多种杀虫剂对柑橘木虱成虫和若虫的毒力及田间药效比较

以柑橘木虱为靶标,采用浸渍法和田间药效试验测定了6种杀虫剂对柑橘木虱成虫、若虫的室内毒力和田间防效,比较研究了多种杀虫剂对柑橘木虱成虫与若虫的毒力和田间药效差异,以期为杀灭柑橘木虱、防控柑橘黄龙病提供参考。结果表明:测试杀虫剂对柑橘木虱若虫的LC₅₀均高于对成虫的LC₅₀,其中55%氯氰菊酯·毒死蜱EC对柑橘木虱成虫和若虫的LC₅₀差别最大,其对成虫的LC₅₀是对若虫的1.46倍,差别最小的20%丁硫克百威EC对成虫的LC₅₀是对若虫毒力的1.15倍;喷药温州蜜柑9d,6种杀虫剂对柑橘木虱成虫的防治效果比若虫平均高7.29%,4.5%高效氯氰菊酯EC、55%氯氰菊酯·毒死蜱EC、20%噻虫胺SC和10%吡虫啉SP对柑橘木虱成虫的防治效果显著高于对若虫的防治效果;将嫩梢芽尖剪掉后喷施杀虫剂9d,6种杀虫剂对柑橘木虱成虫的防治效果比若虫平均仅高1.99%,测试杀虫剂对柑橘木虱成虫与若虫的防治效果无显著差异。说明未充分展开的新叶为柑橘木虱虫卵和低龄若虫提供了保护,使其避免接触喷施的农药,降低了杀虫剂对柑橘木虱若虫的防治效果。建议对柑橘新梢加重喷施杀虫剂,使用复剂杀虫剂和内吸性杀虫剂杀灭柑橘木虱若虫效果更好。

Toxicity Tests and Field Efficacy of Several Pesticides Against Adult and Nymph of Diaphorina citri Kuwayama

Diaphorina citri was used as target,laboratory toxicity and field efficacy testing were conducted by using dipping and spraying methods to determine the efficacy of several insecticides for control of adult and nymph of Diaphorina citri Kuwayama in order to provide a scientific basis for selecting pesticides to control the Diaphorina citri Kuwayama and Huanglongbing(HLB,citrus greening).The results showed that the LC50 values of all tested pesticides insecticides to nymphs were higher than to adult.55% cypermethrin chlorpyrifos EC showed the maximal difference in toxicity between adults and nymphs,and LC50 values of 55% cypermethrin chlorpyrifos EC to adults than nymphs was 1.46 times.The 20% carbosulfan EC have lowest difference in toxicity between adults and nymphs,and LC50 values of 20% carbosulfan EC to adults than to nymphs was 1.15 times.The control effect of six insecticides to adults was average higher 7.29%than that of nymphs after 9 days the insecticides sprayed on satsuma orange.4.5% beta-cypermethrin EC,55% cypermethrin chlorpyrifos EC,20% clothianidin SC and 10% imidacloprid SP had higher control effect on adults than nymphs.However,after 9 days spraying insecticides with cutting off the shoot tips,the control effect of six insecticides to adults was average higher only 1.99% than that of nymphs.There was no significant difference between the control effect of six insecticides to adult and nymphs after 9days spraying insecticides with cutting off the shoot tips.It implied that young nymphs was protected inside the newly developing unfolded leaves where Diaphorina citri oviposited,therefore some nymphs avoided contact with the spray and reduce control effect of insecticides to nymphs.Suggestions on shoot tips should been heavily sprayed with insecticides,and using compound and systemic insecticides are effective in killing nymphs.