Table_6_Effect of surrounding landscape on Popillia japonica abundance and their spatial pattern within Wisconsin vineyards.docx

Landscapes surrounding agroecosystems can provide resources that may benefit insect pests. This project examined the influence of the surrounding landscape on the abundance and spatial pattern of Popillia japonica (Coleoptera: Scarabaeidae) in vineyards. Twenty vineyards across Southern Wisconsin, spanning a gradient of 5-80% cropland in a 1.5km radius surrounding landscape, were sampled in 2017 and 2018 for P. japonica adults and leaf injury. The distribution of P. japonica and leaf injury was assessed by sampling along a transect at the edge, halfway from the edge to the center, and at the center of each vineyard. The proportion of cropland and pasture in the surrounding landscape along with abiotic factors of temperature, precipitation, longitude, and pesticide use (determined using Environmental Impact Quotient) were included in models to explain the variation of P. japonica abundance and leaf injury. No significant relationship was observed between proportion cropland in the surrounding landscape and P. japonica abundance or leaf injury. Combined effects of pasture, longitude, and temperature best explained variation in the abundance of P. japonica adults while longitude, temperature and EIQ best explained variability in leaf injury. Vineyards with more pastures in the surrounding landscape, located further east, and with higher temperatures, generally had more P. japonica adults and vineyards further east with higher temperature and lower EIQ pesticide use generally had higher levels of leaf injury. Additionally, variability in weekly temperature and precipitation influenced weekly abundance, with higher temperatures and less precipitation resulting in greater weekly abundance of P. japonica adults. Significantly more adult P. japonica and greater leaf injury were found at the edges than in the center of vineyards. Our results suggest beetles from the surrounding landscape likely contribute to populations of P. japonica adults found feeding on vines on vineyard edges, and P. japonica abundance and associated leaf injury are influenced by geographical location, local weather conditions, and pesticide use.

农业生态系统周边的景观可为害虫提供有益的生存资源。本研究探讨了周边景观对葡萄园中日本金龟子（Popillia japonica，鞘翅目Coleoptera：金龟子科Scarabaeidae）种群丰度与空间分布格局的影响。研究于2017年与2018年对威斯康星州南部的20个葡萄园开展采样，这些葡萄园周边1.5km半径范围内的农田占比梯度为5%至80%，采样指标包括日本金龟子成虫种群数量与叶片受害程度。通过沿每个葡萄园的边缘、边缘至中心的中点以及果园中心设置样带进行采样，以此评估日本金龟子的分布与叶片受害情况。研究将周边景观中的农田与牧地占比，以及温度、降水量、经度和农药使用情况（通过环境影响商数Environmental Impact Quotient，EIQ测算）等非生物因子纳入模型，以解释日本金龟子种群丰度与叶片受害程度的变异。未发现周边景观中农田占比与日本金龟子种群丰度或叶片受害程度存在显著关联。牧地占比、经度与温度的联合效应最优解释了日本金龟子成虫种群丰度的变异；而经度、温度与EIQ则最优解释了叶片受害程度的变异。周边景观牧地占比更高、位置更偏东且温度更高的葡萄园，其日本金龟子成虫种群丰度通常更高；而位置更偏东、温度更高且EIQ农药使用量更低的葡萄园，其叶片受害程度通常也更严重。此外，周际温度与降水量的变异会影响种群的周度丰度变化：温度越高、降水量越少，日本金龟子成虫的周度种群数量便越高。葡萄园边缘的日本金龟子成虫数量与叶片受害程度均显著高于果园中心区域。本研究结果表明，周边栖息地的日本金龟子成虫可能是葡萄园边缘葡萄藤取食者种群的主要来源；而日本金龟子种群丰度及其伴随的叶片受害程度，受地理位置、局地气象条件与农药使用的共同影响。