Biogeography and habitat preferences of red wood ants of the Formica rufa group (Hymenoptera: Formicidae) in Finland, based on citizen science data

Abstract

Red wood ants (RWA) of the Formica rufa group are ecosystem engineers and important species in boreal and temperateforests. However, the permanent and temporal loss of forest habitats is a serious threat to their existence and is likely toincrease with climate change. Due to the current threat of losing species, quick actions are needed. Reported here is the biogeography,relative abundance and habitat preferences of fi ve species of RWA in Finland based on citizen science data. Speciesthat occur in the lowlands of the Alps also occur throughout the southern parts of Finland. Only two of the fi ve species, F. aquiloniaYarrow, 1955 and F. lugubris Zetterstedt, 1838, were common throughout the country, including northern Lapland. As their namesuggests, RWAs occur mostly in forests and forest edges, but they also sometimes inhabit open or semi-open yards, mires andmeadows. The most forest-specialist species is F. aquilonia and the least F. rufa Linnaeus, 1761. Surprisingly, the meadow woodant F. pratensis Retzius, 1783 is the second most forest dwelling species, however, its preference for forest edges is clearly higherthan for forest interiors. Based on current data, F. rufa may be the most tolerant of living close to buildings as its relative abundancein yards was much higher than that of the other species. The data obtained on distributions and relative abundances couldbe compared in the future with the results of similar surveys to detect changes in species distributions, relative abundances andhabitat preferences.