INTENSIFICATION OF INSECTICIDE RESISTANCE IN UK FIELD POPULATIONS OF THE PEACH-POTATO APHID, MYZUS-PERSICAE (HEMIPTERA, APHIDIDAE) IN 1996

The well-established carboxylesterase-based resistance to insecticides in Myzus persicae Sulzer has recently been accentuated by the appeara nce of aphids with a modified acetylcholinesterase (MACE) insensitive to pirimicarb and the novel aphicide, triazamate. This target site res istance mechanism was found in M. persicae from crops in the UK for th e first time in 1996, together with especially large proportions of ap kids with R-2 and R-3 levels of carboxylesterases, a combination that was associated with serious insecticide failures. This paper describes the incidence of both mechanisms and discusses the implications for f uture recommendations for aphid control in the UK.