Heliodon tiber Reemer

Reemer, Menno & Stahls, Gunilla, 2013, Generic revision and species classification of the Microdontinae (Diptera, Syrphidae), ZooKeys 288, pp. 1-213 : 98-99

Heliodon tiber Reemer sp. n. Figs 91-93, 95

Type specimens.

HOLOTYPE. Adult male. INDONESIA (Sumatra). Label 1: "Fort de Kock / (Sumatra) 920 M. / 1924 / leg. E. Jacobson". Coll. ZMAN.

PARATYPE. Adult male. INDONESIA (Sumatra). Label 1: "Fort de Kock / (Sumatra) 920 M. / 1925 / leg. E. Jacobson"; label 2: "Microdon / fascipennis / Sack". Coll. ZMAN.

Diagnosis.

This is the only known species of Heliodon in which the hind femur is entirely yellow.

Additionally studied specimens.

MALAYSIA: 2 males, Selangor, Gombak Field Stn., 14.XI.1977, leg. B. Bendell; 1 male, Pahang, Frazer’s Hill, 27.X-3.XI.1977, leg. B. Bendell. THAILAND: 1 female, Loei, T1108, Phu Ruea NP, 17°29.652'N, 101°21.020'E, 1167 m., 5-6.xi.2006, pan trap, leg. Patikhom Tumtip, coll. M. Hauser; 1 female, Phetchabun, Nam Nao NP, Heliport, 16°43.156"N, 101°35.118"E, 890 m., 18-25.xii.2006, leg. Noopean Hongyothi, coll. RMNH. VIETNAM: 1 female, Chu Yang Sin Nat. Park, 1-10.VI.2007, mal. trap, leg. C. van Achterberg & R. de Vries; DNA voucher labcode MZH:Y1072, in coll. RMNH.

Description (based on holotype).

Adult male. Body size: 12 mm (paratype 10 mm).

Head. Face occupying about 1/3 of head width in frontal view; black, except brownish yellow on lateral 1/6; entirely white pilose. Gena black; white pilose. Lateral oral margins weakly produced. Frons and vertex black; white pilose. Occiput black; white pilose. Eye pilose, with pile approximately as long as diameter of ocelli. Antennal fossa about as high as wide. Antenna brown; antennal ratio approximately as 3.5:1:2.

Thorax. Mesoscutum black; yellow pilose, with pile thicker and more appressed along anterior margin, along transverse suture and along posterior margin, forming three transverse fasciae. Postpronotum and postalar callus brown; yellow pilose. Scutellum semicircular; with pair of distinct apical calcars with mutual distance about 1/4 of width of scutellum at base; brown; yellow pilose. Pleurae shining black; all pilosity yellowish white. Anepisternum pilose, except anterior part bare ventromedially; with deep sulcus separating anterior from posterior part. Anepimeron entirely pilose. Katepisternum pilose dorsally, bare ventrally. Katatergum long microtrichose, anatergum short microtrichose. Calypter and halter pale yellow.

Wing: Hyaline, except infuscated around apical crossveins, around spur on vein R4+5 and around base of R2+3, crossvein r-m and bm-cu; microtrichose, except bare on cell bc, posterobasal 1/10 of cell c, basally on cell r1 along vein Rs, basal 3/4 of cell br, anterobasal 1/5 of cell cup, basomedian 2/3 of alula.

Legs: Brownish yellow, with tibiae slightly infuscated medially; entirely yellow pilose. Coxae blackish brown; yellow pilose. Trochanters yellow; yellow pilose.

Abdomen. Tergites dark brown, except tergites 2-3 yellow laterally. Tergite 1 yellowish pilose. Tergite 2 yellowish pilose, except silvery white pilose along posterior margin. Tergite 3 silvery white pilose along anterior and posterior margins, yellow pilose along lateral margins, black pilose medially. Tergite 4 silvery white pilose along anterior margin and on posterior 1/2, black pilose medially. Sternites brown. Sternite 1 and 2 white pilose, sternite 3 and 4 black pilose. Male genitalia as in Fig. 95.

Female. As male, except for following differences. Body size 8-12 mm. Overall colouration paler: whereas pale parts are brownish in the examined males, these parts are yellowish in the examined females. The scutellar spines are less strongly developed, and in one of the examined females from Thailand even totally absent.

Etymology.

This species is named after my son Tiber. The epithet is a noun in apposition.

Notes.

In the paratype and in all additionally studied specimens, the pilosity of thorax and abdomen is more golden yellow than in the holotype, also in the parts which are silvery white in the holotype. In most specimens the legs are entirely yellow, without infuscated parts.

The paratype has a label stating " Microdon fascipennis Sack" (or possibly fuscipennis) in what seems to be the handwriting of J.C.H. De Meijere (judged by comparison with figures of de Meijere’s handwriting in De Jong 2000). However, no such name is known to have been given to any Microdontinae , neither by Sack nor by any other author. Either De Meijere was mistaken, or the name is an unpublished manuscript name.