We evaluated the extent of intraspecific and interspecific genetic distances for two highly diverse infraorders of Odonata: Anisoptera and Zygoptera. All cytochrome c oxidase subunit I sequences (cox1), the region chosen for zoological DNA barcoding, present in GenBank for each infraorder were downloaded and curated. For Anisoptera, the final dataset consisted of 2,961 individual cox1 sequences for 536 species and the equivalent numbers for Zygoptera were 2,477 sequences for 497 species. More than 7 million individual genetic comparisons were made and the results indicated that there is a tendency towards a barcoding gap, but that the size of the gap may not be sufficient to robustly infer identities for some taxa. DNA barcoding may be of less use for some odonate taxa, perhaps pertaining to misidentifications in global databases. However, at local scales or with more confined taxonomical sampling, this tool may yet be beneficial in identifying these charismatic organisms.

Motivation: Aquatic insects comprise 64% of freshwater animal diversity and are widely used as bioindicators to assess water quality impairment and freshwater ecosystem health, as well as to test ecological hypotheses. Despite their importance, a comprehensive, global database of aquatic insect occurrences for mapping freshwater biodiversity in macroecological studies and applied freshwater research is missing. We aim to fill this gap and present the Global EPTO Database, which includes worldwide geo‐referenced aquatic insect occurrence records for four major taxa groups: Ephemeroptera, Plecoptera, Trichoptera and Odonata (EPTO).Main type of variables contained: A total of 8,368,467 occurrence records globally, of which 8,319,689 (99%) are publicly available. The records are attributed to the corresponding drainage basin and sub‐catchment based on the Hydrography90m dataset and are accompanied by the elevation value, the freshwater ecoregion and the protection status of their location.Spatial location and grain: The database covers the global extent, with 86% of the observation records having coordinates with at least four decimal digits (11.1 m precision at the equator) in the World Geodetic System 1984 (WGS84) coordinate reference system.Time period and grain: Sampling years span from 1951 to 2021. Ninety‐nine percent of the records have information on the year of the observation, 95% on the year and month, while 94% have a complete date. In the case of seven sub‐datasets, exact dates can be retrieved upon communication with the data contributors.Major taxa and level of measurement: Ephemeroptera, Plecoptera, Trichoptera and Odonata, standardized at the genus taxonomic level. We provide species names for 7,727,980 (93%) records without further taxonomic verification.Software format: The entire tab‐separated value (.csv) database can be downloaded and visualized at https://glowabio.org/project/epto_database/. Fifty individual datasets are also available at https://fred.igb‐berlin.de, while six datasets have restricted access. For the latter, we share metadata and the contact details of the authors.

Here we provide a checklist of the odonates from Amazonas state, Brazil. We registered 324 species and 101 genera, making Amazonas the Brazilian state with the most Odonata species recorded. The families with the highest number of species were Coenagrionidae with 32 genera and 101 species, followed by Libellulidae with 28 genera and 100 species and Gomphidae with 12 genera and 45 species. Some regions of Amazonas state remain poorly explored, such as the southern area, and large municipalities, such as São Gabriel da Cachoeira. This work underlines the importance of the biological diversity from Amazonas state and the Amazonian Biome for Odonata species richness in Brazil and shows that many areas in the world’s largest tropical forest have not yet been sampled.

Recently, Proceratophrys cristiceps was redescribed along with the description of two species from the Caatinga biome: P. aridus and P. caramaschii. However, only a small fraction of the populations related to such species in Northeastern Brazil was examined, and most populations of central Caatinga were not contemplated in this analysis. Comparisons were also based exclusively on external morphology, precluding a more accurate delimitation of such taxa in the light of multiple characters. Such geographic paucity and reliance in only one data source caused the species status of most central Caatinga populations to be uncertain. Thus, the revision of Proceratophrys populations from the Caatinga biome is of utmost importance to establish a solid taxonomic background and to test the validity of the described species. Based on morphologic, morphometric, acoustic, and multilocus genetic data, we define the range of inter‐ and intrapopulation variation in the parameters we analyzed, establishing which ones are useful as diagnostic characters for Proceratophrys in the Caatinga. We found no evidence supporting P. aridus and P. caramaschii as distinct species and thus place them as junior synonyms of P. cristiceps. Our results reinforce the importance of using multiple lines of evidence to avoid taxonomic instability.