Research Articles


, Volume 49, Issue 8, pp 711-713

First online:

Circadian rhythmicity is involved in photoperiodic time measurement in the aphidMegoura viciae

  • M. Vaz NunesAffiliated withDepartment of Biology, Imperial College at Silwood Park
  • , J. HardieAffiliated withDepartment of Biology, Imperial College at Silwood Park

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The photoperiodic clock in the vetch aphidMegoura viciae is generally accepted to be based on a non-circadian mechanism or “hourglass”, as no evidence has been found for the involvement of the circadian system in the photoperiodic response. By using a recently-devised protocol which discriminates between single and repeated night length measurement, we demonstrate here that long-night measurement inMegoura is executed in a repetitive way, and thus that its photoperiodic clock is based on a circadian oscillator after all. However, it is also apparent that the determination of short nights is not repetitive.

Key works

Photoperiodism photoperiodic clock circadian rhythmicity aphid Megoura viciae