Abstract Adults and larvae of the khapra beetle, Trogoderma granarium Everts were exposed to 3000 ppm of phosphine through the Phosphine Tolerance Test. In a first series of bioassays, observations were taken every 2 min and the exposed individuals were classified either as walking normally or as being immobilized (knocked down), i.e., not walking normally. In the second series of bioassays all individuals were exposed for 90 min to phosphine. For both bioassays delayed mortality was noted after a 7 and 14-day post exposure interval. Larvae were found to be more tolerant than adults, as the time required for the individuals to be immobilized was up to 20 min, which was almost twice as long as the time required for the immobilization of the adults. There were high levels of adult mortality 7 days later, and complete (100%) mortality 14 days after the exposure. In contrast, larval mortality was low, for both post-exposures. Adults were 100% immobilized after the termination of the 90-min exposure interval at 3000 ppm of phosphine, while the percentage of the active larvae was extremely low. Regarding the 7 days post exposure interval the percentage of larval immobilization was higher than that of adults, but this was reversed seven days later. Interestingly, development of the larvae was delayed compared to the control, after the 90 min exposure, in contrast to 20 min exposure which did not cause any delayed effect. Our work provides some first data for the evaluation of the influence of short exposures to phosphine on adults and larvae of T. granarium, which may be very useful in creating an effective initial quantification plan for the control of this species.

中文翻译：

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短时间接触磷化氢对 khapra 甲虫、Trogoderma granarium 成虫和幼虫的直接和延迟影响

摘要 通过磷化氢耐受性测试，将 khapra 甲虫 Trogoderma granarium Everts 的成虫和幼虫暴露于 3000 ppm 的磷化氢中。在第一组生物测定中，每 2 分钟进行一次观察，将暴露的个体分类为正常行走或固定（被击倒），即不能正常行走。在第二组生物测定中，所有个体都暴露于磷化氢中 90 分钟。对于这两种生物测定，在暴露后 7 天和 14 天间隔后注意到延迟死亡率。发现幼虫比成虫更耐受，因为个体被固定所需的时间长达 20 分钟，几乎是成虫所需时间的两倍。7 天后成人死亡率很高，和暴露后 14 天完全 (100%) 死亡率。相比之下，两种暴露后的幼虫死亡率都较低。在 3000 ppm 膦的 90 分钟暴露间隔终止后，成虫 100% 被固定，而活跃幼虫的百分比极低。关于暴露后 7 天的间隔，幼虫固定的百分比高于成虫，但 7 天后情况发生逆转。有趣的是，与对照相比，暴露 90 分钟后幼虫的发育延迟，而暴露 20 分钟则不会引起任何延迟效应。我们的工作为评估短时间暴露于磷化氢对 T. granarium 成虫和幼虫的影响提供了一些初步数据，