Leptomorphus tagbanua Borkent, 2012

Borkent, Christopher J. & Wheeler, Terry A., 2012, Systematics and Phylogeny of Leptomorphus Curtis (Diptera: Mycetophilidae) 3549, Zootaxa 3549, pp. 1-117 : 64-65

33. Leptomorphus tagbanua Borkent , new species

( Figures 40, 74, 88, 119, 137, 150, 152)

DIAGNOSIS: The only extant species of Leptomorphus with the following combination of characters: laterotergite and anepisternum brown; wing without apical spot; vein sc-r joining R at ~2X its own length from origin of Rs; segments 3–5 of abdomen noticeably swollen relative to other segments; male genitalia wider than long ( Fig. 119).

This species can be distinguished from the other Oriental and eastern Palaearctic species either by the brown katepisternum ( Fig. 40, yellow in L. babai , L. ornatus and L. titiwangsensis ), or by the wider than long male genitalia with uniquely shaped tergal evaginations at the posterior margin ( Fig. 119).

DESCRIPTION: Male. ( Fig. 40) Head: yellow, taller than wide in anterior view. Antenna with basal 2–3 flagellomeres lighter brown, darkening apically; scape yellow, with brown setae in single apical row extending from dorsum laterally into thick patch covering apicoventral process, basal third, entire medial surface bare, anterobasal patch of setulae present; pedicel yellow, with 2 large bristles, few of setae on apicodorsal margin, none ventrally; flagellomere 1 with tapered base yellow remainder yellow; flagellomere 6 1.0X as long as broad. Clypeus light brown, slightly laterally compressed oval; bristles on clypeus light brown, 4 strong bristles on ventral margin directed ventrally, remaining setae directed medioventrally, clypeus 1.5X as long as face. Face light brown; shape a just longer than wide triangle, with few bristles ventrolaterally. Frons yellow; bare, frontal furrow running 3/4 distance from dorsal margin towards ventral margin, frontal cleft more than 1X diameter of median ocellus anterior of median ocellus. Palpus yellow; segments increasing in length, segment 3 appears spherical (difficult to tell in specimen). Labellum yellow. Eye with inter-ommatidial setulae absent. Occiput yellow with appressed, anteriorly directed setae. Ocelli in a straight line, space between ocelli less than diameter of laterals, lateral ocelli 2X their own diameter from eye margin, ocellar triangle dark brown/black. Thorax: Length 1.03 mm (n = 1). Dark brown. Scutum dark brown with blue-green specks; surface of scutum bare; acrostichal setae absent; dorsocentral setae present as fine setae for most of length; two thirds row of lateral setae present; patch of setae on scutum at wing base present. Scutellum yellow; with 6–8 large bristles and few small bristles. Prescutum brown. Mediotergite dark brown with 6 bristles on posterolateral corners, few medially. Laterotergite brown; anterior margin of laterotergite not reaching katepisternum. Anepimeron brown. Anepisternum dark brown. Katepisternum dark brown. Antepronotum and proepisternum dark brown. Margin of anterior and posterior spiracles yellow with light brown trichia. Metepisternum anterior half brown posterior yellow. Anapleural suture with anterior portion slightly curved dorsally. Halter with basal 1/3 of stem ivory, apical portion and knob dark brown. Legs: principally yellow; extreme anteroapical corner light brown on all femora; tarsi brown. Midfemur without apical spine-like process. Tibia with covering of yellow macrotrichia, foretibia without comb of short setae along length of anteroventral surface ( Fig. 88), tibial spurs yellow, foretibial spur length 2X apical thickness of foretibia, midtibia with faint, dorsal, bare patch of even thickness for 3/4 of its length, placed basally, shortest midtibial spur subequal to length of longest, longest midtibial spur 3.5X apical thickness of midtibia, shortest hind tibial spur subequal to length of longest, longest hind tibial spur 3X apical thickness of hind tibia. Foreleg first tarsomere 1.6X length of foretibia. Wing ( Fig. 74): Length 4.0 mm (n = 1). Hyaline; apical macula absent; medial macula absent. Macrotrichia in all cells, though absent from posterobasal margin of cell a. Setae on basal posterior margin of wing (along base of cell a) alternating long, short. Calypter with a few short setae. Vein sc-r present, apical end joining R at 2X its own length prior to origin of Rs. R 4 absent. R 5 straight, slight posterior turn near tip. M 1 reaching apex just before R 5, apices of M veins fading before wing margin. M 4 -CuA fork arising apically of origin of r-m. A 2 absent. Abdomen: Abdominal segments 3–5 swollen relative to other segments; principally dark brown, T3–5 with anterior 1/3–1/2 yellow. Tergite 8 smaller than other abdominal sclerites and 2 rows of bristles on posterior margin and large patches (~30) laterally. Genitalia ( Fig. 119): orangish yellow. Sternite 9 reduced to long thin sclerite attached to aedeagus. Tergite 9 wider than long oval, posterior margin with a shallow medial indentation and an intricate strongly sclerotized process with many points on lateral corner. Gonocoxite strongly fused with T9 but visible due to difference in sclerotization, placed centrally on T9, medial margin not reaching median line, bearing gonostylus apically. Gonostylus a single broad-based lobe tapering to apex which is bifurcated into two short sclerotized points, gonocoxite III fused to gonostylus basally but forming its own lobe. Aedeagus ~1/2 length of genitalia, broad, rounded base tapering to apex, strongly united basally with S9, apodemes highly reduced. Parameres squared off so essentially only apodemes remain (posterior margin flat), apodemes strongly united with gonocoxal apodemes.

Female adult. Unknown.

Immatures. Unknown.

BIOLOGY: Unknown.

DISTRIBUTION: Coron Island, Philippines ( Fig. 137), 215 masl.

DISCUSSION: This species was compared to the descriptions and figures of the recently described Oriental and Australasian species ( Papp & Ševčík 2011), and is clearly different from all of them and not a junior synonym.

ETYMOLOGY: This species is named for the Tagbanua people, who are the ancestral and current inhabitants of Coron Island where this species was found.

MATERIAL EXAMINED: Holotype: here designated, adult male, pinned, labelled “Coron,/ Busuanga,/ Phil. Is.; Coll. J. Laffoon / VI-21-1945; HOLOTYPE ♂ / Leptomorphus tagbanua / Borkent, new species / Det. C.J. Borkent 2012” [ ISUI].