江苏丘陵地区早春桃园主要小型害虫和天敌发生初探

Preliminary investigation of the main pests of peach trees, and their natural enemies, in early Spring

【目的】监测早春桃园小型害虫及天敌的活动区位分布和发生动态,以期为桃园早春害虫绿色防控措施的制定提供决策依据。【方法】通过黄板诱集研究了桃园早春(2019年3月27日-5月13日)主要小型害虫和天敌种类、数量及其发生动态和活动区位分布,并进行了空间、时间生态位宽度和重叠值分析。【结果】早春桃园主要害虫有叶蝉、蚜虫、蓟马,主要天敌有草蛉、瓢虫、蜘蛛;越冬代叶蝉成虫高峰期在3月下旬,活动区域主要集中于桃园外围中上区域,越冬代蓟马高峰期在4月下旬,而后世代交替,花期活动于中上区域,落花后活动区域下移;瓢虫于园区出蛰后,活动区域上移;草蛉和蜘蛛高峰期与叶蝉同步,活动区域相对均匀,无显著性差异。3种害虫在空间上对资源的利用程度无较大差异,但在时间序列上的发生具有不均匀性,3种天敌对害虫均有较高的重叠值。【结论】桃园早春害虫绿色防控措施中色板应悬挂于园区外侧,高于桃树主干分支10 cm以上的位置,清理桃园周边杂草减少叶蝉基数,阻止迁入桃园;园区内部及时清除杂草,减少蓟马危害,花期不使用色板,减少对天敌和蜜蜂的伤害。

[Objectives]To provide a basis for the establishment of green control measures in peach orchard pests in early Spring.[Methods]The activity,location,distribution and occurrence dynamics of small pests,and their natural enemies,in peach orchards were monitored using yellow board traps in early spring(March 27-May 13),and their spatial and temporal niche widths and overlap values,determined.[Results]The main pests in peach orchards in early spring are leafhoppers,aphids and thrips,and their main natural enemies are lacewings,ladybirds and spiders.The peak of overwintering of adult leafhoppers was in late March,and these were most active in the middle and upper strata of peach trees.The peak of overwintering of thrips was in the late April,with later generations alternating.Most flowering occurs in the upper-middle strata of peach trees,and insect activity moved down the tree after petal fall.Ladybugs moved higher in the tree after completing hibernation.The peak periods of chrysopids and spiders were synchronous with those of leafhoppers,and there was no significant difference in the activity zones of these taxa.There was no significant difference in the utilization of resources among the three pests in space,but their temporal distribution differed;that of the three natural enemies having high overlap with that of pests.[Conclusion]Green control measures for pests in peach orchards in early spring should include colored plate traps hung around the perimeter of the orchard more than 10 cm higher than the main branches of peach trees.Weeds should be removed to reduce the base number of leafhoppers,prevent their migration to peach trees,and to reduce thrip damage.Color plate traps should not be used during the flowering period to reduce the capture of natural enemies and bees.