Correlated responses to neonicotinoid insecticides in clones of the peach-potato aphid, Myzus persicae (Hemiptera: Aphididae).
BACKGROUND
Although there are still no confirmed reports of strong resistance to neonicotinoid insecticides in aphids, the peach-potato aphid (Myzus persicae Sulzer) shows variation in response, with some clones exhibiting up to tenfold resistance to imidacloprid. Five clones varying in response to imidacloprid were tested with four other neonicotinoid molecules to investigate the extent of cross-resistance.


RESULTS
All four compounds-thiamethoxam, thiacloprid, clothianidin and dinotefuran-were cross-resisted, with ED(50) values ranked in the same order as for imidacloprid. Resistance factors ranged up to 11 for imidacloprid, 18 for thiamethoxam, 13 for thiacloprid, 100 for clothianidin and 6 for dinotefuran.


CONCLUSIONS
This variation in response does not appear to be sufficient to compromise the field performance of neonicotinoids aimed at controlling aphids. However, it highlights the need for careful vigilance and stewardship in all M. persicae populations, and a need to consider neonicotinoids as a single cross-resisted group for management purposes.
Foster
Stephen P
SP
Department of Plant and Invertebrate Ecology, Rothamsted Research, Harpenden, Herts AL5 2JQ, UK. stephen.foster@bbsrc.ac.uk
Cox
Diana
D
Oliphant
Linda
L
Mitchinson
Samantha
S
Denholm
Ian
I
D000818:Animals; D001042:Aphids; D018679:Cholinergic Agonists; D007305:Insecticide Resistance; D007306:Insecticides
D018679:Cholinergic Agonists; D007306:Insecticides