Abstract: Newly-hatched nymphs of the small brown planthopper (SBPH, Laodelphax striatellus), including field and sensitive populations, were subjected to high-temperature (35℃) for 1 d, 2 d and 3 d, respectively. The number of yeast-like endosymbiotes in the 3rd instar SBPH reduced by 23.47%-34.23%, 57.86%-61.51% and 88.96%-90.71% after treated with high temperature for 1 d, 2 d, and 3 d, respectively. However, the size of yeast-like endosymbiotes was not obviously affected. Resistance of SBPH to three insecticides (midacloprid, chlorpyrifos and fipronil) decreased with increasing treatment time, with the order of resistance as follows: 1 d>2 d>3 d.

Key words: Laodelphax striatellus, yeast-like endosymbiote, high temperature, pesticide resistance

摘要： 利用35℃高温分别处理灰飞虱田间种群和敏感品系初孵若虫1~3 d，然后移至25℃下饲养至3龄。经1、2和3 d 处理后，灰飞虱体内类酵母共生菌数量分别减少了23.47%~34.23%、57.86%~61.51%和88.96%~90.71%；而类酵母共生菌的个体大小并无显著变化。进一步测定这些灰飞虱种群对杀虫剂吡虫啉、毒死蜱和锐劲特的耐药性，结果表明，高温处理时间越长，灰飞虱对这3种农药的耐药性越弱，即耐药性顺序为1 d>2 d>3 d。

关键词: 灰飞虱, 类酵母共生菌, 高温, 耐药性