Ringdahlia Michelsen, 2014, gen. n.
Creators: name: Michelsen, Verner
Publisher: name: Zenodo
Year: 2014
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Diptera
Anthomyiidae
Ringdahlia

description: Genus Ringdahlia gen. n.
Type species: Hylemyia curtigena Ringdahl, 1935.
Etymology. The new genus is named after the Swedish dipterist Oscar Ringdahl (1885–1966), author of the type species. He was a dedicated collector of Diptera Brachycera from all parts of Sweden. His early acquaintance with the German dipterist Paul Stein (1852–1921) may have given him the impetus to take special interest in the muscoid families (Muscidae, Fanniidae and Anthomyiidae). He soon became the foremost authority on this important but notoriously difficult group of flies in Scandinavia.
Diagnosis. The following combination of characters may help to separate male and female Ringdahlia from other anthomyiid genera: medium sized, sexually dimorphic, body and appendages extensively dark-coloured; arista short-pubescent; male head (Fig. 28) in lateral view with antenna inserted beneath the middle and gena narrow, only half as wide as postpedicel; female frons relatively narrow, on lower part only one-third of total width of head (Fig. 30); setulae on upper occiput and anterior declivity of thorax rather coarse and blunt (Figs. 28, 30); presutural rows of acrostichals wider apart from each other than their distance to dorsocentral rows and with setulae present between rows (Fig. 30); vein C with v setulae; mid tibia with 0 av, 1 ad, 4–6 pd and 0 pv setae; hind tibia with 3–4 pd setae, without p or pv setae, apically without pd and pv setae; male terminalia of unique structure in respect to epandrium, cercal plate and surstyli (Figs. 33–39); female oviscapt (Fig. 43) short, basally thick with large tergites VI and VII partly exposed and covered in grey dusting; field of enlarged spiniform scales developed in ventral “intersegmental” membrane of segment VIII.
Relationships. Hennig (1972, 1976a) admitted that his attempts to classify Hylemyia curtigena Ringdahl in a “modern” genus were either preliminary or poorly substantiated. As shown in the following, morphology presents ample justification for classifying the present species in a new genus, Ringdahlia gen. nov. At first sight, the male of R. curtigena (Fig. 27) looks unremarkable with the typical appearance of an aerial anthomyiid fly, perhaps suggestive of a Botanophila or Lasiomma species. On closer inspection, the male terminalia exhibit a wealth of autapomorphic details presenting no obvious hints on relationships to existing anthomyiid genera. The small, extensively membranized distiphallus is superficially suggestive of Botanophila, but such relationship is not supported by the slender, articulated pregonites. The female, that has now become available for study, has an oviscapt (Fig. 43) without any of the defining characteristics of Chirosiomima (Fig. 12). Besides that, the morphology of the female presents no evidence in support of a closest relationship to any known genus or group of genera.
description: Published as part of Michelsen, Verner, 2014, Taxonomic assessment of Chirosiomima Hennig (Diptera: Anthomyiidae), with proposal of a new genus for Hylemyia curtigena Ringdahl, pp. 86-102 in Zootaxa 3790 (1) on page 97, DOI: 10.11646/zootaxa.3790.1.4, http://zenodo.org/record/252378