Full-text - Norsk entomologisk forening

The larval stages of the genus Bembidion Latr.(Col. Carabidae) I. The larvae of the subgenusChryso bracteon Net. and B. dentellu m Thunb.Johan Andersen,Trornsrz Museum, Tromsa.In connection with an ecological investigation of the beetlefauna on the banks of rivers I have reared the larvae of severalspecies of the genus Bembidion, and among them the followingpreviously not known larvae of the subgenus Chrysobracteon: B.argenteolum Ahr., R. lapponicum Zett. and B. litorale Ol., whereasthe larva of the fourth Scandinavian species - B. velox L. -is still unknown. The last mentioned, judging by the adult, isclearly closely related to B. lapfionicum (Lindroth 1962) and itis reasonable to believe that the larvae of the two species resembleeach other very much, or perhaps cannot be separated.Despite only having the exuviae of a single larva of B. dentellunz,I venture a description of it, as the single specimen deviates somuch from other known larvae of Bembidion that the essentialcharacters given in the description probably will hold good forthe species in general.Material and methodsThe material comprises larvae reared from eggs deposited bythe adults, and larvae collected in the field which pupated andhatched in the laboratory. During the rearing each of the specieswere kept in individual jars on their natural substratum takenfrom the spot where the adults were found. To be certain ofthe abscence of living larvae of Bembidion in the substratumbefore the adults were put in the jars, the substratum was keptdry for several weeks at room temperature (18-20" C) and arelative humidity of 40-50%. Under these circumstances thelarvae are not able to live more than a few hours.