巴氏钝绥螨对二斑叶螨的捕食功能反应

The functional response of Amblyseius barkeri to Tetranychus urticae

为明确巴氏钝绥螨Amblyseius barkeri(Hughes)对二斑叶螨Tetranychus urticae(Koch)的潜在控制能力,采用功能反应方法,在温度为16、20、24、28、32℃,相对湿度(85±5)%条件下对巴氏钝绥螨捕食二斑叶螨的效应进行了研究。结果表明:巴氏钝绥螨对二斑叶螨的卵和若螨表现为嗜食性,对雌成螨表现为非嗜食性。巴氏钝绥螨对二斑叶螨雌成螨、若螨和卵均有较强的捕食作用,捕食功能反应均拟合HollingⅡ型方程,在相同温度下对各螨态的捕食量大小为:卵】若螨】雌成螨。在16~28℃,巴氏钝绥螨对各螨态的瞬间攻击系数(a)、捕食能力(a/Th)、最大日捕食量(1/Th)均随温度的升高而增加,处理时间则缩短,当温度高于32℃时捕食量开始减小。当二斑叶螨密度固定时,巴氏钝绥螨的日平均捕食量则随其自身密度的增加而逐渐降低,说明巴氏钝绥螨存在明显的竞争和自我干扰作用。

To identify the functional response of Amblyseius barkeri (Hughes) to Tetranychus urticae (Koch),the predation of A.barkeri on three stages (egg,nymph and female adult) of T.urticae was examined by using the method of functional response of the predator to the prey at five temperatures (16,20,24,28 and 32 ℃) and RH (85 ± 5) ％ under the laboratory condition.The results showed that A.barkeri preferred eggs and nymphs of T.urticae rather than female adults.Predatory functional response was in accordance with Holling Ⅱ equation.At 16-28 ℃,the attack index (a),the a/Th value,and the maximum predatory number (1/Th) increased,but the average treatment time reduced with increasing temperature.The maximum predatory number reduced when temperature was above 32 ℃.When prey density was fixed,the predation rate decreased with increasing predator density.The results indicated that competition and self interference effect existed in the population of A.barkeri.