SELECTION OF TERRESTRIAL GASTROPOD PREY BY CYCHRINE AND PTEROSTICHINE GROUND BEETLES (COLEOPTERA: CARABIDAE)

Abstract

AbstractI examined the relative feeding preferences of five carabid beetle species for terrestrial gastropod prey.Scaphinotus marginatusFischer, thought to be a snail specialist, discriminated among seven species of potential prey by size and species, with the slugDeroceras reticulatum(Müller) being the most preferred.Scaphinotus marginatusappears to use its elongated and narrowed mouthparts, head, and thorax to prey upon terrestrial snails without having to crush their shells. The relative feeding preferences of four pterostichine generalist predators (Pterostichus adstrictusEschscholtz,P.pensylvanicusLeConte,P.protractusLeConte, andP.surgensLeConte) for two species of small snails [Discus cronkhitei(Newcomb) andEuconulus fulvus(Müller)] also were examined. Although all four carabids ateE.fulvusin varying proportions, onlyP.protractusconsumedD.cronkhitei. I suggest that snail shell thickness and differing feeding preferences affect which snail species are eaten by these pterostichines.