Moss-inhabiting beetles of the West Indies (Insecta: Coleoptera)

This study is the first attempt to assess the diversity of beetles (Coleoptera) in terrestrial moss cushions on three West Indian islands (Hispaniola, Jamaica, and Puerto Rico) based on 10 years of moss sampling in 18 localities. In total 1711 adult beetles were collected. They belong to 234 species from 30 families. The most species and specimen rich families are Staphylinidae (86 morphospecies and 1195 specimens), Curculionidae (61 morphospecies and 131 specimens), and Chrysomelidae (16 morphospecies and 185 specimens). In addition to basic bryobionts feeding on moss tissues, moss cushions host a diverse fauna of mycophagous and saprophagous Coleoptera together with predaceous species of beetles. Our results suggest that community composition in moss inhabiting beetles is determined both by geographical isolation processes and, to a lesser degree, by environmental variation across altitudinal gradients. This confirms that the greater relevance of geographical isolation is a common pattern in organisms with limited dispersal ability. Beetle abundance was not significantly related to either the volume of moss or the substrate. Despite being not significant (but close to), the observed trend was to higher beetle abundance in moss cushions collected on trees than in those collected on soil/rock. This may be resulting from the greater diversity of fungi and higher number of beetle fungivores associated with tree growing moss communities.