Sales Kris, Vasudeva Ramakrishnan, Gage Matthew J G
School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK.
R Soc Open Sci. 2021 Mar 10;8(3):201717. doi: 10.1098/rsos.201717.
With climate change creating a more volatile atmosphere, heatwaves that create thermal stress for living systems will become stronger and more frequent. Using the flour beetle , we measure the impacts of thermal stress from experimental heatwaves in the laboratory on reproduction and survival across different insect life stages, and the extent and pace of any recovery. We exposed larvae, pupae, juvenile and mature adult male beetles to 5-day periods of heat stress where temperatures were maintained at either 40°C or 42°C, a few degrees above the 35°C optimum for this species' population productivity, and then measured survival and reproduction compared with controls at 30°C. Mortality due to thermal stress was greatest among juvenile life stages. Male reproductive function was specifically damaged by high temperatures, especially if experienced through pupal or immature life stages when complete sterility was shown at reproductive maturity; larval exposure did not damage adult male fertility. High temperatures impaired testis development and the production of viable sperm, with damage being strongest when experienced during pupal or juvenile adult stages. Despite this disruption, males recovered from heat stress and, depending on the stage of exposure, testis size, sperm production and fertility returned to normal 15-28 days after exposure. Our experiments reveal how thermal stress from heatwave conditions could impact on insect survival and reproduction across different life stages, and the potential and timescales of recovery.
随着气候变化导致大气更加不稳定，给生物系统造成热应激的热浪将变得更强烈、更频繁。我们以面粉甲虫为研究对象，在实验室中通过实验性热浪来测量热应激对不同昆虫生命阶段的繁殖和生存的影响，以及任何恢复的程度和速度。我们将幼虫、蛹、幼年和成年雄性甲虫暴露于为期5天的热应激环境中，温度保持在40°C或42°C，比该物种种群生产力的最佳温度35°C高出几度，然后与30°C下的对照组相比，测量其生存和繁殖情况。热应激导致的死亡率在幼年生命阶段最高。高温特别损害雄性生殖功能，尤其是在蛹期或未成熟生命阶段经历高温时，生殖成熟时会出现完全不育；幼虫期暴露不会损害成年雄性的生育能力。高温会损害睾丸发育和有活力精子的产生，在蛹期或幼年成年阶段经历高温时损害最为严重。尽管受到这种干扰，雄性仍能从热应激中恢复，根据暴露阶段的不同，暴露后15 - 28天睾丸大小、精子产生和生育能力会恢复正常。我们实验揭示了热浪条件下热应激如何影响不同生命阶段昆虫的生存和繁殖，以及恢复的可能性和时间尺度。
