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Environmental fate of chlorantraniliprole and indoxacarb termiticides and bioefficacy against eastern subterranean termites, Reticulitermes flavipes (Kollar) (Isoptera: Rhinotermitidae)
Abstract
Data regarding the environmental fate and biological activity of chlorantraniliprole and indoxacarb termiticides against Reticulitermes flavipes is limited. Generally, new pesticides are evaluated in agricultural settings; however, the fate of these chemicals in the urban environment is also important. Chlorantraniliprole and indoxacarb were evaluated for their environmental fate and bioefficacy. Chlorantraniliprole persisted longer than indoxacarb under field conditions. Decreases in indoxacarb were initially first-order (<180 >d) with reduced loss >180 d. Indoxacarb concentrations differed based on soil depth as half-lives increased with depth. Chlorantraniliprole loss was more consistent (i.e. zero order) as concentrations steadily declined. Chlorantraniliprole concentrations remained high at 518 d with no differences based on soil depth. High R. flavipes mortality occurred when exposed to indoxacarb and chlorantraniliprole treated soils. Termites were unable to completely penetrate the chlorantraniliprole treated soils; however, complete penetration of some indoxacarb treated soils occurred at 360 d. No repellency to either termiticide was observed. Indoxacarb leached during the initial termiticide application at concentrations higher than its solubility limit. Post-application, indoxacarb concentrations decreased to just above its water solubility. Chlorantraniliprole concentrations in effluent gradually increased with time to its approximate solubility limit in the sandy loam but were never detected in the silty clay loam. Most indoxacarb and chlorantraniliprole remained near the point of application. Mineralization of indoxacarb in urban soils was determined. Temperature had the biggest influence with no differences based on depth. Differences in measured indoxacarb residues, held at different temperatures, strongly suggest the importance of soil microbes on indoxacarb degradation. Indoxacarb losses also occurred over the first 90 d as a result of abiotic degradation and/or bound residue formation. Chlorantraniliprole was more toxic to R. flavipes workers when topically applied. Alternatively, indoxacarb was more toxic to the termites when in soil. A bioavailability ratio was developed and indicated that indoxacarb is more bioavailable to termites in soil when compared to chlorantraniliprole.
Subject Area
Entomology
Recommended Citation
Spomer, Neil A, "Environmental fate of chlorantraniliprole and indoxacarb termiticides and bioefficacy against eastern subterranean termites, Reticulitermes flavipes (Kollar) (Isoptera: Rhinotermitidae)" (2009). ETD collection for University of Nebraska-Lincoln. AAI3359065.
https://digitalcommons.unl.edu/dissertations/AAI3359065