不同类型杀螨剂对棉叶螨的室内活性及田间药效

用玻片浸渍法研究了7种不同类型杀螨剂对棉叶螨的室内活性。结果表明,阿维菌素对棉叶螨的毒杀活性最高,LC50为0.0006 mg/L;其次为唑螨酯、哒螨灵,LC50值分别为0.075 6 mg/L和0.154 8 mg/L;7个杀螨剂中,噻螨酮的室内活性最低,LC50值达到107.58 mg/L。田间药效试验结果表明,1.8%阿维菌素EC和20%哒螨灵EC对棉叶螨的田间防效最好,药后1~7 d的防效均可达到90%以上,速效性好、防效高,且持效期较长,有效控制期可达到药后14 d以上;57%炔螨特EC、20%甲氰菊酯EC、2.5%联苯菊酯EC以及5%噻螨酮EC,药后1~7 d也表现出较高的防效,但持效期短于阿维菌素等药剂。根据不同类型杀螨剂的作用特点提出了相应的田间施药技术。

Contact Toxicities and Field Efficiency of Different Acaricides against the Cotton Red Spider Mites(Tetranychus cinnabarinus)

Contact toxicities of seven acaricides were tested in laboratory by slide dipmethod against the cotton red spider mites(Tetranychus cinnabarinus),The field control effects were also tested.The laboratory experiments showed that the LC50 of abamectin against the cotton red spider mites was 0.000 6 mg/L,with the best toxicity.The LC50 of fenproximate and pyridaben were 0.075 6 mg/L and 0.154 8 mg/L,they showed excellent toxicities.In all acaricides the LC50 of hexythiazo was 107.58 mg/L,with the lower toxicity.Field efficacy experiments showed that 1.8% abamectin EC and 20% pyridaben WP were excellent for controlling cotton red spider mites,the control effect was over 90% after 1~7days.The two acaricides showed higher toxicity,quicker control efficacy and longer control time.The effective control time could last about 14 days.20% fenpropathrin EC,2.5% bifenthrins EC,57% propargite EC,5% hexythiazox EC also had better efficiency against the cotton red spide mites.But their control time is shorter than abamectin.At last the field controlling technique of different acaricides against the cotton red spider mites were put forward.