Stilobezzia (Acanthohelea) mapuche, Cazorla and Spinelli, 2014

Cazorla, Carla G. & Spinelli, Gustavo R., 2014, A revision of the Patagonian predaceous midges of the subgenus Acanthohelea of Stilobezzia excluding the S. (A.) edwardsi group (Diptera: Ceratopogonidae), Journal of Natural History 49, pp. 1-55 : 16-18

Stilobezzia (Acanthohelea) mapuche, Cazorla and Spinelli sp. nov.

( Figures 4, 18)

Diagnosis

The only Patagonian species of Stilobezzia (Acanthohelea) with gonostylus greatly curved subbasally over 90°, aedeagal sclerites heavily sclerotized, slender to mid length and the distal half broadening abruptly and mesally directed with subapical pointed divergent prongs. Female unknown.

Male. Head ( Figure 4A). Dark brown. Antennal flagellum brown, plume dark brown, dense; flagellomeres 1–10 with pale ring above the insertions of the plume setae; antennal ratio 1.51–1.75 (1.58, n = 5). Palpus brown; segment 3 as long as 5; palpal ratio 3.00–3.50 (3.20, n = 6).

Thorax. Scutum uniformly dark brown; scutellum pale with 6 large setae; postscutellum dark brown. Legs brown, hind leg slightly darker than mid and forelegs; hind tibial comb with 8 spines; prothoracic TR 1.70–1.87 (1.79, n = 8); mesothoracic TR 1.91–2.10 (2.02, n = 8); metathoracic TR 1.72–2.00 (1.86, n = 8). Wing ( Figure 4B) length 1.39–1.66 (1.50, n = 10) mm, width 0.49–0.58 (0.54, n = 10), costal ratio 0.68–0.73 (0.71, n = 10); membrane slightly infuscated; second radial cell 2.41–3.36 (2.78, n = 8) × longer than first; cubital fork originating slightly distal to level of base of r-m cross vein; macrotrichia on costa, R 1, R 2, R 3, M 1, M 2, Cua 2, sparse on distal 1/ 3 of cells r 3, m 1, m 2. Halter pale brown.

Abdomen. Dark brown. Genitalia ( Figure 4C): tergite 9 triangular, tapering abruptly distally, extending 0.80 length of gonocoxites, posterior margin rounded; sternite 9 2.45× broader than long, posterior margin straight; sternite 10 triangular, margins wrinkled, produced beyond base of cerci; cerci moderately slender, broadly divergent. Gonocoxite 2.05× longer than greatest breadth; gonostylus 0.72× length of gonocoxite, base stout, greatly curved subbasally over 90°, tip pointed. Parameres subparallel; basal apodemes slender, stem stout, tip bulbous. Aedeagus 0.77× length of basal breadth, composed of two convergent sclerites, each with stem slightly curved, heavily sclerotized, slender to mid length, distal half broadening abruptly, directed mesally with subapical pointed divergent prongs arising from common base, proximal prong directed laterad, distal one directed distad.

Female. unknown.

Distribution

Argentina (Neuquen, Río Negro) , Chile (Santiago) ( Figure 18) .

Types

Holotype male, Argentina, Río Negro prov., Parque Nacional Nahuel Huapi, río Manso superior, 41°14 ′ 28.4 ″ S, 71°44 ′ 12.6 ″ W, 837 m, 7 February to 2 March 2007, A. Garré- F. Montes de Oca , Malaise trap ( MLPA) . Paratypes: 15 males, as follows: same data as holotype , 2 males (one in CNCI, one in USNM); same data except 41° 14 ′ 814 ″ S, 71°46 ′ 58.5 ″ W, 845 m , 2 males; laguna Los Clavos , 41°04 ′ 48.6 ″ S, 71°49 ′ 33.9 ″ W, 1194 m, 5 February to 3 March 2007, A. Garré – F. Montes de Oca , 3 males (one in BMNH), Malaise trap; Parque Nacional Nahuel Huapi, laguna Mercedes , 40°52 ′ 43.4 ″ S, 71°34 ′ 41 ″ W, 899 m, 3–21 January 2008, A. Garré – F. Montes de Oca , 1 male, Malaise trap; Neuquen prov., Parque Nacional Nahuel Huapi, mallin La Heladera , 41°00 ′ 6.4 ″ S, 71°49 ′ 40.3 ″ W, 878 m, 7 January to 4 February 2007, A. Garré – F. Montes de Oca , 6 males, Malaise trap; Chile. Santiago prov., Quebrada de La Plata, Maipú 33°30 ′ S, 70°55 ′ W, 26 April 1966, M. E. Irwin , 1 male, Malaise trap.

Etymology

The name mapuche refers to Mapuche Indians, early inhabitants of southern and central Chile and north-western Argentinean Patagonia.

Discussion

This species is somewhat similar to S. (A.) pabloi . The latter species is clearly distinguishable by the aedeagal sclerites with sclerotized tip with a small mesal notch.