Insecticide-resistant pollen beetles (Meligethes aeneus F) found in Danish oilseed rape (Brassica napus L) fields.

The pollen beetle is the most important pest in Danish oilseed rape fields. In 2001, we screened a broad range of pollen beetle populations for pyrethroid and dimethoate resistance. A standard dip-test was used to test insecticide resistance in 18 populations collected from oilseed winter and spring rape fields. The beetles were treated with four different insecticides: the pyrethroids tau-fluvalinate, lambda-cyhalothrin and esfenvalerate, and the organophosphate dimethoate. The results show that up to 99% of the pollen beetles survived Danish standard doses of pyrethroids and up to 36% of the beetles survived standard doses of dimethoate.