邵东县四代二化螟大发生原因及控防对策

Reasons and Countermeasures of the Four Generation of Chilo suppressalis in Shaodong County

长期以来,邵东县水稻二化螟一般每年发生三代,近年来的暖冬气候条件和栽培制度的变化,出现了不完全四代。2016年,邵东县四代二化螟大发生,造成迟插一季稻和晚稻田出现大量虫伤株,一般发生稻田虫伤株率20%左右,严重稻田虫伤株率达80%以上。县城以南的乡镇发生严重,县城以北的乡镇发生较轻;砂性稻田重于粘性稻田。经调查和分析,主要原因是杂交水稻品种高杆、粗茎营养丰富,单、双稻混栽桥梁田多,长期、单一使用化学农药增强害虫抗药性,持续高气温加快发育进度,三代二化螟发育为四代的比例大幅度增加等。采取冬季清除田间越冬场所的虫源、化蛹高峰期之前翻耕稻田或深水灭蛹、螟蛾羽化初期开始安装二化螟性诱剂、在精准测报的基础上科学使用化学农药等措施进行综合防控,可以达到较好的防控效果。

Three generations of Chilo suppressalis infested usually every year in Shaodong County for a long time,incomplete four generation appeared with the change of climate conditions and cultivation systems in warm winter recent years.The four generation of Chilo suppressalis in2016Shaodong County causing serious consequences:single-season rice transplanting was delayed,and20%to80%insect pest affected rate was found in the fields.Southern township were seriously affected,while lessen harm in the north,and sandy fields are heavier than the sticky.After investigation and analysis,found the main reason is that the nutritious are rich in stem and thick stems of hybrid rice,a large number of single and double rice mixed planting bridge fields,long term and single use of chemical pesticides enhanced pest resistance,sustained high temperatures accelerate the pace of development,and a substantial increase in the proportion of three generation evolved to four generation.Take measures to achieve good control effect including clear the wintering sites in field of insects,plowed field before pupation or deep water destroy,install the sex pheromone in early emergence stage,use the chemical pesticides scientifically on the basis of accurate forecast to conduct comprehensive prevention and control.