三营养级体系烟盲蝽对温室内不同作物种类的选择性

在温室内采用笼罩观察,通过选择性和非选择性试验,在两营养级(作物-天敌)的基础上进一步研究了三营养级(作物-天敌-害虫)体系中烟盲蝽对5种不同植物种类的选择性。以落虫量为选择指标,烟盲蝽成虫选择性结果表明:黄瓜+粉虱成虫、番茄+粉虱成虫、茄子+粉虱成虫、菜豆+粉虱成虫之间不存在差异显著性,但对油菜+蚜虫的选择性较好。烟盲蝽成虫非选择性试验,以其产卵后初孵若蝽量和死亡率为衡量指标,结果表明,烟盲蝽初孵若虫量之间存在显著差异,排序为:黄瓜>番茄>油菜>菜豆>茄子;烟盲蝽死亡率之间存在显著差异,排序为:菜豆+粉虱成虫>茄子+粉虱成虫>番茄+粉虱成虫>黄瓜+粉虱成虫>油菜+蚜虫。烟盲蝽若虫选择性试验,以羽化率为选择指标,结果为:油菜+蚜虫>番茄+粉虱若虫>黄瓜+粉虱若虫>菜豆+粉虱若虫>茄子+粉虱若虫。另外,在茄子+粉虱若虫上的死亡率最高为90.5%,其次为菜豆+粉虱若虫90%,黄瓜+粉虱若虫71.4%,番茄+粉虱若虫42.9%,油菜+蚜虫40%。

Preference of omnivorous natural enemy Cyrtopeltis tenuis Reuter for plants in greenhouses in a tritrophic system

In a tritrophic system,the acceptability and suitability of five kinds of plants by Cyrtopeltis tenuis Reuter were observed in the laboratory under no-choice and choice situations,respectively.The results from choice experiments with C.tenuis adults showed that there were no significant differences among plant and pest systems except cole aphids.In no-choice experiments,there were significant differences among plant and pest systems,according to the larval number hatched from plants.C.tenuis substantially preferred cucumber to tomato,cole,kidney bean and eggplant.The mortality decreased in the following sequence:kidney bean adult white fly,eggplant adult white fly,tomato adult white fly,cucumber adult white fly and cole aphid.The preference of the larvae of C.tenuis for different plants and pests systems was also studied,based on eclosion.It was found that the preference became weaker in the following order:cole aphid,tomato white fly larvae,cucumber white fly larvae,kidney bean white fly larvae,eggplant white fly larve.In addition,the mortality of C.tenuis on eggplant white fly larvae was the highest(90.5%),followed by on kidney bean white fly larvae(90%),cucumber white fly larvae(71.4%),tomato white fly larvae(42.9%)and cole aphid(40%).