Crop Pests Becoming Resistant to Insecticides, Scientists Find

Scientists at Rothamsted Research in the United Kingdom have discovered that grain aphids are becoming resistant to pyrethroid insecticides which may have implications for controlling barley yellow dwarf virus (BYDV). Until recently, growers had good control of this pest with pyrethroids. However, during summer 2011 there were reports of control failures which prompted Rothamsted scientists to test aphid samples for resistance to pyrethroids using scientific techniques such as topical bioassays and DNA diagnostics.

These techniques have allowed the Rothamsted scientists to look for a genetic mutation which occurs in other insect pests and is known to cause insecticide resistance. The scientific analysis conducted at Rothamsted has shown that the mutation was present in 2012 in some areas at high frequency (>50%) and was also present at low levels in 2009 but appeared to take hold in 2011 when pyrethroid control failures were first reported.

View Rothamsted Research's news release at http://www.rothamsted.ac.uk/PressReleases-PRID=227.html.