In this paper the larval morphology of the Palaearctic Meloe subgenera Eurymeloe and Coelomeloe is revised. We describe the first instar larva of Meloe (Eurymeloe) apenninicus, endemic to the Italian peninsula and, comparatively, triungulins of three more species of the subgenus Eurymeloe: M. apivorus, M. ganglbaueri, misidentified in literature, and of M. mediterraneus, incompletely described. Descriptions are accompanied by scanning electron microscope (SEM) photos of diagnostic characters and by a table reporting the size of the morphological details of 11 Euro-Mediterranean species and of M. (Coelomeloe) tuccius. The taxonomic position of the subgenus Coelomeloe and its distinction from Eurymeloe are discussed on the basis of larval morphology. Taxonomical problems concerning some Eurymeloe species are also discussed. A key to first instar larvae of all known Eurymeloe and Coelomeloe triungulins is provided.

The most pervasive macroecological patterns concern (1) the frequency distribution of range size, (2) the relationship between range size and species abundance and (3) the effect of body size on range size. We investigated these patterns at a regional scale using the tenebrionid beetles of Latium (Central Italy). For this, we calculated geographical range size (no. of 10-km square cells), ecological tolerance (no. of phytoclimatic units) and abundance (no. of sampled individuals) using a large database containing 3561 georeferenced records for 84 native species. For each species, we also calculated body mass and its ‘phylogenetic diversity’ on the basis of cladistic relationships. Frequency distribution of range size followed a log-normal distribution as found in many other animal groups. However, a log-normal distribution accommodated well the frequency distribution of ecological tolerance, a so far unexplored issue. Range size was correlated with abundance and ecological tolerance, thus supporting the hypothesis that a positive correlation between distribution and abundance is a reflection of interspecific differences in ecological specialization. Larger species tended to have larger ranges and broader ecological tolerance. However, contrary to what known in most vertebrates, not only small-sized, but also many medium-to-large-sized species exhibited great variability in their range size, probably because tenebrionids are not so strictly influenced by body size constraints (e.g. home ranges) as vertebrates. Moreover, in contrast to other animals, tenebrionid body size does not influence species abundances, probably because these detritivorous animals are not strongly regulated by competition. Finally, contrary to the assumption that rare species should be mainly found among lineages that split from basal nodes, rarity of a tenebrionid species was not influenced by the phylogenetic position of its tribe. However, lineages that split from more basal nodes had lower variability in terms of species geographical distribution, ecological tolerance and abundance, which suggests that lineages that split from more basal nodes are not only morphologically conservative but also tend to have an ecological ‘inertia’