09 December 2021, Guntur: Chilli farmers of Andhra Pradesh and Telangana are facing the worst infestation of thrips in the current season. About 5 lakh hectares is severely affected which translates to an economic impact of about Rs. 3,000 crores. There is a widespread distress among the chilli farmers of the state as it will impact their livelihood.
The occurrence of such large-scale infestation is rare but may become regular with inconsistent regulations. Farmers do not have any effective insecticide available which can control current thrip infestation. Until 2020, the prevalent molecules in the market to control such heavy infestation of thrips, brown plant hopper and pink bollworm were DDVP (dichlorvos) and Phosalone. Both the molecules were phased out / banned post December 2020 by the regulators. Their high efficacy on the insects was due to the unique mode of action (MoA).
DDVP (dichlorvos) is an acetylcholinesterase inhibitor with vapour action. It kills the insect by paralysing the insect’s nervous system. Phosalone is also an acetylcholinesterase inhibitor and an OP compound, non-systemic with contact and stomach action.
The thrips have started to showing resistance to the current approved molecules in the market (mostly neonicotinoids). The agrochemical industry holds the regulators accountable for the current prevailing situation in both the states. As per the industry source, the molecules were banned without a thorough on-ground study considering availability, efficacy, mode of action and affordability of alternatives.
The mode of action (MoA) of the molecules is a key attribute as per Insect Resistance Management (IRM) practices. Developing an agrochemicals with new mode of action is critical and a costly process. Use of molecules with the same mode of action weakens its effectiveness on insects. It is important to have different mode of actions to control periodic invasive and endemic insect / pests like thrips in chilli, pink bollworm and white fly in cotton, fall army worm in corm, locusts, etc.
The industry is of the view that banning a product by regulatory authority because it is banned in other countries or due to campaigns by environmentalists is not a correct measure. The authorities should involve the industry bodies, senior scientists from the plant protection division and farmer representatives to take a calculative decision based on data sets from field trial, pest history, toxicology reports and farmer practices.