The mesosoma is the power core of the ant, containing critical structural and muscular elements for the movement of the head, legs, and metasoma. It has been hypothesized that adaptation to ground locomotion and the loss of flight led to the substantial rearrangements in the mesosoma in worker ants and that it is likely the ant mesosoma has undergone functional modifications as ants diversified into different ecological and behavioral niches. Despite this importance, studies on the anatomy of the ant mesosoma are still scarce, and there is limited understanding of important variation of internal structures across the ant phylogeny. Recent advances in imaging techniques have made it possible to digitally dissect small insects, to document the anatomy efficiently and in detail, and to visualize these data in 3D. Here we document the mesosomal skeletomuscular system of workers of the red wood ant, Formica rufa Linnaeus, 1761, and use it to establish a 3D atlas of mesosomal anatomy that will serve as reference work for further studies. We discuss and illustrate the configuration of the skeletomuscular components and the function of the muscles in interaction with the skeletal elements. This anatomical evaluation of a ‘generalized’ ant provides a template for future studies of the mesosoma across the radiation of Formicidae, with the ultimate objective of synthesizing structural, functional, and transformational information to understand the evolution of a crucial body region of ants.

The Melitaea phoebe group is constituted by six species distributed throughout the Palearctic. One of the most widespread species is Melitaea ornata Christoph, 1893, present from France (Provence) to Central Asia. Recently, populations of M. ornata were discovered in a mountainous region of south-eastern Iberia, although doubts about their taxonomy existed. To clarify the taxonomic status of these populations and to revise the distribution of this taxon in Iberia, we have sequenced mitochondrial (COI barcode region) and nuclear (wg, RPS5, MDH, and EF-1α) markers, and analyzed the male genitalia for 72 Iberian individuals and for all the species of the M. phoebe group. This information was complemented with phenological and ecological data. Our results unveiled that the Iberian M. ornata-like taxon is in fact distributed through most of the Iberian Peninsula, except for the south-west and north-east. In contrast to the univoltine M. ornata, the Iberian taxon can be bivoltine in the wild. The Iberian taxon was retrieved to be related to M. ornata, but the differences in the genetic markers and genitalia were comparable to those found between species in the group. Based on the evidence here presented and according to species delimitation results, we propose to consider the Iberian taxon as a novel species, tentatively named Melitaea pseudornata Muñoz Sariot & Sánchez Mesa, 2019, stat. nov.

El grup Melitaea phoebe està format per sis espècies distribuïdes arreu del Paleàrtic. Una de les espècies més esteses és la Melitaea ornata Christoph, 1893, present des de França (Provença) fins a l'Àsia Central. Recentment, es descobriren poblacions de M. ornata en una regió muntanyosa del sud-est de la península Ibèrica, tot i que existien dubtes sobre la seva taxonomia. Amb l'objectiu d'esclarir l'estatus taxonòmic d'aquestes poblacions i revisar la distribució d'aquest tàxon a la península Ibèrica, hem seqüenciat els marcadors mitocondrials (regió del codi de barres del COI) i nuclears (wg, RPS5, MDH i EF-1α) i hem analitzat la genitàlia masculina de 72 individus ibèrics i de totes les espècies del grup de M. phoebe. Aquesta informació s'ha complementat amb dades fenològiques i ecològiques. Els nostres resultats revelaren que, de fet, el tàxon ibèric de tipus M. ornata es distribueix per bona part de la península Ibèrica llevat del sud-oest i el nord-est. A diferència de la M. ornata, que és univoltina, el tàxon ibèric pot ser bivoltí a la natura. El tàxon ibèric està relacionat amb M. ornata, però les diferències en els marcadors genètics i la genitàlia foren comparables a les trobades entre les diferents espècies del grup. Degut a aquestes diferències i segons els resultats de la delimitació d'espècies, proposem considerar el tàxon ibèric com a una espècie nova, provisionalment anomenada Melitaea pseudornata Muñoz Sariot & Sánchez Mesa, 2019, stat. nov.

Range-restricted upland taxa are prone to population bottlenecks and thus typically have low genetic diversity, making them particularly vulnerable to environmental change. In this study, we used a combination of genotyping-by-sequencing (10,419 SNPs) and mitochondrial COI sequencing to test for population genetic structure within the narrow-range flightless sub-alpine stonefly Zelandoperla maungatuaensis Foster. This species is restricted to only a handful of upland streams along a 4 km stretch of the isolated Maungatua range in southeast New Zealand. We identified striking genetic structure across the narrow range of Z. maungatuaensis, with three deeply divergent allopatric lineages detected. These distinct lineages likely diverged in the early-mid Pleistocene, apparently persisting in separate microrefugia throughout subsequent glacial cycles. Our results illustrate how secondary flight loss can facilitate insect diversification across fine spatial scales, and demonstrate that intraspecific phylogenetic diversity cannot necessarily be predicted from range-size alone. Additional demographic analyses are required to better understand the conservation status of these divergent Z. maungatuaensis lineages, and to assess their potential susceptibility to climate change and other anthropogenic impacts.