numbers.