摘要
对桔园天敌和害虫的空间分布和空间、时间生态的研究表明,3～7月桔园内的主要害虫优势种群有桔全爪螨、矢尖蚧和桔蚜。桔全爪螨的数量分布是南>西>东>北;桔蚜南>东>北>西,而且都是上>中>下,外>内。矢尖蚧的分布是北>南>西>东,中>下>上,内>外。桔园内主要天敌有食螨瓢虫、蜘蛛、寄生蜂,它们的空间分布与其猎物的分布基本相似。天然园内天敌和害虫在时间和空间上的生态位重叠值和宽度都较化防园大,大量施用农药是影响天敌作用的重要原因。主要天敌和害虫在空间生态位上的重叠值都较大,但在时间生态位上的重叠除蜘蛛外都较小,这说明它们对害虫的时间跟随作用不强,因而在害虫生物防治实践中应通过保护、释放天敌来解决这一问题。
The spatial distribution of citrus pests and their natural cncmics in the multiple predator-prey systems was investigated and the spatial and time ecological niches in chemi- cal control and natural control orchards were compared.The results indicated that the dominant pest species in citrus orchards from March to July are Panonychus citri,Unasps yanonensis and A phis citricida.The population density of P.citri in various locations of the tree crown appeared in the order of south>west>cast>north;the distribution of A.citricida—south>cast>north>west.The vertical distribution of the two pests was in the pattern of upper>middle>lower and outside>internal.In contrast,the distribution of U.yanonensia was in the pattern of north>south>west>cast;middle>lower>upper,and internal>outside.Their dominant natural enemies are Stethorus chengi,spiders and parasitoids,whose spatial pattern is quite similar to that of their preys.A comparison of the ecological niches of predators and their preys in chemical and natural control orchards has shown that the values of nitch width and ovcrlaps in both space and time in natural control orchards are greater those in their chemical control counterparts,suggesting that the use of pesticides constitutes an obstacle for the effective action of the natural enemies.The spatial niches of natural enemies greatly overlap those of their preys.However,the values of time overlap for natural enemies and their preys are quite small and have to bc enhanced by pro- tecting and releasing some natural enemies.
出处
《西南农业大学学报（自然科学版）》
CSCD
1991年第6期559-564,共6页
Journal of Southwest Agricultural University
基金
国家自然科学基金资助项目
关键词
桔园
柑桔
害虫
天敌利用
citrus
ccosytem
space distribution
pest-insect survey
utilization of natural enemies
biotic control
