Potato crops could face a much lower virus risk from potato aphids this year.

The Rothamsted Insect Survey’s potato aphid forecasts for 2010 predicts that that peach-potato aphids are unlikely to fly in Scotland before July. In England, predictions of first capture in suction traps are from 24 May at Writtle to 16 July at Newcastle, with most predicted in the second week of June.

Rothamsted’s Richard Harrington said: “Due to the exceptionally cold winter, these first-flight predictions are more than two weeks later than last year’s and about a month later than average. Potato aphid numbers are also expected to be much lower than average during the critical part of the growing season when potatoes are especially susceptible to viruses.”

However, SASA’s Jon Pickup stresses that growers of PVA and PVY susceptible varieties will still need to take account of non-colonising aphids, particularly cereal aphids that could transmit these non-persistent viruses before peach-potato aphids arrive.

“In a potentially late aphid year like this, monitoring is more important than ever,” Dr Pickup warned.