Activity of Bifenthrin, Chlorfenapyr, Fipronil, and Thiamethoxam Against Argentine Ants (Hymenoptera: Formicidae)

Abstract

Bifenthrin, chlorfenapyr, fipronil, and thiamethoxam were evaluated for activity against the Argentine ant, Linepithema humile (Mayr) (Hymenoptera: Formicidae). Mobility impairment and lethal times were determined after topical treatments. Ants were immobilized most quickly by bifenthrin, followed by chlorfenapyr and thiamethoxam. After 2 h, the number of fipronil-treated ants unable to walk out of test arenas did not differ from control ants. Median lethal time (LT50) after topical treatment was lowest in the bifenthrin treatment, followed by thiamethoxam, chlorfenapyr, and then fipronil. Mortality due to horizontal exposure was evaluated at 10, 20, or 30 degrees C, with topically treated ant corpses serving as donors. There was low to moderate horizontal activity in bifenthrin and chlorfenapyr treatments, with no temperature effect in bifenthrin treatments and a positive temperature effect in chlorfenapyr treatments. Mortality in the fipronil treatments was highest and was positively correlated with temperature. Thiamethoxam treatments did not differ from controls at 10 degrees C, but mortality increased with temperature. To evaluate contact activity, either all of 20% of the ants in a cohort were exposed to insecticide-treated pine needles. In both tests, mortality was highest in fipronil and bifenthrin treatments, followed by thiamethoxam, with lowest mortality in chlorfenapyr treatments. Effectiveness as a barrier was evaluated by providing a choice between bridges treated with insecticide or water. Although bifenthrin did not provide an impenetrable barrier, it was the only treatment having fewer ants than its paired control. Mortality data suggest that lack of recruitment rather than repellency account for this result.

Evaluation of Insecticides for the Control of <I>Linepithema micans</I> (Hymenoptera: Formicidae)

“…The efÞciency of Þpronil has been attributed partly to the absence of repellency and to the ability to transfer the active ingredient between individuals in the colony (Rust et al 1996, Scharf et al 2004, Soeprono and Rust 2004, Klotz et al 2007, Wiltz et al 2009). In spite of the transfer ability of Þpronil, which makes it one of the most efÞcient insecticides in controlling many species of ants (Choe and Rust 2008), it was not effective in this study.…”

Food source provisioning and susceptibility of immature and adult Tribolium castaneum on concrete partially treated with chlorfenapyr (Phantom®)

“…Slow-acting compounds would therefore seem to be poor choices for surface treatments; however, in our tests, we were also assessing residual efficacy during a two-week time period, larval susceptibility to the toxicant, and avoidance behavior of larvae to the insecticide. As stated by Wiltz et al (2009), rapidity of kill is not the only desirable quality of a surface toxicant, but in their study, chlorfenapyr was more slower acting than either bifenthrin or fipronil, and chlorfenapyr did not give the same level of control as the other two insecticides.…”

“…In previous studies with adult T. castaneum (Arthur 2008(Arthur , 2009) and in studies with Argentine ants Linepithema humile (Mayr) (Wiltz et al 2009), chlorfenapyr exhibited delayed rather than immediate toxicity. Chlorfenapyr affects oxidative phosphorylation and inhibits ATP synthesis (McLeod et al 2002); hence, it may be slower acting compared with conventional neurotoxins.…”

Different acute toxicity of fipronil baits on invasive Linepithema humile supercolonies and some non-target ground arthropods

“…In particular, a phenylpyrazole systemic insecticide, fipronil, has provided a great horizontal activity against ants (i.e., movement of an active toxic ingredient due to ant-to-ant contact) because of its non-repellent effects (Wiltz et al 2009;Choe et al 2010). Fipronil can be formulated as a solid bait or as a liquid spray (USEPA 1996;White 1998) and provides significant mortality of workers and queens of L. humile in a relatively short period of time (Costa and Rust 1999;Hooper-Bùi and Rust 2000).…”