Residual toxicity of a commercial cypermethrin formulation on grains against four major storage beetles. (September 2019)

• Record Type: Journal Article
• Authors: Gourgouta, Marina; Rumbos, Christos I.; Athanassiou, Christos G.
• Is Part Of: Journal of stored products research. Volume 83(2019)
• Page Start: 103
• Page End: 109
• Publication Date: 2019-09
• Subjects: Cereals -- Cypermethrin -- Residual efficacy -- Stored-product insects; Food -- Storage -- Periodicals; Farm produce -- Storage -- Diseases and injuries -- Periodicals; Entomology -- Periodicals; Food Contamination -- Periodicals; Food Preservation -- Periodicals; Insect Control -- Periodicals; Aliments -- Entreposage -- Périodiques; Produits agricoles -- Entreposage -- Maladies et dommages -- Périodiques; Electronic journals; 631.568
• DOI: 10.1016/j.jspr.2019.05.001
• Languages: English
• ISSNs: 0022-474X

Abstract

Abstract: In the present study, we investigated the residual insecticidal efficacy of a commercial cypermethrin formulation applied on grains (wheat, maize) against adults of Sitophilus oryzae (L.), Oryzaephilus surinamensis (L.), Rhyzopertha dominica (F.) and Prostephanus truncatus (Horn) in laboratory bioassays. The insecticide was applied in its label dose on the grains and a bioassay was initiated at the day of application and every month for four consecutive months (5 bioassays in total). In each bioassay, adult mortality levels were determined after exposure for 7, 14 and 21 d. After the final evaluation, all beetles (dead and alive) were removed and the number of offspring was assessed after an additional interval of 65 d. Based on our results, the application of the tested cypermethrin formulation as a grain protectant provided long-term protection against R. dominica and P. truncatus adults, as in most cases complete control was achieved for these two species, even after four months of storage of the treated commodities. In the case of S. oryzae and O. surinamensis, adult mortality did not reach 100% in any of the cases, moreover, a gradual decline of mortality levels was recorded over the 4-month period of storage. Finally, for S. oryzae and P. truncatus progeny production was notably suppressed by cypermethrin. Results show that the cypermethrin formulation tested could be a valuable tool for stored grain protection, however, factors such as the target species and the storage interval should be taken into consideration. Highlights: Cypermethrin showed high residual efficacy as a grain protectant on wheat and maize. R. dominica and P. truncatus were the most susceptible species, as complete adult control was achieved in most cases. S. oryzae and P. truncatus progeny production was significantly suppressed by cypermethrin.