Colinet Hervé, Lehnhoff Coline, Raynaud-Berton Bréa
Université de Rennes, CNRS, ECOBIO (Ecosystèmes, Biodiversité, Évolution) Rennes France.
Ecol Evol. 2025 Jun 4;15(6):e71515. doi: 10.1002/ece3.71515. eCollection 2025 Jun.
In insects, thermal fertility limits have a narrower tolerance range than survival. Therefore, deciphering these critical limits is crucial for understanding population dynamics during or after harsh winter or summer periods. Here investigated the impact of temperature on male fertility in the invasive pest, . We assessed both developmental and postemergence temperatures, using a range of 11 temperatures from 10°C to 30°C and varying chronic exposure durations. The results revealed asymmetrical thermal performance curves for male fertility, with thermal fertility limits (TFLmin and TFLmax) between 9.8°C and 29°C for developmental temperatures and between 10.05°C and 34.8°C for adult temperatures. Males developed at sub- or supraoptimal temperatures were sterile at emergence, and no recovery occurred if the temperature was maintained. Males developed and maintained at supra-optimal temperatures were more sensitive than those exposed to supra-optimal conditions only during the adult stage, highlighting the cumulative effects of thermal stress across life stages. Supra-optimal temperatures only at the adult stage induced some sterility in initially fertile males after a few days, whereas males exposed to suboptimal temperatures never reached fertility, remaining sterile throughout the experiment. Males that underwent winter-like cold-acclimation were in reproductive quiescence and progressively regained fertility when transferred to 20°C. Morphometric analyses of reproductive organs showed that cold-acclimated winter males had anatomical traits similar to the controls after 12 days of recovery. Despite this, mating tests indicated that cold-acclimated males were less attractive to females, suggesting a cost on reproductive potential. This study defines the thermal limits for male sterility under chronic exposure and highlights a partial recovery of fertility in cold-acclimated winter males. It thus provides key insights into the population dynamics of after winter.
在昆虫中，热生育极限的耐受范围比生存的耐受范围更窄。因此，解读这些关键极限对于理解严冬或酷暑期间及之后的种群动态至关重要。在此，我们研究了温度对入侵害虫[害虫名称未给出]雄性生育力的影响。我们评估了发育温度和羽化后的温度，使用了从10°C到30°C的11个温度范围以及不同的长期暴露时长。结果揭示了雄性生育力的不对称热性能曲线，发育温度下的热生育极限（TFLmin和TFLmax）在9.8°C至29°C之间，成虫温度下的热生育极限在10.05°C至34.8°C之间。在次优或超优温度下发育的雄性在羽化时不育，如果温度保持不变则不会恢复生育力。在超优温度下发育并维持的雄性比仅在成虫阶段暴露于超优条件下的雄性更敏感，这突出了热应激在整个生命阶段的累积效应。仅在成虫阶段的超优温度在几天后会使初始可育的雄性产生一些不育，而暴露于次优温度下的雄性从未达到生育力，在整个实验过程中一直不育。经历了类似冬季冷驯化的雄性处于生殖静止状态，当转移到20°C时逐渐恢复生育力。生殖器官的形态计量分析表明，冷驯化的冬季雄性在恢复12天后具有与对照组相似的解剖特征。尽管如此，交配试验表明冷驯化的雄性对雌性的吸引力较小，这表明其生殖潜力存在代价。本研究确定了长期暴露下雄性不育的热极限，并突出了冷驯化的冬季雄性生育力的部分恢复。因此，它为[害虫名称未给出]冬季后的种群动态提供了关键见解。
