两种植绥螨的同类相残和集团内捕食作用

Cannibalism and intraguild predation of phytoseiid mites Neoseiulus barkeri and Neoseiulus cucumeris

巴氏新小绥螨(Neoseiulus barkeri)和黄瓜新小绥螨(N.cucumeris)是两种多食性植绥螨,主要捕食叶螨和蓟马等,目前在我国广泛应用于农业生物防治中。本文研究了这两种植绥螨种内的同类相残(cannibalism)和种间的集团内捕食作用(intraguild predation)以及相互之间的攻击强度,以明确两者之间的相互关系,为合理构建天敌组合及评估生物防治的作用提供依据。结果显示:两种植绥螨对同种或异种幼螨的捕食量最大,其次是若螨,而对卵的捕食量极低。两种植绥螨对异种幼螨或若螨的捕食量均极显著高于对同种幼螨或若螨的捕食量。可见,无其他猎物存在情况下,两种植绥螨同时发生时更倾向于发生种间的集团内捕食。而巴氏新小绥螨对异种幼螨或若螨的捕食量均高于黄瓜新小绥螨对异种幼螨或若螨的捕食量,并且巴氏新小绥螨和黄瓜新小绥螨相比,巴氏新小绥螨对异种幼螨的攻击性更强,因此当这两种植绥螨发生集团内捕食时,巴氏新小绥螨是潜在的集团内捕食者,而黄瓜新小绥螨是潜在的集团内猎物。

Phytoseiid mites Neoseiulus barkeri and N. cucumeris are the generalists mainly preying on spider mites and thrips, and widely used in agricultural biocontrol. In this paper, the cannibalism and intraguild predation of N. barkeri and N. cucumeris and the female aggressiveness on larvae （quantified as attack probability） in intraguild predation were studied, aimed to elucidate the interrelationships between these two species of predatory mite to reasonably establish a combination of different natural enemies in biological control. The results showed that the phytoseiid mites consumed more con and heterospecific larvae, lesser protonymphs, and seldom con and heterospecific eggs. The adult females of the two species mites exhibited higher predation rates on heterospecific larvae and protonymphs than on conspecific larvae and protonymphs, suggesting that the two species of mites preferentially engaged in intraguild predation in absence of other food sources. The predation rate of N. barkeri on heterospecific larvae and protonymphs was higher than that of N. cucumeri. Moreover, N. barkeri was more aggressive to heterospecific larvae than N. cucumeri in intraguild predation. Therefore, N. barkeri was most probably a potential intraguild predator of N. cucumeris, whereas N. cucumeri was a potential intraguild prey when the intraguild predation occurred between N. barkeri and N. cucumeris.