Pelecorhynchus xanthopleura ( Philippi, 1865 )

Llanos, Lorena, Gonzalez, Christian R. & Córdoba, Mónica Saldarriaga, 2015, Revision of the New World species of the genus Pelecorhynchus Macquart, 1850 (Diptera: Pelecorhynchidae), Zootaxa 3955 (2), pp. 188-210 : 206-208

Pelecorhynchus xanthopleura ( Philippi, 1865)

( Figs. 58–62 )

Coenura xanthopleura Philippi, 1865: 726 . Type locality: Chile, Valdivia. Type ♀, Museo Nacional de Historia Natural, Santiago.

Material examined. Región de O`Higgins: 1 ♂ Cachapoal, Pangal I.1966 Col. Toro; Región de La Araucanía: 1 ♀ Llanquihue, Puerto Toledo, 17.XII.1972 col. L. E. Peña; Región de Los Ríos: 1 ♂ Valdivia 01.I.1957, no col.; 1 ♂ Valdivia 01.I.1952, no col.; 1 ♂ Valdivia 03.I.1981, col. E. Krahmer; 1 ♂ Valdivia, Fundo Caupolicán, without date col. E. Krahmer; 1 ♀ Valdivia, Sto. Domingo 3.I.1982 col. E. Krahmer; 1 ♀ Valdivia, Santo Domingo 27.XII.1963 col. E. Krahmer; 1 ♀ Valdivia, no col; 1 ♀ Valdivia, col. Cerda.

Diagnosis and comments. Body color black. Scutum black with two parallel longitudinal yellowish stripes. Scutellum shining black with black hairs on the distal margin. Pleura with long abundant yellow hairs. Wing infuscated orange. Abdomen shining brown-blackish. Tergite 1 entirely black. Tergites 2, 3 and 4 each with a pair of small, diffuse, lateral, white spots not reaching margins ( Fig. 58 ). This species is close to P. longicauda as indicated by the black hairs on the distal margin of the scutellum, and white spots on tergites 2, 3 and 4, but differs in that P. xanthopleura has the beard and pleura with yellow hairs.

Description. Female (N = 4; length = 20.0 – 21.5 mm). Head: eyes blackish without color pattern when dry, bare. Frons parallel-sided with blackish-brown pruinosity and short black hairs. Parafacial with gray pruinosity and abundant long black hairs. Ocellar triangle elevated with three ocelli. Posterior border of the head and vertex with dark gray pruinosity and short black hairs. Clypeus convex with black pruinosity and long black hairs, continuous with those of the occiput; beard yellowish. Scape and pedicel with dark brown pruinosity and black hairs; first flagellomere larger than the apical flagellomeres, blackish-brown; apical flagellomeres blackish, apically tapered. Maxillary palpus dark brown, with short and abundant black hairs. Proboscis and labellum blackish-brown.

Thorax: scutum black with two parallel longitudinal yellowish stripes and short, sparse black hairs. Scutellum black with black hairs on distal margin ( Fig. 59 ). Pleura with black pruinosity and long, abundant yellow hairs; katepisternum with long black hairs ( Fig. 60 ). Legs dark brown. Coxa brown-blackish with black hairs. Wing infuscated orange along costal margin.

Abdomen: shinning black dorsally with sparse black hairs on all tergites; tergite 1 entirely black; tergites 2, 3 and 4 each with a pair of small, lateral, diffuse, white spots, not reaching the margin. Sternites brilliant black with sparse hairs; sternites 2 and 3 with a pair of white spots; sternite 4 without spots.

Male (N = 6; length: 16.0 – 19.0 mm). Head: eyes black, bare, holoptic. Ocellar triangle elevated with three ocelli. Posterior border of the head with dark gray pruinosity; vertex with short black hairs. Clypeus convex with black pruinosity and long, abundant black hairs on surface. Gena with long black and yellowish hairs, continuous with those of the occiput; beard yellowish. Scape and pedicel with blackish-brown pruinosity and black hairs; first flagellomeres blackish-brown. Maxillary palpus dark brown with abundant black pilosity. Proboscis and labellum blackish-brown.

Thorax: scutum black with two parallel longitudinal whitish stripes and black hairs. Scutellum black with black hairs on distal margin. Pleura with black pruinosity and long abundant yellow hairs. Legs dark brown. Coxa brown-blackish with black hairs. Wing infuscated orange along costal margin.

Abdomen: shining black dorsally with sparse black hairs; tergite 1 entirely black; tergites 2 and 3 each with a pair of lateral whitish spots not reaching the lateral margin; tergite 4 with a pair of white points located near the lateral margin. Sternites blackish-brown, shining; sternites 2 and 3 each with a pair of whitish spots; sternite 4 without white spots. Terminalia ( Fig. 61, 62 ). Cerci one-segmented and prominent, lobate, apically rounded with small setae. Hypoproct about as long as wide, much longer than more dorsally situated cerci; posterior margin with a broad, shallow, v-shaped emargination. Epandrium large, broad, rectangular and strongly arched, with a few setae laterally. Gonocoxite developed, large, curved and very broad. Gonostylus apex with a curved hook dorsally, ventrally with a small rounded protuberance, medial lobe subquadrate, setose. In dorsal view, aedeagus long and broad with two very long hooks, straight, and the space between the hooks is very broad.

Geographic distribution. Chile (Región de O`Higgins to Región de Los Ríos ( Fig. 63 ).

Figures

FIGURE 63. Geographic distribution of Pelecorhynchus xanthopleura (Philippi, 1865).

FIGURES 58 – 62. Pelecorhynchus xanthopleura (Philippi, 1865), female. 58. Adult. 59. Thorax and abdomen in dorsal view. 60. Head and thorax in lateral view. 61. Epandrium and gonocoxites in ventral view. 62. Gonocoxites in dorsal view. Scale bar = 1 mm