麦长管蚜和禾谷缢管蚜对吡虫啉敏感性的比较研究

采用麦穗浸渍法在室内测定了麦长管蚜Macrosiphumavenae(Fabricius)和禾谷缢管蚜Rhopalosiphumpadi(L .)对吡虫啉可湿性粉剂和乳油的敏感度。结果表明 ,禾谷缢管蚜对吡虫啉的敏感度是麦长管蚜的 3～ 4倍 (基于LC50 的比较 )。在北京、河南、江苏、湖北、四川等地同浓度的吡虫啉对禾谷缢管蚜的防治效果要好于麦长管蚜 (特别是在低浓度时尤为明显 )。依据我国不同省份小麦穗蚜的优势种不同 ,建议用吡虫啉防治小麦穗蚜时 ,在南方麦区 ,禾谷缢管蚜为优势种的麦田 ,吡虫啉用药量为 15～ 3 0g(a.i) hm2 ;北方麦区 ,以麦长管蚜为优势种的麦田 ,吡虫啉的用药量应大于 3 0g(a.i) hm2 。

Susceptibility of Macrosiphum avenae and Rhopalosiphum padi to imidacloprid

Susceptibilities of Macrosihpum avenae (Fabricius) and Rhopalosiphim padi (L.) to imidacloprid were determined by ear residue bioassay method in lab.The results showed that based on LC 50 , susceptibility of R.padi to imidacloprid was 2～3 times than that of M.avenae .Results of field trials in Peking,Henan,Jiangsu,Hubei and Sichuan Province also showed that the efficacy of imidacloprid to R.padi was better than to M.avenae by using the same dosage.Based on the difference of preponderant species of aphids between provinces,We propose that when the preponderant species is R.padi in south area of China,the proper application of imidacloprid should be 15～30 g.a.i/hm\+2,and when the preponderant species is M.avenae in north area of China,more than 30 g.a.i/hm\+2 of imidacloprid should be properly applied.