Toxicity and risk of permethrin and naled to non-target insects after adult mosquito management

• Published in: Ecotoxicology (London) Vol. 19; no. 6; pp. 1140 - 1146
• Main Authors: Schleier, Jerome J. III, Peterson, Robert K. D
• Format: Journal Article
• Language: English
• Published: Boston Boston : Springer US 01.08.2010; Springer US; Springer; Springer Nature B.V
• Subjects: Adults; Animals; Aquatic insects; Bioassay; Bioassays; Crickets; Earth and Environmental Science; Ecological risk assessment; Ecology; Ecotoxicology; Environment; Environmental Management; Environmental Pollutants - toxicity; Gryllidae - drug effects; Health aspects; Indicator species; Indicators (Biology); Insecticides; Insects; lethal concentration 50; Lethal Dose 50; Mosquito Control; Mosquitoes; Naled - toxicity; Organophosphate; Permethrin; Permethrin - toxicity; Pyrethrins; Pyrethroid; Risk; Risk Assessment; Toxicity; Pyrethroid; LC50; Mosquito control; Organophosphate; Indicator species
• ISSN: 0963-9292; 1573-3017
• DOI: 10.1007/s10646-010-0497-9

We derived laboratory LC50 values, assessed non-target insect risks, and conducted a field bioassay for ultra-low-volume (ULV) aerosol applications of insecticides used to manage adult mosquitoes. The house cricket, Acheta domesticus (L.), was used as an indicator species for medium- to large-bodied ground dwelling insects. The 24-h LC₅₀ values for Permanone® (formulated product of permethrin), Permanone + piperonyl butoxide (PBO), technical grade permethrin, and technical grade permethrin + PBO ranged from 0.052 to 0.9 μg/cm². The 24 h LC₅₀ for technical grade naled and Trumpet® (formulated product of naled) were 0.038 and 0.44 μg/cm², respectively. The synergist ratio was 2.65 for Permanone + PBO and 1.57 for technical grade permethrin + PBO. The toxicity of technical grade permethrin was about 10-fold greater than Permanone. A risk assessment using modeled estimated environmental concentrations resulted in risk quotients (RQ) that exceeded regulatory levels of concern, but when compared to field-derived actual environmental concentrations RQs did not exceed a regulatory level of concern, except in the case of technical grade naled. These results were expected because higher tiered risk assessments using field-verified data generally lead to lower risk estimates. Field bioassays using caged crickets showed no significant mortality for permethrin or naled after a single truck-mounted ULV application. The results of the risk assessment using actual environmental concentrations are supported by the field bioassays and suggest that a single ULV application of synergized or unsynergized permethrin and naled most likely will not result in population impacts on medium- to large-bodied insects.