Assessing the Diversity and Systematics of Brachyopini Hoverflies (Diptera: Syrphidae) in the Iberian Peninsula, Including the Descriptions of Two New Species

Simple Summary Hoverflies are a diverse family of insects (6000+ species) providing multiple ecosystem services and direct benefits to society, for example, in pollination and pest control. The extent to which hoverflies can benefit society depends on how well their basics are known, i.e., taxonomy (classification), biology and ecology. Small and inconspicuous hoverflies such as those of the genera Chrysogaster, Melanogaster, Lejogaster, Orthonevra and Riponnensia (tribe Brachyopini) do not usually catch the attention of the general public neither of scientists, and their classification is often poorly known at least in areas of their range. So, the aim of the present work is to gain knowledge in the classification of hoverflies by studying the species of the five genera above-mentioned in the Iberian Peninsula, which has one of the highest biodiversity levels in Europe. We discovered and described two new species from Spain, promoted a subspecies to species and proposed other nomenclatural acts to stabilise these hoverflies' classification in Europe. Our results are reinforced with DNA analysis to locate the studied species in a wider systematic framework within the Brachyopini. Five genera of Brachyopini, Chrysogaster Meigen, 1800, Melanogaster Rondani, 1857, Lejogaster Rondani, 1857, Orthonevra Macquart, 1829 and Riponnensia Maibach et al. 1994a are here revised from the Iberian region. Two new species, Melanogaster baetica Ricarte and Nedeljkovic, sp. n. and Orthonevra arcana Ricarte and Nedeljkovic sp. n., are described from Spain, and a third species, Chrysogaster coerulea Strobl in Czerny and Strobl, 1909 stat. n., is reinstated as valid and redescribed. A lectotype is designated for Orthonevra plumbago (Loew, 1840). The holotype of Orthonevra incisa (Loew, 1843) and the lectotype of O. plumbago are described in detail and illustrated. Melanogaster baetica sp. n. is similar to Melanogaster parumplicata (Loew, 1840) in male genitalia morphology, while O. arcana sp. n. is similar to O. incisa in the entirely-pollinose sternum I and the conspicuous incision on the posterior margin of tergum V in female. The first Iberian record of Chrysogaster rondanii Maibach and Goeldlin de Tiefenau, 1995 is provided, whilst Melanogaster aerosa is removed from the Iberian checklist of Syrphidae. Identification keys are presented to the five Brachyopini genera and 18 species now reported from the Iberian Peninsula (Chrysogaster, 6 spp.; Lejogaster, 2 spp.; Melanogaster, 3 spp.; Orthonevra, 5 spp.; Riponnensia, 2 spp.). COI (Cytochrome c oxidase subunit I) barcodes of the two new species plus C. coerulea, Chrysogaster solstitialis (Fallen, 1817), Orthonevra nobilis (Fallen, 1817) and Orthonevra frontalis (Loew, 1843) were successfully obtained from Spanish specimens. A COI-based tree was produced to locate these taxa in a wider systematic framework within the tribe.

Automated summary

The study aims to deepen the understanding of hoverfly taxonomy, especially in the Iberian Peninsula, one of the regions with the highest biodiversity in Europe.