不同光照条件下城市绿地蜜粉源植物对天敌昆虫种群的影响

Effect of Insectary Plants on Natural Enemy Insects in Urban Green Space under Different Light Conditions

蜜粉源植物具有保育天敌昆虫的重要功能,城市绿地中针对性地应用蜜粉源植物,将有助于激活绿地生态系统的自我调控机制,提升绿地生态系统的稳定性。选择以夏至草为地被层优势种的草地(100%自然光)、疏林草地(50%自然光)、林下草地(25%自然光)及裸地(100%自然光)为研究样地,采用黄板诱集的方法对样地中自然天敌种群进行研究,分析不同光照条件下蜜粉源植物对天敌昆虫种群的影响。获得的天敌昆虫标本分属瓢虫、草蛉、食蚜蝇和寄生蜂4类,且以瓢虫和寄生蜂为优势种群。研究表明:天敌数量方面,草地极显著多于裸地(p<0.01),显著多于林下草地(p<0.05);疏林草地显著多于裸地(p<0.05)。天敌种群丰富度指数和多样性指数呈现出草地>裸地>疏林草地>林下草地的规律;均匀度指数呈现出裸地>草地=疏林草地>林下草地的规律。光照强度对天敌丰富度指数、多样性指数、均匀度指数及优势天敌中的瓢虫数量具有极显著影响(p<0.01)。为提升天敌昆虫多样性,应优先在全光照环境下种植蜜粉源植物;为有效进行多异瓢虫、龟纹瓢虫等瓢虫类天敌的招引,应优先选择阳性或中性蜜粉源植物并将其种植于全光照或半光照环境中,乔木宜作上木,灌木与地被植物宜植于林缘或疏林中。

Insectary plants play an important role in the conservation of natural enemy insects.The targeted application of insectary plants in urban green space will activate the self-regulation mechanism of green space ecosystem and improve the stability of green space ecosystem.Under different light conditions for the study of insectary plants impact on natural enemy insect populations,grassland(100%natural light),open forest grassland(50%natural light),understory grassland(25%natural light)and bare land(100%natural light)are selected as the research sample plots,and the natural enemy population were studied with yellow plate trapping method.The insect specimens obtained belong to 4 kinds:ladybugs,lacewings,syrphid flies and parasitoids.The results showed that the number of natural enemies in grassland is significantly higher than that in bare land(p<0.01)and in understory grassland(p<0.05).The number of natural enemies in open forest grassland is significantly higher than that in bare land(p<0.05).The natural enemy population richness index and diversity index showed the rule of that grassland>bare land>open forest grassland>understory grassland.The evenness index presents the rule that bare land>grassland=open forest grassland>understory grassland.The illumination intensity had a significant effect on the abundance index,diversity index,evenness index and the number of dominant natural enemies of ladybirds(p<0.01).In order to improve the diversity of natural enemies,it is better to plant insectary plants under full light environment than other conditions.In order to effectively attract the natural enemies of ladybugs,such as Hippodamia variegate and Propylea japonica,sun insectary plants or neutral insectary plants should be selected and planted under full-light or semi-light environment,trees should be used as upper wood,and shrubs and ground cover plants should be planted on the edge of forest or in the open forest.