Oxysarcodexia chaetopygialis ( Williston, 1896 )

Souza, Carina Mara De, Pape, Thomas & Thyssen, Patricia Jacqueline, 2020, Oxysarcodexia Townsend, 1917 (Diptera: Sarcophagidae) - a centennial conspectus, Zootaxa 4841 (1), pp. 1-126 : 37-38

Oxysarcodexia chaetopygialis ( Williston, 1896)

( Figs 66–69 )

Sarcophaga chaetopygialis Williston, 1896: 366 ; Saint Vincent and the Grenadines, Saint Vincent. Lectotype male (designated by Dodge 1965: 507) and an unspecified number of paralectotypes in AMNH (none examined). [Described from “numerous specimens” ( Williston 1896: 366).]

Diagnosis. Male. Length 6.5–7.0 mm. Postocular plate with golden pollinosity. Ocellar bristles well developed. Thorax with grayish with pale golden pollinosity laterally. Two well-differentiated posterior and 1–3 smaller anterior post-sutural dorsocentrals. Apical scutellar bristles absent. Wing vein R 1 with 2–3 setulae dorsally. Legs brownish. Abdomen with silvery pollinosity, T5 without golden pollinosity. T3 with 2 pairs of lateral marginal bristles, T4 with undifferentiated median marginal bristles and 1 pair of lateral marginal bristles. ST5 with deep median cleft with margins almost parallel and with pilosity and bristles along margins of arms. Cercus sinuous with pointed obliquely cut apex and dorsal subapical barb. Cercus with bristles ventrally only in distal third. Cerci with distal third of cercus as broad as middle part in posterior view; parallel, with apices slightly diverging. Pregonite broad, of equal width from base to apex (sometimes hiding the vesica in lateral view); unicolorous. Postgonite with expanded base gradually narrowing to apex; unicolorous. Phallus short; distiphallus broad in lateral view, with smooth ventroapical margin, square/oblong apex and sinuous dorsal outline. Vesica symmetrical, with rounded median projection of main branch; distal lobes reduced, rounded, membranous, without spines.

Remarks. This species can be recognized by the sinuous cercus in lateral view and the light yellow distiphallus, which is enlarged ventroapically ( Figs 67–68 ). The pregonite is dark brownish and very broad, not rarely covering the vesica in lateral view ( Fig. 68 ). As already stressed by Dodge (1965), O. chaetopygialis very rarely presents a single setula on vein R 1 on each wing; generally it has 2–3 setulae, and it is the sole species of Oxysarcodexia with setulae on this vein. Dodge (1965: 507) identified one female from Jamaica as O. chaetopygialis (“ 1 ♀, “ Jamaica,” with no other data, from the University of Arkansas (WSU)”), but we consider this record as tentative and in need of confirmation from male specimens, considering the significant distance between Jamaica and Saint Vincent, which is the only island so far known to harbour this species.

Distribution. NEOTROPICAL.? Jamaica, Saint Vincent and the Grenadines ( Saint Vincent).

Biology. Unknown.

Material examined. [♂] [ Jamaica] Majorca 1500′ St. Vincent, W. I., VII–VIII.1972 / Malaise trap, A. D. Harrison / Oxysarcodexia chaetopygialis (Will.) det. Lopes [ NHMD] // [♂] [ Jamaica] Majorca 1500′ St. Vincent, W. I., VII–VIII.1972 / Malaise trap, A . D. Harrison / Oxysarcodexia chaetopygialis ♂ (Will.) Det. Lopes [ MNRJ] .

Figures

FIGURES 60–69. Oxysarcodexia spp., males. 60–62. Oxysarcodexia carvalhoi Lopes (Brazil, São Paulo, Campinas, LIE). 60. Habitus, lateral view. 61. Terminalia, lateral view. 62. Terminalia, posterior view. 63–65. Oxysarcodexia catica Souza & Buenaventura, holotype (Colombia, Antioquia, Medellín, Pajarito, CE-TdeA). 63. Habitus, lateral view. 64. Terminalia, lateral view. 65. Terminalia, posterior view. 66–69. Oxysarcodexia chaetopygialis (Williston) (Saint Vincent, Majorca, MNRJ and NHMD). 66. Habitus, lateral view. 67. Terminalia, lateral view, without pregonite. 68. Terminalia, lateral view, with pregonite covering the vesica. 69. Terminalia, posterior view.