Effects of the mosquito larvicide, temephos, to non-target organisms in a saltmarsh community. Final report for 1992 studies.

Abstract

This investigation was undertaken to assess the impact of the mosquito larvicide Abate (temephos), on nontarget saltmarsh organisms and to determine whether its use creates an unacceptable hazard within the marsh. This report encompasses laboratory toxicity tests and field larviciding applications from April 1 through December 31, 1992. Field surveys and larvicide application monitoring were performed within the areas normally treated to ensure that the investigation was carried out under normal field application conditions. Areas chosen for this study are the St. Jude and Bonita Springs marsh areas in south Florida. Methods developed during previous years were applied to assess acute and sublethal effects during field applications and controlled laboratory tests. A series of laboratory toxicity tests were performed to determine the acute toxicity of temephos to larvae of the marsh fiddler crab and the mangrove tree crab. These results provide information needed to assess the potential ecological risk to crab larvae from temephos concentrations observed following field larvicide applications. The results of the study are described.