亚洲玉米螟的一个生活史特征——体重与温度呈正相关

A life-history trait of the Asian corn borer, Ostrinia furnacalis (Lepidoptera: Pyralidae)-positive correlation between body weight and temperature

【目的】温度是变温动物最重要的环境因子,影响了所有的生活史特性。本研究旨在探明亚洲玉米螟Ostrinia furnacalis生活史特性随温度变异的特点。【方法】在恒温20,22,24,26,28,30和32℃,光周期16L∶8D室内条件下,测定了亚洲玉米螟南昌种群从卵孵化到化蛹和化蛹到成虫羽化的时间,以及蛹和成虫的体重。【结果】亚洲玉米螟幼虫和蛹的历期及总发育历期随温度的升高显著缩短。雄性幼虫历期和总发育历期显著短于雌性,显示了雄性先熟现象。生长速率与温度呈正相关。雌性生长速率在较低温度下显著低于雄性,但在高温下显著高于雄性。体重和温度之间的相关性没有遵循温度-体型大小法则,雌雄个体在高温下体重更重,雌性个体显著大于雄性,显示了雌性偏向的性体型二型性(sex size dimorphism,SSD)。与任希法则相反,亚洲玉米螟的SSD指数和体重随温度升高趋于增大。雄蛹在变态中比雌蛹丢失了更多的重量,导致成虫期的SSD指数大于蛹期。【结论】高温不仅显著缩短了亚洲玉米螟发育历期,而且导致了其在成熟时体重更大。亚洲玉米螟雌雄间的生活史特性存在较大差异。

【Aim】Temperature is the most important environmental factor for ectotherms and affects all aspects of life-history traits. This study aims to understand how life-history traits vary with temperature in the Asian corn borer,Ostrinia furnacalis. 【Methods】The developmental duration from egg hatching to pupation and from pupation to adult eclosion,and the pupal and adult weight were examined in the Nanchang population of O. furnacalis at 20,22,24,26,28,30 and 32℃ under a photoperiod of 16 L∶8 D in the laboratory. 【Results】The larval and pupal duration and total developmental duration of O.furnacalis were significantly decreased with the increasing of rearing temperature. The larval duration and total developmental duration were significantly shorter in males than in females,showing the protandry phenomenon. The growth rate was positively correlated with temperature. The growth rates of femaleswere significantly lower than those of males at low temperatures but significantly higher than those of males at high temperatures. The relationship between body weight and rearing temperature in O.furnacalis did not follow the temperature-size rule,and both males and females gained heavier body weight at high temperature. Females were significantly larger in size than males at all temperatures,showing a female biased sex size dimorphism（ SSD）. Contrary to Rensch＇s rule,the SSD index and body weight of O. furnacalis tended to increase with rising temperature. Male pupae lost significantly more weight at metamorphosis compared to females,resulting in higher SSD index in adults than in pupae. 【Conclusion】High temperature not only significantly shortens developmental duration,but also results in heavier body weight at maturity in O. furnacalis. There are significant differences in life-history traits between females and males of O. furnacalis.