A predicted rise in temperatures over the next few days after the recent heavy rainfall will encourage orange wheat blossom midge to fly. If these flights coincide with warm weather forecast for next weekend, this will produce optimal conditions so monitoring is essential.

A predicted rise in temperatures over the next few days after the recent heavy rainfall will encourage orange wheat blossom midge to fly.

If these flights coincide with warm weather forecast for next weekend, this will produce optimal conditions so monitoring is essential.

"The first week in June will be a critical time to monitor crops for levels of adult midge," said Graham Jellis, HGCA director of research.

High risk fields in 2004 are a likely source of midge attack in 2006, even if they were in set-aside or a break crop last year. Crops are at risk to orange wheat blossom midge from growth stage 53-59, but once in flower the crop becomes resistant to attack and need not be sprayed.

Sprays should be applied when the adults are first seen and pheromone trap thresholds are the best

guide (20-30 midges over 2 nights).

"Crops should only be sprayed if yield or quality penalty is likely. Once the larvae have entered the floret no products are effective and spraying will be detrimental to beneficial species," said Jon Oakley, of Adas.

"Conservation headlands and pollen and nectar buffer strips are a vital reservoir for natural predators of orange wheat blossom midge."

For an information pack, log on to the HGCA website at www.hgca.com.