松突圆蚧种群室内耐热性的季节变化

Seasonal variation in heat tolerance of Hemiberlesia pitysophila Takagi

通过室内人工模拟高温暴露试验,采用松突圆蚧死亡率和半致死高温累积LSHIT50等指标,比较分析害虫种群耐热性的季节变化。结果表明,随着暴露温度的升高,松突圆蚧的死亡率总体上逐渐增大。松突圆蚧的耐热性与其处在的发育阶段(虫态)有关,1龄若虫、2龄性分化前若虫、雌成虫在43和45℃高温暴露下的死亡率在春、夏、秋、冬各季节之间差异不显著,但夏季2龄性分化前若虫、2龄性分化后雌若虫和种群总体相对于其他季节,具有明显较强的耐热性,种群表现出较强的季节适应特征。松突圆蚧致死高温为45℃左右。

By means of the artificial heat exposure methods, the mortality and semi-lethal sum of high injurious temperature （LSHIT50） of Hemiberlesia pitysophila among different seasons and developmental stages were analyzed and compared, and the heat tolerance and seasonal adaptability were also synthetically evaluated. The results showed that the mortality gradually increased with rising of the temperature and the heat-tolerance was related to the developmental stages, and the difference in the mortality of 1st instar nymph, 2nd instar nymph before sex differentiation, and female adults at high temperature of 43 and 45 ℃ among different seasons was insingnificant. But the 2nd instar nymph before sex differentiation, the 2nd instar female nymph after sex differentiation and the entire population had significantly higher heat tolerance in summer than in other seasons, and appeared to a clearly seasonal adaptability characteristics. The lethal high temperature might be fluctuated around 45 ℃.