Summary.
Assessing the influence of temperature and precipitation on insect counts at the Family level.
All insects respond directly and indirectly to changes in climate variables (Stenage and Ayres, 2010) however we are still building knowledge on the long-term and population-level responses of many insect groups (Kocsis and Hufnagel, 2011; Halsch et al., 2021). Long-term data from the Zoological Museum at the University of Copenhagen in Denmark provides comprehensive insect abundance data for two insect Orders (Coleoptera and Lepidoptera). The data provides an excellent opportunity to contribute to the growing knowledge of long-term climate effects. This project is unique as it will look at abundances at a higher taxonomic level than previous work with this data, will incorporate the effects of both temperature and precipitation, and will look at climate variation.
Myrrha octodecimguttata, a species counted 63 times at the Zoological Museum between 1992-2009 (image link)
Pleuroptya ruralis, a species counted 134 times at the Zoological Museum between 1992-2009 (image link)
Yearly and monthly counts of Families within each Order were explored and analyzed alongside local temperature and precipitation magnitude and variation. This provided evidence on whether insect abundance in the city of Copenhagen is climate-dependent. Yearly counts showed boom/bust cycles in abundant Coleopteran Families, but not for Lepidopteran Families. Overall, monthly temperatures had a weak but positive relationship within Coleoptera and Lepidoptera and monthly precipitations appeared to have no strong trends with insect abundance in either Order. Bootstrapping of correlation coefficients showed that climate variable magnitudes during the summer months were the most important for influencing insect abundance. These results potentially indicate other ecological processes at play within the city of Copenhagen or potential buffering of climate dependencies by spatial characteristics of the area.
Argyresthia goedartella, a species counted 226 times at the Zoological Museum between 1992-2009 (image link)
Cantharis pallida, a species counted just 1 time at the Zoological Museum between 1992-2009 (image link)