巴氏新小绥螨对二斑叶螨的捕食功能及控制潜力研究

为明确巴氏新小绥螨Neoseiulus barkeri对二斑叶螨Tetranychus urticae的捕食功能反应和对其种群的潜在控制能力,在实验室相对湿度85%±5%、光照L∥D=16h∥8h、5个温度梯度16、20、24、28℃和32℃下进行捕食功能反应和个体间干扰反应试验,并在25℃下研究了巴氏新小绥螨对二斑叶螨的种群控制能力。结果表明:在16~28℃温度范围内,巴氏新小绥螨对二斑叶螨各螨态的捕食功能反应均属于HollingⅡ型,随着温度升高,攻击系数、捕食能力、最大日均捕食量均升高,而处理时间缩短;28℃时捕食量达到最高,处理时间最短,当温度高于32℃时捕食量开始下降。二斑叶螨密度固定时,巴氏新小绥螨的平均捕食量随其自身密度的增加而逐渐降低,说明巴氏新小绥螨存在明显的相互干扰作用。巴氏新小绥螨对二斑叶螨种群的控制能力,随着益害比的增加,二斑叶螨种群数量显著下降,益害比在一定比值内时巴氏新小绥螨对二斑叶螨种群表现出明显的控制能力。其中当益害比为5∶30时二斑叶螨种群数量在第6天就能得到控制。

Functional response and control potential of Neoseiulus barkeri to Tetranychus urticae

To identify the functional response and control potential of Neoseiulus barkeri to Tetranychus urticae,the predation of three stage (egg,nymph and female adult) of T.urticae by N.barkeri was examined at five temperatures (16,20,24,28 and 32℃) and RH (85±5)％ under laboratory conditions.The results showed that the predatory functional response was fitted to Holling Ⅱ equation in 16-28℃,the attack index (a),a / Th value,and the maximum predatory number (1/Th) alSo increased,but the average treatment time reduced with increasing temperature.The maximum predatory number and the shortest treatment time achieved at 28℃.The 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 N.barkeri.The population quantity of T.urticae decreased obviously with the increase in the ratio of predator to prey,and as the ratio of predator to prey changed within certain range,the predator showed good control capability to the prey.When the ratio was 5∶30,the population quantity of T.urticae could be controlled after 6 days.