2026/07/10 by Rajeswaran Jagadeesan, Manoj K. Nayak, Manoj K Nayak
Agricultural and Biological Sciences · #Insect Pest Control Strategies #Pesticide Exposure and Toxicity #Insect behavior and control techniques
paper · doi:10.1093/jee/toag221
Abstract Sulfuryl fluoride (SF) has been widely applied for the disinfestation of stored commodities for over 2 decades; however, information on baseline susceptibility in field insect populations is not well established. In the current study, detailed dose mortality response curves were established for 18 Rhyzopertha dominica (Fabricius) (Coleoptera: Bostrichidae) and 12 Cryptolestes ferrugineus (Stephens) (Coleoptera: Laemophloeidae) populations that were collected from various grain storage facilities across Australia. Laboratory reference strains of both species were also used for comparison. Adult beetles (2 wks posteclosion) were exposed to a series of SF concentrations (0.05 to 2.5 mg l−1) over 48 h (2.4 to 120 g hm−3). Mortality responses for each population/strain of R. dominica and C. ferrugineus were recorded and analyzed. Key lethal estimates such as LC50, LC95 and LC99 were calculated for each population/strain and compared to assess inherent variation in susceptibility to SF. Comparison of lethal estimates along with other analyzed outputs identified 2 discriminating doses (DDs): 0.9 mg L−1 (43 g hm−3) for R. dominica and 2.0 mg L−1 (96 g hm−3) for C. ferrugineus over 48 h, which can be effectively used to discriminate SF-resistant individuals from their susceptible counterparts. Comparison of these results with the previously established DD for Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae) (1.75 mg L−1 or 84 g hm−3) confirms that toxicity responses to SF are species-specific, highlighting the need for continued monitoring of resistance to SF in the field. This information has significant implications for the grain industry that is currently using SF as a phosphine-resistance breaker.