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为了解松突圆蚧Hemiberlesia pitysophila Takagi对海拔的热适应性,通过极端温度暴露试验和过冷却点测定,比较了不同海拔梯度(80～725m)上冬季松突圆蚧1龄若虫、2龄性分化前若虫和雌成虫的热耐受性。结果表明:(1)不同海拔松突圆蚧的热耐受性具有显著差异,主要表现为海拔391m区域2龄性分化前若虫和雌成虫的耐寒性,以及雌成虫的耐热性均显著较强;除2龄性分化前若虫的耐寒性外,该虫的热耐受性未表现出随海拔升高而显著增强的趋势。这一结果不支持气候变化假说,但说明海拔是限制松突圆蚧种群扩张和地理分布的重要因素。(2)海拔梯度上,1龄若虫和2龄性分化前若虫中耐寒性与耐热性的相关性均不显著,但在雌成虫中呈显著正相关,说明海拔梯度上松突圆蚧耐寒性和耐热性的关系与其发育阶段有关。(3)海拔梯度上,雌成虫的过冷却点与其致死中低温的相关性未表现出显著水平。本文结果有助于深入理解松突圆蚧的热适应性和地理分布特征。
In order to understand the thermal adaptability of Hemiberlesia pitysophila Takagi to altitude, the first instar nymphs of Hemiberlesia pitysophila Takagi at different altitudes (80 ~ 725 m) were compared by means of extreme temperature exposure test and subcooling point, Thermal tolerance of pre-differentiation nymphs and female adults. The results showed that: (1) There were significant differences in the thermal tolerance of P. crassicifolia at different altitudes, mainly showing the cold tolerance of the 2nd instar nymphs and female adults at 391 m above sea level, and the heat tolerance of female adults In addition to cold tolerance of 2-instar nymphs, the thermal tolerance of this insect did not show a significant increase with altitude. This result does not support the climate change hypothesis, but it shows that elevation is an important factor that limits the population expansion and geographical distribution of P. elegans. (2) There was no significant correlation between cold tolerance and heat tolerance of the first instar nymphs and the second instar nymphs at the altitudinal gradient, but there was a significant positive correlation between the cold tolerance and heat tolerance of female adults And the relationship between heat resistance and its developmental stage. (3) On the altitudinal gradient, the correlation between the subcooling point of female adults and its lethal mid-low temperature did not show a significant level. The results of this paper will help us to understand the thermal adaptability and geographical distribution characteristics of P. crassipes.