Meurisse Nicolas, Pawson Stephen
Scion, Rotorua, New Zealand.
Scion, Ilam, Christchurch, New Zealand.
PLoS One. 2017 Apr 13;12(4):e0174111. doi: 10.1371/journal.pone.0174111. eCollection 2017.
Long distance dispersal to locate suitable breeding sites is recognized as a key trait influencing the population dynamics and distribution of bark beetles and other saprophytic insects. While dispersal behavior has been studied for a range of aggressive 'tree killing' bark beetles, few have considered the dispersal behaviour of non-aggressive saprophytic bark beetles that utilize kairomones (host volatiles). We present the results of a mark-recapture experiment that examined adult dispersal patterns of the saprophytic bark beetle Hylurgus ligniperda. Releases took place in summer and autumn 2014, in a clearcut pine forest in the central North Island, New Zealand. Both flight-experienced and flight-naïve adults were marked and released in the center of a circular trap grid that extended to 960 m with 170 or 200 panel traps baited with a kairomone blend of alpha-pinene and ethanol. Of the 18,464 released H. ligniperda, 9,209 (49.9%) of the beetles flew, and 96 (1.04%) of the beetles that flew were recaptured. Individuals were recaptured at all distances. The recapture of flight-experienced beetles declined with dispersal distance, and a diffusion model showed heterogeneous dispersal tendencies within the population. Our best model estimated that 46% of flight-experienced beetles disperse > 1 km, and 1.6% > 5 km. Conversely, no declining pattern was shown in the recapture of flight-naïve beetles, suggesting that emerging H. ligniperda may require a period of flight to initiate chemotropic orientation behavior and subsequent attraction to traps. We discuss the implications of these findings for the management of phytosanitary risks. For instance, combining landscape knowledge of source populations with dispersal processes facilitates estimation of pest pressure at economically sensitive areas such as harvest and timber storage sites. Quantitative dispersal estimates also inform pest risk assessments by predicting spread rates for H. ligniperda that has proven establishment capabilities in other countries.
长途扩散以寻找合适的繁殖地点被认为是影响树皮甲虫和其他腐生昆虫种群动态及分布的关键特性。虽然已经对一系列具有攻击性的“杀树”树皮甲虫的扩散行为进行了研究，但很少有人考虑利用信息素（寄主挥发物）的非攻击性腐生树皮甲虫的扩散行为。我们展示了一项标记重捕实验的结果，该实验研究了腐生树皮甲虫木长小蠹（Hylurgus ligniperda）成虫的扩散模式。释放实验于2014年夏秋季节在新西兰北岛中部一片皆伐的松树林中进行。有飞行经验和无飞行经验的成虫均被标记并释放到一个圆形诱捕网格的中心，该网格延伸至960米，设有170或200个用α-蒎烯和乙醇的信息素混合物诱饵的诱捕板。在释放的18464只木长小蠹中，有9209只（49.9%）飞行，飞行的甲虫中有96只（1.04%）被重新捕获。在各个距离都有甲虫被重新捕获。有飞行经验的甲虫的重捕率随扩散距离下降，扩散模型显示种群内存在异质扩散趋势。我们的最佳模型估计，46%有飞行经验的甲虫扩散超过1公里，1.6%超过5公里。相反，无飞行经验的甲虫的重捕率没有呈现下降模式，这表明新羽化的木长小蠹可能需要一段时间的飞行来启动向化性定向行为并随后被诱捕器吸引。我们讨论了这些发现对植物检疫风险管理方面的影响。例如，将源种群的景观知识与扩散过程相结合，有助于估计经济敏感区域（如采伐和木材储存地点）的害虫压力。定量扩散估计还通过预测在其他国家已证实具有定殖能力的木长小蠹的传播速度，为害虫风险评估提供信息。
