有益真绥螨与巴氏新小绥螨的集团内捕食和同类相残作用

【目的】有益真绥螨Euseius utilis是北方地区广泛分布的一种多食性植绥螨,而巴氏新小绥螨Neoseiulus barkeri目前在我国广泛应用于农业害虫的生物防治中。本研究旨在对巴氏新小绥螨在本地的应用进行风险评估及为与有益真绥螨的联合释放提供依据。【方法】本研究在室内通过一系列实验,比较了实验室饲养的巴氏新小绥螨和采自内蒙古农业大学校园的有益真绥螨的雌成螨对同种或异种未成熟螨的捕食量、存活时间及产卵量的差异,检测了有益真绥螨与巴氏新小绥螨两种植绥螨相互之间的攻击强度以及种内和种间的相互作用。【结果】两种植绥螨都难以刺吸同种或异种植绥螨的卵,而对同种或异种植绥螨幼螨的捕食量最大,其次是对若螨。在无共同食物的情况下,有益真绥螨雌成螨对同种植绥螨幼螨的攻击性比对异种植绥螨幼螨的攻击性强(BreslowDay检验:χ~2=13.84,df=1,P0.001),且有益真绥螨对同种植绥螨幼螨的捕食量(9.10±1.65头)高于对异种植绥螨幼螨的捕食量(5.31±1.43头)(T检验:t=5.487,P0.001),巴氏新小绥螨对异种植绥螨幼螨的捕食量(7.48±0.75头)高于对同种植绥螨幼螨的捕食量(4.75±0.58头)(T检验:t=9.110,P0.05)。【结论】有益真绥螨更倾向于捕食同种幼螨而发生同类相残;巴氏新小绥螨更倾向于捕食异种幼螨而发生集团内捕食。

Intraguild predation and cannibalism in the phytoseiid mites Euseius utilis and Neoseiulus barkeri (Acari: Phytoseiidae)

Aim] Euseius utilis is a generalist and widely distributed in northern areas of China,while Neoseiulus barkeri is widely used in biocontrol of agricultural pests.The study aims to assess the risk of N.barkeri to local species and establish a reasonable combination of different natural enemies in biological control.Methods] In a series of experiments under laboratory conditions,the rates of intraand interspecific predation on immature mites,survival time,and oviposition for the adult females of N.barkeri bred in the laboratory and E.utilis collected from the campus of Inner Mongolia Agricultural University were compared in order to study the aggressiveness and con-and heterospecific interactions between the two species of phytoseiid mites.Results] The females of the two species had difficulties in piercing phytoseiid eggs,and both phytoseiid mites consumed more con-and heterospecific larvae than protonymphs.E.ulitis was more aggressive than N.barkeri in intraguild predation in absence of shared food (Breslow-Day test:X2 =13.84,df=1,P ＜0.001).The average daily predation number of E.ulitis on conspecific larvae (9.10 ± 1.65) was higher than that on heterospecific larvae (5.31 ± 1.43) (T test:t =5.487,P ＜ 0.001),whereas the average daily predation number of N.barkeri on heterospecific larvae (7.48 ±0.75) was higher than that on conspecific larvae (4.75 ±0.58) (T test:t =9.110,P ＜0.05).Conclusion] E.ulitis is preferentially engaged in cannibalism by consuming the conspecific larvae,whereas N.barkeri is preferentially engaged in intraguild predation by consuming the heterospecific larvae.