biodiversity of carabidae beetles (coleoptera: carabidae) in agroecosystems of azadshahr region, golestan province, northern iran

ground beetles (family carabidae) with more than 40,000 described species worldwide are one of the most important generalist predators in agroecosystems. because of their habit of feeding on agricultural pests and weed seeds, in this study we tried to assess their biodiversity in agroecosystems of azadshahr region, eastern golestan province. samples were collected for some main crops, using pitfall traps during 2009 and 2010 and two indices, including simpson's reciprocal index and shannon-weaver index were used to measure diversity and structure of the community. results showed that there were a high species richness of ground beetles in this region and 24, 22, 18, 18 and 12 species were identified in rape seed, wheat, tomato, broad bean and soybean fields, respectively. dominant species in these crops were harpalus distinguendus duftchmid, agonum dorsale (pontoppidan), poecilus cupreus (l.), agonum dorsale (pontoppidan), and harpalus rufipes (de geer), respectively. the values of shannon and simpson indices in these ecosystems were 2.16, 2.57, 1.81, 2.22 and 2.00, and 4.93, 10.09, 4.21, 6.16 and 6.12, respectively. the highest (7.1±0.85) and the lowest (0.45±0.12) numbers of beetles were captured in margins of rape seed and soybean fields, respectively.