Outbreak reasons of Laodelphax striatellus population.

Abstract

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.