Effects of photoperiods on activity level, developmental time, body size and metabolic rate in the nymph of cricket, Gryllus varius (Orthoptera: Gryllidae)
Author of the article:ao-Ting LI** Makio TAKEDA***
Author's Workplace：Graduate School of Science and Technology, Kobe University, Kobe 657-8501, Japan
Key Words：photoperiods, activity, developmental time, body size, metabolic rate, crickets
Abstract： [Objectives] In order to investigate photoperiodic modulation on the behavior and development of the crickets, including the effects on activity level, developmental time, body size and feeding. [Methods] Observation was manipulated by using video camera to monitor the activity of the nymphs and analyzed the behaviors. [Results] Under 12L︰12D, nymphal development took longer, reached a relatively larger body size but the activity level was lower with less defecation than under 16L︰ 8D. This suggests that the metabolic rate was higher in long photoperiod. The differences between the two photoperiods were statistically significant. The result also indicated that bigger animals tended to live longer at a lower metabolic rate with lower activity level. [Conclusion] The photoperiods definitely affect the development of the crickets. There may be a specific connection that combines the activity level, developmental time, body size and metabolic rate together. The bigger individuals tend to live longer at a lower metabolic rate with lower activity level, while the smaller ones live shorter at higher metabolic rate and activity level.