Twenty years of Dipterology through the pages of Zootaxa.

We present a summary and analysis of the Diptera-related information published in Zootaxa from 2001 to 2020, with a focus on taxonomic papers. Altogether, 2,527 papers on Diptera were published, including 2,032 taxonomic papers and 1,931 papers containing new nomenclatural acts, equivalent to 22% of all publications with new nomenclatural acts for Diptera. The new nomenclatural acts include 7,431 new species, 277 new genera, 2,003 new synonymies, and 1,617 new combinations. A breakdown by family of new taxa and new replacement names proposed in the journal during the last two decades is provided, together with a comparison of Zootaxa's output to that of all other taxonomic publications on Diptera. Our results show that the journal has contributed to 20% of all biodiversity discovery in this megadiverse insect order over the last 20 years, and to about 31% in the last decade.

Ecological and Societal Services of Aquatic Diptera.

More than any other group of macro-organisms, true flies (Diptera) dominate the freshwater environment. Nearly one-third of all flies-roughly 46,000 species-have some developmental connection with an aquatic environment. Their abundance, ubiquity, and diversity of adaptations to the aquatic environment position them as major drivers of ecosystem processes and as sources of products and bioinspiration for the benefit of human society. Larval flies are well represented as ecosystem engineers and keystone species that alter the abiotic and biotic environments through activities such as burrowing, grazing, suspension feeding, and predation. The enormous populations sometimes achieved by aquatic flies can provide the sole or major dietary component for other organisms. Harnessing the services of aquatic Diptera for human benefit depends on the ingenuity of the scientific community. Aquatic flies have played a role as indicators of water quality from the earliest years of bioassessment. They serve as indicators of historical and future ecological and climate change. As predators and herbivores, they can serve as biological control agents. The association of flies with animal carcasses in aquatic environments provides an additional set of tools for forensic science. The extremophilic attributes of numerous species of Diptera offer solutions for human adaptation to harsh terrestrial and extraterrestrial environments. The potential pharmaceutical and industrial applications of the symbiotic microbial community in extremophilic Diptera are better explored than are those of dipteran chemistry. Many flies provide valuable ecological and human services as aquatic immatures, but are also pests and vectors of disease agents as terrestrial adults. The scientific community, thus, is challenged with balancing the benefits and costs of aquatic Diptera, while maintaining sustainable populations as more species face extinction.

The Neotropical tanyderid Araucoderus gloriosus (Alexander) (Diptera, Tanyderidae), with description of the egg, larva and pupa, redescription of adults, and notes on natural history.

Larvae, pupae and adults of Araucoderus gloriosus (Alexander) were collected during fieldwork in Chilean Patagonia, December 2013 and January 2014. Eggs were obtained from females that oviposited in captivity. Association of all life stages is based on co-occurrence and rearing of individual larvae to adults. A diagnosis for the genus and species is provided. Descriptions of the egg, larva and pupa and redescriptions of the male and female are completed. Eggs of A. gloriosus are the first described for Tanyderidae. Natural history characteristics for this species, including microhabitat, copulatory behavior and oviposition, are discussed.

A new genus and species of net-winged midge from Madagascar (Diptera: Blephariceridae: Blepharicerinae).

Larvae of a species from the subfamily Blepharicerinae were first discovered in the 1950's, but the lack of additional records prevented description of the species. A recent study of important additional specimens from the late Brian Stuckenberg has provided the basis for describing this unusual fly. This paper provides a description of larvae, pupae, and adults of Aphromyia stuckenbergi gen. et sp. nov., and a brief discussion of its phylogenetic position within the family. The latter is confounded by marked adult colocephaly (reduction of the head) and concomitant reduction in mouthparts, and by lack of recent collections that would permit molecular analyses and further morphological study. Known from only two collections, the most recent nearly 60 years ago, this highly endemic and rare fly is arguably one the most endangered species in Madagascar.

The larvae of Nymphomyiidae (Diptera, Insecta) - ancestral and highly derived?

Larval head structures of Nymphomyia dolichopeza were examined and described in detail. The conditions are compared to those of other dipteran representatives. Our results support the monophyly of Nymphomyiidae. Potential apomorphies are dimorphic crochets on the abdominal prolegs and the complete loss of the tentorium. Possible synapomorphies of Nymphomyiidae and Deuterophlebiidae could be the rows of spatulate macrosetae covering the ventral surface of the labrum-epipharynx, the presence of distinct teeth along the anterior premento-hypopharyngeal margin, the absence of labral microtrichia and some other affinities concerning the life history of the two groups. A clade Blephariceromorpha is also supported by some larval features. Potential synapomorphies of Nymphomyiidae, Deuterophlebiidae and Blephariceridae are the vestigial M. labroepipharyngalis, the absence of a movable premandible, crochet-tipped prolegs, the complete loss of spiracles and non-retractable anal papillae. A clade Nymphomyiidae and Chironomidae is only weakly supported by characters of the larval head. The anteriorly serrate and posteriorly fused hypostoma is a potential apomorphic character. Our results support neither phylogenetic affinities between Nymphomyiidae and Axymyiidae nor a sistergroup relationship between Nymphomyiidae and the remaining Diptera. However, a comprehensive cladistic analysis is not presented in our study.

Episodic radiations in the fly tree of life.

Flies are one of four superradiations of insects (along with beetles, wasps, and moths) that account for the majority of animal life on Earth. Diptera includes species known for their ubiquity (Musca domestica house fly), their role as pests (Anopheles gambiae malaria mosquito), and their value as model organisms across the biological sciences (Drosophila melanogaster). A resolved phylogeny for flies provides a framework for genomic, developmental, and evolutionary studies by facilitating comparisons across model organisms, yet recent research has suggested that fly relationships have been obscured by multiple episodes of rapid diversification. We provide a phylogenomic estimate of fly relationships based on molecules and morphology from 149 of 157 families, including 30 kb from 14 nuclear loci and complete mitochondrial genomes combined with 371 morphological characters. Multiple analyses show support for traditional groups (Brachycera, Cyclorrhapha, and Schizophora) and corroborate contentious findings, such as the anomalous Deuterophlebiidae as the sister group to all remaining Diptera. Our findings reveal that the closest relatives of the Drosophilidae are highly modified parasites (including the wingless Braulidae) of bees and other insects. Furthermore, we use micro-RNAs to resolve a node with implications for the evolution of embryonic development in Diptera. We demonstrate that flies experienced three episodes of rapid radiation--lower Diptera (220 Ma), lower Brachycera (180 Ma), and Schizophora (65 Ma)--and a number of life history transitions to hematophagy, phytophagy, and parasitism in the history of fly evolution over 260 million y.

Adult head structures of Deuterophlebiidae (Insecta), a highly derived "ancestral" dipteran lineage.

Adult head structures of Deuterophlebia coloradensis were examined, 3-dimensionally reconstructed and described. The results are compared to those of other representatives of basal dipteran lineages, primarily Nymphomyia dolichopeza (Nymphomyiidae) and Edwardsina gracilis (Blephariceridae). The head structures are extremely simplified. The labrum, mandibles, maxillae and labium are completely reduced. Only eight pairs of muscles are present. These modifications are possibly linked with the extremely short life span and non-feeding of adults. Possible synapomorphies of Deuterophlebiidae + Nymphomyiidae are the loss of all mouthparts, the elongation of the terminal antennal segment, and the loss of M. tentoriobuccalis anterior. An alternative placement of Deuterophlebiidae as sister group of Blephariceridae is only suggested by the origin of M. tentorioscapalis posterior on the vertex. Blephariceromorpha (Deuterophlebiidae, Nymphomyiidae, Blephariceridae) is only weakly supported by features of the adult head. The missing frontoclypeal and clypeolabral suture and the origin of M. tentorioscapalis on the head capsule are potential autapomorphies. Our results do not support a sister group relationship between Deuterophlebiidae and the remaining Diptera. A reliable reconstruction of basal dipteran relationships is impeded by missing morphological data for many potential key taxa.

Assessing macroinvertebrate biodiversity in freshwater ecosystems: advances and challenges in DNA-based approaches.

Assessing the biodiversity of macroinvertebrate fauna in freshwater ecosystems is an essential component of both basic ecological inquiry and applied ecological assessments. Aspects of taxonomic diversity and composition in freshwater communities are widely used to quantify water quality and measure the efficacy of remediation and restoration efforts. The accuracy and precision of biodiversity assessments based on standard morphological identifications are often limited by taxonomic resolution and sample size. Morphologically based identifications are laborious and costly, significantly constraining the sample sizes that can be processed. We suggest that the development of an assay platform based on DNA signatures will increase the precision and ease of quantifying biodiversity in freshwater ecosystems. Advances in this area will be particularly relevant for benthic and planktonic invertebrates, which are often monitored by regulatory agencies. Adopting a genetic assessment platform will alleviate some of the current limitations to biodiversity assessment strategies. We discuss the benefits and challenges associated with DNA-based assessments and the methods that are currently available. As recent advances in microarray and next-generation sequencing technologies will facilitate a transition to DNA-based assessment approaches, future research efforts should focus on methods for data collection, assay platform development, establishing linkages between DNA signatures and well-resolved taxonomies, and bioinformatics.