Sub-lethal effects of the neurotoxic pyrethroid insecticide Fastac® 50EC on the general motor and locomotor activities of the non-targeted beneficial carabid beetle Platynus assimilis (Coleoptera: Carabidae)

Authors

  • Ene Tooming,

  • Enno Merivee,

    Corresponding author
    1. Estonian University of Life Sciences, Institute of Agricultural and Environmental Sciences, Tartu, Estonia
    • Correspondence to: Enno Merivee, Estonian University of Life Sciences, Institute of Agricultural and Environmental Sciences, 1 Kreutzwaldi Street, 51014 Tartu, Estonia. E-mail: Enno.Merivee@emu.ee

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  • Anne Must,

    1. Estonian University of Life Sciences, Institute of Agricultural and Environmental Sciences, Tartu, Estonia
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  • Ivar Sibul,

    1. Estonian University of Life Sciences, Institute of Agricultural and Environmental Sciences, Tartu, Estonia
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  • Ingrid Williams

    1. Estonian University of Life Sciences, Institute of Agricultural and Environmental Sciences, Tartu, Estonia
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Abstract

BACKGROUND

Sub-lethal effects of pesticides on behavioural endpoints are poorly studied in carabids (Coleoptera: Carabidae) though changes in behaviour caused by chemical stress may affect populations of these non-targeted beneficial insects. General motor activity and locomotion are inherent in many behavioural patterns, and changes in these activities that result from xenobiotic influence mirror an integrated response of the insect to pesticides. Influence of pyrethroid insecticides over a wide range of sub-lethal doses on the motor activities of carabids still remains unclear.

RESULTS

Video tracking of Platynus assimilis showed that brief exposure to alpha-cypermethrin at sub-lethal concentrations ranged from 0.01 to 100 mg L−1 caused initial short-term (< 2 h) locomotor hyperactivity followed by a long-term (>24 h) locomotor hypo-activity. In addition, significant short- and long-term concentration and time-dependent changes occurred in general motor activity patterns and rates.

CONCLUSION

Conspicuous changes in motor activity of Platynus assimilis beetles treated at alpha-cypermethrin concentrations up to 75 000-fold lower than maximum field recommended concentration (MFRC) suggest that many, basic fitness-related behaviours might be severely injured as well. These changes may negatively affect carabid populations in agro-ecosystems. Long-term hypo-activity could directly contribute to decreased trap captures of carabids frequently observed after insecticide application in the field. © 2013 Society of Chemical Industry

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