杀虫剂对羽摇蚊四龄幼虫的急性毒性研究

Acute Toxicity of Insecticides to Fourth-Instar Chironomus Plumosus Larva

测定了4.5%氯氰菊酯乳油、10%苯扎溴铵溶剂和5%马拉硫磷溶剂3种杀虫剂对羽摇蚊四龄幼虫的急性毒性。结果表明,3种杀虫剂处理羽摇蚊幼虫4天,随着杀虫剂浓度的增加,每天的存活率呈下降趋势。氯氰菊酯对羽摇蚊幼虫的24h-LC50、48h-LC50、72h-LC50、96h-LC50分别为20.865、3.073、0.801、0.375mg/L,苯扎溴铵对羽摇蚊幼虫的24h-LC50、48h-LC50、72h-LC50、96h-LC50分别为1.358、0.201、0.024、0.013mg/L;马拉硫磷对羽摇蚊幼虫的24h-LC50、48h-LC50、72h-LC50、96h-LC50分别为15.393、3.343、0.613、0.305mg/L。苯扎溴铵对羽摇蚊四龄幼虫的毒性最高,其次为马拉硫磷,氯氰菊酯毒性最低。

Acute toxicity of three insecticides（4.5% Cypermethrin EC,10% Benzalkonium Bromide Solution and 5% Malathion Solution） to fourth-instar larva of Chironomus plumosus（Diptera： Chironomidae） were evaluated under laboratory exposure experiment conditions.The Results showed that the survival rate of Chironomus plumosus declined with increasing concentration of the three insecticides at 96h course.The 24h-LC50,48h-LC50,72h-LC50 and 96h-LC50 of Cypermethrin to Chironomus plumosus larva were 20.865,3.073,0.801 and 0.375mg/L;The 24h-LC50,48h-LC50,72h-LC50 and 96h-LC50 of Benzalkonium Bromide to Chironomus plumosus larva were 1.358,0.201,0.024 and 0.013mg/L;The 24h-LC50,48h-LC50,72h-LC50 and 96h-LC50 of Malathion to Chironomus plumosus larva were 15.393,3.343,0.613 and 0.305mg/L.The acute toxicity of Benzalkonium Bromide was the highest among the three insecticides but the acute toxicity of Cypermethrin was the lowest.