NEW DELHI – Facing a major agricultural crisis from invasive pests, India has turned to an unconventional solution: importing insects to fight its battles. In 2022, the country made a rare move, importing parasitic wasps from Africa to combat the Cassava Mealybug, an invasive pest that was devastating crops in southern states.
The mealybug, a pest native to South America, found its way to India and, without any natural predators, spread rapidly. First detected by farmers in Kerala’s Thrissur district in April 2020, the pest quickly multiplied, slashing cassava yields from 35 tonnes per hectare to just 3-5 tonnes. This created an agricultural crisis, particularly in Tamil Nadu and Kerala, which account for the majority of India’s cassava production.
Rather than resorting to a widespread use of chemical pesticides, the Indian Council of Agricultural Research (ICAR) opted for a sustainable method known as classical biological control. They imported the parasitoid wasp, Anagyrus lopezi, a natural enemy of the mealybug that had successfully controlled the pest in Africa in the 1970s. After a rigorous quarantine and inspection process at the National Bureau of Agricultural Insect Resources (NBAIR) in Bengaluru, the wasps were released in March 2022. The tiny wasps lay their eggs inside the mealybugs, with the larvae eventually killing the host.
This isn’t the first time India has used this strategy. The country has a history of importing beneficial insects to manage pest populations. In the 1950s, a predatory beetle was brought in from Australia to save citrus crops from a destructive pest in Kerala. Earlier still, in the 1930s, ladybird beetles were imported to combat the cottony cushion scale disease on citrus plants.
Experts argue that this approach, while sounding risky, is tightly regulated and offers a long-term, environmentally safe alternative to chemical pesticides. It helps maintain a natural ecological balance, prevents pests from developing resistance to chemicals, and provides a low-cost solution for farmers. As foreign pests continue to find their way into India through various means—from strong winds to cargo shipments—this biological method of pest management is gaining new attention as a vital tool for ensuring food security.