eDNA cavity-nesting wild bees. eDNA allows non-lethal detection of cavity-nesting wild bees and their parasitoids

Wild bees are important pollinators for flowering plants, including crops. Wild bee populations are facing dramatic declines due to a variety of stressors, including such as habitat loss and pesticide use. Research focused on wild bees has increased over the last three decades, yet species identifications are still relying on lethal sampling, followed by time- and labour-intensive pining and morphological analysis. The use of DNA metabarcoding for species detection offers a time- and cost-effective alternative to traditional approaches and can potentially facilitate non-lethal sampling. We developed a DNA metabarcoding workflow to identify cavity-nesting wild bees, wasps and parasitoids using environmental DNA collected from vacated nest tubes. We compared different nest sizes and sample types , in terms of DNA quantity and quality and their effect on Hymenoptera detection at the species level. We further tested whether we could detect species mixtures.