昭平县第三代稻纵卷叶螟大发生原因及防治对策

第三代稻纵卷叶螟是昭平县早稻主要害虫,2005~2006年均达到大发生程度,其原因主要与暴雨频繁、气候条件适宜稻纵卷叶螟迁入和虫卵孵化及幼虫存活、成虫迁入量大、第二代残留基数高、寄主品种丰富、天敌控害能力下降有关。生产上主要制定了准确测报,掌握防治适期;及时做好第二代稻纵卷叶螟的防治工作,减少第二代残虫基数;科学用药,采用防治效果好、对天敌相对安全的化学农药适时适量施用等对策。

Major causes for break-out of rice leaf folder of the 3rd generation in Zhaoping County and its control countermeasures

Rice leaf folder of the 3rd generation,the main pest in early rice in Zhaoping County,broke out heavily during 2005-2006 due to the frequent storm and climate condition that were suitable for rice leaf folder's migration,eggs hatching and larvae survival,large amounts of adult pests migration,high rate of remnants of 2nd generation pests,rich amounts of host varieties and the decline of the natural enemy's prevention ability.In the production,some countermeasures were put forward,which include:1) the accurate forecast should be established to master the proper period for control;2) the control should be done at the right time to reduce the statistic number of the 2nd generation larva;3) spraying pesticides scientifically,that is applying the pesticides with appropriate amount at the right time,which is relatively safe for leaf folder's natural enemy.