The station's entomologist Mike Lole said the peach-potato aphid inexplicably seems to have the ability to develop resistance more quickly than other aphid species.
"It's been a constant race to keep ahead of the pest," he said. "We need to know which insecticide groups remain effective against it."
All peach-potato aphids have resistance to one or more of the major aphicidal chemical groups - the OPs, pyrethroids and carbamates, he explained. Pymetrozine (Plenum) and the neonicotinoids, such as thiacloprid (Calypso), are still effective. "If neonic-resistance arises, as it has in some other insect species worldwide, we could be in trouble," he added.
Lole is working on resistance monitoring with Rothamsted Research Station's Dr Steve Foster. "The important thing is not to overuse the neonics. It says on the insecticide labels not to use two successive sprays from the same group to help prevent the build up of resistance," he said.
Lole added that since July 2008, the peach-potato aphid seems to have been conspicuous by its absence but it is likely to reappear as the weather warms up.
The cold winter reduced the populations of both aphids and their natural enemies but aphids can multiply much more quickly under suitable conditions.
HDC soft fruit specialist Scott Raffle said that both protected and outdoor strawberries and raspberries can be attacked by the peach-potato aphid. But unlike on potatoes, it is not a major vector of viruses affecting these crops.
To supply samples of peach-potato aphids to ADAS Rosemaund, phone 01432 820444 or email email@example.com.