A study of the larva of Carabdytes upin Balke, Hendrich and Wewalka (Cleoptera : Adephaga : Dytiscidae), with comments on the phylogeny of the colymbetinae

Description of structures of the second and third instars of Carabdytes upi n Balke, Hendrich, and Wewalka are presented, including detailed chaetotaxa l and porotaxal analyses. Larvae of Carabdytes Balke, Hendrich and Wewalka are compared phylogenetically with those of other genera of the subfamily C olymbetinae. Carabdytes belongs to the tribe Colymbetini based on the synap omorphies of (i) a more distal insertion of the primary seta CO7 on procoxa , (ii) the presence of marginal basoventral spinulae on tarsal claws, and ( iii) a more distad insertion of the primary pore ANg on antennomere 4. With in the Colymbetini, Carabdytes is characterized by a fewer number of natato ry setae which may represent either a plesiomorphic condition or an adaptat ion to a creeping way of life.