Foraging activity of the carabid beetle Pterostichus melanarius Ill. in field margin habitats

The foraging activity of the carabid beetle Pterostichus melanarius was studied in a capture-recapture experiment in field margin habitats. Two rectangular enclosures were installed over a succession of habitats with a decreasing prey availability: a hedge, a mixed crop strip and an adjacent crop culture. Marked starved and satiated individuals were released in the enclosures and recaptured during 8 days. Initial satiation state had a significant effect on activity. Also, the initial displacements of beetles depended both on the habitat and on the initial satiation state. R melanarius appeared to have flexible habitat-use, depending mainly on three factors: the satiation state, the habitat preference of the species, and the prey availability in the habitat. (C) 2002 Elsevier Science B.V. All rights reserved.