亚致死剂量百草枯对七星瓢虫捕食及限域搜索行为的影响

Sublethal effect of Paraquat on predation and area-restricted searching behavior the Ladybird Beetle Coccinella septempunctata(Coleoptera:Coccinelidae)

摘要: 采用室内生物测定方法对七星瓢虫在亚致死剂量百草枯作用下的捕食和限域搜索行为进行了测定.毒力实验研究结果表明,田间常用百草枯体积比(20 mL/L)低于七星瓢虫成虫的LC50,对七星瓢虫幼虫的杀伤作用死亡率为95.7%.捕食速率测定结果显示,LC20剂量的百草枯会对七星瓢虫尤其是其幼虫的捕食速率产生显著影响,24 h七星瓢虫幼虫、雌成虫、雄成虫的捕食速率分别下降了31.32%,23.47%和25.60%.此外,百草枯对七星瓢虫的限域搜索行为也产生了显著影响,百草枯处理后七星瓢虫搜索速率降低,搜索范围缩小.

Abstract: The impact of sublethal doses of Paraquat on predation and area-restricted searching behavior of the ladybird beetle Coccinella septempunctata,most commonly simply called the ladybird,was studied by infecting ladybirds with different concentration of Paraquat and watching their life history.The results showed that although the commonly used concentration(20 mL/L)of paraquat in field was lower than the LC50 for female and male adults,it could cause 95.7% mortality to larvae.The predation speeds and area-restricted searching effects of both adults and larvae ladybirds were significantly affected by Paraquat.