Abstract Phosphine (PH3) fumigation resulting in sub-lethal exposure has led to the development of phosphine resistance in many stored-product insect species worldwide and is a major challenge to the continued effective use of phosphine. In 2016 phosphine resistance was found in Tribolium castaneum (Herbst) and Plodia interpunctella (Hubner) collected from California dried fruit and nut processing facilities. Although Oryzaephilus surinamensis (L.) infests grain, dried fruit, and nuts in storage and processing facilities, phosphine resistance in this species has not been studied in the United States. In this study, the discriminating dose of phosphine for O. surinamensis eggs was estimated using a laboratory susceptible strain; it was found to be 28.4 ppm over a 72-h fumigation period (1 mg/L of phosphine = 714.18 ppm or 1 ppm = 0.0014 mg/L). Discriminating dose bioassays were used to determine phosphine resistance in both eggs and adults of 14 different populations collected from California and Oklahoma. Resistance to phosphine was detected in four out of 14 populations in adults and nine out of 14 populations in eggs and ranged from 2 to 100%. Phosphine percent survival values in both adults and eggs of three populations, namely, Box BR, Box BF, and OKWat were >90%. Lethal concentration values required to kill 99% of individuals in samples for adults of these three populations were predicted as 320.5, 290.7, and 263 ppm, respectively, and those for eggs were 1030.7, 1055.9, and 564.5 ppm, respectively, over a 72-h fumigation period. This study confirms that phosphine resistance is present in O. surinamensis in the United States.

中文翻译：

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美国锯齿状甲壳虫 Oryzaephilus surinamensis 的磷化氢抗性

摘要 磷化氢 (PH3) 熏蒸导致亚致死暴露，导致世界范围内许多储藏产品昆虫对磷化氢产生抗药性，这对磷化氢的持续有效利用构成了重大挑战。2016 年，在从加利福尼亚干果和坚果加工设施收集的 Tribolium castaneum (Herbst) 和 Plodia interpunctella (Hubner) 中发现了磷化氢抗性。尽管 Oryzaephilus surinamensis (L.) 在储存和加工设施中侵染谷物、干果和坚果，但美国尚未研究该物种的磷化氢抗性。在这项研究中，使用实验室敏感菌株估计了 O. surinamensis 卵的磷化氢识别剂量；在 72 小时的熏蒸期间发现其为 28.4 ppm（1 毫克/升磷化氢 = 714.18 ppm 或 1 ppm = 0.0014 毫克/升）。区分剂量生物测定用于确定从加利福尼亚和俄克拉荷马州收集的 14 个不同种群的卵和成虫的磷化氢抗性。在 14 个成虫种群中的 4 个和鸡蛋中 14 个种群中的 9 个中检测到对磷化氢的抗性，范围从 2% 到 100%。三个种群（即 Box BR、Box BF 和 OKWat）的成虫和卵的磷化氢百分比存活率值 >90%。这三个种群的成人样本中杀死 99% 个体所需的致死浓度值分别预测为 320.5、290.7 和 263 ppm，鸡蛋的致死浓度值分别为 1030.7、1055.9 和 564.5 ppm，超过 72- h 熏蒸期。该研究证实，美国的 O. surinamensis 存在磷化氢抗性。