Evaluation of nontarget effects of methoprene applied to catch basins for mosquito control

Abstract

The mosquito larvicide methoprene is a juvenile growth hormone mimic that is widely used to control mosquito larvae in stormwater catch basins. This study addresses two concerns pertaining to methoprene's use for mosquito control. First, measurements of methoprene concentrations were made from water in catch basins that had been treated with methoprene and from an adjoining salt pond near where the treated catch basins emptied. The concentrations of methoprene in catch basins and at drainage outlets after application at the rates currently used for mosquito control in southern Rhode Island were 0.5 ppb and lower, orders of magnitude below what has been determined as detrimental to organisms other than mosquitoes. Second, the effects of methoprene on the communities that live in catch basins were evaluated both in simulated catch basins in the laboratory and in actual catch basins in the field. We found no evidence of declines in abundances of any taxa attributable to the application. Furthermore, we found no consistent changes in community-level parameters (e.g., taxonomic richness, and dominance-diversity relationships) related to methoprene application in either field or laboratory trials. Journal of Vector Ecology 35 (2): 372-384. 2010.

Non-target effects of methoprene and larvicidal surface films on invertebrate predators of mosquito larvae

“…A lack of effects after the addition of methoprene to aquatic communities was found by Butler et al (2010), albeit in a different study system than ours. In field tests, Miura and Takashi (1973) also found few negative effects of methoprene on non-target organisms, except for some aquatic Diptera.…”

Effects of Methoprene on Female Reproduction, Longevity and F1 Progeny Development in the Cotton Bollworm MothHelicoverpa armigera(Hübner) (Lepidoptera: Noctuidae)

“…Methoprene is environmentally friendly and virtu-ally nontoxic to mammals; it can be applied to grain and water with few application risks. Hence, most studies that have investigated the impact of methoprene on pests have focused on stored product and aquatic insects (Butler et al 2010;Athanassiou et al 2011;Wijayaratne et al 2012). Furthermore, methoprene does not typically affect adults but instead interferes with normal growth and development of immature insects; thus, most previous studies focused on immature insects, and the effects of methoprene on adults and their filial generation have received less attention.…”

Fate of methoprene in temperate salt marsh ditches following aerial applications

“…In comparison, liquid methoprene, after initial testing in mesocosm experiments , has only occasionally been tested for following applications (Siemering 2004;Zulkowsky et al 2005;, with most samples finding no detectable concentrations. Methoprene has been analyzed for even more rarely in sediments (Siemering 2004); once, organic matter collected following a laboratory mesocosm test of methoprene briquets was analyzed (Butler et al 2010).…”