Freezing cold yet diverse: dissecting a high-Arctic parasitoid community associated with Lepidoptera hosts

Despite increasing worldwide interest in host-parasitoid food webs, the parasitoid communities of the high Arctic remain poorly explored. To allow analyses of global patterns, and to detect the effects of ongoing climate change, such data are urgently needed. In this paper, we describe a systematic effort to characterise the high-Arctic Hymenoptera and Diptera parasitoid community associated with Lepidoptera hosts of the Zackenberg Valley (74 degrees 30'N, 21 degrees 00'W), northeast Greenland. Here, we first sampled adult parasitoids by a combination of Malaise traps, pitfall traps, and, less extensively, yellow pan traps and sweep netting. We then identified the host use of individual parasitoid taxa by rearing a large number of host individuals and species across multiple years. We now describe our preliminary findings on the species diversity of the target community, on trophic links between hosts and parasitoids, and on the sampling effort and techniques needed to characterise the community. We report on 30 local parasitoid taxa representing four families, three of which are species new to Greenland. In describing the community, we make a specific effort to summarise what is known about the taxonomy, phenology, and host use of the component species, to the benefit of future research in the area.