TOXICITY OF THE INSECTICIDE PERMETHRIN IN WATER AND SEDIMENT TO NYMPHS OF THE BURROWING MAYFLY HEXAGENIA RIGIDA (EPHEMEROPTERA: EPHEMERIDAE)
1983; Cambridge University Press; Volume: 115; Issue: 8 Linguagem: Inglês
10.4039/ent1151007-8
ISSN1918-3240
AutoresM. K. Friesen, John F. Flannagan, Terry D. Galloway,
Tópico(s)Insect Resistance and Genetics
ResumoAbstract The 6 LC50 for nymphs of Hexagenia rigida exposed to permethrin-contaminated water without sediment was estimated to lie between 0.58 and 2.06 μg/L. No nymphs survived a 6 h exposure to 7.63 μg/L. Laboratory simulated application of 7.3 g/ha permethrin to H. rigida nymphs in culture resulted in a final mortality of 88.0 ± 15.2% after a 1-day exposure, and 100.0% after a 7 day exposure; initial permethrin concentrations in water were estimated to be 7.63 μg/L and maximum mean concentrations in sediment, measured 1 and 7 days after application, were estimated to be approximately 50 μg/kg dry weight. Exposure of nymphs to sediment contaminated 8 days previously resulted in 100.0% mortality. An application of 0.6 g/ha resulted in final mortality of up to 45.0 ± 4.1%. Lethal effects occurred in some cases between 1 and 4 and possibly up to 10 weeks after application.
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