Monica Pitzalis

Phylogeny and evolutionary history of the blister beetles (Coleoptera, Meloidae).

Meloid beetles are well characterised by both morphological and biological features. Previous phylogenetic hypotheses based on morphological characters assumed the repeated parallel evolution of complex biological novelties. In this work relationships among several taxa of the four subfamilies and almost all tribes representing meloid diversity are examined by using mitochondrial (16S) and nuclear (ITS2) DNA sequences, in 25 genera (using Anthicidae as outgroup). Secondary structure of 16S and ITS2 rRNAs were modelled. ITS2 structure represents a synapomorphic condition for the family and informative characters at the tribal level. Phylogenetic hypotheses based on separate and combined analysis of the 16S and ITS2 rDNA sequences, and morpho-biological characters were tested, and compared with previous morphological classifications. Molecular dating allowed an outline of the main steps of the evolutionary history of Meloidae, which evolved during Early Cretaceous and then radiated considerably with the adoption of hypermetaboly and parasitic behaviour, and with repeated, parallel evolution of larval phoresy on its hosts.

Systematics and biogeography of the genus Actenodia (Coleoptera: Meloidae: Mylabrini)

Abstract The genus Actenodia Laporte de Castelnau (Meloidae: Mylabrini) is revised. It includes 18 species distributed in the Mediterranean and Saharo‐Arabian regions, and in eastern and southern Africa; A. carpanetoi sp.n. from Mozambique is described. The bionomics of the genus is summarized, according to a collection of records on phenology, elevation, habitat preference and host plants. A classification of the genus is proposed after a morphological cladistic analysis: one Afrotropical lineage clearly emerged with three distinct groups of species, whereas other taxa, all Palaearctic except A. mirabilis, remained unresolved. The analysis of the nuclear internal transcribed spacer 2 rDNA sequences of some Palaearctic and Afrotropical species supports the distinction of the Afrotropical lineage. The first instar larvae of two species, A. chrysomelina from southern Africa and A. denticulata from Arabia, are described for the first time and compared with two other Palaearctic species described previously; inferences from larval morphology are discussed. The adult morphology of all species is described briefly and illustrated, and a key to the species is provided, as well as locality data. Three new synonymies are proposed: A. extera Dvořák, 1993syn.n. =A. septempunctata Baudi di Selve, 1878; A. sexpunctata Pic, 1948syn.n. =A. curtula Fähraeus, 1870 ; A. unimaculata lanzai Kaszab, 1973syn.n. =A. unimaculata Pic, 1908. The biogeography of the genus is discussed within the framework of a more general analysis of the disjunct distribution models.

Comparative analysis of species diversity of Isopoda Oniscidea and Collembola communities in burnt and unburnt habitats in central Italy

Abstract The structure and diversity of Isopoda and Collembola communities are described and compared in burnt and unburnt sites occupied by oak and pine forests within a Mediterranean coastal ecosystem in central Italy (near Rome) to assess the effect of fire on these soil arthropods. The community succession, starting just after the fire, proceeded differently in the examined sites, showing distinct ecological responses between Collembola and Isopoda, as evinced by cluster analysis among sites and comparisons of species abundances. The burnt oak forest communities, less damaged by fire, were quite different from the burnt pine forests, which had few species, usually more abundant in individuals. Examining the mean of the whole abundance of each site, particularly in isopods, burnt sites showed greatly reduced values in comparison with unburnt sites. Both springtail and isopod communities of burnt sites showed a continuous turnover, evidenced by both temporally restricted species and temporal variations in species richness determined by post‐fire recolonisation. The species succession produced disequilibria of monthly and yearly abundances, which interacted with monthly variations in community structure determined by meteorological factors. The community structure stabilisation in burnt ecosystems during the succession is also demonstrated by the increasing of Shannon diversity and evenness values, particularly in Collembola. On the basis of temporal values of species richness and Shannon diversity values recorded for each site, two main patterns can be recognised: (1) oak forests were more diverse than pinewoods, and (2) unburnt sites were temporally more diverse than the burnt ones, because they host communities mostly subject to seasonal changes, especially due to some variations in humidity, rainfall and temperature. Burnt habitats tended to change their species composition more drastically, without any clear relationship with seasonally, because of the interaction of recolonisation with seasonal replacing of species, which determine a greater value of final “entropy”, as observed by the total annual values of Shannon diversity.

Time of diversification in the Cape fauna endemisms, inferred by phylogenetic studies of the genus Iselma (Coleoptera: Meloidae: Eleticinae).

The endemic diversification of the Cape zone fauna and the phylogenetic relationships among the 30 species of the blister beetle genus Iselma are investigated. We analysed morphological, molecular (mtDNA 16S) and combined datasets of characters using a number of approaches (maximum parsimony, maximum likelihood, Bayesian inference analyses). We propose hypotheses of diversification times among taxa from molecular clock analyses. Morphological and molecular analyses produced similar results. According to maximum likelihood molecular studies, radiation within the genus Iselma occurred during the Pliocene and Pleistocene, roughly contemporaneously with the shift in African climate, vegetation and faunal assemblages. Two main lineages, one Namibian and one South African, separated c. 4.9 Ma. Within the South African lineage we identify two groups of endemic species, one in Little Karoo and one that extend towards southern Namaqualand. The remaining South African groups of species are spread through Namaqualand and the southwestern Cape area. These include several endemisms, with different times of diversification during the Pleistocene, probably related in part to glacial cycles. These endemisms are distributed in small areas of the following ecosystems: coastal Strandveld, Succulent Karoo and particularly Fynbos.

What is driving the community structure of insects in arid ecosystems of Southern Africa? An example with blister beetles (Coleoptera: Meloidae)

A considerable part of community ecology literature questioned what are the main drivers of ecological relationships in an organismal community. We analysed this focal question by studying blister beetle (Meloidae) assemblages in Southern Africa. We explored the ecological distribution of 48 species across underlying bioclimatic (e.g. temperatures and precipitation regimes), environmental factors (biomes, vegetation structure) and the taxonomic heterogeneity of each groups inhabiting major biomes of Namibia across their main biological and ecological traits, by Canonical Correspondence in order to get an ordination plot. Monte Carlo methods were used to test for randomness of the data ordination. Ordination plot identified three main assemblages, one being constituted by strictly semiarid savannah species (camelthorn, mountain, karstweld, thornbush, mixed tree and shrub, dwarf shrub, mopane and forest savannahs), one much larger and less homogenous second assemblage, inclusive of more generalist species from Karoo and semi-desert habitats, living also in arid savannahs, and the third one including Nama Karoo species. All the three assemblages were taxonomically very heterogeneous, showing that phylogenetic relationships are probably less relevant than interspecific ecological relationships among species of the same group to determine present-day community structure in these animals.

Assessing patterns of co-occurrence and nestedness of arthropod assemblages in an artificial–natural Mediterranean forest mosaic (Isopoda Oniscidea, Coleoptera Carabidae)

We compared two soil arthropod assemblages (Isopoda Oniscidea and Coleoptera Carabidae) in an artificial–natural Mediterranean forest mosaic. Using data from pitfall traps, we investigated through a co-occurrence analysis whether local ecomosaic supported non-random organized arthropod assemblages, and we compared the results between the two taxa. We evaluated “the effect of reforestation” on forest species of both assemblages using nestedness and indicator value analyses, and wing morphology analysis in the case of the ground beetle assemblage. A significant difference between the assemblages is turned out, probably because woodlouse are more specialized in spatial niche than ground beetles. Overall, there is a clear evidence of randomness in the woodlouse assemblage structure. Moreover, forest woodlouse species and brachypterous ground beetles appear affected by “the effect of reforestation” in the study area.