College of Plant Protection, State Key Laboratory of Yunnan Biological Resources Protection and Utilization, Yunnan Agricultural University, Kunming, 650201, China.
Tea Research Institute, Yunnan Academy of Agricultural Sciences, Kunming, 650205, China.
Parasit Vectors. 2024 Oct 5;17(1):418. doi: 10.1186/s13071-024-06480-6.
The effects of low temperatures on parasitic wasps are crucial for maintaining farmland biodiversity and enhancing biological control, especially given the implications of global warming and frequent extreme cold events.
We studied the effects of different low temperatures (-8 ± 1 °C, -4 ± 1 °C, 0 ± 1 °C, 4 ± 1 °C, and 8 ± 1 °C) on the mating frequency and duration of male adults of Trichopria drosophilae and the number of pupae beaten by female adults, and constructed the age-stage two-sex life table of T. drosophilae.
This study found that male T. drosophilae adults exposed to low temperatures for 12 h significantly altered their mating behavior, peaking between 15:00 and 17:00. As the temperature dropped during the exposure, both the mating frequency of T. drosophilae and the duration of pupal beating were affected. The survival rate of female adults dropped from 39.55% at 8 °C to just 21.17% at -8 °C. Low-temperature treatment shortened the development period and lifespan for T. drosophilae adults. They developed 4.71 days faster and had a total lifespan that was 10.66 days shorter than those in the control group after being exposed to -8 °C. Furthermore, the average number of eggs laid by females at -8 °C was 4.46 less than that at 8 °C and 6.16 less than that in the control group, which laid an average of 21.55 eggs. The net reproductive rate (R) of T. drosophilae decreased with lower temperatures, reaching a low of 23.64 at -8 °C. Conversely, the intrinsic growth rate (r) actually increased as temperatures dropped, with the lowest value being 0.21 at -8 °C.
The findings indicate that short-term exposure to low temperatures hampers the growth and population increase of T. drosophilae, thereby reducing their effectiveness as biological control agents.
低温对寄生蜂的影响对于维持农田生物多样性和增强生物防治至关重要，特别是考虑到全球变暖的影响和频繁出现的极端寒冷事件。
我们研究了不同低温（-8±1°C、-4±1°C、0±1°C、4±1°C 和 8±1°C）对黑带食蚜蝇雄成虫交配频率和交配持续时间以及雌成虫击打蛹数的影响，并构建了黑带食蚜蝇的龄期-两性生命表。
本研究发现，暴露于低温 12 小时的黑带食蚜蝇雄成虫的交配行为显著改变，在 15:00 至 17:00 之间达到高峰。随着暴露期间温度的降低，黑带食蚜蝇的交配频率和蛹击打的持续时间都受到影响。雌成虫的存活率从 8°C时的 39.55%下降到-8°C时的 21.17%。低温处理缩短了黑带食蚜蝇成虫的发育周期和寿命。与对照组相比，它们在暴露于-8°C 时发育速度快了 4.71 天，总寿命缩短了 10.66 天。此外，雌虫在-8°C 时产的卵平均比 8°C 时少 4.46 个，比对照组少 6.16 个，对照组平均产卵 21.55 个。黑带食蚜蝇的净生殖率（R）随温度降低而降低，在-8°C 时达到最低值 23.64。相反，内禀增长率（r）随着温度的降低而实际增加，在-8°C 时达到最低值 0.21。
研究结果表明，短期暴露于低温会阻碍黑带食蚜蝇的生长和种群增加，从而降低其作为生物防治剂的效果。
