Langkawiana maculata, Ík, Jan Šev Č, 2009

Ík, Jan Šev Č, 2009, Langkawiana maculata gen. et sp. n. from Malaysia and its systematic position in the tribe Robsonomyiini (Diptera: Keroplatidae), Zootaxa 2221, pp. 58-66 : 59-63

Langkawiana maculata sp. n.

Type material. Holotype male: MALAYSIA, Pulau Langkawi, Gunung Raya, mixed forest near the top, 670 m, 31.1.2009, J. Ševčík leg. ( SMOC).

Description. Male. Body length 3.8 mm.

Head. Dark brown. Ocelli absent. Compound eyes relatively narrow, mainly in the upper half, 1.6 times as high as broad in lateral view, shortly pubescent. Cerebral sclerite large, subcircular, with a median longitudinal furrow in posterior half and a transverse row of black setae. Frontally and laterally separated from the rest of head by a broad membranous area ( Fig. 2 ). The membraneous area continues behind compound eyes. Orbital sclerite well developed, as a subrectangular longitudinal sclerite separated by membraneous area. Frons in the form of a shallow triangular bare sclerite with sagital furrow ( Fig. 2 ). Antennae with dark setae on each segment, not longer than its diameter. Length of antenna 2.7 mm. Scape and pedicel brownish yellow. Scape slightly longer than wide, pedicel shorter than wide, rounded. Flagellum dark brown (basal two segments paler), cylindrical, tapering towards apex, with 14 flagellomeres, the first 10 flagellomeres 4 to 6 times as long as wide, the apical 4 segments slender and difficult to differentiate. Mouthparts and palpi yellowish, palpomere 2 brown. Palpus five segmented, sparsely covered with setae, two basal palpomeres tiny and fused. Palpomeres 3–5 not much longer than wide, palpomere 3 darker and slightly swollen.

Thorax. Mostly dark brown. Scutum with two rows of dorsocentral setae and laterally with prealar and postalar setae. Scutellum dark brown, with a row of fine subapical setae, without long apical bristles. Mediotergite and laterotergite bare, dark brown. Anepisternum all brown, with black setae on its upper half, slightly excavated on the upper half of hind margin. Preepisternum 2 (katepisternum of Matile 1990) bare, dark brown with its upper third pale. Anepimeron (mesepimeron of Matile 1990) mostly brown, apparently fusing with preepisternum 2 but well separated from laterotergite ( Fig. 3 ). Haltere yellowish, slightly longer than the first abdominal tergite.

Wing. Hyaline, its membrane covered with microtrichia, without macrotrichia. Tip of wing darkened. A distinct dark band through the middle of wing ( Fig. 4 ). Wing length 2.55 mm. Wing width 0.95 mm. Ratio of length to width 2.68. Costa produced beyond R5 to 4/5 of the distance of the tips of R5 and M1. Costa and radial veins covered with macrotrichia. Sc ending free. Radio-median fusion distinct, as long as the stem of M-fork. Basal portion of media developed. CuA1 approaching CuA 2 in the middle of wing. CuP fold-like, dark and distinct, almost reaching wing margin. Vein A1 less distinct, but reaching wing margin. Anal angle of wing relatively acute. Alula absent.

Legs. Mostly yellowish brown, covered with dark trichia. Fore coxa brownish yellow, mid and hind coxa darkened. C1 covered with setae mainly on front and hind side, C2 with several setae at apical third and C3 with a longitudinal row of posterolateral setae, shorter than the width of coxa. Hind coxa widens towards its base. Femora sparsely clothed with fine dark trichia, not longer than maximum width of femur. Mid and hind femur darkened, mainly towards the apical part. All tibiae with numerous trichia about as long as tibial diameter, tending to form more or less distinct dense rows. The apex of fore tibia widened, without distinct anteroapical depressed area. Fore tibia with one apical spur, as long as maximum tibial diameter. Two remarkably small spurs present on both mid and hind tibia, shorter than tibial diameter and resembling tibial setae. Tarsal claws simple.

Abdomen. Tergite 1 all dark brown, apically pointed. T2-T7 pale with a wide dark apical band. Sternite 1 dark, S2-S7 mostly yellowish, with narrow dark apical band. Segment 8 all dark. Length of abdomen 2.6 mm.

Terminalia. Light brown. Length of terminalia 0.3 mm. Tergite 9 short, transverse (fig. 5). Caudal margin of gonocoxites evenly rounded, forming a shallow depression. Basiphallus in the form of a dorsal sclerified bridge, distiphallus basally sclerotized (fig. 6). Gonostylus simple, apically blunt, with a single subapical dark tooth.

Female. Unknown.

Biology. Unknown. The specimen was captured in the driest climatic season at the island. Etymology. The specific name refers to the markings on wings and abdomen.

Figures

FIGURE 2. Langkawiana maculata gen. et sp. n., head from above (scale bar 0.2 mm); cs = cerebral sclerite, f = frons, os = orbital sclerite

FIGURE 3. Langkawiana maculata gen. et sp. n., thorax in lateral view (scale bar 0.2 mm); a = anepisternum, e = anepimeron, p = preepisternum 2, l = laterotergite, m = mediotergite

FIGURE 4. Langkawiana maculata gen. et sp. n., right wing (scale bar 1 mm)