Control Action Of Pardosa Astrigera L. Koch To Two Pests In Cabbage Field And Influence On Its Controlling Pest Effect With Low Dose Pesticide

In the article, the control action of Pardosa astrigera L.Koch to vegetable aphides and Plutella xylostella was studied in laboratory, field and caged field. At the same time, the influence of on the controlling pest effect with low dose Imidacloparid was analyzed. These results showed the Pardosa astrigera L.Koch had a major control effect in cabbage field. It played an important role in sustainable management. 1. The control action of Pardosa astrigera to two pests was studied in caged field. The control rate to two pests and each pest was positively correlated with density of spiders within 24h. Because Pardosa astrigera had a strong control power to Plutella xylostella, the density of Plutella xylostella decreased greatly in 24h. The control rate of Pardosa astrigera to Plutella xylostella was negatively correlated with density of spiders because of mutual interference among spiders within 24-48h. 2. The niche of three species in cabbage field was also analyzed. Quantitative estimation of niche breadth and overlap were done, according to temporal niche, spatial niche and temporal-spatial two dimensional niche. The control action was studied according niche breadth and niche overlap of Pardosa astrigera and two pests. 3.Under the laboratory condition, the functional responses of Pardosa astrigera to two pests were analyzed in predator-one prey system. The maximum number of the predation, the functional responses to density of preys and the mutual interference among individual predator were all analyzed. Model of the integrated response of the spider to its own density and prey density had also been constructed. Holling-â…¡and Hassell-Varley's equation can appropriately describe the predation functional responses. After tested by x2,the calculated value and experiment value were close. It indicated that these equations simulated the predation action well. 4. Under the laboratory condition, the selective predation of Pardosa astrigera to two preys was studied by Murdoch's equations in predator-multiple preys system. It indicated that Pardosa astrigera had a different predatory tendency to different preys. In the co-existence system of three species, Pardosa astrigera had a strong tendency to Plutella xylostella. In addition, predatory proportion, total predation action to every prey, the functional response to every prey and the rate of predation action were studied. The total number of the predation was positively correlated with density of Plutella xylostella and negatively correlated with...