Medetera subgrisescens, Naglis, Stefan & Bickel, Daniel J., 2012

Naglis, Stefan & Bickel, Daniel J., 2012, Medetera (Diptera, Dolichopodidae) of Sri Lanka, Zootaxa 3188, pp. 55-63 : 61-62

Medetera subgrisescens sp. nov.

( Fig. 6 )

Type material examined. HOLOTYPE: SRI LANKA. 3: “ Sri Lanka Col. Dist. Colombo 50 ft. elev. Museum Gardens 15 January 1977 ”; “K.V. Krombein, P. Fernando, D.W. Balasooriya, V. Gunawardane” ( USNM). PARA- TYPES: SRI LANKA. 1 3, 2 Ƥ: Rad. Dist., Uggalkaltota, 350 ft., 31.i.–8.ii.1970, Davis & Rowe; 1 Ƥ: Anu. Dist., Padavija, 180 ft., 2–8.xi.1970, O.S. Flint Jr.; 1 Ƥ: Pol. Dist., Pimburettawa, 13 mi. S-Mannampitiya, 9–12.xi.1970, 1850 ft., O.S. Flint Jr.; 3 Ƥ: Kan. Dist., Peradeniya , 26–28.iii.1971, P. & P. Spangler; 3 Ƥ: Kan. Dist., 5 mi NW Mahiyangana, 30.iii.–9.iv.1971, P. & P. Spangler; 1 Ƥ: Kan. Dist., Peradeniya Botanical Gardens, i.1971, Piyadasa & Somapala (all USNM); 1 3: W. Prov., Colombo, Colpetty, 5–13.i.1962, Loc. 2 ( MZLU); 1 Ƥ: Mihintale, 20.ii.1974, A.E. Stubbs & P.J. Chandler ( BMNH).

Description. Male. Length (holotype): Body 2.5 mm, wing 2.5 mm. Head: Frons, face and clypeus metallic green with ochreous pruinosity; palpus metallic green shining; proboscis dark brown, massive; antenna entirely dark brown; lower postoculars white. Thorax: Dorsum metallic olive-green, with dusting of grey pruinosity, more densely on mesonotal depression and scutellum; thoracic setae black, except as noted; 2 strong dc bordering mesonotal depression and 2 smaller anterior setae, half as long as dc; ac very small, shorter than distance between ac rows; 2 strong scutellars and 2 lateral setae, one-half length of medians; pleura metallic olive-green, with greyish pruinosity; proepisternum with 2–3 strong pale setae below. Legs: Entirely yellow, except fore coxa infuscated, mid and hind coxae dark brown with metallic reflections. Fore leg: coxa with pale apical setae; remainder of leg without major setae; relative podomere ratios: 62/62/30/ 26/17/9 /8. Mid leg: coxa with 2 anterolateral setae; tibia with black ad/pd setal pair at 1/5, and 1 black apicoventral seta; relative podomere ratios: 64/79/50/ 29/19/9 /7. Hind leg: coxa with 1 pale lateral seta; femur with some pale dorsal setae on basal half; tibia with small ad/pd setal pair at 1/5, with small subapical seta dorsally and small black apical tooth (MSSC); basitarsus with small basal tubercle opposite of tibial tooth (MSSC); relative podomere ratios: 65/98/18/ 47/24/11 /7. Wing: Veins yellowish; R4+5 and M distinctly converging towards wing margin; CuAx ratio: 0.6; RMx ratio: 4.3; lower calypter pale yellow, with fan of yellow setae; haltere pale yellow with dark brown stem. Abdomen: Dark metallic olive-green; setae white; epandrium black, cercus and surstylus dark brown. Male genitalia ( Fig. 6 ): epandrium pyriform; hypandrium with acute apex; epandrial seta absent; epandrial lobes almost fused, median lobe with bifurcate and ventrally branched seta, lateral lobe with blade-like flattened seta; dorsal arm of surstylus longer and bifurcate apically, with 2 subapical setae, ventral arm with 2 strong apical setae; cercus with ventral curved projection and blade-like apical seta. Female: Similar to male, but lacking MSSC.

Etymology. The species name is derived from the closely related M. grisescens .

Remarks. Medetra subgrisescens belongs to the diadema-veles species-group which includes two Oriental species. It is similar to M. grisescens de Meijere but can be separated by the characters given in the key. From M. opaca Bickel the new species can be distinguished by its body length which is more than 2 mm, and by the structure of the male genitalia. The species listed as M. grisescens from Sri Lanka in Bickel (1987) belongs to M. subgrisescens . Medetera grisescens was originally described from Java ( Indonesia) and is widely distributed from the Seychelles, throughout south-east Asia including southern China to eastern Australia and the Pacific Islands, including Hawaii ( Bickel 1987). Considering the closely related new species, we assume that M. grisescens represents a species-complex and M. subgrisescens occurs at least in Sri Lanka. Medetera subgrisescens is somewhat similar in genitalic morphology to M. gotohorum Masunaga & Saigusa, 1998 from Japan and China, but can be separated by the apical tooth on the hind basitarsus.

Figures

FIGURE 6. Medetera subgrisescens sp. nov. male hypopygium, left lateral view (scale bar = 0.1 mm).