虫害诱导的植株对小菜蛾取食和生长发育的影响

The effect of competition by Phyllotreta stridata on the feeding and growth of Plutella xylostella

本文从菜田生态系统的角度出发,就黄曲条跳甲Phyllotreta striolata(Fabricius)取食诱导对小菜蛾Plutella xylostella(L.)造成的影响进行了研究。黄曲条跳甲取食诱导对小菜蛾取食的影响比较明显,一般来说,黄曲条跳甲少量或短时间的取食会刺激小菜蛾幼虫在相应叶片上的取食,反之则会抑制;而且不同的寄主,不同完整度的叶片(即是否被黄曲条跳甲取食过)上的承载能力不同,芥菜、白菜、菜心和萝卜的承载力弱于甘蓝和芥蓝,黄曲条跳甲取食过的叶片弱于未被黄曲条跳甲取食过的叶片;不同数量的黄曲条跳甲取食对小菜蛾的产卵量影响显著,对其余生物学参数影响不显著,少量的黄曲条跳甲取食会刺激小菜蛾的产卵,多数则会抑制。

The effect of competition by the striped flea beetle（SFB） Phyllotreta striolata（Fabricius） on the feeding and growth of the diamondback moth（DBM） Plutella xylostella（L.） was studied.Low numbers of SFB,or short feeding periods by this insect,will stimulate DBM to feed on the same leaves.Conversely,higher SFB numbers and longer feeding periods inhibited feeding by DBM.DBM carrying capacity varied with host and the level of competition.The carrying capacity of Brassica juncea,B.parachinensis,B.chinensis and R.sativus were lower than that of B.alboglabra and B.oleracea.DBM subject to competition by SFB had significantly different fecundity to those without competitors.Other biological parameters weren＇t significantly affected by competition from SFB.Small numbers of SFB stimulated oviposition of DBM but higher numbers inhibited this.