Deep Interstitial Habitat as a Refuge for Agabus paludosus (Fabricius) (Coleoptera: Dytiscidae) During Summer Droughts

Abstract

We report information about the presence of Agabus (Gaurodytes) paludosus (Fabricius, 1801) within the interstitial zone of the streambed of the Po River (NW Italy) during droughts. During August and November 2004, we found adult and larval stages at depths of 70–90 cm below the surface when no water was present in the channel. These findings are discussed in the context of the origin of stygobiont diving beetles.