木瓜秀粉蚧在海南的适生性及空间分布型研究

The Potential Geographic Distribution and Spatial Pattern of Paracoccus marginatus in Hainan Province

木瓜秀粉蚧是热带和亚热带地区重要的危险性害虫,本研究利用最大熵模型(Max Ent)和地理信息系统(GIS)软件,依据该虫的分布数据和20个环境因子预测其在海南的适生性,并对木瓜秀粉蚧在木薯地中的空间分布型进行了分析。结果表明:木瓜秀粉蚧在海南的高度适生区主要有陵水、乐东、东方、昌江、海口西部等地,模型的AUC值为0.982,表明该模型预测结果可靠;影响其分布的主要环境因子有年均降水量、最冷季度平均温度、年温度变化范围和最湿润季度降水量等,因子贡献率分别为23.7%、16.5%、14.2%和12.1%;用聚集度指标法确定木瓜秀粉蚧在木薯上一定密度下的空间分布为聚集分布,并采用m*-m回归法和Taylor幂法则对其进行了验证;成虫在木薯植株上的分布,表现为上、中层的虫口密度显著高于下层。研究结果对提高木瓜秀粉蚧的监测和防控水平具有指导意义。

Paracoccus mar ginatus Williams and Granara de Willink is one of the most serious pests in tropical and subtropical regions. In this paper, the areas of potential geographic distribution and the suitability level in Hainan for P. marginatus was predicted using Max Ent and Arc GIS software, based on which the distribution of P.marginatus and 20 environmental factors, and spatial pattern of P. marginatus in cassava field was researched.The results showed that the optimum suitable areas in Hainan was mainly in Lingshui, Ledong, Dongfang,Changjiang, western Haikou, and other areas, and the AUC value of Max Ent ecological niche models reached 0.982, indicating that the predicted results was fairly well. Results showed that annual precipitation（the contribution rate is 23.7%）, mean temperature of coldest quarter（16.5%）, temperature seasonality（14.2%） and precipitation of wettest quarter（12.1%） were the forcing environmental factors. The results showed that the adults of P. marginatus presented an aggregated distribution under certain density condition, and results were tested by m^＊-m regression formulations and power law of Taylor using related aggregation index. Furthermore, the number of P. marginatus on the upper or middle of cassava was significantly greater than on the lower part. This study would provide technical support for the long-term and efficient monitoring of the occurrence and harm of P. marginatus.