Myrmecophily is not a risk factor for long‐term occupancy trends of central European Lycaenidae butterflies

Abstract As anthropogenic pressures continue to increase, generalist species tend to be more resilient than specialised species. Specialisation can take various forms, among else dependence on other species through biotic interactions. Some Lycaenid butterflies (gossamer‐winged butterflies: blues, coppers and hairstreaks; Lycaenidae Leach, 1815)) rely on host ants for larval care and survival (myrmecophily). This dependence may pose an additional threat. To investigate whether myrmecophily is associated with the long‐term trends of Lycaenids, we compared 40‐year occupancy trends derived from occupancy‐detection models of ant‐independent, facultative and obligate myrmecophile Lycaenidae in a central European model region. Contrary to our expectations, obligate myrmecophile butterflies did not show more declines compared to ant‐independent ones. Five out of seven obligate myrmecophile butterflies increased, while five out of eight ant‐independent Lycaenids decreased. Trends among facultative butterflies were highly ambiguous. The differences between the groups were not significant. Although obligate myrmecophile butterflies are protected significantly more often under stricter rules, the degree of protection did not affect Lycaenid long‐term trends. European obligate myrmecophile butterflies interact with several ant species within widespread genera (primarily Myrmica Latreille, 1804, also Formica Linnaeus, 1758 and Lasius Fabricius, 1804) potentially protecting the larvae against environmental impacts and thus mitigating the effects of changing conditions on the butterflies. Incomplete understanding of the varying degrees of ant affiliation hinders the identification of specific interactions that may require increased conservation efforts. In our rapidly changing world, monitoring changes in the opportunities and strengths of species interactions is needed to prevent coupled species' extinctions and improve conservation outcomes.