Retrocitomyia sisbiota, Mello-Patiu, Cátia Antunes De & Salazar-Souza, Mônica, 2016

Mello-Patiu, Cátia Antunes De & Salazar-Souza, Mônica, 2016, Retrocitomyia Lopes, 1982 (Diptera: Sarcophagidae): new species, new records, key to males, and an updated catalog, Zootaxa 4171 (3), pp. 534-548 : 535-539

Retrocitomyia sisbiota sp. nov.

( Figs 1–9 , 14 )

Diagnosis. Male cercus, in posterior view, with cercal prong curved and falciform, and a cluster of short setae from the middle of the cercal base to the base of the cercal prong; phallus with vesica consisting of two, ventrally joined lobes with apical margin curved laterally, and phallus with juxta longer than wide, with a straight apical margin (posterior view) and swollen lateral margins (in lateral view). Female ST8 large, not fused to ST7, with two depressed, rounded lateral areas separated by a longitudinal, central, less sclerotized strip.

Description. Male (n = 74). Length: 7–10 mm.

Head. Parafacial, fronto-orbital plate and posterior ocular orbits with intense golden pruinosity; fronto-orbital plate with a row of setulae from the upper region to the gena; face with light silver pruinosity and parafacial dark gray ( Fig. 1 ); frons about 0.26x head width at level of ocellar triangle; frontal vitta blackish along its whole length; 6 well-developed frontal setae reaching level of apex of pedicel; reclinate orbital seta present and more developed than the largest frontals, proclinate orbital setae absent; ocellar setae as developed as the upper frontals, postocellar seta similar to outer vertical seta; inner vertical seta the largest of the vertex, outer vertical seta undifferentiated from postocular setae; gena and genal groove with intense golden pruinosity, gena with black upper setae and pale lower setae; postgena gray with silvery pruinosity and pale setae; occiput gray with an upper row of black setulae and the remaining setulae pale; antenna with pedicel dark gray and postpedicel blackish, with light gray pruinosity; arista long plumose on basal 2/3; palpus black.

Thorax. Gray with silvery pruinosity and three dark brown longitudinal bands. Chaetotaxy: acrostichals 0+1, dorsocentrals 3 (the posteriormost stronger) + 2 (inserted in posterior half of distance from suture to scutellum), intra-alars 1+2, supra-alars 1+3, postpronotals 3; postalar wall setulose; scutellum with 2 marginal setae, a pair of preapical setae and a pair of long and crossed apical setae; postalar callus with 2 setae; katepisternal setae 3, almost in a straight line; merals 6–8; proepisternum bare, prosternum setulose in posterior half. Wing: hyaline, costal spine present, vein R4+5 with dorsal setulae on 3/4 of distance to crossvein r-m, vein R1 bare, cell r4+5 open at wing margin, third costal sector ventrally bare. Legs: blackish-brown; fore tibia with 2 median-basal anterodorsal setae, 1 median and 1 preapical posterior setae, and 1 preapical dorsal seta; mid femur with 2 strong median anterior setae, a row of 4 setae on anteroventral margin, 2 apical posterior setae, and a row of setae along posteroventral margin (but without a ctenidium); mid tibia with 2 median anterior setae, 1 median ventral seta, 1 basal posterior seta and 2 posterior setae in the apical third; hind trochanter with normal median-ventral setae; hind femur with rows of dorsal, anterodorsal, anteroventral and posteroventral setae, and 1 longer preapical anteroventral seta; hind tibia with 1 median and 1 apical anterior setae, 1 basal, 2 median and 1 apical setae on the anterodorsal and posterodorsal surfaces, and 1 preapical ventral seta.

Abdomen. Brown with pattern of silvery-gray pruinosity ( Fig. 1 ); syntergite 1+2, T3 and T4 each with one lateral marginal seta, T4 with one pair of stronger median marginal setae, T5 with about 18 marginal setae; ST5 with short lobes, apically expanded and truncated ( Figs 1–2 ).

Terminalia. Syntergosternite 7+8 and epandrium brown with pale golden pruinosity on almost the entire dorsal surface except for a glabrous anterior band ( Figs 1–2 ; cercus, pregonite, postgonite, and phallus blackish-brown; syntergosternite 7+8 with 6 long and strong marginal setae ( Figs 2 , 5 ); cercus enlarged and flattened, with a depression and numerous setae along its inner margin in basal half (posterior view), cercal prong curved and falciform (posterior view), with some short setae ( Figs 2 , 5–6 , 14 ); surstylus narrow and elongated, with several long setae in apical half and a membranous lateral projection ( Fig. 5 ); postgonite short, with a conspicuously laterally curved and pointed apex, and a dilated region near the apex with a small ventral seta ( Fig. 14 ); pregonite long and setulose on its dorsal surface, with a curved apex; phallus short, compact and dark blackish-brown ( Fig. 2 ), basiphallus short ( Fig. 7 ); vesica well sclerotized, formed of two ventrally-joined lobes with apical margin curved laterally ( Figs 2 , 7–8 ); juxta well sclerotized, with a straight apical margin (posterior view) and swollen lateral margins (lateral view) ( Figs 2 , 7–8 ).

Female (n = 17). Length: 7–8 mm. Differs from male as follows:

Head. Frons about 0.34x head width at level of ocellar triangle; 5–6 well-developed frontal setae; 2 proclinate orbital setae similar to or slightly longer than reclinate orbitals; outer vertical seta about 2/3 to 1/2 of length of inner vertical seta. Thorax. Scutellum with 2 long marginal setae, a pair of small preapical setae and no apical setae. Abdomen. T5 with posterior margin yellowish-brown, and with 7–8 pairs of premarginal setae besides the large number of smaller marginal setae ( Fig. 3 ); T6 as 2 narrow bare plates, almost attached by an extremely narrow membranous dorsal join; spiracles 6 and 7 located in the intersegmental membrane ( Fig. 9 ). Epiproct undivided and ventrally projected, with 2–3 pairs of well-developed setae ( Fig. 9 ); hypoproct broad. ST4 and ST5 each with a pair of large setae on posterior margin, and both slightly oval and narrower than ST6. ST6 and ST7 united, but with a well-defined delimitation between them and both with their posterior margin medially concave and with a cluster of setae on their lateral margins ( Fig. 9 ). ST8 wide and not fused to ST7, with two depressed, rounded lateral areas separated by a longitudinal, central, less sclerotized strip, where 1–2 pairs of well-developed distal setae are inserted ( Fig. 9 ); posterior margin slightly V-shaped; lateral areas and posterior margin conspicuously covered with golden pubescence ( Figs 3 , 9 ). Vaginal plate dark and glabrous, very sclerotized, as wide and as long as ST8, with a triangular sclerotized signum at its proximal end ( Figs 3 , 9 ).

Type-material. Holotype ♂: “ BRAZIL, MS [Mato Grosso do Sul], Corumbá / Passo do Lontra—B.E.P [Base de Estudos do Pantanal / UFMS] / 19º34’20.9”S 57º00’58.0”W / Shannon [trap] (peixe) [= fish] / 06.xii.2011 / Patiu & Patiu col. [leg.] [printed on white paper] / Sisbiota / CNPq/FAPESP [vertical]” // “ Holotype [printed on red paper, black frame]” // “ Retrocitomyia / sisbiota Mello-Patiu / & Salazar-Souza, 2016 [handwritten on white paper] / Det. C.A. Mello-Patiu [printed]” ( MNRJ) . Paratypes (73 ♂ and 17 ♀ in total): same data as holotype, 46 ♂, 6 ♀ (37 MNRJ, 15 MZUSP) ; same data as holotype except 07. xii.2011, 4 ♂, 5 ♀ (4 MNRJ, 5 MZUSP) ; same data as holotype except hand net, Lamas, Nihei & equipe leg., 9 ♂, 1 ♀ ( MZUSP) ; same data as previous except 07. xii.2011, 5 ♂, 4 ♀ (7 MNRJ, 2 MZUSP) ; same data as previous except yellow pan trap, 06. xii.2011, 2 ♂ ( MZUSP) ; same data as previous except 07. xii.2011, 3 ♂ ( MZUSP) ; same data as previous except Malaise trap, 02–17. xii.2011, 1 ♂, 1 ♀ ( MNRJ) ; same data as previous except 16–31. i.2012, 1 ♂ ( MNRJ) ; same data as previous except 02–17. xi.2012, 1 ♂ ( MNRJ) ; same data as previous except modified van Sommeren trap, 07. xii.2012, 1 ♂ ( MZUSP) .

Etymology. The species epithet, sisbiota , is a noun in apposition derived from the name of the project that allowed us to collect this species.

Remarks. The Sisbiota – Diptera project included many collection sites in a number of habitats; however, the new species was collected exclusively in one, annually flooded locality in the south Pantanal in the state of MS, suggesting that it is possibly endemic. It was attracted by several means: by using rotten fish as bait in Shannon and modified van Sommeren traps, or with hand nets, Malaise traps, and yellow pan traps.

A comparative analysis among species of Retrocitomyia with a short and wide cercus revealed that the male terminalia of R. sisbiota are morphologically very similar to those of R. paraguayensis and R. mexicana for the presence of a median constriction along the outer margin of the cercus (posterior view). The three species can be differentiated by the following features of the cercus: a setose elevation near the inner margin in R. mexicana ( Fig. 23 ), a band of clustered short setae in a depressed median area in R. sisbiota ( Fig. 14 ), and a cluster of hair-like setae at the base of the cercal prong in R. paraguayensis ( Fig. 17 ).

A comparison between females of R. sisbiota and R. retrocita showed that they share a similar epiproct in the shape of a tongue-like setose plate ventrally projected together with the cerci, a well-sclerotized vaginal plate, and a sclerotized signum (in which the spermathecal ducts are inserted). Females of these two species can be differentiated mainly by T6 wide and setose and ST8 longer than wide with lateral round depressions in R. retrocita , and T6 narrow and bare and ST8 wider than long with a longitudinal central unsclerotized strip between the lateral areas in R. sisbiota .

Figures

FIGURES 1 – 3. Retrocitomyia sisbiota sp. nov. 1. Male habitus (paratype, MNRJ), lateral view. 2. Male terminalia (paratype, MNRJ), lateral view. 3. Female terminalia (paratype, MZSP), ventral view. Scale bars = 1 mm.

FIGURES 4 – 9. Retrocitomyia sisbiota sp. nov. 4. Male sternite 5 (paratype, MNRJ), ventral view. 5. Terminal segments of male abdomen (paratype, MNRJ), lateral view. 6. Male cerci (paratype, MNRJ), posterior view. 7. Phallus (paratype, MNRJ), lateral view. 8. Phallus (paratype, MNRJ), ventral view. 9. Female terminalia (paratype, MNRJ), ventral view. Abbreviations: bp = basiphallus, ce = cercus, ep = epandrium, hy = hypoproct, jx = juxta, ls = lateral stylus, ms = median stylus, pp = paraphallus, ST = sternite, su = surstylus, T = tergite, ve = vesica, vp = vaginal plate. Scale bars = 0.2 mm.

FIGURES 14 – 19. Male terminalia, posterior view. 14. Retrocitomyia sisbiota sp. nov. (paratype, MNRJ). 15. Retrocitomyia fluminensis Lopes (specimen from MS, Bodoquena). 16. Retrocitomyia mizuguchiana Tibana & Xerez (specimen from MS, Corumbá). 17. Retrocitomyia paraguayensis Lopes (specimen from MT, Chapada dos Guimarães); 18. Retrocitomyia retrocita (Hall) (specimen from MT, Chapada dos Guimarães). 19. Retrocitomyia adolenda (Lopes) (paratype, MNRJ). White arrows point to the postgonite.

FIGURES 20 – 24. Male terminalia. 20. Retrocitomyia trinitatensis Lopes (holotype, CNC), epandrium and cerci in posterior view. 21. Retrocitomyia trinitatensis Lopes (holotype, CNC), phallic complex in lateral view. 22. Retrocitomyia andina Lopes (paratype, MNRJ), terminalia in lateral view. 23. Retrocitomyia mexicana Lopes (paratype, MNRJ), terminalia in posterior view. 24. Retrocitomyia urumajoensis Lopes (paratype, MNRJ), terminalia in posterior view. Black arrows point to the postgonite. Abbreviations: jx = juxta, ve = vesica.