Current address: Department of Pesticide Regulation, 1001 I st. P.O. Box 4015, Sacramento, California 95812, USA.
Ant control efficacy of pyrethroids and fipronil on outdoor concrete surfaces
Version of Record online: 27 JUN 2013
© 2013 Society of Chemical Industry
Pest Management Science
Volume 70, Issue 2, pages 271–277, February 2014
How to Cite
Jiang, W., Soeprono, A., Rust, M. K. and Gan, J. (2014), Ant control efficacy of pyrethroids and fipronil on outdoor concrete surfaces. Pest. Manag. Sci., 70: 271–277. doi: 10.1002/ps.3555
- Issue online: 13 JAN 2014
- Version of Record online: 27 JUN 2013
- Accepted manuscript online: 9 APR 2013 01:56PM EST
- Manuscript Accepted: 9 APR 2013
- Manuscript Received: 20 DEC 2012
- ant control;
Urban and residential concrete surfaces are often treated with pesticides to control ants. Run-off from irrigation/rainfall can remove pesticides from concrete and contaminate urban waterways. Recent regulations and mitigations in regions such as California aim to reduce insecticide run-off (e.g. pyrethroids), but are often proposed without adequate consideration of their impact on ant control efficacy.
We carried out an outdoor study with a side-by-side comparison between pesticide run-off potential and residual ant toxicity after exposing treated concrete to summer conditions and simulated precipitations.
Treatments with bifenthrin, permethrin or fipronil all showed fast ant knockdown initially, and over 50% of ants were killed within 16 h after 1-min contact with the treated surfaces. Shorter ant median lethal time (LT50) was observed on concrete treated with over-the-counter (OTC) granule/dust formulations than OTC liquid or professional formulations. However, the treated surfaces rapidly lost ant control efficacy after outdoor exposure and repeated precipitations. Except for OTC solid permethrin treatment, the ant toxicity disappeared after 20 days for all other formulation treatments. In contrast, pesticides were detected in run-off water from simulated precipitations even 89 days after the treatment, with levels above 0.5 µg L−1 for bifenthrin, 30 µg L−1 for permethrin and 0.15 µg L−1 for fipronil. Pyrethroid run-offs from OTC solid formulations were >10 times higher than the other two formulations.
The results suggested viable options for run-off mitigation include decreasing use on concrete such as using crack/spot treatments instead of broadcast applications, limiting pesticide use on hardscapes away from water contact, and avoiding using dust/granule formulations on hardscapes. © 2013 Society of Chemical Industry