Thermoprofile Parameters Affect Survival of Megachile rotundata During Exposure to Low-Temperatures
Thermoprofile Parameters Affect Survival of Megachile rotundata During Exposure to Low-Temperatures
复制标题
热分布参数影响大叶轮在低温下的存活
DOI：
10.1093/icb/icz126
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发表时间：
2019
影响因子：
2.6
通讯作者：
Greenlee, Kendra J.
中科院分区：
文献类型：
--
作者：
Yocum, George D.;Rinehart, Joseph P.;Rajamohan, Arun;Bowsher, Julia H.;Yeater, Kathleen M.;Greenlee, Kendra J.
暴露在低温胁迫下的昆虫可能会遭受寒冷伤害，但结合波动的温度曲线可以提高存活率并阻止亚致死效应的发展。人们对保护性热分布所需的具体参数知之甚少，因为大多数研究测试的热分布范围有限。例如，具有波形轮廓的热轮廓可能比方形轮廓表现更好，但是很少对这两个轮廓进行比较。在这项研究中，苜蓿切叶蜂（Megachile rotundata）、有眼色素的蛹和准备羽化的成虫的两个发育阶段暴露于八种温度曲线中的一种，时间长达 8 周。所有热曲线的基础温度均为 6°C，峰值温度为 12°C 或 18°C。峰值温度的持续时间根据热曲线的形状（方形或波形）而变化。另外两种处理作为对照，即恒定 6°C 和基础温度为 6°C 的波动热状态 (FTR)，每天通过 20°C 的单个 1 小时脉冲中断。与恒定 6°C 相比，所有测试热曲线均显着提高了存活率。与 FTR 控制相比，峰值温度为 18°C 的热曲线优于 12°C 曲线。暴露于 18°C 轮廓的眼睛色素阶段的蜜蜂根据轮廓的形状分为两组，与波浪轮廓相比，方形轮廓的存活率更高。暴露于 18°C 环境的羽化准备阶段的蜜蜂均比 FTR 对照中的蜜蜂有显着更高的存活率。与预期相反，与生态相关性最差的热曲线（方形）具有最高的存活率，并阻止了亚致死效应的发展（延迟出现）。
Insects exposed to low temperature stress can experience chill injury, but incorporating fluctuating thermoprofiles increases survival and blocks the development of sub-lethal effects. The specific parameters required for a protective thermoprofile are poorly understood, because most studies test a limited range of thermoprofiles. For example, thermoprofiles with a wave profile may perform better than a square profile, but these two profiles are rarely compared. In this study, two developmental stages of the alfalfa leafcutting bee,Megachile rotundata, eye-pigmented pupae, and emergence-ready adults, were exposed to one of eight thermoprofiles for up to 8 weeks. All the thermoprofiles had a base of 6°C and a peak temperature of either 12°C or 18°C. The duration at peak temperature varied depending on the shape of the thermoprofile, either square or wave form. Two other treatments acted as controls, a constant 6°C and a fluctuating thermal regime (FTR) with a base temperature of 6°C that was interrupted daily by a single, 1-h pulse at 20°C. Compared with constant 6°C, all the test thermoprofiles significantly improved survival. Compared with the FTR control, the thermoprofiles with a peak temperature of 18°C outperformed the 12°C profiles. Bees in the eye-pigmented stage exposed to the 18°C profiles separated into two groups based on the shape of the profile, with higher survival in the square profiles compared with the wave profiles. Bees in the emergence-ready stage exposed to 18°C profiles all had significantly higher survival than bees in the FTR controls. Counter to expectations, the least ecologically relevant thermoprofiles (square) had the highest survival rates and blocked the development of sub-lethal effects (delayed emergence).