Title: Food source provisioning and susceptibility of immature and adult Tribolium castaneum on concrete partially treated with chlorfenapyr (Phantom®) Authors
Submitted to: Journal of Pest Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: August 16, 2011
Publication Date: April 1, 2012
Citation: Arthur, F.H., Fontenot, E.A. 2012. Food source provisioning and susceptibility of immature and adult Tribolium castaneum on concrete partially treated with chlorfenapyr (Phantom®). Journal of Pest Science. 85(2): 277-282. http://dx.doi.org/10.1007/s10340-011-0380-3. Interpretive Summary: A new insecticide, Phantom®, will kill the red flour beetle, a major pest of stored products, but there is no information on how well it will work when food is present. We exposed adult red flour beetles, and also larvae and pupae, on a concrete surface that was partially treated with Phantom®. Food (flour) was put in the untreated area of the concrete. Some adults were able to escape insecticide exposure and lay eggs in the flour. Larvae were more susceptible than adults and usually died before they could reach the adult stage, even if they reached the flour. Residual control of larvae lasted for several weeks. Results show mobile adults could escape exposure to Phantom®, but the larvae could not and were therefore more susceptible to the insecticide.
Technical Abstract: A series of experiments were conducted in which adults, pupae, and 4-week-old larvae of Tribolium castaneum (Herbst), the red flour beetle, were exposed separately on concrete arenas partially treated (14.4 % of the total area) with the insecticide chlorfenapyr (Phantom®) at 1.1 g active ingredient/square meter. A flour food source (patch) was also provided in the untreated portions of the arenas. In the first trial, adult mortality averaged 60.0 ± 10.6 %, but progeny production occurred in the provided food patches. Pupal mortality was only 8.3 ± 3.1%, indicating that when adult emergence occurred those adults were able to escape exposure, and there was no difference in progeny production from that in untreated controls (P = 0.27). In the second trial, few larvae exposed in choice and no-choice arenas were able to emerge as normal adults. In a final trial, residual efficacy declined during a 3-week period, with larvae being more susceptible than adults. Results show mobility of life stage may be a determining factor when assessing susceptibility of T. castaneum to contact insecticides.