Sperm morphology and phylogeny of lagriids (Coleoptera,Tenebrionidae)

The systematics of tenebrionids remain unclear, principally at the subfamily level, as is the case of the Lagriinae. Considering that sperm morphology has contributed to the various insect group phylogenies, in this work we describe the structure and ultrastructure of these cells in Lagria villosa. Sperm in this species exhibit a strong morphological similarity to those of Tenebrio molitor and Tribolium castaneum, the only two species of Tenebrionidae with previously described sperm. In tenebrionids, the flagellar components offer good diagnostic characters, e.g. the symmetry of mitochondrial derivatives in L. villosa differentiates sperm of this species from those of Te. molitor and Tr. castaneum. However, the lateral association of the nucleus with flagellar components, the form of accessory bodies, and the presence of material connecting the axoneme to the accessory bodies and mitochondrial derivatives indicate that the three species form a sister group. Therefore, the sperm morphology of L. villosa support lagriid beetles as a subfamily (Lagriinae) of Tenebrionidae.     

Co-occurrence of species with various geographical ranges, and correlation between area size and number of species in geographical scale

Co-occurrence of species of various geographical ranges is important to correct endemism evaluation. This co-occurrence is shown as non-hazardous. Influence of area size on species richness is assumed to be different with respect to endemic and non-endemic species. The territory of Israel and Sinai is subdivided into twenty biotic provinces. We segregated three hundred and twenty-five tenebrionid species inhabiting this territory into endemic, regional and ubiquitous species. Regression of the number of endemic species on the number of regional species is non-linear. Two distinct regression lines correspond to hot and cool areas. The number of ubiquitous species depends positively on numbers of both endemic and regional species, and negatively on their product. Ubiquitous species are predominantly synanthropic, and inability to tolerate competition with other tenebrionids is assumed as the basis of numerical relationships with other species. Correlation between numbers of endemic and non-endemic species of bird and mammal and size of area is analysed at the broad geographical scale. Relationships between area size evaluation and the numbers of endemic and non-endemic species are always different. The square root of the area km² is always more important in species richness determination than area itself. This variable is a linear characteristic of the area and its significance is discussed. Possible ecological interactions between species of various geographical ranges are also considered. A new method of evaluation of the level of faunal endemism is proposed.     

Micro-scale distribution of some arthropods inhabiting a Mediterranean sandy beach in relation to environmental parameters

A study on the spatial distribution of two tenebrionids and an isopod species was conducted at a small extent. Two species of the genus Phaleria were chosen because of their sympatric distribution and apparently similar adaptations to the beach environment. These scavenger species were studied in association to Tylos europaeus. Distributions, both perpendicular and parallel to the shoreline, were studied simultaneously with a grid of 20 × 20 pitfall traps arranged at a distance of 1 m from each other. Faunal samples were collected at two different hours of the night and core samples of sand were taken next to each pitfall trap for successive laboratory analysis. An index of dispersion was applied to test for aggregation of all species and of environmental parameters on the total, across- and long-shore. Kolmogorov–Smirnov two-sample test was used to compare the distributions between species. Regression analyse were applied to evaluate relationships between environmental parameters and species distributions. The study showed that the distribution of Phaleria species and T. europaeus was scale-dependent. The species and the values of the environmental parameters showed aggregated distributions both across- and long-shore. Aggregations of each Phaleria species differed according to their resting and foraging phases. For all species, sand moisture and salinity were the most important parameters explaining distribution. Granulometric parameters were correlated with the choice of the resting areas of both Phaleria species, whereas the spatial distribution of T. europaeus was correlated to the distribution of the organic matter.