Oxysarcodexia riograndensis Lopes, 1946

Souza, Carina Mara De, Pape, Thomas & Thyssen, Patricia Jacqueline, 2020, Oxysarcodexia Townsend, 1917 (Diptera: Sarcophagidae) - a centennial conspectus, Zootaxa 4841 (1), pp. 1-126 : 94-95

Oxysarcodexia riograndensis Lopes, 1946

( Figs 241–243 )

Oxysarcodexia riograndensis Lopes, 1946b: 103 ; Brazil, Rio Grande do Sul, São João de Montenegro. Holotype male and three male paratypes in MNRJ.

Diagnosis. Male. Length 7.0–8.0 mm. Postocular plate with golden pollinosity. Ocellar bristles well developed. Thorax and abdomen with silvery pollinosity, T5 without golden pollinosity. Two well-differentiated posterior and 1–3 smaller anterior post-sutural dorsocentrals. Apical scutellar bristles present. Legs blackish. T3 with 2 pairs of lateral marginal bristles, T4 with 1 pair of median marginal and 2 pairs of lateral marginal bristles. ST5 with deep median cleft with margins almost parallel and with pilosity. Cercus straight in lateral view, with expanded obliquely cut apex. Cercus with bristles ventrally absent only on middle portion. Cerci with distal third narrower than middle part in posterior view; diverging. Pregonite and postgonite both with expanded base, gradually narrowing to apex; unicolorous. Distiphallus with ventroapical concavity with serrated margin (resembling a pointed projection), square/oblong apex, sinuous dorsal outline and medium-sized dorsoapical swelling. Vesica symmetrical, with lateral lobes and rounded median projection of main branch; distal lobes well developed, rounded, sclerotized, with spines only on ventral surface.

Remarks. See under O. bikini . The female of O. riograndensis has an undivided T7 ( Tibana & Mello 1985). This species was included in a pictorial key to females of nine species of Sarcophagidae of forensic importance in southern Brazil ( Vairo et al. 2015).

Distribution. NEOTROPICAL. Argentina (Jujuy), Brazil (Minas Gerais, Paraná , Pernambuco, Rio de Janeiro, Rio Grande do Sul, São Paulo).

Biology. This species has been reared from a corpse in the bloated stage and collected on the premises of an institute of legal medicine, using chicken liver as bait by Oliveira & Vasconcelos (2010). For these reasons, it is considered a necrophagous/omnivorous species ( Oliveira & Vasconcelos 2010) and an early visitor in entomological forensic cases ( Vasconcelos et al. 2013). We have reared Oxysarcodexia riograndensis on minced bovine meat at LIE, observing a larval development time of 6 days and time from pupation to adult emergence of 9 days. In a study comparing the attractiveness of baits, Linhares (1981) observed that human feces and mouse carcasses were more attractive than chicken viscera, a pattern confirmed by Mendes & Linhares (1993). Sunlight is preferred to shade areas ( Linhares 1981). This fly has been collected using mouse, rat, rabbit and pig carcasses, dead fish, rotten squid, chicken liver, rotten bananas with yeast, and human feces as bait ( Ferreira 1979; Mendes & Linhares 1993; Carvalho & Linhares 2001; Moretti et al. 2008; Rosa et al. 2011; Vairo et al. 2011; Vasconcelos & Araujo 2012; Vasconcelos et al. 2013; Dufek et al. 2016; Faria et al. 2018). Adult specimens have been found in the Brazilian Cerrado (collected only in the dry period), urban, rural or forest environments ( Linhares 1981; Mendes & Linhares 1993; Moretti et al. 2008; Rosa et al. 2011; Vairo et al. 2011; Vasconcelos & Araujo 2012; Vasconcelos et al. 2013; Faria et al. 2018). Dufek et al. (2016) collected this species only in undisturbed part of Argentinean wetlands.

Type material examined. Holotype ♂: [Brazil] S. JOÃO DE MONTENEGRO RIO GRANDE DO SUL DAGORSO-COL 1-933 / Oxysarcodexia riograndensis n. sp. 44 Det. H. S. Lopes / HOLOTYPE / MNRJ 2252 [typed vertically on left side of label] [ MNRJ] // paratype ♂: [Brazil] ANGRA DOS REIS L.T col 9-93 / Paratype / Oxysarcodexia riograndensis n. sp. 44. Det. H. S. Lopes [ MNRJ] .

Other material examined. [ ♂] BRAZIL: São Paulo, Campinas , UNICAMP, 18.VII.2010 , C. M. Souza / O. riograndensis , Campinas-SP, 18/08/2010 [ LIE] .

Figures

FIGURES 237–243. Oxysarcodexia spp., males. 237–240. Oxysarcodexia rimata sp. n., holotype (Ecuador, Napo Province, MZPUCE). 237. Habitus, lateral view. 238. Terminalia, lateral view. 239. Terminalia, posterior view. 240. Terminalia, ventroapical view. 241–243. Oxysarcodexia riograndensis Lopes (Brazil, São Paulo, Campinas, LIE). 241. Habitus, lateral view. 242. Terminalia, lateral view. 243. Terminalia, posterior view.