Stilobezzia ( Acanthohelea ) varia Ingram and Macfie, 1931

Stilobezzia ( Acanthohelea) varia Ingram and Macfie, 1931 View in CoL

( Figures 14, 22)

Stilobezzia varia Ingram and Macfie, 1931: 191 View in CoL (male, female; Chile)

Stilobezzia ( Neostilobezzia) varia: Das Gupta and Wirth, 1968: 143 View in CoL (in list); Wirth, 1974: 44 (in catalogue of New World species south of USA).

Stilobezzia ( Acanthohelea) varia: Spinelli and Wirth, 1993: 51 View in CoL (in list; Argentina); Borkent and Wirth, 1997: 109 (in World catalogue); Spinelli and Grogan, 1999: 709 (distribution); Borkent and Spinelli, 2000: 53 (in catalogue of species of southern USA); Borkent and Spinelli, 2007: 86 (in Neotropical synopsis); Borkent, 2014: 136 (in online World catalogue).

Diagnosis

The only Patagonian species of Stilobezzia ( Acanthohelea) with size and coloration highly variable; pleura is dark brown and legs are yellowish brown to dark brown, with dark, stout hairs; tarsomere 1 of hind leg with stout basal spine. Males gonostylus as long as gonocoxite, nearly straight but curving to pointed tip and parameres with stem rod-shaped, slightly divergent distally, with bulbous tip. Females sternite 8 with anterior margin straight, lateral margins subparallel and posteromedian excavation V-shaped.

Male. Head ( Figure 14). Dark brown. Antennal flagellum dark brown, plume dark brown, dense; antennal ratio 1.47–1.70 (1.62, n = 15). Palpus brown, segment 3 as long as 5; palpal ratio 3.57–4.40 (3.87, n = 18).

Thorax. Scutum dark brown to black, except humeral pits, two lateral bands and prescutellar depression yellowish brown; scutellum yellowish brown with 12–18 large, 6–10 thinner setae; postscutellum dark brown. Pleura dark brown, katepisternum partially paler. Legs yellowish brown to dark brown, with dense setae; coxae brown, hind coxa darker, distal half of hind femur darker; tarsomere 1 of mid leg, hind leg with basal stout spine; hind tibial comb with 10 spines; prothoracic TR 1.61–1.81 (1.71, n = 16), mesothoracic TR 1.74–2.00 (1.89, n = 16), metathoracic TR1.63–1.86 (1.73, n = 16). Wing ( Figure 14B) length 2.28–2.84 (1.55, n = 19) mm, width 0.74– 0.89 (0.82, n = 19) mm, costal ratio 0.68–0.77 (0.73, n = 10); membrane infuscated; second radial cell 3.00–5.33 (4.28, n = 16) × longer than first; cubital fork originating slightly distad to level of base of r-m cross vein; macrotrichia on costa, R 1, R 2, R 3, M 1, distal margin of cell r 3, sparse on cell m 1. Halter pale.

Abdomen. Dark brown. Genitalia ( Figures 14C, D): tergite 9 extending 0.80 of gonocoxites length, posterior margin rounded; sternite 9 8.45× broader than long, with posteromedian excavation broad, shallow; sternite 10 wide, stout, produced beyond base of cerci; cerci elongated, divergent. Gonocoxite stout, 1.3× longer than greatest breadth, inner margin with short, mesal tubercle directed mesad; gonostylus as long as gonocoxite, nearly straight, curving to pointed tip. Parameres subparallel ( Figure 14D), basal apodemes sclerotized; stem rod-shaped, slightly divergent distally, bulbous tip. Aedeagus 0.76 length of basal breadth, composed of two sinuous sclerites, each with mesal 1/3 broad, narrowing to apex.

Female. Similar to male, with the following notable sexual differences:

Head ( Figure 14E). Antennal ratio1.50–1.87 (1.57, n = 18); palpal ratio 2.86–3.86 (3.41, n = 18). Mandible with 7 coarse teeth.

Thorax. Scutellum with 10–14 large, 6–10 thinner setae. Hind tibial comb with 8–9 spines; prothoracic TR 1.64–1.93 (1.78, n = 19), mesothoracic TR 1.88–2.19, (2.02, n = 19), metathoracic TR 1.70–2.00 (1.88, n = 20). Wing ( Figure 14F) length 2.05–2.66 (2.45, n = 22) mm, width 0.79–0.91 (0.93, n = 22) mm, costal ratio 0.69–0.80 (0.76, n = 10); second radial cell 2.64–5.71 (3.97, n = 22) X longer than first; cubital fork originating at level of base of r-m; macrotrichia on costa, R 1, R 3, M 1, M 2 y CuA 2, abundant on distal 1/4 of cell r 3 and apex of cell m 1, sparse on cell m 2. Halter pale.

Abdomen. Yellowish brown to dark brown, with dense setae. Genitalia ( Figure 14G): anterior margin of sternite 8 straight, lateral margins subparallel; posteromedian excavation V-shaped; sternite 10 with 5 pairs of setae; cerci short; two ovoid spermathecae with short necks, measuring 8.10–14.40 (10.20, n = 21) by 5.90–10.30 (8.30, n = 21) µm and 7.0–11.40 (8.40, n = 21) by 5.90–10.00 (7.50, n = 21) µm; plus a third rudimentary spermatheca.

Distribution

Argentina ( Neuquen, Río Negro, Chubut, Santa Cruz, Tierra del Fuego) ; Chile (Malleco, Cautin, Valdivia, Osorno, Llanquihue, Chiloé, Magallanes) ( Figure 22) .

Types

Holotype male, Chile, Chiloé prov. , Ancud , 17–19 December 1926, P. and M. Edwards; Other paratypes: same data as holotype, 1 male, 1 female; Llanquihue prov., Puerto Varas, 16 December 1926, P. and M. Edwards, 1 female; Río Negro prov., Bariloche, 1 December 1926, P. and M. Edwards, 1 female ( BMNH).

Other specimens examined

Argentina, Neuquen prov., Parque Nacional Lanín, arroyo Quechuquina and lago Lacar, 18 January 2006, W. Grogan – G. Spinelli, 1 male, sweep net; lago Paimún, 10 February 1989, G. Spinelli, 2 males, 1 female, sweep net; lago Queñi, 28 January 1988, G. Spinelli, 1 male, sweep net; same data except 6–8 February 1999, P. Marino, 1 female, Malaise trap; lago Huechulafquen, 2 March 1998, G. Spinelli, 2 females, CDC light trap; lago Tromen, 7 February 1986, G. Spinelli, 1 female, sweep net; San Martín de los Andes, 23 April 1982, M. Gentile, 1 female, light trap; Villa La Angostura, 11–15 January 2004, G. Spinelli, 3 males, light trap; Río Negro prov., río Manso, 1 February 1986, G. Spinelli, 2 females, sweep net; Parque Nacional Nahuel Huapi, río Guillelmo, 20 January 2006 W. Grogan – G. Spinelli, 1 male, sweep net; Parque Nacional Nahuel Huapi, Puerto Blest, 9 December 1992, G. Spinelli, 1 male, sweep net; same data except 41°01 ′ 34.4 ″ S, 71°48 ′ 55.7 ″ W, 791 m, 13–16 December 2007, A. Garre – F. Montes de Oca, 1 male, at light; arroyo Challhuaco, 26 January 1988, G. Spinelli, 1 female, sweep net; lago Gutiérrez, January 2003, J. Liotta, 1 female, 1 male, light trap; Parque Nacional Nahuel Huapi, cerro Tronador, 25 January 1988, G. Spinelli, 2 males, sweep net; Parque Nacional Nahuel Huapi, río Manso Superior, 41°14 ′ 28.4 ″ S, 71°44 ′ 12.6 ″ W, 837 m, 15 January 2007, A. Garré – F. Montes de Oca, 13 females, sweep net; Parque Nacional Nahuel Huapi, arroyo Llum 41°16 ′ 13.3 ″ S, 71°30 ′ 56.7 ″ W, 857 m, 18 December 2006 to 4 January 2007, A. Garré – F. Montes de Oca, 1 male, 1 female, Malaise trap; Parque Nacional Nahuel Huapi, mallin La Cortadera, 41°05 ′ 13 ″ S, 71°48 ′ 26 ″ W, 769 m, 8 January to 3 February 2007, A. Garre – F. Montes de Oca, 1 male, 2 females, Malaise trap; 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, A. Garré – F. Montes de Oca, 1 female, Malaise trap; Parque Nacional Nahuel Huapi, arroyo Grande, 41°02 ′ 21.6 ″ S, 71° 48 ′ 27 ″ W, 763 m, 4–25 February 2007, A. Garre – F. Montes de Oca, 1 female, Malaise trap; Parque Nacional Nahuel Huapi, arroyo Ñireco (Complejo Challhuaco) 41°11 ′ 51.9 ″ S, 71°19 ′ 40.5 ″ W, 962 m, 20 December 2006 to 23 January 2007, Garré – Montes de Oca, 3 males, 5 females, Malaise trap; 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, 1 male, 1 female Malaise trap (USNM); Chubut prov., Parque Nacional Los Alerces, margen E lago Futalaufquen, 20 January 1988, G. Spinelli, 2 males, 1 female, sweep net; same data except El Alerzal, 20 January 1988, G. Spinelli, 1 male; cerro Galera, 2–4 December 2002, G. Spinelli, 1 male, Malaise trap; Santa Cruz prov., Los Glaciares, lago Roca, 10 January 1988, G. Spinelli, 1 female, 1 male, sweep net; lago del Desierto, 11 December 1996, 1 female, 4 males, sweep net; lago San Martín, estancia La Maipú, laguna Talca, 8 December 2002, G. Spinelli, 1 male, sweep net; Tierra del Fuego prov., Parque Nacional Tierra del Fuego, 7–9 December 2005, G. Spinelli, 19 males, 12 females, Malaise trap; 6 December 2005, G. Spinelli, 1 female, sweep net; camino a Lapataia, 1 March 1993, G. Spinelli, 1 female, sweep net.

Chile: Malleco prov. , Termas de río Blanco, 1080 m, 22 January 1964, M. Irwin – L. Stange, 1 female, 1 male, sweep net; Cordillera de Las Raíces , 40 km E Curacautín, 1450 m, 5 February 1979, D. Davis – M. Davis – B. Akerbergs, 1 female, sweep net; Parque Nacional Conguillo , 21 December 1984, J. A. Downes, 1 male, 1 female (JAD1658/1/7,8) ( CNCI) ; same data except 22 December 1984, 1 male, 1 female; Cautin prov ., 12 km N Loncoche , 280 m., 10 November 1966, E. Schlinger, sweep net; Valdivia prov ., Isla Teja , 3 December 1984, J. A. Downes, 1 male, 1 female, sweep net (JAD1658/1/7,8) ( CNCI) ; same data except 1 December 1984, 2 males, 2 females (JAD 1657/1/6,7,9,12) ( CNCI) ; same data except University farm, 12 December 1984, 3 males, 2 females (JAD 1666/1/1,2,3,4,5) ( CNCI) ; same data except 13 December 1984, 1 female (JAD 1667/1/1) ( CNCI) ; Osorno prov. , Pucatrihue , Puente Hermoso , 29 January 1978, P. J. Spangler, 1 female, sweep net; Llanquihue prov., Fundo San Martín, 15 December 1984, J. A. Downes, 1 male, sweep net (JAD 1669/2/4) ( CNCI) ; Chiloé prov. , Ancud, 1 January 1985, J. A. Downes, 1 female, sweep net (JAD 1688/3/12) ( CNCI) ; Huillinco , 2 January 1985, J. A. Downes, 1 male, sweep net (JAD 1689/2/2) ( CNCI) ; Magallanes prov. , Bahia Scourfield, 17–25 February 1980, D. Lanfranco, 2 males, 3 females, Malaise trap .

Discussion

The variability observed between specimens of Stilobezzia ( A.) varia from different localities with respect to coloration, size and pilosity is notorious and unique among the species of the subgenus Acanthohelea .

This species is very similar to S. pabloi . Characters for distinguishing both species are in the key and in the discussion section of that species.