We investigate the presence of cryptic species among three highly variable nereidid polychaetes commonly found in Australian coral reefs − Nereis denhamensis Augener, 1913, Perinereis suluana (Horst, 1924) and Pseudonereis anomala Gravier, 1901 − based on morphological and molecular data (mitochondrial cytochrome c oxidase subunit I, COI, and nuclear histone H3). DNA extracted and sequenced from 70 specimens from northern Australia and the Philippines indicated the existence of eight species: three matched the types of existing species; four are newly described (Nereis heronensis, sp. nov., N. lizardensis, sp. nov., Perinereis pictilis, sp. nov. and Pseudonereis anomalopsis, sp. nov.) from NE Australia, and one species is described but not named due to lack of material. Nereis denhamensis, N. heronensis, sp. nov. and N. lizardensis, sp. nov. are distinguished from each other by proboscidial paragnath number and morphology of the metamorphosed female. Perinereis suluana can only be separated from P. pictilis, sp. nov. by colour pattern, while Pseudonereis anomala, P. anomalopsis, sp. nov. and P. sp. differ in colour pattern and the number and arrangement of paragnaths. Nereis (Lycoris) tydemani from Maluku, Indonesia, is newly synonymised with P. anomala. Divergence times estimated using COI indicated that speciation in all three groups occurred in the mid Miocene (20–17 ± 7 mya), which corresponds to a period of restricted east–west dispersal as Australia collided with the Indo-Malay archipelago, followed by range expansion opportunities in NE Australia as a result of flourishing coral reefs responding to warming seas and rising sea levels.

Despite their great importance as pests of cultivated plants worldwide, members of the family Tetranychidae have never been subjected to a thorough cladistic analysis to reveal the history and relationships among related genera. Herein, we provide the first phylogenetic analysis and taxonomic review of species of the genera Aponychus, Paraponychus and Stylophoronychus using morphological characters. The results indicate a monophyletic clade uniting the aforementioned genera, although none of the three genera were recovered as monophyletic. We reinstate the tribe Aponychini as the taxon containing those three genera. Aponychus bambusae and A. aequilibris are herein considered junior synonyms of Stylophoronychus vannus and A. corpuzae, respectively.

We incorporated new data to re-evaluate the biogeographical patterns in the Mexican Transition Zone (MTZ) through the recognition of congruence in the geographic distributions of Mexican passalids (Coleoptera : Passalidae). We used three different approaches to parsimony analysis of endemicity (PAE): (1) the use of specific distribution data; (2) the application of a null model of significant co-occurrence to the specific distribution data; and (3) the use of predicted potential distributions through ecological niche modelling. Overall, these approaches sharpened the delimitation of distributions in three general zones. General zone (GZone) 1 includes species of restricted distribution in the state of Chiapas; the grid cells that make up this zone lie mainly in the Chiapas biogeographical province. GZone 2 includes species of restricted distribution located mainly in the states of Veracruz, Puebla, Hidalgo and Queretaro; the grid cells of this zone lie mainly in the Sierra Madre Oriental province. GZone 3 includes species with restricted distribution occurring mainly in the states of Guerrero and Oaxaca; the grid cells of this zone lie mainly in the Sierra Madre del Sur biogeographical province. The patterns of distributional congruence found in this study revealed three important distributional zones for the passalid species within the MTZ highly coincident with patterns proposed by Halffter.

The mite order Opilioacarida is widely distributed in the tropical and sub-tropical zones of the world, where it is rare and poorly known. On the American continent only two genera, 14 species and one subspecies are known. This work aimed to describe a new species of Caribeacarus from the state of Pará, in the eastern part of the Brazilian Amazon. A phylogenetic analysis of the species in this genus is also presented, and interpreted along with the historical biogeography of this genus in Central and South America. A key to the species of Caribeacarus is provided.

Diversity and speciation in Australia’s alpine biota are poorly understood. Here we present a molecular phylogeny of the Australian alpine grasshopper genus Kosciuscola (Sjösted) that currently includes five described species. These grasshoppers are of interest not only because of their alpine distribution but also for the extraordinary colour change exhibited by the species K. tristis, whose males turn turquoise when their body temperature exceeds 25°C. We reconstructed the phylogeny with two fragments of the mitochondrial genome using parsimony, maximum likelihood and Bayesian analyses and our data support the current taxonomy. Further, our data show little geographic structuring within some clades, which is puzzling since members of Kosciuscola are brachypterous. Finally, our data coupled with our observations on colouration provide evidence for a genetically distinct clade of K. tristis in the Victorian Alps. This is among the first molecular studies of an alpine invertebrate and one of a few on non-endangered, widespread Australian alpine species. More phylogenetic studies in the Australian Alps are required if we are to understand the evolution of alpine fauna and establish baseline data to monitor their response to climate change.

The genus Megalothorax Willem, 1900 is redefined along with a redescription of the type species M. minimus Willem, 1900 and the description of five new species (M. granulosus, sp. nov., M. nigropunctatus, sp. nov., M. perspicillum, sp. nov., M. svalbardensis, sp. nov. and M. willemi, sp. nov.). We describe and comment on broad sets of discriminating characters for Megalothorax systematics. For the first time, trichobothria are recorded for Neelipleona, probably of generic importance. The described species are provided with DNA data (COI, 16S and 28S) and included in a molecular-based phylogenetic analysis. The traditional distinction between minimus-group and incertus-group is discussed in the light of DNA and morphology components. A key to the worldwide Megalothorax species is provided.