A greenfly outbreak is cutting into Assam's second flush, the harvest that gives the tea its brightness and strength, with yields down by up to 55%, researchers said.

The sap-sucking leafhopper is hitting gardens across Assam and West Bengal hardest from May to July, when the second flush comes in. Losses so far range from 11% to 55%, depending on the garden, Joydeep Phukan, secretary of the Tea Research Association, said. Gardens typically earn more than 30% of their annual revenue on this one flush, a measure of how much is riding on it.

Phukan said rising temperatures and reduced rainfall have accelerated the insect's reproduction. Greenfly damage also opens bushes to a secondary infection, Fusarium dieback, compounding the loss.

The chemicals approved under India's Plant Protection Code have grown largely ineffective, Phukan said, as the pest builds resistance. The Tea Research Association, based at the Tocklai institute in Jorhat, is testing Chlofenapyr 10SC as a replacement, but it still awaits a label-claim approval from the Central Insecticides Board for use on tea.

A pest once confined to the warmer months is now turning up year-round, Phukan said, a shift he tied to the changing climate. P.K. Bezboruah, a former Tea Board of India chairman, told Business Standard the pattern raised the possibility of "a possible act of bio-aggression in the northeastern zone" that authorities should investigate. He offered no evidence for the claim, and no government body had responded to it.

For drinkers, the practical effect is plain: less second-flush Assam of the usual quality this year, and no working chemical fix yet to stop the slide.

Sources: The Assam Tribune, "Greenfly infestation slashes tea yields by up to 55% in Assam and Bengal"; Business Standard, "Tea industry flags concern over greenfly attacks resulting in crop loss".