Getting the Most out of Arthropod Biodiversity Surveys: A Comparison of Survey Techniques and Taxonomic Groups

Due to the high costs and large numbers involved with surveys of terrestrial arthropods, biodiversity surveys of this group typically rely on a select group of taxa sampled using a single technique. These surrogate taxa are often selected on the basis of ease of identification and survey, but there is limited empirical evidence to show how well the diversity of these groups relates to the total number of arthropod morphospecies within a particular region. We surveyed terrestrial arthropods at 14 vegetation remnants within the Murrumbidgee Irrigation Area, in south-western New South Wales (Australia) by pitfall trapping, beating, sweeping and fogging. Our aim was to determine whether there were any taxa and a single sampling technique that best represented the total number of morphospecies in all assemblages at all sites, in order to provide the most efficient survey methods for future monitoring. Taxa included in the analysis were Araneae, Diptera, Coleoptera, Hemiptera and Hymenoptera (excluding Formicidae). No taxa collected using pitfall trapping were significantly correlated with the overall number of morphospecies. However, Coleoptera and Hemiptera from sweep samples were significantly, albeit weakly, correlated with the overall number of morphospecies collected using all sampling methods.