It all began one fine winter’s day in 2014 when a researcher at the Indian Council of Agricultural Research (ICAR)-Indian Institute of Horticultural Research (IIHR), Bengaluru, found white patches on tomato leaves at an experimental field.
Bending down for a closer look, the researcher spotted small greenish larvae crawling inside the leaves. These symptoms were new to him, so he consulted the Division of Entomology and Nematology at the Institute.
To verify for themselves, Akshay Kumar Chakravarthy and his team visited the field. They found gallery-like whitish patches. Entomologist Vaddi Sridhar discovered hundreds of small yellow eggs under the tomato leaves and small pinholes in the tomatoes.
The team concluded that the pest was new to India. Soon, DNA barcoding confirmed the larvae to be Tuta absoluta — the tomato moth.
The team had to check if the pest had spread. Soon, they found that it had attacked the solanaceous crops of a nearby farmer, causing damage to tomato, potato and eggplant crops.
Initially, farmers flooded tomato fields with chemicals. But the pest continued burrowing into leaves. Tuta absoluta mines tomato leaves to eat the chlorophyll content and lives in between two epidermises. Hence, insecticides sprayed on leaves do not affect it.
The IIHR recommended using the integrated pest management approach, which synergises cultural, biological and bio-rational methods. The farmers were advised to remove and burn infested plants.