入侵害虫悬铃木方翅网蝽越冬后期在豫北寄主树干上的分布研究

【目的】入侵害虫悬铃木方翅网蝽近年来严重威胁我国城市行道树二球悬铃木的健康,受害严重时造成树木死亡。在越冬后期对悬铃木树干上的悬铃木方翅网蝽成虫的越冬习性开展研究,能为冬季防治积累生物学研究基础。【方法】早春随机调查河南省新乡市行道树二球悬铃木树干栓皮层外层下方隐藏的悬铃木方翅网蝽成虫,比较阳侧和阴侧虫口密度。同时记载悬铃木树干0.00~0.50 m、0.51~1.00 m、1.01~1.50 m、1.51~2.00 m 4个不同高度区段范围和树干皮层外层皲裂程度在5%以下、5%~25%、25%~50%、50%~75%、75%~95%、95%以上6个等级条件下害虫的虫口密度。【结果】栖息在悬铃木树干树皮下方的悬铃木方翅网蝽在阴面更多,阴面和阳面的虫口密度差异达极其显著水平(F=6.63)(F0.01(1,19)=1.0132),P=0.00]。对寄主树干4个不同高度区段的虫口密度比较后,发现在树干1.0~1.5 m区段间的虫口密度最大,平均11.5头;且虫口密度在悬铃木不同高度区段间存在极显著差异(F=26.91)(F0.01(3,56)=4.1519),P=0.00]。悬铃木树皮的不同皲裂程度对悬铃木方翅网蝽虫口密度的影响达极其显著水平(F=31.02)(F0.01(3,56)=4.1519),P=0.00],在树皮外皮50%~75%皲裂程度条件下的虫口密度最大,平均9.8头。利用双因素方差分析方法分析树干不同高度和树皮不同皲裂等级的互作对虫口密度的分布影响达显著水平(F=2.46)(F0.05(9,56)=2.0519),P=0.0195]。【结论】华北地区害虫秋冬防治时,在寄主悬铃木树干的最好涂白时机是在害虫全部下树后的12月上中旬进行,涂白高度以树干1.0~2.0 m范围为宜。本研究对悬铃木方翅网蝽在越冬期的预防和治理有较为重要的参考价值。

The post-overwintering spatial distribution of the invasive sycamore lace bug Corythucha ciliata under the bark of the host tree Platanus acerifolia in north Henan

Aim] The invasive sycamore lace bug, Corythucha ciliata, has caused great harm to Chinese urban sycamore trees, especially to Platanus acerifolia, sometimes causing the death of weak host trees. Investigation to the pest post-overwintering habit under the bark of the host trees is essential to discover more effective control measures during winter seasons.Method] During mid-March 2017, the damaged sycamore trees were carefully surveyed to assess the population density of the lace bug in Xinxiang, Henan, China. The pest populations were compared between shady and sunny sides of the host trunk, or among four different tree height classes (0.00-0.50 m; 0.51-1.00 m; 1.01-1.5 m; 1.51-2.00 m), and among six classes of number of bark cracks (<5%, 5%-25%, 25%-50%, 50%-75%, 75%-95% and > 95%).Result] Pest population density under the host bark on the sunny side was statistically higher than that on the shady side(F=6.63>F_0.01(1,19)=1.0132, P<0.001)]. Trunk height within 1-1.5 m had the highest population density, with a mean of 11.5(F=26.91>F_0.01(3,56)=4.1519, P<0.001)]. The number of cracks of the bark was also an influential factor for overwintering. The mean pest population density under the bark of trees of 1-1.5 m and 50%-75% of cracks reached 9.8, which was significantly higher than with other classes of cracks on the bark(F=31.02>F_0.01(3,56)=4.1519, P<0.001)]. The interaction of tree height and bark crack intensity also significantly influenced the pest population density(F=2.46>F_0.05(9,56)=2.0519, P=0.0195)].Conclusion] In Northern China, preventive measures with white lime water on the bark of host trees was more effective when applied in early or mid-December and on trees of 1.0-2.0 m after the crawl down of these pests. The result of this study implies more effective and economic control measures in winter season can be considered in the process of strategy for this serious pest in urban sycamore trees.