Leptomorphus tabatius Borkent, 2012

Borkent, Christopher J. & Wheeler, Terry A., 2012, Systematics and Phylogeny of Leptomorphus Curtis (Diptera: Mycetophilidae) 3549, Zootaxa 3549, pp. 1-117 : 63-64

32. Leptomorphus tabatius Borkent , new species

( Figures 35, 73, 78, 120, 137, 150, 152)

DIAGNOSIS: The only extant species of Leptomorphus with the following combination of characters: laterotergite and anepisternum brown; wing without apical spot; segments 3–5 of abdomen noticeably swollen relative to other segments; male genitalia with tergite 9 bearing two long lateral processes posteriorly, so that tergite 9 is ~2X as long as wide ( Fig. 120).

This species can be distinguished from the other Oriental and eastern Palaearctic species either by the brown katepisternum and metepisternum ( Fig. 35, both completely yellow in L. babai , L. ornatus and L. titiwangsensis ), or by the posterolateral yellow spots on the scutum and the long evaginations (more than half the length of the genitalia) at the posterior margin of the male genitalia ( Fig. 120).

DESCRIPTION: Male. ( Fig. 35) Head: ( Fig. 78) light yellow, somewhat dorsoventrally compressed in anterior view. Antenna with basal 2–3 flagellomeres lighter brown, darkening apically; scape yellow, with black setae in single apical row extending from dorsum laterally into thick patch covering apicoventral process, basal third and entire medial surface bare, anterobasal patch of setulae absent; pedicel light brown, with 5–6 setae on apicodorsal margin, none ventrally; flagellomere 1 with tapered base light brown remainder brown; flagellomere 6 1.1X as long as broad. Clypeus light yellow, dorsoventrally elongate oval; bristles on clypeus brown, 4 strong bristles on ventral margin directed ventrally, remaining setae directed medioventrally, clypeus 1.6X as long as face. Face light yellow; shape a slightly wider than tall triangle, with few bristles ventrolaterally. Frons yellow; bare, frontal furrow running full distance from dorsal margin towards ventral margin, frontal cleft more than 1X diameter of median ocellus anterior of median ocellus. Palpus yellow; segment 1 hidden behind eye, segments increasing in length, segment 5 2X length of segment 4 with apex slightly swollen, segment 3 spherical with apicolateral depressed patch of fine yellow setae partially encircled by strong dark setae. 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 black. Thorax: Length 1.19 mm (n = 1). Dark brown. Scutum dark brown with a pair of small yellow posterolateral spots; surface of scutum bare; acrostichal setae absent; dorsocentral setae present as fine setae for most of length; multiple rows of lateral setae present; patch of setae on scutum at wing base present. Scutellum light yellow; without large bristles but few small bristles. Prescutum light brown. Mediotergite dark brown with 8 bristles on posterolateral corners, anteromedial patch of small setae. Laterotergite brown; anterior margin of laterotergite not reaching katepisternum. Anepimeron brown with posterodorsal corner yellow. Anepisternum brown. Katepisternum brown. Antepronotum and proepisternum brown. Margin of anterior spiracle brown and posterior spiracle yellow, both with light brown trichia. Metepisternum light brown. Anapleural suture with anterior portion slightly curved dorsally. Halter with basal 1/ 3 of stem ivory, apical portion and knob dark brown. Legs: Light yellow except for joint of hind femur and tibia which is brown; extreme anteroapical corner dark brown on all femora. Midfemur without apical spine-like process. Tibia with covering of brown macrotrichia, foretibia without comb of short setae along length of anteroventral surface, foretibial and anterior midtibial spurs brown, remainder yellow, foretibial spur length 2X apical thickness of foretibia, midtibia with strong, dorsal, bare patch of even thickness for 2/3 of its length, placed basally, shortest midtibial spur subequal to length of longest, longest midtibial spur 4X apical thickness of midtibia, shortest hind tibial spur subequal to length of longest, longest hind tibial spur 3.5X apical thickness of hind tibia. Foreleg first tarsomere 1.7X length of foretibia. Wing ( Fig. 73): Length 5.0 mm (n = 1). Hyaline; apical macula absent; medial macula absent. Macrotrichia in all cells. Setae on basal posterior margin of wing (along base of cell a) alternating long, short. Calypter with a group of macrotrichia. 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 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 to 2X thickness of other segments; tergites 3–5 with anterior 1/3–1/2 yellow, remainder brown. Tergite 8 smaller than all other abdominal sclerites, with 8 bristles on each apicolateral corner and few bristles along posterior margin but not as complete row (missing from medial 1/4). Genitalia ( Fig. 120): light yellow. Sternite 9 reduced to long thin sclerite attached to aedeagus. Tergite 9 longer than wide, basal 1/3 rounded and then spreading apically into strongly pointed lateral lobes and deep V-shaped medial notch, mediobasal corner of lobes with two sclerotized points ventrally. 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. Aedeagus 1/4 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: Sulawesi, Indonesia ( Fig. 137), 820 masl .

DISCUSSION: This species appears to have male genitalia similar to, but sufficiently distinct from, those of L. alienus Papp & Ševčík. We were unable to examine specimens of that species for comparison and cannot comment further on the relationship.

ETYMOLOGY: This species name is derived from the Tolaki for ‘fat’ (taba) ‘belly’ (tia), in reference to the swollen abdomen. Tolaki is the language spoken by the people of the Mekongga Mountains of Sulawesi, where the holotype was collected .

MATERIAL EXAMINED: Holotype: here designated, adult male, pinned with genitalia in plastic vial on pin, labelled “ Indonesia, se Sulawesi, North Kolaka / Rante Angin, Tinukari, Mekongga Mt. / 23.vi–1.vii.2010, ICBG team, 401 masl / 3.639444°S, 121.151111°E / CSCA11 L042; HOLOTYPE ♂ / Leptomorphus tabatius / Borkent, new species / Det. C.J. Borkent 2012” [ MZB]. The holotype was collected as part of the International Cooperative Biodiversity Group: Indonesia study of this biodiversity hotspot. This study was funded by the National Institute of Health ( NIH) with the support of the Indonesian Institute of Sciences ( LIPI). We thank them for providing us with this specimen for our study.