A revision of the species allied to Dasyhelea patagonica Ingram and Macfie (Diptera: Ceratopogonidae) Author Díaz, Florentina Author Spinelli, Gustavo R. Author Ronderos, María M. text Journal of Natural History 2010 2010-11-05 44 45 - 46 2825 2849 http://dx.doi.org/10.1080/00222933.2010.512424 journal article 10.1080/00222933.2010.512424 1464-5262 5212142 Dasyhelea ona Díaz and Spinelli sp. nov. ( Figures 2 , 5 ) Diagnosis The only species of the patagonica group with posteromedian margin of the sternite 9 slightly concave and bearing a crescent-shaped sclerite followed by two reniform, stout processes directed caudad, the parameres lacking posteromedial protection. The female subgenital plate has two slender processes arising from laterodistal margins of gonopore, and the spermathecae are distinctly pyriform. Figure 5. Dasyhelea ona Díaz and Spinelli sp. nov. : (A–F) male, (G–L) female. (A) Flagellum. (B) Left palpus. (C) Wing. (D) Genitalia (ventral view). (E) Sternite 9. (F) Parameres. (G) Flagellum. (H) Clypeus. (I) Left palpus. (J) Wing. (K) Subgenital plate. (L) Spermathecae. Scale bars 0.05 mm. Male. Similar to female with usual sexual differences. Flagellum as in Figure 5A . Palpus ( Figure 5B ) with third segment bearing scattered sensilla; PR 4.18 (3.57–4.83, n = 8). Scutellum with 16–20 long setae and 6–14 shorter ones. Wing ( Figure 5C ) length 1.45 mm ( 1.40–1.52 mm , n = 7), width 0.44 mm ( 0.42–0.48 mm , n = 7), CR 0.49 (0.47–0.51, n = 7). Genitalia ( Figure 5D ): tergite 9 tapering distally, extending to level of apex of gonocoxite, apicolateral process slender, with apical seta; cercus with two or three setae; sternite 9 ( Figure 5E ) 0.6 times longer than greatest width, posteromedian margin slightly concave, with crescent-shaped sclerite followed by two reniform, stout processes directed caudad. Gonocoxite stout, 2.2 times longer than greatest width, with short, blunt anteromedian process; gonostylus slender, 0.9 times longer than gonocoxite, narrow base, nearly straight, tip pointed. Parameres ( Figure 5F ) without posteromedian projection; basal arms slender, fused distally, with blunt tip. Aedeagus well sclerotized, 0.55 times longer than greatest width, basal arch extending to 0.3 of total length; basal arms stout, elongated, recurved; posterolateral arms triangular, distal margin slightly concave, with posteriorly directed, recurved filament with pointed tip. Female. Head dark brown. Eyes contiguous by width of two ommatidia. Antenna with flagellum ( Figure 5G ) pale brown; AR 0.94 (0.88–1.05, n = 9). Clypeus ( Figure 5H ) with eight or nine setae. Palpus ( Figure 5I ) pale brown; third segment with two subbasal capitate sensillae; PR 3.66 (3.00–4.25, n = 9). Thorax. Scutum dark brown, scutellum with 14–20 long setae and 10–22 shorter ones. Legs dark brown, tarsi slightly paler; hind tibial comb with five spines; prothoracic TR 1.86 (1.61–2.06, n = 9), mesothoracic TR 1.86 (1.57–2.25, n = 8), metathoracic TR 1.99 (1.75–2.11, n = 9). Wing ( Figure 5J ), length 1.28 mm ( 1.12– 1.42 mm , n = 9), width 0.52 mm ( 0.46–0.60 mm , n = 9), CR 0.49 (0.47–0.54, n = 9); membrane slightly infuscated, densely covered with macrotrichiae; second radial cell open; cubital fork at same level of distal portion of first radial cell. Halter pale brown. Abdomen. Dark brown. Subgenital plate ( Figure 5K ) rectangular with rounded anteromesal margin, posterolateral arms stout; two short, slender processes arising from laterodistal margin of gonopore. Two pyriform spermathecae ( Figure 5L ), subequal, with straight, stout necks, measuring 0.056 by 0.042 mm and 0.052 by 0.038 mm , necks 0.006 mm . Distribution Argentina ( Tierra del Fuego ). Type material Holotype male, Argentina , Tierra del Fuego prov. , Parque Nacional Tierra del Fuego , laguna Negra (turbera), 54 ◦ 50 ′ 42.1 ′′ S , 68 ◦ 35 ′ 17.9 ′′ W , 15 m , 4–7 December 2008 , M. Donato - G. Spinelli , Malaise trap . Paratypes 7 males , 9 females , as follows: same data as holotype 6 males , 5 females ( 5 males , 4 females in MLP; 1 male , 1 female in NHM ); same data except 1 female , red. Tierra del Fuego prov. , ruta complementaria a (turbera), 54 ◦ 21 ′ 42.3 ′′ S , 66 ◦ 39 ′ 42.4 ′′ W , 40 m , 3 December 2008 , G. Spinelli , 3 females , red ( MLP ); Lago Yehuin , 54 ◦ 21 ′ 39.6 ′′ S , 67 ◦ 46 ′ 44.4 ′′ W , 45 m , 5 December 2008 , G. Spinelli , 1 male , red ( MLP ) . Etymology The species is named after the Ona indians, early inhabitants of Tierra del Fuego island. Discussion The male genitalia of this new species are similar to D . gargola . However, the latter species lacks the posteromedian crescent-shaped sclerite and reniform processes of the sternite 9, and the parameres show a distinct slender posteromedian projection that is produced beyond the aedeagus body. The female is clearly distinguished from other species by the pyriform spermatheca and by the presence in the subgenital plate of two slender processes arising from laterodistal margins of gonopore.