Department of Crop and Forest Sciences, University of Lleida-Agrotecnio-CERCA Center, Lleida, Spain.
Centro de Investigação de Montanha, Instituto Politécnico de Bragança, Bragança, Portugal.
Pest Manag Sci. 2022 Oct;78(10):4223-4233. doi: 10.1002/ps.7040. Epub 2022 Jul 12.
Temperature directly influences the survival, development and reproduction of insects and limits their biological activity. The alfalfa weevil (Hypera postica Gyllenhal) is a destructive pest of alfalfa crops in Spain and in most of the alfalfa production countries. The knowledge of how temperature affects the fitness of this pest can be used to predict its activity in current or forecasted environmental conditions and to develop more accurate control strategies.
We evaluated the fitness of alfalfa weevil at eight constant temperatures (8-36 °C) at 4 °C intervals by using life tables and models for the description of temperature-dependent development rates. We found that most of the parameters we studied were temperature dependent. Development was observed at all temperatures. However, postembryonic survival was optimal at 16 °C but very low at 36 °C. Adults did not reproduce at 8, 32 or 36 °C. The highest fecundity and net reproductive rate were observed at 20 °C, but the highest intrinsic rate of increase occurred at 24 °C. We predicted the phenology of the pest based on the heat needed for development, the cumulative degree days from the beginning of October to the end of May, and the day length in the study region.
Our prediction was validated using field data reporting the first occurrence of larval instars and adults, revealing that no more than two generations are possible within an annual cycle. In a hypothetical case where average monthly temperatures increase by 1-2 °C, the number of generations would not change. © 2022 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
温度直接影响昆虫的生存、发育和繁殖，并限制其生物活动。苜蓿叶象（Hypera postica Gyllenhal）是西班牙和大多数苜蓿生产国家苜蓿作物的一种破坏性害虫。了解温度如何影响这种害虫的适合度，可以用来预测其在当前或预测的环境条件下的活动，并制定更准确的控制策略。
我们通过生命表和描述温度依赖性发育率的模型，在 8-36°C 的 8 个恒温下评估了苜蓿叶象的适合度，恒温间隔为 4°C。我们发现，我们研究的大多数参数都是温度依赖的。在所有温度下都观察到了发育。然而，胚胎后存活率在 16°C 时最佳，但在 36°C 时非常低。成虫在 8、32 或 36°C 时不繁殖。在 20°C 时观察到最高的繁殖力和净生殖率，但最高的内禀增长率发生在 24°C。我们根据发育所需的热量、10 月初至 5 月底的累积度日以及研究区域的日照长度来预测害虫的物候。
我们使用报告幼虫和成虫首次出现的田间数据验证了我们的预测，结果表明，在一个年度周期内，不可能出现超过两代的情况。在平均每月温度升高 1-2°C 的假设情况下，世代数量不会改变。© 2022 作者。Pest Management Science 由 John Wiley & Sons Ltd 代表化学工业协会出版。
