Chloromerus orientalis, Nartshuk, E. P., 2013

Nartshuk, E. P., 2013, Grassflies of the subfamily Chloropinae (Diptera: Chloropidae) from Vietnam and Thailand, with descriptions of two new species, Zootaxa 3702 (6), pp. 534-544 : 535-537

Chloromerus orientalis sp. n.

Type material. Holotype: female. Thailand: Loei, Phu Ruea NP, Subhnonghin, 17°28.772'N 101°21.308'E, 860 m, 5.vii.-12.vii. 2006, Malaise trap, Patikhom Tamtip (T 310). Holotype is deposited in the Entomological Section of QSBG (Queen Sirikit Botanical garden; PO box 7, Mae Rim Chiang Mai 50180, Thailand).

Diagnosis. The new species is distinguished from all known species of the genus by larger body, length 6 mm; other known species have length of body 2.5–3.75 mm. New species has strongly thickened hind femora and all femora are yellow. It shares these characters with C. parus Becker , C. pallidion Becker , C. trimaculata Malloch , and C. varians Malloch. The new species has a granulose thorax like C. trimaculata . It is distinguished from all above listed species by colour of the ocellar triangle with central black stripe and two lateral spots and black thorax except dark yellow postpronotum and lateral sides along notopleura. Scutellum and pleura black, covered with white setulae.

Description. Head yellow. Ocellar triangle occupying whole frons, with rounded apex, granulose, dark yellow with black central line, two black round spots on sides, and small black mark on hind corners. Ocellar triangle covered with short whitish setulae. Gena wrinkled, wide at rear.

Antenna separated by flat wide keel. Postpedicel longer than wide, dark yellow, blackish on upper margin. Palpi black narrow. Arista thin, white.

Scutum black, granulose, evenly covered with very short whitish setulae. Postpronotum and sides of scutum along notopleura dark yellow. Scutellum with six small tubercles on margin, granulose, mostly black, and narrow dark yellow posteriorly, covered with very short whitish setulae.

Pleura as granulose as scutum, black except propleura and notopleura.

Abdomen dorsally dark yellow in the middle with base and tergites 5 and 6 black. Lateral sides of all tergites black. Tergites covered with whitish setulae, which are a little longer than setulae on scutum and scutellum. Venter of abdomen whitish.

Wing hyaline, veins brown. Vein R 2+3 close to costal vein. Veins R 4+5 and M 1+2 widely divergent. Transverse vein r-m situated beyond of middle of cell dm. Halteres whitish. All coxae yellow, fore and middle legs yellow. Hind femora strongly enlarged, four times thicker than tibia, black except for yellow base, hind tibia curved and partly black, hind tarsi yellow.

Length 6 mm.

Male: Unknown.

Distribution. Thailand.

Remarks. Moore (1976) suggested that species of Chloromerus might be plant feeders as are many other Chloropidae . He described swarming of Chloromerus sp. near striatifrons (Becker) at the top of trees in Australia. I observed the swarming of Platycephala scapularum (Becker) in Uzbekistan in crowns of trees near an irrigation ditch.

Etymology. The species is named after the distribution in the Oriental Region.