桃蛀螟为害对春玉米镰孢穗腐病发生及产量损失的影响

摘要

[Aim] The yellow peach moth,Conogethes punctiferalis (Guenée),has become the major insect pest of corn in Huang-Huai-Hai Region.This study aims to clarify the relationship between the occurrence of C.punctiferalis and the severity of corn ear rot,and the effect of ear infestation by C.punctiferalis on corn yield loss.[Methods] The corn ears were inoculated with neonate larvae of C.punctiferalis and Fusarium verticillioides singly or complexly at the silking,blister and milk stages of corn ears,respectively,and then the damage degree of C.punctiferalis,the occurrence rate of ear rot,the disease index and the corn yield were investigated.[Results] For different inoculated developmental stages of corn ears,the disease index by the complex inoculation with C.punctiferalis larvae and F.verticillioides was the highest,followed by the single inoculation with C.punctiferalis larvae,and then by the single inoculation with F.verticillioides.When the corn ears were inoculated with C.punctiferalis larvae at the silking stage of corn ears,the occurrence of the corn ear rot and the borer damage was the most serious.The corn yield components were affected when the corn ears were complexly inoculated with both C.punctiferalis larvae and F.venicillioides,with the highest yield loss per ear (33.09％) at the silking stage and 22.50％ and 10.13％ yield loss per ear at the blister and milk stages,respectively.[Conclusion] The yellow peach moth infestation during the developmental stage of corn ears significantly aggravates the occurrence of corn ear rot and causes heavier yield loss of corn.%[目的]桃蛀螟Conogethes punctiferalis (Guenée)已经成为黄淮海玉米穗期的重要害虫,本研究的目的是探究桃蛀螟发生危害与玉米镰孢穗腐病发病程度和玉米产量损失之间的关系.[方法]在玉米吐丝、灌浆和乳熟期,通过人工接种法将桃蛀螟初孵幼虫及拟轮枝镰孢菌Fusarium verticillioides单接或复合接种到玉米果穗上,收获时调查果穗上桃蛀螟为害级别、镰孢穗腐病发病率及病情指数,测定玉米产量.[结果]在玉米果穗的不同发育阶段,镰孢穗腐病病情指数均以复合接种处理最高,单接虫次之,单接菌最低.在单接虫处理中,镰孢穗腐病的发生程度及桃蛀螟为害级别均以吐丝期最重.拟轮枝镰孢菌与桃蛀螟复合侵染危害后,使得玉米产量性状发生改变,导致产量下降,以吐丝期危害影响最大,单穗损失率为33.09％,灌浆期和乳熟期分别为22.50％和10.13％.[结论]玉米穗期桃蛀螟的为害明显会加重镰孢穗腐病的发生,从而导致了更严重的玉米产量损失.