"As well as black bean aphid, pea aphids are also building up in spring bean crops.

"Monitor crops carefully, and treat if 10 per cent of plants are infested with black bean aphid. Pea aphids are particularly damaging where they are present on the bean pods, causing distortion and failure of pods to fill."

She added that pea aphids are continuing to build up in pea crops. Crops must be monitored carefully and Ward advised spray treatment if 20 per cent of plants in the crop have aphids present.

Yield loss can still occur up to the stage where the all the pods up to the fourth node are filled. Control of aphids is more important than waiting for the pea moth spray, Ward added.

Meanwhile, pea moths continue to be caught in traps, said Ward, although numbers remain low in some areas.

She said: "Where thresholds have been reached, crops with pods left to fill are still susceptible to damage."

Spray dates are available through the PGRO telephone service.

- For more information see PGRO Technical Update 185. The update, including revised recommendations for spraying this year, is available on the PGRO website. For further details on the bruchid research project, see www.pgro.org/bruchid-link.