Department of Entomology, University of Minnesota, 219 Hodson Hall, 1980 Folwell Avenue, St. Paul, MN 55108, USA.
J Econ Entomol. 2011 Aug;104(4):1423-9. doi: 10.1603/ec10429.
The mold mite Tyrophagus putrescentiae (Shrank) is a common pest of stored food products. Until recently, commodity and facility treatments have relied on acaricides and fumigants to control this mite. However, T. putrescentiae will cause infestations in areas where acaricide or fumigant use may be restricted, prohibited, or highly impractical. Because temperature is an essential factor that limits the survival of arthropod species, extreme temperatures can be exploited as an effective method of control. Making low-temperature treatments reliable requires better temperature-time mortality estimates for different stages of this mite. This was accomplished by exposing a representative culture (eggs, nymphs, and adults) of noncold-acclimated T. putrescentiae to subfreezing temperatures to determine their supercooling points (SCPs), lower lethal temperatures (LLTs) and lethal times (LTimes) at set temperatures. The results indicate that the adult and nymphal stages of T. putrescentiae are freeze intolerant; based on 95% CIs, the adult LLT90 of -22.5 degrees C is not significantly different from the SCP of -24.2 degrees C and the nymphal LLT90 of -28.7 degrees C is not significantly different from the SCP of -26.5 degrees C. The egg stage seems to be freeze tolerant, with an LLT90 of -48.1 degrees C, significantly colder by approximately 13.5 degrees C than its SCP of -35.6 degrees C. The LTime demonstrates that 90% of all mite stages of T. putrescentiae can be controlled within commodity or packaged product by freezing to -18 degrees C for 5 h. By achieving the recommended time and temperature exposures, freezing conditions can be an effective way of controlling mites and reducing chronic infestations.
腐食酪螨（ Tyrophagus putrescentiae ）是一种常见的储存食品害虫。直到最近，商品和设施处理还依赖于杀螨剂和熏蒸剂来控制这种螨虫。然而，在杀螨剂或熏蒸剂使用可能受到限制、禁止或极不切实际的地方，腐食酪螨会引起虫害。因为温度是限制节肢动物物种生存的一个重要因素，所以极端温度可以被利用来作为一种有效的控制方法。要使低温处理可靠，需要对这种螨虫的不同阶段进行更好的温度-时间致死估计。这是通过将非耐寒驯化的腐食酪螨的代表性培养物（卵、若虫和成虫）暴露于亚冷冻温度下，以确定其过冷点（SCP）、致死低温（LLT）和在设定温度下的致死时间（LTimes）来实现的。结果表明，腐食酪螨的成虫和若虫阶段不耐冻；基于 95%置信区间，成虫的 LLT90 为-22.5°C，与 SCP -24.2°C 没有显著差异，若虫的 LLT90 为-28.7°C，与 SCP -26.5°C 没有显著差异。卵期似乎耐冻，其 LLT90 为-48.1°C，比 SCP -35.6°C 冷约 13.5°C。LTimes 表明，在商品或包装产品中，通过在-18°C下冷冻 5 小时，可以控制腐食酪螨的所有若虫阶段的 90%。通过达到推荐的时间和温度暴露，可以将冷冻条件作为控制螨虫和减少慢性虫害的有效方法。
