26 December 1997

Minor pests a major threat?

MINOR cereal pests could assume major importance as grain assurance takes off.

Orange wheat blossom midge, thrips and grass and cereal mites all feed on developing grain, encouraging fungal growth, explains Jon Oakley of ADAS Bridgets, Hants. That can lead to the production of carcinogenic mycotoxins.

"The role of minor pests in initiating secondary fungal infection is currently underrated. Midge larvae feed in a pool of sap, creating a fungal garden."

More sap leaked

Thrips prick grain as they feed, encouraging more sap to leak out, and mites carry fungus on their bodies which quickly infects grazed areas, he says.

Such pests are difficult to detect and control is tricky since treatments have to be applied during ear formation and emergence, he explains. But they will need watching in future.