Hidden biodiversity in microarthropods (Acari, Oribatida, Eremaeoidea, Caleremaeus).

A challenge for taxonomists all over the world and across all taxonomic groups is recognizing and delimiting species, and cryptic species are even more challenging. However, an accurate identification is fundamental for all biological studies from ecology to conversation biology. We used a multidisciplinary approach including genetics as well as morphological and ecological data to assess if an easily recognizable, widely distributed and euryoecious mite taxon represents one and the same species.

Morphological analysis of the oribatid mite species Scutovertex pannonicus Schuster and description of its juvenile stages (Acari: Oribatida: Scutoverticidae).

This paper provides a detailed redescription of the adult as well as the first morphological description of all juvenile instars (inclusive egg, prelarva and earlier larval stages) of Scutovertex pannonicus. The adults are characterized by their relatively large size (692-892 μm), their well developed sharply bordered foveae which are regularly distributed on the whole notogaster, except in the central field and the posterior notogastral brush-like setae ps1, h1,-h3. The exochorion of the eggs shows the typical structures for the genus Scutovertex like 'mushrooms' and granules with the species-specific expression of the 'mushrooms' and its substructures.

Discrimination of Oribotritia species by oil gland chemistry (Acari, Oribatida).

The chemical composition of secretions from opisthonotal (oil) glands in four species of the oribatid mite genus Oribotritia (Mixonomata, Euphthiracaroidea, Oribotritiidae) was compared by means of gas chromatography--mass spectrometry. The secretions of all, O. banksi (from North America) and three Austrian oribotritiids (O.

Ancestral state reconstruction reveals multiple independent evolution of diagnostic morphological characters in the "Higher Oribatida" (Acari), conflicting with current classification schemes.

Background: The use of molecular genetic data in phylogenetic systematics has revolutionized this field of research in that several taxonomic groupings defined by traditional taxonomic approaches have been rejected by molecular data. The taxonomic classification of the oribatid mite group Circumdehiscentiae ("Higher Oribatida") is largely based on morphological characters and several different classification schemes, all based upon the validity of diagnostic morphological characters, have been proposed by various authors. The aims of this study were to test the appropriateness of the current taxonomic classification schemes for the Circumdehiscentiae and to trace the evolution of the main diagnostic traits (the four nymphal traits scalps, centrodorsal setae, sclerits and wrinkled cuticle plus octotaxic system and pteromorphs both in adults) on the basis of a molecular phylogenetic hypothesis by means of parsimony, likelihood and Bayesian approaches.