Context

The pine wood nematode (PWN) is an invasive species which was introduced into Europe in 1999. It represents a major economic and ecological threat to European forests. In Europe, the maritime pine is the main host and Monochamus galloprovinciallis is its only vector.

Objectives

Our goal was to analyze the effect of landscape heterogeneity on the vector’s dispersal. We further aimed at developing a new method to locate the origin of insects captured in a systematic network of pheromone traps.

Methods

A mark-release-recapture experiment was carried out in a heterogeneous landscape combining maritime pine plantations, clear-cuts and isolated patches of broadleaved and mixed forests in the southwest of France. Least-cost path analysis was used to model dispersal trajectories and assign friction values to each land-use type in the landscape. We used the trap’s geographical coordinates, capture levels and mean friction values of neighbouring patches to calculate a weighed barycentre and the position of the release of marked beetles.

Results

Least Cost Path modelling revealed the vector’s tendency to avoid habitat patches such as mixed or deciduous forests and not avoid clear-cuts. The weighted barycentre method was greatly improved when the friction values of the trap’s surrounding land-uses were used.

Conclusions

Our study demonstrates the value of applying landscape ecology concepts and methods to improve our understanding and prediction of pest invasion processes. A practical application is the design of systematic grids of pheromone traps to locate the infection focus from which PWN vectors originate in a newly colonized area.

中文翻译：

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对跨异质景观的Monochamus galloprovincialis分散轨迹建模以通过捕获网络来优化监视

语境

松木线虫（PWN）是一种入侵物种，于1999年引入欧洲。它代表了对欧洲森林的主要经济和生态威胁。在欧洲，海洋松是主要寄主，而Monochamus galloprovinciallis是其唯一媒介。

目标

我们的目标是分析景观异质性对矢量扩散的影响。我们进一步旨在开发一种新方法来定位在信息素陷阱的系统网络中捕获的昆虫的起源。

方法

在法国西南部的海洋松树人工林，开阔地带和阔叶混交林的孤立斑块的异质景观中进行了标记释放-重新捕获实验。最小成本路径分析用于对分散轨迹进行建模，并为景观中的每种土地利用类型分配摩擦值。我们使用陷阱的地理坐标，捕获水平和邻近斑块的平均摩擦值来计算称重重心和标记甲虫释放的位置。

结果

最小成本路径建模表明，矢量趋向于避免生境斑块（如混交或落叶林），并且避免避免砍伐。当使用捕集阱周围土地利用的摩擦值时，加权重心法得到了极大的改进。

结论

我们的研究证明了应用景观生态学概念和方法来提高我们对害虫入侵过程的理解和预测的价值。实际应用是设计信息素陷阱的系统网格，以定位感染的焦点，PWN载体从感染点起源于新定居的区域。