Circabidian rhythm in a large black chafer Holotrichia parallela

许多生物体的生物活动与地球上的环境周期同步。然而，大型黑金龟子Holotrichia parallela有一个独特的2天节律。成虫在白天呆在地下，每隔一天晚上出现在地面上。我们对这种节律进行了生态学和时间生物学研究。标记和再捕获研究表明，甲虫重复出现在同一棵树上，在6月至9月的隔日觅食。据认为，2组共域发生在不同的日子。捕获的甲虫具有明显的内源性活动节律，周期约为48h。对光脉冲的相位响应表明，这种昼夜节律是由生物钟驱动的。

Many organisms synchronize their biological activity with environmental cycles on the earth. However, the large black chafer Holotrichia parallela have a unique 2-day rhythm. Adults remain under ground in the daytime and appear on the ground every other night. We have made an ecological and chronobiological study on this rhythm. Mark and recapture study suggested that beetles repeatedly appear on the same tree for feeding on alternate days from June to September. It is thought that 2 groups occurred sympatrically on different days. The captured beetles showed a clear endogeneous activity rhythm with a period of about 48 h. Phase responses to light pulses suggested that this circabidian rhythm is driven by a circadian clock.