七星瓢虫对桃蚜的捕食功能反应研究

Study on the Functional Response of Coccinella septempunctata L. to Myzus persicae

七星瓢虫(CoccinellaseptempunctataL.)是宁夏银川十字花科菜田捕食桃蚜(Myzuspersicae)的天敌优势种之一.在实验室自然温度条件下,对七星瓢虫捕食桃蚜进行了初步研究,结果表明:其功能反应属HollingⅡ型,Na=0.9851Nt/(1+0.001267Nt).随着桃蚜密度的增大,七星瓢虫的捕食量也逐渐增加,每头瓢虫的捕食上限为777.5头.每捕食1头桃蚜所需时间Th为0.001286d,瞬时的猎物发现率(攻击率)a′为0.9851.而且七星瓢虫对桃蚜的捕食作用在一定的空间范围内受其自身的密度制约,相互间存在干扰.

Coccinella septempunctata L. is one of the dominant species of natural enemies to Myzus persicae in cruciferae vegetables in Ningxia, and it shows a good preventing effect on the Myzus persicae. This paper studied the preying action of Coccinella septempunctata to Myzus persicae in laboratory, and the result showed that its functional response type of the preying was Holling II model which can be modeled as N_a =0.9851N_t /(1+0.001267N_t). With the increase of density of Myzus persicae, the preying quantity of Coccinella septempunctata increased gradually, and the maximal preying quantity of Myzus persicae was 777.5 aphids. According to the result, the preying time of Myzus persicae was 0.001286 day per aphid with the instantaneous preying rate of 0.9851. Moreover, preying action of Coccinella septempunctata in a certain space was limited by its density.