Stibasoma flaviventre Macquart

Stibasoma flaviventre (Macquart)

(Figs. 40–48)

Tabanus flaviventre Macquart, 1848: 171 (description).

Stibasoma flaviventre; Lutz, 1915: 106 –108 (translation of the original description); Kröber, 1932: 243, 244, 257 (citation, key, redescription); Fairchild, 1971: 76 (catalog); Goodwin, & Murdoch, 1974: 112 (larvae). Fairchild, 1986: 76, 78 (key, diagnosis); Fairchild & Burger, 1994: 113 (catalog).

Tabanus dives Walker, 1848: 166 (description).

Stibasoma dives; Knab, 1913: 408, 411 (key, citation); Lutz, 1915: 108 (designation as a junior synonym of S. flaviventre); Kröber, 1932: 243, 257, 259 (citation).

Stibasoma euglossa Lutz, 1915: (pl. 21, fig. 22); Kröber, 1932: 242, 258 (citation, designation as a junior synonym of S. flaviventre); Fairchild, 1961: 230 (citation). Stibasoma sulfurotaeniata Kröber, 1931: 338 (description); Kröber, 1932: 243, 244, 259 (citation, key, citation); Fairchild, 1960: 5 (designation as a junior synonym of S. flaviventre).

Stibasoma stilbium Fairchild, 1953: 264 (description); Fairchild, 1953a: 241 (citation). Fairchild, 1986 (?junior synonym).

Stibasoma sulfurotaenium; Fairchild, 1971: 76 (catalog, misspelled).

Stibasoma flaviventre pulla Fairchild & Aitken, 1960: 5 (description). NEW SYNONYM.

Diagnosis. Thorax predominantly black, abdomen dark brown with yellow stripes.

Redescription. Female (holotype S. flaviventre). Head. Frons black, black hairs, silver pollinosity laterally, mid-callus best seen in dorsal view and few white hairs. Frontal callus as broad as frons, black. Subcallus dark brown, with dense silver pollinosity. Base of antenna with yellow pollinosity. Scape and pedicel dark brown to black, with black hairs; basal flagellomere of the flagellum dark brown to black, with golden pollinosity. Basal flagellomere with ventral angle and dorsal spine reaching the second flagellomere. Face, parafacia, gena and postgena dark brown with silver pollinosity; gena with dark brown hairs; postgena with mixed white and black hairs. Palpus inflated, black, with black hairs.

Thorax. Scutum and scutellum dark brown with yellowish-gray pollinosity, with dense black hairs. Postpronotal lobe light brown, with black hairs distally and few white hairs proximally; notopleuron dark brown with black hairs; proepisternum brown with white hairs proximally and black hairs distally; proepimeron dark brown with black hairs; anepisternum and anepimeron dark brown with dense black hairs; few white hairs on base of wing, beside the basicosta; katatergite dark brown with yellowish-gray pollinosity and black hairs; katepisternum dark brown, with black hairs and yellowish-gray pollinosity, best seen in anterior view, and black hairs; katepimeron dark brown with gray pollinosity best seen in dorsal view. Coxa dark brown to black with yellowish-gray pollinosity and black hairs. Tibiae 1 and 2 with white hairs proximally on the anterior, anterodorsal, posterodorsal and posterior sides; tibia 3 with white hairs proximally on the anterior and anterodorsal sides. The remaining parts of the leg dark brown to black with black hairs, except for reddish hairs on the ventral side of the tarsus. Wing yellowish, except cells bc and ma light-brown; apex of the wing almost hyaline. Venation brown. Pterostigma yellow. Halter brown, with yellowish apex.

Abdomen. Tergites light brown, almost yellow. Tergite 1 with dense black hairs; tergite 2 with mixed black and reddish hairs proximally, distal margin with a row of yellow hairs, best seen in posterior view. The other tergites with dark brown hairs proximally, reddish in anterior view and distal margin with a row of yellow hairs, best seen in posterior view. Sternite 1 dark brown with black hairs; the other sternites dark brown with mixed reddish and dark brown hairs proximally and the distal margin yellow with yellow hairs, forming bands.

Measurements. (n = 2, holotype S. flaviventre and Sangre Grande, 18.vi.1959) Body length: 13.43– 16.57mm. Wing length: 12.86–14.71mm. Frontal index: 4.65–5.17. Divergence index: 1.28–1.31.

Redescription. Male (holotype S. euglossa). Head. Dorsal part of the eye dark red, with large ommatidia; ventral and lateral parts of the eye black, with small ommatidia. Subcallus dark brown with silver pollinosity. Scape and pedicel dark brown with black hairs; flagellum orange with golden pollinosity. Basal flagellomere with dorsal spine reaching the first flagellomere. Face and parafacia dark brown with silver pollinosity. Gena and postgena dark brown, with sparse silver pollinosity and dense dark brown hairs. Palpus brown with long dark brown hairs.

Thorax. Scutum and scutellum dark brown, with dense dark brown to black hairs. Postpronotal lobe lighter than the scutum, with white hairs proximally and dark brown hairs distally. Notopleuron dark brown with dark brown to black hairs. Proepisternum dark brown, with white hairs proximally and black hairs distally. Proepimeron dark brown with dark brown to black hairs. Anepisternum and anepimeron dark brown with dark brown hairs. Katatergite dark brown with dark brown to black hairs. Katepisternum dark brown with sparse silver pollinosity and dark brown hairs. Katepimeron dark brown with dense silver pollinosity. Leg dark brown with dark brown hairs, except for white hairs proximally on the anterior, anterodorsal, dorsal, posterodorsal and posterior sides of tibiae 1 and 2; for white hairs proximally on the anterior and anterodorsal sides of tibia 3; and for reddish hairs on the ventral side of the tarsus. Wing yellow with yellow venation, except for the costal vein brown; base of the wing light brown (cells ma and bc; la enfuscated). Pterostigma yellow. Halter light brown with yellowish apex.

Abdomen. Tergites yellow with brown hairs proximally and yellow hairs on the distal margins. Sternites yellow, with brown hairs proximally and rows of yellow hairs on the distal margins.

Measurements. (n = 1, holotype S. euglossa) Body length: 17.4mm. Wing length: 15.9mm.

Variations. The color of the tergite´s integument may vary from light brown almost yellow to dark brown. The color of the sternite´s integument may vary from brown to almost black and the hairs on the proximal portion of the sternites may be only dark brown to black, or mixed with reddish hairs.

Type-locality. Brazil (Amazonas: Rio Negro).

Distribution. Mexico (Tabasco) to north of Brazil.

Type material examined. Stibasoma flaviventre: “ Type ” “ Tabanus \ flaviventris\ n. sp.\ Rio Negro\ (left Fairm.) Macq” “ Brazil:\ Rio Negro\ ex. coll. J. Bigot:\ ex. Coll. G.H.Verral.\ B.M. 1914-500” “ HOLOTYPE ” “ HOLOTYPE \ Tabanus \ flaviventris Macquart\ det. J.E.Chainey 1978” “ BMNH (E)# 253477” (Holotype, female BMNH). Stibasoma euglossa: “Pará\ 2-913” “ Stibasoma \ euglossa Lutz \ HOLOTYPE ” “Nº T 625\ Inst. O. Cruz\ Coleção A. Lutz” (Holotype, male, IOC). Stibasoma flaviventre pulla: “Tree station, Elev, 95º\ Rio Grande Forest\ Sangre Grande\ Trinidad B.W.I.\ 1-21/IV/58.” “TH.G. Aitken coll.\ Exman 11.30am.” “ Stibasoma flaviventre \ pulla Fchld & Aitken\ PARATYPE ” (Paratype, female, UNH).

Additional material examined. BRAZIL. Amazonas: female, Manaus, Reserva Ducke, 05-16.viii.1994, J. A. Rafael & J. Vidal, (INPA); female, idem, AM 0 10 Km 54, 02º45’33”S 59º51’03”W, 21-31.vii.1997, R.L.M. Ferreira, A.L. Henriques & J.F. Vidal, (INPA); male, idem, Reserva Ducke, Ig[arapé] Acará, Campinarama, 24.vii.2003, S.R.S Torreias & J.C.B. Fernandes, (INPA); male, idem, 08.ix.2003, S.R.S Torreias & J.C.B. Fernandes, (INPA); female, idem, 15.x.2003, S.R.S Torreias & J.C.B. Fernandes, (INPA); female, São Gabriel da Cachoeira, Morro 6 lagos, 28.ix a 6.x. 199?, J.A. Rafael & J. Vidal, (INPA); Pará: male, Belém, without date, Damasceno, (MZSP); female, idem, Floresta APEG, 13 a 16.viii.1983, I.S.Gorayeb, (MPEG); female, Benevides, PA-408 Km 0 6, 25.vi.1981, R.B. Neto, (MPEG). COLOMBIA. Nariño: female, Barbacoas, 22.iii.1974, M.Cooper, (BMNH); Putumayo: female, Vila Garzon, 1.i.1991, M.Cooper, (BMNH); GUYANA. Demerara-Mahaica: female, Georgetown, 1911, S. Harris, (BMNH); Potaro-Siparuni: female, Kaieteur, 7.ix.1937, Richards & Smart, (BMNH). HONDURAS. Atlántida: female, Tela (Lancetilla), 7.ix.1953, without collector, (MPEG); female, idem, 7.iv.1954, Santos, (MPEG); female, idem, 15.iv.1954, Santos, (UNH). TRINIDAD AND TOBAGO. Trinidad: female, Sangre Grande, Rio Grande Forest, 18.vi.1959, TH.G. Aitken, (UNLP). VENEZUELA. Amazonas: female, Yavita, 2º55’ N 67º26’W, ix.1947, René Lichy, (BMNH).

Remarks. We analyzed a representative sample of S. flaviventre and the holotype of S. flaviventre pulla and the variations in body color suggest intermediate forms, hence we consider both to be the same species. Figures 46–48 refer to the type material of S. flaviventre pulla.