The evolution of a cicannual clock as the optimal life history strategy in the varied carpet beetle

各种地毯甲虫的幼虫生长一到三年或更长时间。成虫在每年春季出茧，由生物钟控制，即以一年为周期的生物钟。在本研究中，生态生理学研究了这种生物钟的进化。在野外调查中，成虫体型存在地理差异，这与幼虫期的变化有关。在大多数种群中，个体的幼虫期为1 - 2年或2 - 3年，即三种生活史中的两种。在室内实验中，大多数成虫对的后代幼虫表现出三种生活史中的两种。成虫可能通过亲代投卵来控制幼虫期。因此，这可能是一种混合策略。该物种具有可变的长幼虫期的周期时钟的进化可能涉及通过混合策略最大化适应度。

Larvae of the varied carpet beetle Anthrenus verbasci grow for one to three years or more. The adults emerge in spring every year by controlling with the circannual clock, i.e. a biological clock with a period of about one year. In the present study, the evolution of this circannual clocks was eco-physiologically investigated. In the field researches, the body sizes of the adults showed geographical variation, which was involved in the variation of larval periods. In most population, individuals would have larval periods of 1 and 2 years or 2 and 3 years, i.e. two of three types of life history. In laboratory experiments, the progeny larvae in most of adult pair showed two of three types of life history. The adults might control the larval period by parental investment to egg. Thus, it might be a mixed strategy in the adults. The evolution of a circannual clock of this species having variable long larval periods would be involved in maximizing the fitness by mixed strategy.