Annual activity and life cycles of carabid beetles in two forest communities

The annual activity and life cycles of thirteen species of carabid beetles coexisting in two forests in Belgium were studied by recording above-ground activity of adult and larval populations, and by examining the reproductive condition of adults in the course of the year. The cycles were far more complex and diversified than suggested by previous works. Besides typical "spring breeders" and "autumn breeders", species were found

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  with a continuous reproductive period from spring to autumn,
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  with several variable breeding periods, part of the population overwintering as adults, part as larvae,
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  with a breeding period that begins facultatively in autumn and continues the next spring,
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  with a winter reproduction.

Comparison of life cycles in Scandinavia and In Belgium also shows their variability in relation to climate. More flexible and varied cycles are made possible by the milder winters further south. Existing classifications of life cycles of carabids appear unable to account for such a diversity and variability.