Dasyhelea patagonica Ingram and Macfie, 1931

Díaz, Florentina, Spinelli, Gustavo R. & Ronderos, María M., 2010, A revision of the species allied to Dasyhelea patagonica Ingram and Macfie (Diptera: Ceratopogonidae), Journal of Natural History 44 (45 - 46), pp. 2825-2849 : 2839-2843

Dasyhelea patagonica Ingram and Macfie, 1931

( Figures 6 , 7 )

Dasyhelea patagonica Ingram and Macfie, 1931: 182 (male, female, Argentina); Wirth, 1974: 17 (in catalogue of south USA species); Spinelli and Wirth, 1993: 30 (in list; Argentina); Borkent and Wirth, 1997: 57 (in World catalogue); Spinelli, 1998: 325 (in list; Argentina); Borkent and Spinelli, 2000: 25 (in catalogue of south USA species); Borkent and Spinelli, 2007: 60 (in Neotropical catalogue); Borkent, 2009: 68 (online catalogue).

Dasyhelea chilensis Ingram and Macfie, 1931: 186 (female, Chile); Wirth, 1974: 17 (in Neotropical catalogue); Borkent and Wirth, 1997: 53 (in World catalogue); Borkent and Spinelli, 2000: 25 (in catalogue of south USA species); Borkent and Spinelli, 2007: 60 (in Neotropical catalogue), Borkent, 2009: 61 (online catalogue). NEW SYNONYMY.

Diagnosis

The only species of the patagonica group with at most 28 scutellar setae and the tarsi paler than femora. The posteromedian margin of the male sternite 9 has a deep rounded excavation and the posterolateral margins of the excavation are pointed.

Male. Similar to female with usual sexual differences. Flagellum as in Figure 6A . Palpus ( Figure 6B ) with third segment narrowed at midportion, with scattered sensilla; PR 4.18 (3.84–4.54, n = 3). Scutellum with 14–18 long setae and 10 shorter ones. Wing ( Figure 6C ) length 1.25 mm (1.18–1.34 mm, n = 3), width 0.37 mm (0.36– 0.40 mm, n = 3), CR 0.47 (0.45–0.50, n = 3). Genitalia ( Figure 6D ): tergite 9 rounded distally, extending to level of apex of gonocoxite, apicolateral process slender, with apical seta; cercus with three or four setae; sternite 9 ( Figure 6E ) 0.45 times longer than greatest width; posteromedian margin with deep rounded excavation, posterolateral margins of excavation pointed. Gonocoxite stout, 2.0 times longer than greatest width, with conspicuous anteromedian process, directed anteromesad; gonostylus 0.9 times longer than gonocoxite, narrow base, slender, nearly straight, tip pointed. Parameres ( Figure 6F ) with basal arms slender; posteromedian projection slender, reaching distal portion of aedeagus, tip blunt. Aedeagus strongly sclerotized, 0.4 times longer than greatest width, basal arch extending to 0.4 of total length; basal arms slender, directed laterad; posterolateral arms with recurved, ventrally directed tips.

Female. Head dark brown. Eyes contiguous by width of one or two ommatidia. Antenna with flagellum ( Figure 6G ) dark brown, AR 0.96 (0.88–1.00, n = 8). Clypeus ( Figure 6H ) with seven to nine setae. Palpus ( Figure 6I ) dark brown; third segment with four sub-basal capitate sensillae; PR 3.79 (3.23–4.16, n = 10).

Thorax. Scutum dark brown, scutellum with 13–16 long setae and six to eight shorter ones. Legs dark brown, tarsi paler; hind tibial comb with five spines; prothoracic TR 1.82 (1.73–2.00, n = 10), mesothoracic TR 1.90 (1.76–2.06, n = 10), metathoracic TR 1.91 (1.75–2.23, n = 10). Wing ( Figure 6J ), length 1.12 mm (1.00– 1.42 mm, n = 10), width 0.47 mm (0.42–0.58 mm, n = 10), CR 0.49 (0.48–0.52, n = 10); membrane slightly infuscated, densely covered with macrotrichiae; cubital fork at same level of middle length of second radial cell. Halter dark brown.

Abdomen. Dark brown. Subgenital plate ( Figure 6K ) rectangular, anterior margin rounded mesally; posterolateral arms straight, with pointed, mesally directed tip. Two ovoid spermathecae ( Figure 6L ), subequal, with straight necks, measuring 0.050 by 0.044 mm and 0.046 by 0.034 mm, necks 0.040 mm.

Distribution

Argentina (Neuquen, Río Negro), Chile (Llanquihue, Osorno, Valdivia).

Type material

Dasyhelea patagonica . Holotype male, Argentina, Río Negro prov., Lago Gutiérrez ; 3–14 November 1926, F. and M. Edwards; allotype female, same data except Bariloche, 1 December 1926, F. and M. Edwards ( NHM, examined) .

Dasyhelea chilensis . Holotype female, Chile, Llanquihue prov. , Casa Pangue, 4–10 December 1926, F. and M. Edwards ( NHM, examined).

Other specimens examined

Argentina: Neuquen prov., lago Curruhe , 20 November 1994, G. Spinelli, 1 male, 2 females ( MLP) . Río Negro prov., Parque Nacional “Nahuel Huapi”, lago Villarino , 5 December 1992, G. Spinelli, 2 males, 1 female ( MLP) ; Parque Nacional Nahuel Huapi, Manso Medio, La Cantera, 41 ◦ 21 ′ 16 ′′ S, 71 ◦ 42 ′ 27.3 ′′ W, 764 m, 15 January to 7 February 2007, Garré- Montes de Oca , 2 females, Malaise trap ( MLP) ; same date except 11–30 December 2007, Garré- Montes de Oca , 2 females, Malaise trap ( MLP) .

Chile: Valdivia prov. , Mehuin, 27 December 1992, G. Spinelli, 1 female, red. Osorno prov., camino a Pucatrihue, 29 November 1992, G. Spinelli, 2 females, red ( MLP) .

Discussion

This species, restricted to northern Patagonia, is the smallest of the patagonica group and is the one with fewer scutellar setae (at most 28). The female subgenital plate is similar to that of D. gargola , another north patagonian species. Characters to distinguish the male genitalia from those of D. dellapei may be found in the key and in the discussion under the description of the later species.

The synonymy of D. chilensis under D. patagonica is based on the examination of the types of both species. They only differ in the tarsi colouration, very slightly darker in the female holotype of D. chilensis , something in itself that is insufficient to recognize another species.

Figures

Figure 6. Dasyhelea patagonica Ingram and Macfie: (A–F) male, (G–L) female. (A) Flagellum. (B) Right palpus. (C) Wing. (D) Genitalia (ventral view). (6) Sternite 9. (F) Parameres. (G) Flagellum. (H) Clypeus. (I) Left palpus. (J) Wing. (K) Subgenital plate. (L) Spermathecae. Scale bars 0.05 mm.

Figure 7. Distribution of Dasyhelea patagonica, Dasyhelea reynoldsi and Dasyhelea shannoni.