Fate and effects of esfenvalerate in agricultural ponds

Abstract

The fate of esfenvalerate was investigated by sampling and chemical analysis after spraying of an artificial pond (25 g a.i./ha) and in the laboratory with [14C]esfenvalerate by trapping of 14CO2 and fractionation of the sediment. The effects were investigated on pelagic communities in enclosures in a natural lake and in the laboratory on surface (Cymatia coleoptrata) and sediment (Chironomus riparius) insects. The latter were used in sediment-plus-water and in water-only tests, measuring effects on emergence and mortality. The measurements in the artificial pond indicated exposure concentrations in the surface microlayer, water column, and sediment of 0.4 microgram/L, 0.05 microgram/L, and 9 micrograms/kg dry weight, respectively, two weeks after application. The degradation studies showed a limited mineralization (26.5%) of [chorophenyl-14C]esfenvalerate during 112 d. Part of the substance was transformed to water-soluble compounds (18.1%) or compounds attached to fulvic acids (26.2%), humic acids (14.2%), or nonextractable sediment constituents (8.8%). The formulated product Sumi-Alpha 5 FW caused 100% mortality to Cymatia coleoptrata after surface application of 0.13 g a.i/ha. Effects on zooplankton were recorded at 0.005 microgram/L of esfenvalerate. The 96-h median lethal concentration for first-instar larvae of Chironomus riparius was 0.13 microgram/L, whereas the delayed emergence lowest-observed-effect concentration was 0.8 microgram/L.

Pyrethroid Insecticides: Use, Environmental Fate, and Ecotoxicology

“…Reduced adult emergence of mayflies was observed 29 days after one-hour exposures to 0.01 µg/L esfenvalerate, a concentration three orders of magnitude lower than concentrations determined to result in acute mortality in this species (Beketov & Liess, 2005). Interestingly, the emergence of Chironomus riparius larvae from artificial ponds was stimulated at low esfenvalerate concentrations (0.1 and 0.2 µg/L), but was delayed by concentrations of 0.8 µg/L and greater (Samsøe-Petersen et al, 2001). However, given that the life cycles of semi-aquatic insects are finely attuned to seasonal and environmental cues, improperly timed emergence can result in new adults emerging into inhospitable climatic conditions.…”

“…This disruption of behavioral homeostasis can alter feeding rates, cause loss of coordination and paralysis, or stimulate hyperactivity that may increase exposure to predators, both of which can have ecologically-relevant consequences. Surface insects were observed to be susceptible to pyrethroid over-spray, exhibiting a rapid loss of coordination and paralysis in response to esfenvalerate only a few hours after application (Samsøe-Petersen et al, 2001). Following sublethal aquatic exposures to cypermethrin, cyfluthrin, and deltamethrin, red swamp crayfish exhibited similar responses (Morolli et al, 2006).…”

“…Smaller bluegill sunfish were present in ponds treated with high esfenvalerate applications (233 g a.i./ha) and authors theorized that this was a result of: 1) reductions in copepod and cladoceran prey and 2) benthic feeding habits of this stage of bluegill causing an increased exposure to sediment-bound esfenvalerate (Webber et al, 1992). Esfenvalerate applications to an artificial pond system resulted in increased community chlorophyll production, likely a result of reduced grazing pressures, as cladocerans and copepods were reduced (Samsøe-Petersen et al, 2001). Bacterial and algal blooms were observed following deltamethrin applications, resulting most likely from indirect effects of a reduction in invertebrate grazer populations (Hanson et al, 2007).…”

Degradation of esfenvalerate in illuminated water-sediment system

“…When esfenvalerate was applied as 0.1% acetonitrile solution in darkness, 14 CO 2 finally amounted to 21.8% of the applied 14 C. More formation of CO 2 as compared with the illuminated studies was accounted for by predominantly microbial processes in the presence of sediment. Samsfe-Petersen et al 26) have reported mineralization of less than 5% in the same period from [phenoxyphenyl-14 C]esfenvalerate in darkness when applied to a Danish pond water-sediment system at 5 and 98 ppb. This difference was likely to stem from the lower temperature (15°C) in their study.…”

Threshold Levels for Effects of Insecticides in Freshwater Ecosystems: A Review

“…These factors are likely to mitigate the contribution of a runoff application to the effects of a combined spray and runoff application. Particularly in drift simulating applications to stagnant waters, clear concentration gradients of insecticides can be found in the first hours posttreatment (Muir et al, 1992;Fairchild and Eidt, 1993;Crum and Brock, 1994;Farmer et al, 1995;Samsøe-Petersen et al, 2001). Shortly after drift applications, most of the active ingredient is then found in the superficial water layer.…”