烟剂对韭菜迟眼蕈蚊防效及经济效益与安全性评价

Efficiency, economic benefit, and safety, of fumigation to control Bradysia odoriphaga (Yang et Zhang) (Diptera: Sciaridae)

【目的】通过室内与温室试验相结合,综合评价了烟剂对韭菜迟眼蕈蚊Bradysia odoriphaga(Yang et Zhang)的控制效果,为韭蛆的绿色防控提供技术支持。【方法】采用玻璃方箱法测定了敌敌畏烟剂和异丙威烟剂对韭菜迟眼蕈蚊成虫的熏蒸毒力;在温室比较了2种烟剂与生产中普遍使用的毒·辛乳油灌根方法的药效,通过测产并结合投入成本分析了各自取得的经济效益,最后进行药剂的残留检测。【结果】敌敌畏烟剂对韭菜迟眼蕈蚊成虫的熏蒸毒力较强;中剂量敌敌畏烟剂和高剂量异丙威烟剂对成虫的防效分别为96.21%和86.05%,对幼虫的防效分别为97.08%和90.00%,极显著高于毒·辛乳油灌根处理(77.36%,P<0.01),分别实现增产41.71%和30.75%,新增总收益分别达到20 507.94元/hm^2和15 118.28元/hm^2,投入产出比分别为1∶16.28和1∶10.33。经检测,韭菜样本在检出限内无敌敌畏残留,而用药15 d后异丙威残留量为0.186 mg/kg,低于最大残留限量标准。【结论】烟剂熏蒸是比较理想的韭菜迟眼蕈蚊绿色防控手段,生产上可选用敌敌畏烟剂和异丙威烟剂。

[Objectives] To provide a practical method for controlling the Chinese chive maggot, Bradysia odoriphaga. [Methods] The efficiency of using fumigation to control the Chinese chive maggot, Bradysia odoriphaga, was evaluated comprehensively in laboratory bioassays and greenhouse experiments. The toxicity of dichlorvos FU and isoprocarb FU to B. odoriphaga adults was measured in a glass chamber. The control efficiency of these two kinds of fumigants and chlorpyrifos-phoxim EC were compared using plot tests in a greenhouse, and the relative economic benefit of the three fumigants was analyzed by estimating yield in relation to cost. Finally, residues of the various fumigants used were measured and compared. [Results] Dichlorvos FU was the most toxic of the fumigants tested to B. odoriphaga adults. The results of greenhouse experiments show that the control efficiency of a medium dosage of 15% dichlorvos FU and a high dosage of 10% isoprocarb FU was up to 96.21% and 86.05%, respectively. The control efficiency of these pesticides against larvae was up to 97.08% and 90.00%, respectively, significantly higher than that of 20% chlorpyrifos-phoxim EC （P〈0.01）. Moreover, 15% dichlorvos FU and 10% isoprocarb FU increased yield by 41.71% and 30.75%, respectively, gave financial returns of 20 507.94 Yuan/hm2 and 15 118.28 Yuan/hm2, respectively, and had input-output ratios of 1 ： 16.28 and 1 ： 10.33, respectively. Rigorous monitoring found that any dichlorvos residues in Chinese chive samples were below the limit of detection. The isoprocarb residue after 15 days was 0.186 mg/kg, which is below the MRL standard. [Conclusion] Fumigation was an effective, environmentally friendly way of controlling B. odoriphaga. Dichlorvos FU and isoprocarb FU are recommended for controlling this pest in Chinese chive crops.