Formosargus variegatus James, 1969

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, Journal of Natural History 56 (37 - 40), pp. 1513-1562 : 1547-1550

Formosargus variegatus James, 1969

( Figure 25 )

Formosargus variegatus James, 1969: 342 (orig. descr.).

Type locality: Philippines, Palawan, Mantalingajan Range, Pinigisan , 600 m. Holotype: ♂ [ UZMC], Allotype: ♀ [ UZMC] .

Formosargus variegates Yang et al., 2014: 417 . Incorrect subsequent spelling.

Refs: James, 1975: 18 (cat.); Woodley, 2001: 190 (cat.).

Diagnosis

Both scutal medial band and a pair of anterior lateral dark brown maculae discontinued at transverse suture; posterior part of scutum with a U-shaped dark brown macula; scutellum completely yellowish ( Figure 25 ); anepisternum widely dark brown, laterotergite and mediotergite dark brown. All hind tarsomeres yellowish.

Material examined

Type material. HOLOTYPE ( Figure 25 (a–c)), ♂ labelled: ‘ Philippines, Palawan / Mantalingajan / Pinigisan 600 meter / 24 September 1961 /Noona Dan Exp. 61–62 [printed on white paper]’; ‘Caught in/malaise-traps/inside forest [printed on white paper]’; ‘zmuc/ 00026038 [printed on white paper]’; ‘ Formosargus / variegatus / ♂ James / HOLOTYPE [handwritten on red paper]’ ( UZMC). The holotype has the last four mid tarsomeres missing.

Geographic distribution

Oriental Region. Philippines (Palawan) ( Figure 26 ).

Comments

Formosargus variegatus has a scutum colour pattern similar to that seen in F. trivittatus sp. nov., since both species have at least three dark bands over the anterior part of the scutum, with yellow between the bands and the end of each of posterior lateral band connected to the medial band posteriorly. In F. variegatus , however, the medial band is completely interrupted at the transverse suture and the posterior lateral bands are strongly fused medially in the form of a semi-ellipse ( Figure 25 ), while in F. trivittatus sp. nov., the medial band is narrowed at the level of the transverse suture and the posterior lateral bands are weakly connected to it, forming a triangular macula ( Figure 7 (h)).

Figures

Figure 7. Thorax of Formosargus species, dorsal view. (a–b) F. kerteszi (a. male, holotype [DEI]; b. female, Philippines). (c) F. lineatus, male; arrow: medial band. (d) F. sagittocerus, male. (e) F. berezovskiyi sp. nov., female, paratype; arrow: mediotergite. (f) F. borneensis sp. nov., female, holotype; arrow: notopleural macula. (g) F. mangoleensis sp. nov., female, holotype; arrow: mediotergite. (h) F. trivittatus sp. nov., male, holotype; arrow: anterior lateral band. (i) F. woodleyi sp. nov., male, holotype.

Figure 25. Formosargus variegatus, male, holotype [UZMC]. (a) Habitus, dorsal view.(b) Habitus, lateral view. Arrow points to a modified structure in the mid leg. (c) Labels (© Natural History Museum of Denmark, University of Copenhagen).

Figure 26. Geographic distribution of Formosargus. Squares represent holotypes records; circles represent paratypes, and additional material. Three of the ‘lines’ of faunal division are shown: 1. Wallace’s Line; 2. Weber’s Line; 3. Lydekker’s Line. ‘Wallacea’ is the area that lies between Wallace’s Line and Lydekker’s Line.