4种庇护植物对苹果园梨小食心虫及其主要天敌的种群动态影响

Effects of four species of refuge plants on population dynamics of oriental fruit moth,Grapholita molesta and its major natural enemies

【目的】为探索庇护植物对苹果园梨小食心虫的调控作用。【方法】于2017年在北京市延庆区进行果园小区试验,系统调查果园覆盖万寿菊、万寿菊+翠菊、黑麦草+紫花苜蓿和常规管理下梨小食心虫的种群动态和蛀果率,同时分析主要天敌种群数量的时序动态。【结果】结果表明:不同庇护植物处理下梨小食心虫和主要天敌的动态趋势基本一致,但在梨小食心虫发生高峰期,万寿菊+翠菊处理的梨小食心虫数量(头/诱捕器)显著低于对照区,对照9.78>黑麦草+紫花苜蓿6.56>万寿菊+翠菊5.78>万寿菊5.58。3个处理的蜘蛛类数量显著大于对照,黑麦草+紫花苜蓿处理对瓢虫和草蛉数量有明显的增助作用;3个处理的梨小食心虫和天敌数量的益害比大于对照区,对照区的蛀果率显著大于几种庇护植物处理。果园覆盖庇护植物不仅降低梨小食心虫的种群数量和危害程度,也增加天敌对害虫的控制作用。

【Objective】To study the regulatory role of refuge plants on oriental fruit moth,Grapholita molestain apple orchard.【Methods】An orchard plot experiment was conducted from May to November 2017in Yanqing County,Beijing.The orchard was divided into four plots,with three plots covered with refuges Tagetes erecta L.,Tagetes erecta L.+Callistephus chinensis(L.)Nees,Lolium perenne L.+Medicago sativa L.,respectively and one covered nothing as control.The population dynamics of G.molesta,with its major natural enemies and boring rate were investigated and analyzed.【Conclusion】The results showed that the population dynamics of G.molesta and its major natural enemies under different refuge plants were identical,with peak values(heads/trap lure)ranked as CK(9.78)>Lolium perenne L.+Medicago sativa L.(6.56)>Tagetes erecta L.+Callistephus chinensis(L.)Nees(5.78)>Tagetes erecta L.(5.58).Of which,the peak value of control was significantly higher than that covered with Tagetes erecta.In addition,the number of spiders in each of the three plots planted with refuges was significantly larger than that in control,and the numbers of coccinellids and chrysopids in the treatment of Lolium perenne L.+Medicago sativa L.were both significantly increased.The number ratios of G.molesta to natural enemies in the areas covered with refuge plants were all greater than that of the control,and the fruit-boring rate by G.molestain the control area was significantly greater than those of any treated plants.In a word,planting of refuge plants in orchards not only reduced the population and the damage degree of G.molesta,but also increases the control effects of natural enemies on pests.