灰飞虱种群暴发成灾原因剖析

灰飞虱Laodelphaxstriatellus(Fall n)作为多种植物病毒病的传毒介体,近年来发生数量呈逐年锐增态势,给水稻生产造成了严重的损失。研究表明,灰飞虱种群的暴发有其生理生态基础。种群具有的强抗逆能力和多态现象增加了种群在各种环境条件下的存活机会;体内共生菌的感染增大了种群的繁殖力。暖冬及春季偏高气温与偏少降雨使种群的存活率提高、发育加速;免耕及种植方式的多样性,使得灰飞虱种群从麦田等地转移到稻田的桥梁质量提高、数量增多;种群抗药性的产生与抗性水平的提高,造成主要药剂对灰飞虱防效的下降,致使种群始终处于高数量水平;同时,承灾体水稻抗虫能力的脆弱,最终触发灰飞虱种群的大暴发与成灾。近年灰飞虱的大发生是种群内外多种因素共同作用的结果。另外,文中还对灰飞虱种群暴发成灾及测报中急需解决的问题进行了讨论。

Outbreak reasons of Laodelphax striatellus population

As the most important vector of some plant virus transmission, the populations of small brown planthoppers (SBPH), Laodelphax striatellus, were trended to increase in recent years, and it caused serious damage to rice plant. There are some physiological and ecological bases for the outbreak of this pest. So some outbreak reasons of the SBPH populations were analyzed and reviewed. The higher stress resistance and polymorphism of the population increased the survival probability, and the infection of symbiotes bacteria resulted in the higher fecundity. Additionally, the warm winter, the higher temperature in spring and the reduced rainfall increased the survival and development rate of the SBPH populations. And the various planting patterns in the recent years improved the transformation routes of L. striatellus from wheat to paddy fields. Moreover, the resistance of L. striatellus to pesticides and the susceptivity of rice plants to L. striatellus made the population size increase quickly. The interaction of these factors led to the population outbreak. In addition, the urgent issues of the mechanisms of population outbreak and forecast of L. striatellus were also discussed.