A study of ground beetles (Carabidae, coleoptera) at adjacent woodland and grassland habitats in Durham, north-east England

Communities of Carabid beetles have been studied at adjacent woodland and grassland habitats in Durham, north-east England during the period 1988 May 12 to December 23.From a total of 25 Carabid species identified, the data obtained on a subset of some 17 species were sufficient to permit a discussion of the biological seasons of adult individuals. Many measurements have been taken of the frequency of capture, the distance of movement, the length of the mandible tip, the ratio of the length of the abdomen to that of the elytra, the numbers and volumes of eggs, and the maturity of the reproductive organs of both sexes. It is suggested that the results of the present work are compatible with those of previous studies of ground beetles at various habitats in north-west Europe, which have revealed a shift of the time of occurrence of the breeding and emergence seasons depending upon the harshness of the local environmental conditions. The composition of the communities of Carabid species at the Durham woodland and grassland sites has also been investigated. The dominant species in the two habitats were found to be Pterostichus madidus and Nebria brevicollis.