The insect exoskeleton is a multifunctional coat with a continuum of mechanical and structural properties constituting the barrier between electromagnetic waves and the internal body parts. This paper examines the ability of beetle exoskeleton to regulate internal body temperature considering its thermal permeability or isolation to simulated solar irradiance and infrared radiation. Seven Neotropical species of dung beetles (Coleoptera, Scarabaeinae) differing in colour, surface sculptures, size, sexual dimorphism, period of activity, guild category and altitudinal distribution were studied. Specimens were repeatedly subjected to heating trials under simulated solar irradiance and infrared radiation using a halogen neodymium bulb light with a balanced daylight spectrum and a ceramic infrared heat emitter. The volume of exoskeleton and its weight per volume unit were significantly more important for the heating rate at the beginning of the heating process than for the asymptotic maximum temperature reached at the end of the trials: larger beetles with relatively thicker exoskeletons heated more slowly. The source of radiation greatly influences the asymptotic temperature reached, but has a negligible effect in determining the rate of heat gain by beetles: they reached higher temperatures under artificial sunlight than under infrared radiation. Interspecific differences were negligible in the heating rate but had a large magnitude effect on the asymptotic temperature, only detectable under simulated sun irradiance. The fact that sun irradiance is differentially absorbed dorsally and transformed into heat among species opens the possibility that differences in dorsal exoskeleton would facilitate the heat gain under restrictive environmental temperatures below the preferred ones. The findings provided by this study support the important role played by the exoskeleton in the heating process of beetles, a cuticle able to act passively in the thermal control of body temperature without implying energetic costs and metabolic changes.

Contrary to what was assumed regarding the presence of respiratory proteins in insects, a functional hemocyanin was recently found in larvae and adults of the stoneflies species Perla marginata, whereas in the close species Perla grandis, hemocyanin functionality was deduced from sequence data. In order to verify if the presence of this ancient trait is widespread within the order and to investigate why stoneflies have maintained it, we have extended the search for hemocyanin to species of other Plecoptera families. In particular, we assessed the presence of hemocyanin in the larval stage of nine Plecoptera species, belonging to six of the seven families of the European stonefly-fauna, and analyzed its potential functionality as deduced by sequence data. We cloned and sequenced the corresponding cDNAs and studied their expression with RT-PCR technique. Moreover, we performed homology studies using the deduced amino acid sequences. On the basis of our analysis, we hypothesized a functional role of the hemocyanin only for two species: Dinocras cephalotes and Isoperla grammatica (Perloidea). In all the investigated Nemouroidea and in Siphonoperla torrentium (Perloidea), this protein may have been lost. Larval size, life-cycle length, trophic role and environmental induction are discussed as possible explanations of these different physiological requirements.

Subspecies is a debated taxonomic rank that, in some cases, could indicate that a speciation process is taking place. Studying the degree of co-occurrence among subspecies along environmental gradients may help to determine its taxonomic status. In this study, we explore the distribution of two subspecies of Canthon rutilans along spatio-temporal and temperature gradients in the Atlantic Forest of southern Brazil in order to reinforce their current subspecies status or to support their consideration as two different species. A yearly survey conducted along an elevational transect (from 250 m to 1630 m) shows that there is no spatio-temporal overlap between the two taxa. We collected 899 individuals of Canthon rutilans cyanescens and 29 individuals of Canthon rutilans rutilans. C. rutilans cyanescens can be found at 250 m (all year except in June), 430 m (August to April), and 840 m (September to April) in elevation, and when the air temperature oscillates from 15.3 °C to 24.0 °C. C. rutilans rutilans can be found at 1360 m (October to February), 1630 m (January) in elevation, and when the air temperature oscillates from 14.4 °C to 18.6 °C. Furthermore, local temperature data taken during the survey indicates that both subspecies also have a limited overlap in their thermal response curves. All these results suggest that these two taxa could be considered as two different species with dissimilar physiological and ecological requirements probably as a consequence of temperature-mediated divergent adaptation. Further molecular data can confirm or reject this supposition in the near future.

Hemocyanin is a respiratory protein that occurs in the main lineages of Arthropoda. In insects hemocyanin is presently known in many orders. Recently, a functional hemocyanin has also been found in the Plecoptera. Further studies have revealed that hemocyanin seems to be not uniformly distributed within this order. In this paper we report additional data, obtained with RT-PCR sequencing, on the presence of hemocyanin in different stonefly species. In addition, we summarise the present knowledge about the distribution of hemocyanin in the Plecoptera. Biological aspects such as larval size, life cycle length, trophic roles and environmental induction are discussed as possible factors that may be correlated with the presence or absence of hemocyanin in the studied species.

The blister beetle (Coleoptera: Meloidae) fauna of Namibia is studied. The species are arranged within a catalogue containing information on their general distribution, including a list of localities and brief taxonomic remarks. Zoogeographic and ecological analyses were carried out and a photographic appendix, with images and maps of almost all Namibian species, is included. According to a chorological analysis, the Namibian blister beetle fauna appears to be zoogeographically distinct because of the dominance of western southern African elements. The faunistic levels of similarity among distinct areas in Namibia are also analysed. Several of the endemic species are related to the xeric ecosystems referable to the Namib Desert, Succulent Karoo and Nama Karoo biomes, but the highest diversity is related to the ecosystems referable to the Savannah biome. A total of 148 species belonging to 28 genera, eight tribes and three subfamilies (Eleticinae,  Meloinae, Nemognathinae) are recorded from this southern African country. Five new genera (Namibeletica gen. nov., Eleticinae Eleticini; Dilatilydus gen. nov. and Desertilydus gen. nov., Meloinae Lyttini; Paramimesthes gen. nov. and Namylabris gen. nov, Meloinae Mylabrini) and a total of 13 new species are described: 11 new species from Namibia (Psalydolytta gessi sp.nov., Paramimesthes namibicus sp.nov., Namylabris adamantifera sp.nov., Hycleus arlecchinus sp.nov., H. planitiei sp.nov., H. dvoraki sp.nov., H. aridus sp.nov., H. san sp.nov., Nemognatha fluviatilis sp.nov., "Zonitoschema" deserticola sp.nov., Zonitoschema dunalis sp.nov.); a new Namibeletica from the Angolan Namib (N. angolana) and a new Afrolytta Kaszab, 1959 from the S African Namaqualand (A. namaqua), both close to Namibian borders. Fourty-eight species and the genus Apalus Fabricius, 1775 are recorded for the first time from Namibia, and a few other species from South Africa (1), Zambia (1), Botswana (1) and Congo (1). The following new synonymies are proposed: Lytta pleuralis var. inpleuralis Pic, 1911 = Lydomorphus (Lydomorphus) thoracicus (Erichson, 1843), syn. nov.; Lytta benguellana Pic, 1911 = Prionotolytta melanura (Erichson, 1843), syn. nov.; Actenodia amoena ssp.anthicoides Kaszab, 1955b = Hycleus amoenus (Marseul, 1872), syn. nov.; Decapotoma csikii Kaszab, 1953 = Hycleus benguellanus (Marseul, 1879), syn. nov.; Nemognatha capensis Péringuey, 1909 = Nemognatha peringueyi Fairmaire, 1883, syn. nov. Several new combinations in the genus Hycleus Latreille, 1817 are also established.