Medeventor nubosus Wheeler

Wheeler, Terry A., 2007, Two new genera of oscinelline Chloropidae (Diptera) from Costa Rica, Zootaxa 1413, pp. 47-53 : 49-50

Medeventor nubosus Wheeler , sp. n.

( Figs. 1–7 )

Description: Total length 4–5mm. Overall colour medium brown; head paler, with frontal triangle pruinose but distinct, not reaching anterior margin of frons; most cephalic setae reduced, outer vertical seta strongest, inner vertical, ocellars and postocellars only slightly differentiated from interfrontal setulae ( Fig. 1 ); interfrontal setulae and fronto-orbital setulae dense, fine, pale; gena dark yellow, genal height 0.5–0.6 times eye height ( Fig. 1 ), face with small, relatively broad carina between antennal bases, extending ventrally halfway to ventral margin of face ( Fig. 2 ); antenna with patch of short dorsal setae on pedicel, first flagellomere round, yellow, arista black, pubescent; palpus yellow, swollen; proboscis black, short but sclerotized and geniculate.

Scutum apparently shining (although holotype is covered with dull residue), evenly covered with long, pale setulae, holotype with 1 anterior, 1 posterior notopleural seta (paratypes with 1+2 notopleural setae, see Remarks); scutellum with apical and subapical setae only slightly longer and darker than surrounding setae. Legs long, fore femur inflated in holotype, at least 3 times diameter of fore tibia (not as broad in paratypes). Wing pale gray, veins dark, ratio of costal sectors C1: C2: C3: C4 – 1: 1: 0.5: 0.3.

Abdomen slightly paler than thorax.

Male genitalia ( Figs. 5–7 ): epandrium approximately as long as high in lateral view, broad in posterior view, with dense setae on posterior half; surstylus pointed, evenly tapering, recurved in lateral view, with dense patch of fine setae anteromedially near base, and scattered fine setae distally; hypandrium robust anteriorly, pregonites, postgonites and phallic guide all well-sclerotized and fused with hypandrium anteriorly; basiphallus long and well-sclerotized, distiphallus shorter than basiphallus, membranous; cerci broad, only slightly rounded ventrally in posterior view, with fine setae; subepandrial sclerite with setulose lobe between base of surstylus and cercus.

Type material: Holotype ɗ: COSTA RICA: Prov. Puntarenas, Monteverde, 1995, B.J. Sinclair (CNC). Paratypes: 1Ψ: COSTA RICA: Prov. Guanacaste, Liberia, Parque Nacional Santa Rosa, Sector Santa Rosa, Area Adm. 300m, vii.1999, J. Sullivan and A.A. Pérez, Malaise, L N 313000 359800, #56027, INB0003115663 (INBio); 1? (sex unknown, abdomen damaged): COSTA RICA: Prov. Guanacaste, Parque Nacional Rincón de la Vieja, Est. Las Pailas, 800m, 10–21.xi.1993, M.A. Zumbado, D.G. García and G. Rodríguez, L N 306300_388600, #2559, INBIOCRI001827899 (INBio).

Etymology: The species name is from the Spanish nuboso (cloudy), referring to the cloud forests that surround the type locality.

Remarks: Differences in the texture of the frontal triangle and scutum; number of notopleural setae and diameter of the fore femur between the holotype and paratypes suggest that multiple species may be represented or that sexual dimorphism may exist in the species. Unfortunately, all type specimens are dirty or damaged to some degree so it is difficult to speculate on which of the two possible explanations is more likely. Additional specimens in good condition will be required to resolve the question. For the present, the species description is based on the holotype and differences in the paratypes are noted where relevant

Although known from only three specimens, this species is widespread in a range of habitats in Costa Rica from high elevation cloud forest at Monteverde to lowland dry forest in Guanacaste. Because its size and appearance are atypical for Chloropidae , additional specimens may be present but unidentified in museum collections. Medeventor nubosus is the largest known chloropid in Costa Rica; the species described below is the smallest.

Figures

FIGURES 1 – 7. Medeventor nubosus. 1. head, lateral. 2. head, anterior. 3. wing. 4. male abdomen, posterior portion, ventral. 5. male genitalia, lateral. 6. male genitalia, posterior. 7. male genitalia, ventral. Abbreviations: st — sternite; ses — subepandrial sclerite. Scale bars = 1.0 mm (Fig. 3), 0.2 mm (Figs. 6 – 8).