Insecticidal effect of contact insecticides against stored product beetle populations with different susceptibility to phosphine. (December 2018)

• Record Type: Journal Article
• Authors: Agrafioti, P.; Athanassiou, C.G.
• Is Part Of: Journal of stored products research. Volume 79(2018)
• Page Start: 9
• Page End: 15
• Publication Date: 2018-12
• Subjects: Insecticides -- Phosphine resistance -- Treated commodity -- 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.2018.06.002
• Languages: English
• ISSNs: 0022-474X

Abstract

Abstract: In the present work we evaluated the effect of alpha-cypermethrin, pirimiphos-methyl and spinetoram on field and laboratory strains of Sitophilus oryzae (L.) and Oryzaephilus surinamensis (L.) with different susceptibility levels to phosphine. The field populations were collected from storage facilities in Greece and were characterized as resistant by using the Food and Agriculture Organization (FAO) protocol, based on the same protocol, populations were characterized as susceptible to phosphine. The insecticides were applied at three dose rates (0.1, 1 and 10 ppm) on wheat and adult mortality was measured after 7, 14 and 21 days of exposure, while progeny production was assessed 65 days later. For S. oryzae populations, complete control was noted at the highest dose on pirimiphos-methyl and spinetoram, while mortality caused by alpha-cypermethrin was 62 and 100% for the field and laboratory populations, respectively. For O. surinamensis, complete control was recorded at the highest dose only on alpha-cypermethrin for the laboratory population, in contrast with the field population, where mortality was only 32% after 21 days of exposure. In general, the variations among populations were negligible for spinetoram, probably due to the fact that the populations tested were not previously exposed to this active ingredient. In contrast, the lowest susceptibility of the field populations to the other two insecticides can be attributed to the fact that these populations might have been exposed to these active ingredients, while any hypothesis for cross-resistance with phosphine has to be examined more thoroughly. Highlights: Field and laboratory populations of Sitophilus oryzae and Oryzaephilus surinamensis were evaluated for their resistance to phosphine and also for their susceptibility to different contact insecticides. For both species, field populations were found resistant to phosphine while laboratory populations were found susceptible to phosphine. Pirimiphos-methyl and spinetoram were effective for both field and laboratory populations, while alpha-cypermethrin was more effective for the laboratory population. The results indicate that field populations of stored product insects that are resistant to phosphine may not be controlled by certain contact insecticides.