苜蓿蚜药剂防治试验

A Experiment on Chemical Control of Black Bean Aphid (Aphis craccivora Koch)

使用九种药剂进行蚜虫的毒力测定,并计算LC_(50)值.结果:浓度值域在0.082%～2.83%之间,相差36.4倍,表明各药剂对蚜虫毒力差异很大.田间药剂防治试验结果,抗蚜威、菊马、敌杀死、杀灭菊酯在喷雾浓度分别为3500～4500倍.3500～4000倍、3000～4000倍、2000～3000倍时,防效最佳,依次为88.6%～91.2%、87.6%～97.7%、86.7%～87.2%和85.2%～86.9%.证明在蚕豆始花期末,每亩依上述各药剂浓度的稀释倍液66.7kg喷雾,防治效果显著.

The median lethal concentrations (LC50 ) of 9 pesticides obtained after their toxicities were tested. Minimum and maximum were from 0.082% to 2.83% and differed 36.4 times between them. This showed that the toxicity was very different in various pesticides. Through field trial for control of Aphis craccivora, the following chemicals were screened primarily: pirimicarb, juma emulsion (a compound formulation of fenvalerate & malathion) ,decamethrin and fenvalerate. Their suitable concentrations for field spraying are 3 500 - 4 500,3 500-4 000,3 000-4000 and 2000-3000 times, respectively. The corresponding control effects are 88.6% - 91.2% ,87.6% - 90.7% ,86.7 - 87.2% and 85.2% -86.9% .The experimental result also indicated that control effect looked better obviously when those pes-licides were used (according to above- mentioned concentration, each pesticide spraying dilution 66.7kg per Chinese mu) in later period of flowered broadbean. The paper writer suggest these chemicals are wor-thy of application in practice.