title: The neonicotinoid insecticide imidacloprid repels pollinating flies and beetles at field-realistic concentrations.
abstract: Neonicotinoids are widely used systemic insecticides which, when applied to flowering crops, are translocated to the nectar and pollen where they may impact upon pollinators. Given global concerns over pollinator declines, this potential impact has recently received much attention. Field exposure of pollinators to neonicotinoids depends on the concentrations present in flowering crops and the degree to which pollinators choose to feed upon them. Here we describe a simple experiment using paired yellow pan traps with or without insecticide to assess whether the commonly used neonicotinoid imidacloprid repels or attracts flying insects. Both Diptera and Coleoptera exhibited marked avoidance of traps containing imidacloprid at a field-realistic dose of 1 µg L(-1), with Diptera avoiding concentrations as low as 0.01 µg L(-1). This is to our knowledge the first evidence for any biological activity at such low concentrations, which are below the limits of laboratory detection using most commonly available techniques. Catch of spiders in pan traps was also slightly reduced by the highest concentrations of imidacloprid used (1 µg L(-1)), but catch was increased by lower concentrations. It remains to be seen if the repellent effect on insects occurs when neonicotinoids are present in real flowers, but if so then this could have implications for exposure of pollinators to neonicotinoids and for crop pollination.
authors: Biological and Environmental Sciences, School of Natural Sciences, University of Stirling, Stirling, Scotland.
authors: Amy H
authors: AH
authors: Easton
authors: Dave
authors: D
authors: Goulson
mesh_terms: D000818:Animals; D018678:Cholinergic Agents / Q000494:pharmacology*; D001517:Coleoptera / Q000187:drug effects*; D004175:Diptera / Q000187:drug effects*; D007093:Imidazoles / Q000494:pharmacology*; D007306:Insecticides / Q000494:pharmacology*; D000073943:Neonicotinoids; D009574:Nitro Compounds / Q000494:pharmacology*; D054817:Pollination
chemical_list: D018678:Cholinergic Agents; D007093:Imidazoles; D007306:Insecticides; D000073943:Neonicotinoids; D009574:Nitro Compounds; C082359:imidacloprid
references: Science. 2012 Apr 20;336(6079):351-2
references: 22461500
references: Annu Rev Entomol. 2007;52:81-106
references: 16842032
references: J AOAC Int. 2007 Mar-Apr;90(2):485-520
references: 17474521
references: Ecotoxicology. 2010 Jan;19(1):207-15
references: 19757031
references: Pest Manag Sci. 2012 Jun;68(6):819-27
references: 22488890
references: Proc Natl Acad Sci U S A. 2011 Apr 5;108(14):5909-14
references: 21422295
references: Science. 2012 Apr 20;336(6079):348-50
references: 22461498
references: Trends Ecol Evol. 2005 Jul;20(7):367-73
references: 16701398
references: Science. 2006 Oct 20;314(5798):397
references: 17053115
references: Annu Rev Entomol. 2008;53:191-208
references: 17803456
references: Ecotoxicology. 2011 Jan;20(1):149-57
references: 21080222
references: J Econ Entomol. 2008 Dec;101(6):1743-8
references: 19133451
references: Nature. 2012 Nov 1;491(7422):105-8
references: 23086150
references: PLoS One. 2012;7(1):e30023
references: 22253863
references: PLoS One. 2012;7(1):e29268
references: 22235278