Formosargus berezovskiyi Fachin & Hauser 2022, sp. nov.
Creators: name: Fachin, Diego Aguilar
name: Hauser, Martin
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Diptera
Stratiomyidae
Formosargus
Formosargus berezovskiyi

description: Formosargus berezovskiyi sp. nov.
(Figures 1, 4 (a), 6(a), 7(e), 9(b), 15(c), 17(e–f), 19(b–c))
Diagnosis (female)
Dark brown pilosity on vertex area and ocellar tubercle (Figure 6 (a)); upper frons as wide as long, longer than frontal callus and lower frons combined. Scutal medial band broad, roughly as wide as one-third of scutum (Figure 7 (e)), only narrowing at level of transverse suture; mediotergite dark. Abdominal tergites marked with dark brown, a transverse proximal band on tergite 1 and subrectangular spots, narrowed medially, on tergites 2– 5 (Figure 19 (b)).
Material examined
HOLOTYPE, 1 ♀ (with puparium pinned beneath label), TAIWAN, Orchid Island, Chungui Bridge, 22.0°N 121.57°E, 20.iv–01.v.1997, V. Berezovskiy, coll. (LACM). PARATYPES, 3 ♀ (1 ♀ with left wing slide-mounted, genitalia dissected and stored in microvial with glycerine) (each puparium pinned beneath label), same data as holotype (LACM). Two females have an additional label mentioning that each adult emerged from the puparium on 21.v.1997.
Additional material. 1 ♂, TAIWAN, Orchid Island, Lanyu Weather Station, - 22.037306°S 121.558333°E [Note: male specimen not collected; only known from photograph (Figure 1)].
Description
Female. Length (n = 4): body mm, 5.0–6.0; wing mm, 5.0. Head (Figures 4 (a), 6(a)). Vertex area as long as ocellar tubercle, with medium dark brown pilosity. Upper frons as wide as long, slightly longer than lower frons; black lateral area of upper frons nearly as wide as ocellar tubercle width, with short dark brown pilosity; anterior margin of upper frons with median triangular extension slightly pointing towards antennal insertion. Fourth flagellomere rounded, as wide as each previous flagellomere. Face slightly shorter than lower frons. Thorax (Figure 7 (e)). Medial dark brown band over scutum broad, nearly as wide as one-third of scutum width, homogeneous in width along its entire extension, except for a narrowing at level of transverse suture; pleuron mostly yellowish, with only a small dark brown macula on anepisternum, mediotergite dark brown. Wing (Figure 9 (b)). R2+3 originating at r–m level, weakly curved on basal third, nearly straight on apical two-thirds. Abdomen. Tergite 1 with a dark brown transverse band proximally; tergites 2–5 with a pair of dark brown subrectangular spots; only spots of tergite 4 connected medially. Terminalia (Figures 15 (c), 17(e–f)). Genital fork equally wide on distal two-thirds, with a subtle widening at level of posterolateral process insertion; posterior, lateral and anterior margins projecting backwards; basal one-third abruptly narrowing into a wide and rounded anterior end; posterior bridge bilobed; posterolateral process wider on basal one-third, narrowing from midway to apex, nearly parallel on distal half; genital opening elliptical.
Male
Only known from a photograph (Figure 1).
Etymology
The specific epithet is a patronym dedicated to Vladimir V. Berezovskiy, a senior hymenopterist technician at the Entomology Research Museum in Riverside, USA, who first found the larva and identified the specimens in the LACM collection as belonging to Formosargus.
Geographic distribution
Oriental Region. Taiwan (Orchid Island) (Figure 26).
Comments
This new species is the second species from Taiwan, but it is only found on Orchid Island, while Formosargus kerteszi is reported from the southern tip of the main island, which is the type locality, and now also in the Philippines (Figure 26). The male of F. berezovskiyi sp. nov., only known from a photograph (Figure 1), is very similar in the colour pattern to the male of F. kerteszi, with a single medial scutal band, but one important difference, also present in the females, is the shape and width of the band. In F. berezovskiyi sp. nov. it is clearly narrowed at the level of the transverse suture and wider than in other species, as much as one-third the width of the scutum (Figures 1, 7 (e)), while in F. kerteszi, the scutal band is more linear and thinner (Figures 7 (a,b)). Besides these features, females of F. berezovskiyi sp. nov. can be separated from all the other one-striped females by the presence of a black mediotergite and abdominal tergites strongly marked with dark brown (Figure 19 (b)).
description: Published as part of Fachin, Diego Aguilar & Hauser, Martin, 2022, Revision of Formosargus James, 1939 (Diptera: Stratiomyidae): five new species in an otherwise rare genus and Amsaria Adisoemarto, 1974 as a generic synonym, pp. 1513-1562 in Journal of Natural History 56 (37 - 40) on pages 1551-1552, DOI: 10.1080/00222933.2022.2117107, http://zenodo.org/record/7318178