Amrik Singh, 46, a Bathinda-based farmer, was in despair after the entire cotton crop on his three-acre land was destroyed by whitefly in 2017. He then decided not to sow cotton anymore and switched to cultivate other crops, such as paddy.

Amrik wasn't the only one. Hundreds of other farmers in Punjab bore the brunt of the pest attack. Earlier in 2015, the whitefly attack on cotton fields destroyed over 70 percent of the standing cotton crop.

The increasing frequency of pest attacks on the state's farmlands forced the state government to deliberate over the issue. Experts and agricultural scientists have now brought the focus on beneficial insects, whose population has substantially eroded over the past years owing to indiscriminate use of pesticides and chemicals by farmers in the state.

State Agriculture Department Joint Director Dr Sukhdev Singh said excessive use of chemicals on farmlands was also killing agriculture-friendly insects useful in controlling the population of pests.

He attributed the rise of whitefly attacks to the decline in the population of such friendly insects. Whitefly sucks the sap from leaves, causing poor photosynthesis, and triggers leaf curl virus disease.

Alarmed by the situation, the state government formed a contingency plan under which farmers were advised to not use chemicals during the first 60 days of crop sowing.

BD Sharma, Assistant Plant Protection Officer at Jalandhar's Central Integrated Pest Management Centre, said indiscriminate use of pesticides had depleted the population of friendly insects, including ladybugs, spiders and chrysoperla.

"After sustained efforts, now the population of beneficial insects is improving in fields of Punjab," he added.

The area under cotton cultivation in the state was 5.11 lakh hectares in 2009-10. It declined to 3.39 lakh hectares in 2015-16 and further to 2.57 lakh hectares in 2016-17, according to the state government. This was the time when whitefly attack on the crop sent alarm bells ringing among the farming community.

Many farmers in the state's Malwa region, which is known for its cotton crop, have started growing paddy and Basmati owing to the threats posed by the pests. Amrik Singh said the minimum support price (MSP) of paddy and the low risk of pest attacks has aided his shift from cotton to paddy.

Long-term use of pesticides has also made an impact on the fertility of the soil in Punjab and also on the micro-organisms helpful in agriculture.

A study by Punjab Agricultural University (PAU), Ludhiana, noted: "Indiscriminate, long-term and over-application of pesticides have severe effects on soil ecology that may lead to alterations in or the erosion of beneficial or plant probiotic soil microflora. Weathered soils lose their ability to sustain enhanced production of crops/grains on the same land. However, burgeoning concern about environmental pollution and the sustainable use of cropping land have emphasised inculcation of awareness and the wider application of tools, techniques and products that do not pollute the environment at all or have only meagre ecological concerns."

The PAU has been conducting seminars and lectures on the importance of beneficial insects in agriculture for farmers from far off areas of the state. Recently, the Department of Entomology in association with Indian Council of Agricultural Research held a seminar in which techniques of Integrated Pest Management —- an approach to sustainably manage insects —- were explained.