Since the human population is continuously growing, sufficient food with low environmental impact is required. Especially, the challenge of providing proteins will deepen and insects can contribute to a more sustainable and efficient source of protein for human consumption. Tenebrio molitor larvae are highly nutritious and rearing mealworms is more environmentally friendly compared to the production of traditional livestock meat. To use T. molitor as a more sustainable alternative to conventional proteins, it is essential to apply diets from a local and sustainable source. Therefore, the objective of this study was to find local by-products or leftovers which can be used in mass production of larvae as a main substrate. Feeding trials investigating twenty-nine different substrates were conducted to evaluate larval growth performance and adult reproduction by determining development times, survival rates, biomass, and fecundity. Several suitable by-products were identified that can be used in high quantities as single component diet for T. molitor rearing, revealing a high survival rate, short development time, high mean total biomass, and successful breeding. The most successful substrate—malt residual pellets—was found to be an alternative to the most used substrate, wheat bran. Furthermore, corn germ meal, sweet chestnuts, bread remains, soybeans, sweet potatoes, and wheat germs have been discovered to be suitable diets for T. molitor. Moreover, the findings of this study contribute towards using several substrates as supplements.

As a result of the increasing focus on alternative protein sources which are ideally still sustainable, the yellow mealworm, Tenebrio molitor, has come into focus. To verify its suitability as a food source in relation to human health, an analysis of the microbiome of larvae of T. molitor is pertinent. Subsequently, the focus of this study was, on the one hand, to analyze the influence of the substrate on the microbial load of the larvae microbiome, and, on the other hand, to determine which processing methods ensure the risk-free consumption of mealworms. For this purpose, mealworms were grown on 10 different substrates derived from by-products of food production (malt residual pellets, corn germ meal, chestnut breakage and meal, wheat bran, bread remains, draff, nettle, hemp seed oil cake, oyster mushrooms with coffee grounds, pumpkin seed oil cake) and microbial loads were analyzed using different selective media. Further starvation/defecation and heating (850 W for 10 min) methods were used to investigate how the reduction of microorganisms is enabled by these methods. The results showed that there was no significant relationship between the microbial load of the substrate and the mealworm. Starvation and defecation led to a lower stock of microorganisms. Heating led to a significant microbial reduction in non-defecated mealworms. The group of defecated and heated mealworms showed no detectable microbial load. In conclusion, firstly, the choice of substrate showed no effect on the microbial load of larvae of Tenebrio molitor and secondly, heating and starvation allow risk-free consumption. This study makes an important contribution for evaluating the safety of mealworms as a sustainable protein source in human nutrition.

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. According to phylogenetic (based on mitochondrial and nuclear genes) and species delimitation analyses, five distinct putative species were detected and supported by high genetic distances. These genetic lineages correlate well with ecological data, and each species could be associated to its own (micro)habitat. Subsequently, slight morphological differences were found and provide additional evidence that five different species occur in Central and Southern Europe. The minuteness and the characteristic habitus ofCaleremaeus monilipestempted to neglect potential higher species diversity. This problem might concern several other “well-known” euryoecious microarthropods. Five new species of the genusCaleremaeusare described, namelyCaleremaeus mentobellussp. nov.,C. lignophilussp. nov.,C. alpinussp. nov.,C. elevatussp. nov., andC. hispanicussp. nov. Additionally, a morphological evaluation ofC. monilipesis presented.

Two new opilionid species from suborder Cyphophthalmi, family Sironidae, Siro franzi Karaman & Raspotnig sp. nov. and Siro ozimeci Karaman sp. nov., from Austria and Croatia respectively, are described and illustrated. Both species show a close relation to two other relict sironid species from the southern and eastern parts of the Alps, Siro valleorum and Siro crassus. All four species are treated here as a monophyletic, alpine group of genus Siro, opposed to the remaining two European sironids, S. rubens and S. carpaticus (palaeoeuropean Siro group). The history of the alpine Siro group parallels the history of a part of the dynamic European archipelago in the Mediterranean Tethys area, which became a part of the Alpine orogeny. Diversification of the alpine Siro group is the result of the orogenic evolution of the Alps, linked to the Austroalpine and South Alpine tectonic units.

Dragonflies and damselflies are important indicator species for quality and health of (semi-)aquatic habitats. Hitherto, 78 species of Odonata have been reported for Austria. Ecological data, Red List assessments, and a dragonfly association index exist, but population- and species-level genetic data are largely lacking. In this study, we establish a comprehensive reference DNA barcode library for Austrian dragonflies and damselflies based on the standard barcoding marker COI. Because of the increasing significance of environmental DNA (eDNA) analyses, we also sequenced a segment of the mitochondrial 16S rRNA gene, a marker often used in eDNA metabarcoding approaches. In total, we provide 786 new COI barcode sequences and 867 new 16S sequences for future applications. Sequencing success was >90 percent for both markers. Identification success was similar for both markers and exceeded 90 percent. Difficulties were only encountered in the genera Anax Leach, 1815, Chalcolestes Kennedy, 1920, Coenagrion Kirby, 1890 and Somatochlora Selys, 1871, with low interspecific genetic distances and, consequently, BIN (barcode index number) sharing. In Anax, however, individual sequences clustered together in species-specific groups in the COI tree. Irrespective of these challenges, the results suggest that both markers perform well within most odonate families in terms of sequencing success and species identification and can be used for reliably delimiting Austrian species, monitoring, and eDNA approaches.