Department of Grain Science and Industry, Kansas State University, Manhattan, KS 66506, USA.
J Econ Entomol. 2011 Feb;104(1):317-24. doi: 10.1603/ec10067.
Heat treatment of food-processing facilities involves using elevated temperatures (50-60 degrees C for 24-36 h) for management of stored-product insects. Heat treatment is a viable alternative to the fumigant methyl bromide, which is phased out in the United States as of 2005 because of its adverse effects on the stratospheric ozone. Very little is known about responses of the cigarette beetle, Lasioderma serricorne (F.) (Coleoptera: Anobiidae), a pest associated with food-processing facilities, to elevated temperatures. Responses of L. serricorne life stages to elevated temperatures were evaluated to identify the most heat-tolerant stage. Exposure of eggs, young larvae, old larvae, and adults during heat treatment of a food-processing facility did not clearly show a life stage to be heat tolerant. In the laboratory, exposure of eggs, young larvae, old larvae, pupae, and adults at fixed times to 46, 50, and 54 degrees C and 22% RH indicated eggs to be the most heat-tolerant stage. Time-mortality responses at each of these three temperatures showed that the time for 99% mortality (LT99) based on egg hatchability and egg-to-adult emergence was not significantly different from one another at each temperature. Egg hatchability alone can be used to determine susceptibility to elevated temperatures between 46 and 54 degrees C. The LT99 based on egg hatchability and egg-to-adult emergence at 46 degrees C was 605 and 598 min, respectively, and it decreased to 190 and 166 min at 50 degrees C and 39 and 38 min at 54 degrees C. An exponential decay equation best described LT99 as a function of temperature for pooled data based on egg hatchability and egg-to-adult emergence. Our results suggest that during structural heat treatments eggs should be used in bioassays for gauging heat treatment effectiveness, because treatments aimed at controlling eggs should be able to control all other L. serricorne life stages.
食品加工设施的热处理涉及使用高温（50-60°C 持续 24-36 小时）来管理储存产品中的昆虫。热处理是替代熏蒸剂甲基溴的可行方法，自 2005 年以来，由于其对平流层臭氧的不利影响，美国已逐步淘汰甲基溴。对于与食品加工设施相关的害虫烟草甲（Lasioderma serricorne（F.））（鞘翅目：拟步行甲科）对高温的反应，人们知之甚少。评估 L. serricorne 各生命阶段对高温的反应，以确定最耐热的阶段。在食品加工设施的热处理过程中，暴露于卵、幼虫、老幼虫和成虫，并未清楚显示出哪个生命阶段具有耐热性。在实验室中，将卵、幼虫、老幼虫、蛹和成虫在固定时间暴露于 46、50 和 54°C 和 22% RH 下，结果表明卵是最耐热的阶段。在这三个温度下的时间-死亡率响应表明，基于卵孵化率和卵到成虫的出现率的 99%死亡率（LT99）的时间在每个温度下彼此之间没有显著差异。单独的卵孵化率可用于确定在 46 至 54°C 之间对高温的敏感性。基于卵孵化率和卵到成虫的出现率的 46°C 下的 LT99 分别为 605 和 598 分钟，而在 50°C 下分别降低至 190 和 166 分钟，在 54°C 下分别降低至 39 和 38 分钟。基于卵孵化率和卵到成虫的出现率的汇集数据的 LT99 作为温度的函数，最佳描述为指数衰减方程。我们的结果表明，在结构热处理期间，在生物测定中应使用卵来评估热处理效果，因为旨在控制卵的处理应该能够控制 L. serricorne 的所有其他生命阶段。
