Far from its home in Central America, a small fly, barely a few millimetres long, has been found ravaging coconut and banana plantations in south India.
The Rugose Spiraling Whitefly ( Aleurodicus rugioperculatus) , native to Belize, Guatemala and in the swamps of Florida in southern United States, has been discovered for the first time in the plantations of Tamil Nadu and Kerala.
“It damaged most of the plantations in Pollachi district (near Coimbatore) and Kerala. If not contained, there is a high chance it can spread towards Karnataka, Andhra Pradesh and Goa,” said K. Selvaraj, scientist, Division of Molecular Entomology, National Bureau of Agricultural Insect Resources (NBAIR), Bengaluru, who was part of the team that surveyed and identified the insect.
Farmers reported the insect first in July in Palakkad and Pollachi. In November, after morphological and molecular identification by researchers from NBAIR and the Institute of Wood Science and Technology, it was proved that it was a previously unseen insect, Rugose Whitefly.
The Whitefly, which has a lifespan of barely 40 days, was discovered in 2004 in Latin America. Since then, it has rapidly spread to Florida, where researchers have found that over 100 species of plants — ornamental and edible — can host the insect.
NBAIR director Chandish R. Ballal believes the fly may have entered the country through the seedling of ornamental plants, and judging by the severity of damage, it perhaps experienced its first outbreak in Palakkad. Around the region, it is found to have damaged more than 25 hectares of plantations.
Containment measures
Biopesticides and natural weather changes may be the best chance now to contain the spread of the destructive insects.
Initial observations show that the insect spreads rapidly when the weather is warm and humid — aggravated this year owing to failed monsoons. The northeast rain bringing down temperatures and the imminent arrival of winter may help contain the insect.
Moreover, researchers say there has been marked improvement in the fight against the pest in plantations that have not been sprayed with chemicals. “When they spray pesticides, it kills the Green lacewing ( Chrysoperla zastrowi sillemi) , which is a natural predator of the whitefly. We have told farmers to use only biological agents such as starch powder or neem spray instead of chemicals,” said Dr. Ballal.
NBAIR is also supplying the Green Lacewing to farmers for immediate relief.
