Species distribution models can predict the suitable climatic range of a potential biological control agent (BCA), but they provide little information on the BCA's potential impact. To predict high population buildup, a prerequisite of biocontrol impact, studies are needed that assess the effect of environmental factors on vital rates of a BCA across the environmental gradient of the BCA's suitable habitats, especially for the region where the BCA is considered for field release. We extended a published species distribution model with climate-dependent vital rates of Ophraella communa, a recently and accidentally introduced potential BCA of common ragweed, Ambrosia artemisiifolia in Europe. In field and laboratory experiments, we collected data on climate-dependent parameters assumed to be the most relevant for the population buildup of O. communa, i.e., temperature driving the number of generations per year and relative humidity (RH) determining egg hatching success. We found that O. communa concluded one generation in 334 cumulative degree days, and that egg hatching success strongly decreased from > 80% to < 20% when RH drops from 55% to 45% during the day. We used these values to spatially explicitly project population densities across the European range suitable for both A. artemisiifolia and the beetle and found that the present distribution of the beetle in Europe is within the range with the highest projected population growth. The highest population density of O. communa was predicted for northern Italy and parts of western Russia and western Georgia. Field observations of high impact on A. artemisiifolia with records of 80% aerial pollen reduction in the Milano area since the establishment of O. communa are in line with these predictions. The relative importance of temperature and RH on the population density of O. communa varies considerably across its suitable range in Europe. We propose that the combined statistical and mechanistic approach outlined in this paper helps to more accurately predict the potential impact of a weed BCA than a species distribution model alone. Identifying the factors limiting the population buildup of a BCA across the suitable range allows implementation of more targeted release and management strategies to optimize biocontrol efficacy.

中文翻译：

---

预测生物防治剂的影响：将分布模型与气候相关的生命率集成在一起。

物种分布模型可以预测潜在生物防治剂（BCA）的合适气候范围，但它们几乎没有提供有关BCA潜在影响的信息。为了预测高种群增长，这是生物防治影响的先决条件，需要进行研究以评估环境因素对BCA合适栖息地的环境梯度范围内BCA生命率的影响，特别是对于考虑将BCA释放的地区。我们扩展了已发布的物种分布模型，该模型具有与气候有关的欧弗拉菌通气率，这是最近偶然引入的常见豚草欧洲青蒿的潜在BCA。在野外和实验室实验中，我们收集了与气候有关的参数的数据，这些参数被认为与O种群的增长最相关。communa，即，温度驱动每年的世代数和相对湿度（RH）决定卵孵化成功。我们发现，沙丁鱼在334个累积度日内结束了一代，卵孵化成功率在白天从RH的55％降至45％时从> 80％大大降低到<20％。我们使用这些值在空间上明确地预测了适用于青蒿和甲虫的整个欧洲范围内的人口密度，并发现欧洲目前甲虫的分布在预计人口增长最高的范围内。据预测，意大利北部，俄罗斯西部的部分地区和乔治亚州西部的com.una种群密度最高。对A有高影响的实地观察。自建立欧米茄以来，米兰地区的花粉减少80％的记录与这些预测是一致的。温度和相对湿度对欧洲通temperature种群密度的相对重要性在欧洲的适当范围内变化很大。我们建议，与单独的物种分布模型相比，本文概述的统计和机理相结合的方法有助于更准确地预测杂草BCA的潜在影响。确定限制BCA种群在适当范围内积累的因素，可以实施更具针对性的释放和管理策略，以优化生物防治功效。communa在其适合的欧洲范围内差异很大。我们建议，与单独的物种分布模型相比，本文概述的统计和机理相结合的方法有助于更准确地预测杂草BCA的潜在影响。确定限制BCA种群在适当范围内积累的因素，可以实施更具针对性的释放和管理策略，以优化生物防治功效。communa在其适合的欧洲范围内差异很大。我们建议，与单独的物种分布模型相比，本文概述的统计和机理相结合的方法有助于更准确地预测杂草BCA的潜在影响。确定限制BCA种群在适当范围内积累的因素，可以实施更具针对性的释放和管理策略，以优化生物防治功效。