ECOLOGICAL STUDY FOR CIRCADIAN CLOCK-ANALYSIS OF ADAPTIVE SIGNIFICANCE OF ECLOSION TIMING AND LOCOMOTOR ACTIVITY RHYTHMS

对于在土壤中化蛹的昆虫，昼夜温度循环可以为成虫羽化在一天中的适当时间发生提供主要时间线索（Zeitgeber）。而在土壤中，由于土壤导热系数低，温度循环的相位随深度的增加而延迟。因此，位于土壤中较深处的puerum可以补偿Zeitgeber的深度依赖性相位延迟，以避免不合时宜的出现。我们研究了成年羽化时间的洋葱苍蝇，迪利亚antiqua，在不同深度的土壤中，在实验室中的各种热周期下，以确定是否确实发生这样的补偿化蛹。我们发现，随着温度循环幅度的减小，古猿能够提前羽化时间来补偿Zeitgeber随深度变化的相位延迟，许多双翅目昆虫在清晨羽化。这种趋势与环境条件的昼夜变化有关。解释这一现象的一个著名假设是，早晨相对潮湿和凉爽的空气将有利于新出现的成虫的翅膀伸长（Pitendridge 1954）。然而，对于干燥和高温是如何干扰新出现的苍蝇的翅膀伸长，在科温特却知之甚少。为了验证这一假设，研究了湿度和温度对西施舌翅伸长的影响。在20 ~ 35 ℃的温度范围内，干燥对翅的伸长没有不良影响，即使相对湿度低于10%，大多数个体也能成功地伸长翅。与湿度相比，高温对翅长的干扰作用较大。因此，避免中午高温至少部分地参与了成虫清晨羽化的适应意义。

For the insects pupating in the soil, the day-night temperature cycle may provide a primary time cue (Zeitgeber) for adult eclosion to occur at an appropriate time of the day. In the soil, however, the phase of temperature cycle is delayed with depth because of the low heat conductivity of soil. Therefore pupae located deeper in the soil might compensate for the depth-dependent phase delay of Zeitgeber to avoid mistimed emergence. We examined the adult eclosion timing of the onion fly, Delia antiqua, pupating at different depths in soil and under various thermoperiods in the laboratory to determine if such compensation indeed occurs. We found that D.antiqua is able to compensate for the depth-dependent phase delay of the Zeitgeber by advancing the eclosion timing in response to the amplitude of the temperature cycle decreasing with depth.Many dipteran insect emerge as adults in early morning. This trend would be associated with diel change in environmental conditions. One of the well-known hypothesis explaining this phenomenon is that relatively humid and cool air in the morning would favor the wing elongation of newly emerged adults (Pitendrigh 1954). At oresent, however, little is known how desiccation and high temperature disturb the wing elongation of newly emerged flies. To test this hypothesis, influence of humidity and temperature on wing-elongation of D.antiqua was examined. In the temperature range from 20C to 35C, desiccation has no harmful effect on the wing elongation; even if RH fell below 10%, most individuals examined elongated their wings successfully. Contrast to humidity, high temperature disturbed the wing-elongation considerably. Thus, avoidance of mid-day high temperature would be at least in part involved in the adaptive significane of early morning adult eclosion.