不同温度下巴氏新小绥螨对西花蓟马初孵若虫的捕食功能

为明确巴氏新小绥螨[Neoseiulus barkeri(Hughes)]对西花蓟马[Frankliniella occidentalis(Pergande)]初孵若虫的捕食效应,在相对湿度RH 85%±5%,5个温度梯度16、20、24、28、32℃,光照L∥D=16h∥8h条件下选取西花蓟马的初孵若虫进行捕食功能反应。结果表明:巴氏新小绥螨对西花蓟马初孵若虫的捕食功能反应属于HollingⅡ型方程。在16~28℃温度范围内,巴氏新小绥螨对西花蓟马初孵若虫的攻击系数、捕食能力、最大日捕食量均随温度升高而增加,处理时间则缩短,28℃时日捕食量最高达14.471 8头,处理时间最短为0.069 1d。温度达到32℃时,捕食量下降。当西花蓟马初孵若虫的种群密度一定时,巴氏新小绥螨的平均捕食量随其自身密度的增加而降低。说明猎物密度固定时巴氏新小绥螨存在明显的相互干扰作用。

Predatory functional response of Neoseiulus barkeri on newly hatched nymphs of Frankliniella occidentalis

In order to determine the functional response of Neoseiulus barkeri (Hughes)on the 1st instar nymphs of Frankliniella occidentalis Pergande,the predation was examined at five constant temperatures (16,20,24,28 and 32℃) under the laboratory conditions (RH 85%±5% and photoperiod L∥D=16 h∥8 h).The results showed that the preda-tory functional response fitted Holling typeⅡmodel.At the range of 16 28℃,the attack index (a ),the a/T h value and the maximum predatory capacity (1/T h )of N.barkeri increased with the temperature,and the average treatment time decreased.The maximum predatory capacity was 14.471 8 individuals per day,while the minimum handling time was 0.069 1 day at 28℃.The maximum daily predatory capacity reduced when the temperature was above 32℃.The av-erage daily predatory capacity decreased with the increase of predator density when prey density was fixed,which indica-ted that predator competition and interference were obvious as prey density was fixed.