剑麻蔗根锯天牛为害情况调查及药剂筛选

目的]了解剑麻蔗根锯天牛为害情况并筛选有效药剂。方法]调查大田剑麻上蔗根锯天牛的为害情况,观测幼虫体态特征,并通过室内试验和大田试验筛选蔗根锯天牛防治药剂。结果]东方红农场13队等部分幼龄麻暴发疑似蔗根锯天牛,幼虫为害植株头部,致根基部被咬食与茎被蛀空,叶片失水退绿、卷缩披垂,甚至停止生长或枯死,影响植株生长量至少180 d。幼虫体长53~80 mm,圆筒形,前端扁平,后端稍窄,老熟幼虫为乳黄色;上颚、头和前胸背板为黑褐色和黄褐色,体表光亮;腹部第1~7节背面正中隆起时有扁"田"字形纹等,经鉴定该虫为蔗根锯天牛幼虫。室内药剂筛选试验表明,48%噻虫胺毒土800倍、5%甲拌磷毒土55倍的防治效果理想,死亡率达100%;50%噻虫嗪毒土1 000倍的防治效果也较好。大田试验表明,噻虫胺、噻虫嗪与其他药剂混配的防效在80%以上。结论]试验结果为剑麻蔗根锯天牛的防治提供了理论依据。

Investigation on Damage Situation of Dorystenes (paraphus) granulosus Thomson to Agave sisalana Perr.ex Engelm.and Drug Screening

Objective] The aim was to understand damage situation of Dorystenes (paraphus) granulosus Thomson to Agave sisalana Perr.ex Engelm.and screen out drugs.Method] We investigated the damage situation of Dorystenes (paraphus) granulosus Thomson to Agave sisalana in field,observed the physical characteristics of larvae,and screened drugs for Dorystenes (paraphus) granulosus Thomson through laboratory and field trials.Result] Some young Agave sisalana in the 13th team of Dongfang Red Farm occurred suspected Dorystenes (paraphus) granulosus Thomson,and the larvae damaged the head of plant,and the leaves lost water and green,even stopped growth and died so as to affect the plant growth for 180 days at least.The length of larvae was 53-80 mm,cylindrical,had flat front end and slightly narrow back-end,and the mature larvae was creamy yellow.The palate,head and pronotum were dark brown and tawny,and the surface was brightness,so it was identified as Dorystenes (paraphus) granulosus Thomson.The indoor drug screening test showed that 800 times of 48% clothianidin poison soil and 55 times of 5% phorate poison soil had ideal control effect,with 100% of mortality.The 1 000 times of 50% thiamethoxam poison soil had good control effect.Field trials showed that the mixtures of clothianidin and thiamethoxam with other agents had more than 80% of control effect.Conclusion] The results provide theoretical basis for the control of Dorystenes (paraphus) granulosus Thomson.