Ground beetles (Coleoptera: Carabidae) assemblages in two agricultural landscapes in North-Eastern Algeria

Abstract

The ground beetles of two agricultural landscapes were studied in the semi-arid region of north-eastern Algeria (Constantine). Between 1998 and 2000, the ground beetles (Carabidae) of a cereal field edge and a cherry orchard edge were studied using ten pitfall traps installed at each site and also collecting them from under shelters. The results showed that the cereal field edge contained a greater diversity of carabid beetles compared to the cherry orchard edge. Thus, the richness, abundance and Shannon index of carabid species were noticeably higher along the cereal field edge than the cherry orchard edge. This difference is probably due to the stability of the first biotope. This also explains the low affinity observed between the species assemblage of both edges, as indicated by the Jaccard''s similarity of the three years which was found to be very low (15%, 21%, 20%). Adaptative parameters of species, like diet, flying ability and body size, showed that polyphagous, flying and small sized species are more frequent along the cherry orchard edge, whereas along the cereal field edge, which was considered an undisturbed habitat, predators were more frequent. Xerophilic species prevailed in both habitats and the number of hygrophilic species was higher along the cereal field edge than along the cherry orchard edge.