Formosargus woodleyi sp. nov.

(Figures 4 (f), 6(f), 7(i), 8(i–j), 9(c), 10(f), 14, 20(e–f))

Diagnosis (male)

Darkest species of the genus. Scutum and abdomen widely marked with dark brown with coppery to bluish reflections (Figure 20 (e, f)). Ocellar tubercle much longer than vertex (Figure 4 (f)); frons, frontal callus, and face narrower than seen in other species, less than one-sixth of head width (Figure 6 (f)); upper frons longer than wide, as long as lower frons; anterior margin straight (Figure 6 (f)). M1 and M3 normally sclerotised (Figure 9 (c)).

Material examined

HOLOTYPE, 1 ♂ (left wing slide-mounted; genitalia dissected and stored in microvial with glycerine), PHILIPPINES, Luzon [Island] P.I., [Benguet], Zool. Park. Baguio 4500’, 02–04 January 1966, D.R. Davis (USNM).

Description

Male. Length (n = 1): body, 6.0 mm; wing, 6.0 mm. Head (Figure 4 (f), 6(f)). Vertex area much shorter than ocellar tubercle. Upper frons longer than wide, nearly as long as lower frons; upper frons black lateral area width shorter than half of ocellar tubercle width, with short dark brown pilosity; anterior margin of upper frons straight at the edge with lower frons. Fourth flagellomere dark brown, pointed apically, as long as previous flagellomeres combined. Face slightly shorter than lower frons. Thorax (Figure 7 (i)). Scutum with a bluish dark macula covering almost entire surface, except for a thin line on transverse suture and postalar callus yellowish; scutellum mostly dark brown with weak copper shine, distal and lateral margins pale yellow; pleuron yellow in the background with a wide dark brown macula over anepistenum; laterotergite and mediotergite dark brown. Basal third of mid and hind femora, last four fore and mid tarsomeres, and last three hind tarsomeres dark brown; mid legs with a pointed structure at base of tibia and a long seta at base of first tarsomere (Figure 8 (i, j)). Wing (Figure 9 (c)). R2+3 originating at r–m, weakly sinuous towards wing margin. M1 and M3 completely discernible, but weaker than M2. Abdomen. Mostly dark, with coppery to bluish metallic reflections dorsally; yellowish only between tergites 1 and 2 medially, at centre from extreme posterior margin of tergite 2 to extreme anterior margin of tergite 4 and from extreme posterior margin of tergite 4 to basal half of tergite 5, and in each lateral corner between tergites 2 and 3, 3 and 4, and 4 and 5. Terminalia (Figures 10 (f), 14). Ventral margin of genitalia strongly U-shaped at centre, without median projection; synsternite with a pair of long and well-developed inner projections, with almost right angle at base, curved on next one-third, and straight on last third, with strong bristles apically, slightly exceeding distal margin of genitalia. Lobes of phallus enlarged on distal half; parameral sheath shorter than gonostylus, wider at base. Gonostylus wide on basal one-third, with a long spatulate expansion.

Female

Unknown.

Etymology

The specific epithet is a patronym honouring Norman E. Woodley, a great expert in Diptera with major contributions to the systematics and taxonomy of Stratiomyidae. He recognised this new species as belonging to the genus Formosargus and made it available to us.

Geographic distribution

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

Comments

Formosargus woodleyi sp. nov. can be easily distinguished from others by a body mostly dark, nearly completely dark on the scutum, with bluish reflections over it, especially in the scutum and abdomen (Figure 20 (e, f)). Besides these features, this is the only species of the genus that has the upper frons clearly longer than wide, also slenderer compared to other males (Figure 6 (f)), also it has a much bigger ocellar tubercle, which is wider than the vertex (Figure 4 (f)), and M1 and M3 veins completely discernible (Figure 9 (c)). The remaining species are predominantly yellow or reddish, at most only considerably marked with black over the scutum, but never with a metallic shine.