Dedicated to the memory of Erwin Bünning, Tony Lees and Colin Pittendrigh, pioneering investigators of time measurement in insect photoperiodism.
Unity and diversity in the insect photoperiodic mechanism*
Article first published online: 23 JUN 2011
© 2011 The Entomological Society of Japan
Volume 14, Issue 3, pages 235–244, July 2011
How to Cite
SAUNDERS, D. S. (2011), Unity and diversity in the insect photoperiodic mechanism. Entomological Science, 14: 235–244. doi: 10.1111/j.1479-8298.2011.00463.x
- Issue published online: 5 JUL 2011
- Article first published online: 23 JUN 2011
- Received 14 April 2011; accepted 17 April 2011.
- clock models;
- insect photoperiodism
This review examines some of the models to account for time measurement in insect photoperiodism. It considers the supporting evidence for these models and the attempts to discriminate among them. Although hourglass timers may exist, it is suggested that most photoperiodic mechanisms, including many hourglass-like timers, are circadian-based, making Bünning's original hypothesis, that the circadian system somehow provides the essential “clockwork” for photoperiodic timing, the most persuasive unifying principle. The apparent diversity among modern species in their modes of time measurement is probably the result of differences between the underlying circadian systems that were adopted for seasonal night length measurement as the insects, or groups of insects, moved northwards into areas with a pronounced winter season. Photoperiodic time measurement, therefore, exhibits both unity (in their common circadian basis) and diversity in detail. Attention to this diversity may provide invaluable insights into the problem of photoperiodic time measurement at comparative, and molecular, levels.