Data from: Resource specialists lead local insect community turnover associated with temperature – analysis of an 18-year full-seasonal record of moths and beetles

Insect responses to recent climate change are well documented, but the
role of resource specialization in determining species vulnerability
remains poorly understood. Uncovering local ecological effects of
temperature change with high-quality, standardized data provides an
important first opportunity for predictions about responses of resource
specialists, and long-term time series are essential in revealing these
responses. Here, we investigate temperature-related changes in local
insect communities, using a sampling site with more than a quarter-million
records from two decades (1992–2009) of full-season, quantitative light
trapping of 1543 species of moths and beetles. We investigated annual as
well as long-term changes in fauna composition, abundance and phenology in
a climate-related context using species temperature affinities and local
temperature data. Finally, we explored these local changes in the context
of dietary specialization. Across both moths and beetles, temperature
affinity of specialists increased through net gain of hot-dwelling species
and net loss of cold-dwelling species. The climate-related composition of
generalists remained constant over time. We observed an increase in
species richness of both groups. Furthermore, we observed divergent
phenological responses between cold- and hot-dwelling species, advancing
and delaying their relative abundance, respectively. Phenological advances
were particularly pronounced in cold-adapted specialists. Our results
suggest an important role of resource specialization in explaining the
compositional and phenological responses of insect communities to local
temperature increases. We propose that resource specialists in particular
are affected by local temperature increase, leading to the distinct
temperature-mediated turnover seen for this group. We suggest that the
observed increase in species number could have been facilitated by
dissimilar utilization of an expanded growing season by cold- and
hot-adapted species, as indicated by their oppositely directed
phenological responses. An especially pronounced advancement of
cold-adapted specialists suggests that such phenological advances might
help minimize further temperature-induced loss of resource specialists.
Although limited to a single study site, our results suggest several local
changes in the insect fauna in concordance with expected change of
larger-scale temperature increases.