Oxysarcodexia marina ( Hall, 1938 )

Mariluis, Pablo Ricardo Mulieri Juan Carlos & Patitucci, Luciano Damián, 2010, Review of the Sarcophaginae (Diptera: Sarcophagidae) of Buenos Aires Province (Argentina), with a key and description of a new species, Zootaxa 2575, pp. 1-37 : 21-22

Oxysarcodexia marina ( Hall, 1938)

( Figs. 10 , 22 )

Apelophyla marina Hall, 1938: 257 .

Description of female. Body length = 6.4–7.2 mm. Head. Head length at antennal base 1.11–1.05 head length at vibrissal level. Microtomentum of parafacial and fronto-orbital plate, gena, and postorbital areas distinctly golden. Genal and postcranial setae black. Antenna black, first flagellomere black with dark microtomentum, length 0.25–0.28 head height, arista plumose. The females differ from males by the possession of wider front (0.34–0.38 of head width), two pairs of proclinate fronto-orbital bristles, the anterior bristle half the size of the posterior one. Thorax. Postpronotal lobe, notopleuron, anepimeron, anepisternum and median stripes of scutum with grey microtomentum. Proanepisternum bare. Chaetotaxy: acrostichals 4–3 (small)+1 (prescutellar), dorsocentrals 3+3, intra-alars 2+2, supra-alars 2+3, anterior postpronotal 1, basal postpronotal 2, postalars 2, notopleurals 4 (two big and two small), katepisternals 3 with the median one a little smaller and inserted near the anterior one. Scutellum with basal and lateral pairs, apical absent, discals one pair. Wing hyaline, tegula black, yellow-orange basicosta and veins, R1 bare, R4+5 setulose in proximal 0.67 or less of distance to crossvein r-m, costal spine not differentiated, third costal sector without ventral setae, lower calypter whitish to brown. Legs black; middle femur without posteroventral ctenidium on its apical portion. Abdomen. Tergites with spots of gray microtomentum. Tergites 1+2, 3 and 4 without erect marginal setae. Tergite 5 with a complete row (five pairs) of erect marginal setae. Terminalia. Tergite 6 with membranous median area covered with golden microtomentum, and sclerotized blackish laterals. T8 present. Sternite 6 black, sternite 7+8 with golden microtomentum, not convex at basal part and having a broad concave brown apical area ( Figs. 10 , 22 ).

Distribution: Neotropical – Argentina (Buenos Aires, Mendoza).

Material studied: Buenos Aires: 1 ɗ El Carretero, Magdalena, 10.X.2000 ( FAUBA); 2 Ψ Campana, Campana, III.2003, Mariluis leg. ( ANLIS); 1 ɗ Isla Paulino, Berisso, 25.IV.2004 ( ANLIS); 3 ɗ, 1 Ψ Reserva Ecológica Costanera Sur, Ciud. Aut. Buenos Aires, 24.IX.2003, on liver, Mulieri leg. ( ANLIS); 1 ɗ Ministro Rivadavia, Alte. Brown, 17.V.2005 on faeces, Mulieri leg. ( ANLIS); 1 ɗ Ministro Rivadavia, Alte. Brown, V.2006 on faeces, Mulieri leg. ( ANLIS); 1 ɗ San Claudio, Carlos Casares, I.2008 on Ludwigia spp. ( ANLIS).

Remarks: The specimens examined agree with the descriptions given by Hall (1938) and Lopes (1975) based on the male type material. This species is similar in general morphology and coloration to O. paulistanensis . However, males of these species are easy to separate by coloration of syntergosternite 7+8 (black in O. marina ) and the absence of apical scutellar bristles in the male of O. marina . Illustrations of male terminalia can be found in Hall (1938) and Dodge (1966). In addition, Lopes (1975) provided a detailed redescription of genitalic structures based on type material. The sternites of female terminalia resemble in general shape and coloration those of O. varia .

Biology: This species was captured in grasslands along the coastline of Río de la Plata, Buenos Aires using rotten cow liver and dog faeces as baits ( Mariluis et al. 2007; Mulieri et al. 2008). Flower visitor of Onagraceae ( Ludwigia spp.)

Figures

FIGURES 8 – 13. Female terminalia, postero-ventral view. 8. Oxysarcodexia varia. 9. O. terminalis. 10. O. marina. 11. O. paulistanensis. 12. O. bicolor. 13. Sarcophaga (Lipoptilocnema) koehleri.

FIGURES 22 – 25. 22. Oxysarcodexia marina, female abdominal ST 7 + 8. 23. O. paulistanensis, female abdominal ST 7 + 8. 24. O. bicolor, female abdominal ST 7 + 8. 25. Sarcophaga (Lipoptilocnema) koehleri, female abdominal ST 6 and ST 7. Scale bars = 0.20 mm. The arrows show the concavity of the sternites. Abbreviation: ST, sternite.