Department of Entomology, Texas A&M University, College Station, TX, USA.
School of Chemistry, University of Lincoln, Lincoln-Lincolnshire, United Kingdom.
J Therm Biol. 2019 Oct;85:102405. doi: 10.1016/j.jtherbio.2019.102405. Epub 2019 Aug 28.
Determining the thermal tolerance of an organism is important when assessing its activity time and survival rate in a given environment. However, thermal tolerance is not a static trait and may be influenced by a number of environmental and organismal factors. We report the results of three experiments investigating the effects of environmental temperature, exposure duration, age, sex, and nutrient availability on the upper thermal tolerance of the adult secondary screwworm, Cochliomyia macellaria. The probability of knockdown and survival was determined using a static method for different environmental temperatures (22, 40, 42, 44, or 45 °C), exposure durations (1, 2, 4, or 6 h), and nutrient availabilities (no food or water, water only, or both food and water) for both sexes and two age classes (young = 7-9 days post pupal emergence, old = 10-12 days post pupal emergence). In general, environmental temperature and exposure duration had the greatest effects on both the probability of knockdown and survival. As temperature or duration increased, the probability of knockdown increased while the probability of survival decreased. The availability of nutrients (water only or food and water) increased thermal tolerance at moderate temperatures (42 and 44 °C), but had no effect at 45 °C. Female flies were more thermally tolerant than males, regardless of nutrient availability. And age exhibited negligible effects on the probabilities of knockdown or survival, regardless of nutrient availability. These data show multiple environmental factors affected the thermal tolerance of C. macellaria. Thus, such aspects of basic thermal biology should feature more prominently in applied fields using blow flies, including but not limited to forensic entomology, disease ecology, and pollination ecology.
确定生物体的耐热性在评估其在特定环境中的活动时间和存活率时非常重要。然而，耐热性不是一个静态特征，可能会受到许多环境和生物体因素的影响。我们报告了三项实验的结果，这些实验研究了环境温度、暴露持续时间、年龄、性别和营养供应对成年次生螺旋蝇 Cochliomyia macellaria 上限耐热性的影响。使用静态方法确定了不同环境温度（22、40、42、44 或 45°C）、暴露持续时间（1、2、4 或 6 小时）和营养供应（无食物和水、只有水或食物和水）下雌雄两性和两个年龄组（幼龄=化蛹后 7-9 天，老龄=化蛹后 10-12 天）的击倒概率和存活率。一般来说，环境温度和暴露持续时间对击倒概率和存活率都有最大的影响。随着温度或持续时间的增加，击倒的概率增加，而存活的概率降低。在中等温度（42 和 44°C）下，营养物质的可用性（仅水或食物和水）增加了耐热性，但在 45°C 时没有影响。无论营养供应如何，雌性苍蝇比雄性苍蝇更耐热。年龄对击倒概率或存活率的影响可以忽略不计，无论营养供应如何。这些数据表明，多种环境因素影响了 C. macellaria 的耐热性。因此，在使用苍蝇的应用领域中，包括但不限于法医昆虫学、疾病生态学和授粉生态学，基本热生物学的这些方面应该更加突出。
