Nigranitida costata (Wulp)

Webb, Donald W. & Metz, Mark A., 2004, The South American genus Nigranitida Metz (Diptera: Therevidae: Therevinae) with the description of three new species, Zootaxa 757, pp. 1-16 : 4-7

Nigranitida costata (Wulp)

costata ( Wulp 1888:368 orig. desc.) ( Psilocephala ); Metz et al. (2003:241 comb. change, NT desig.) ( Nigranitida ). Type locality Cordova [ Argentina]. NT female (MEI 084113) in NHMW. atra ( Kröber 1911:512 orig. desc.) ( Psilocephala ); Metz et al. (2003:241 comb. change, syn. desig., trans. orig. desc.) ( Nigranitida ). Type locality Poterillos [Potrerillos], Mendoza Province, Argentina. HT female (MEI 084113) in NHMW as NT of costata .

Diagnosis. Like Nigranitida gibba and N. irwini in lacking setae on the katepisternum. It differs from N. gibba and N. irwini by having the halter and maxillary palpus dark brown, the setae on the male mesonotum white; and the female wing veins with a dark brown margin. It is separated from the female of N. irwini by having the frons dark reddish brown, glossy with a small area of gray pruinescence ventrolaterally and covering the ocellar tubercle (female of N. gibba is unknown).

Redescription of male.

Morphometric variation (n=4).

Body length 5.5–5.6, 5.5 mm.

Head. Length 0.70–0.88, 0.79 mm. Frons pruinescence silver gray, black dorsally. Antenna black, Ant/HL 0.67–0.76, 0.71; scape length 0.16–0.20, 0.18 mm, length/width 1.6–1.8, 1.7, scape/pedicel length 1.6–2.0, 1.8, scape/flagellum width 0.83–0.86, 0.84, setae dark reddish brown, white ventrally, elongate; pedicel length 0.08–0.11, 0.10 mm, length/width 0.83–1.10, 0.91; flagellum length 0.30–0.36, 0.33 mm, length/width 2.5–2.8, 2.6, flagellum/scape length 1.8–1.9, 1.8. Parafacial pruinescence silver gray. Maxillary palpus dark brown; length 0.28–0.40, 0.36 mm, length/width 4.7–6.0, 5.1; setae pale yellow. Genal setae white. Occipital setae white becoming appressed, lanceolate dorsolaterally; macrosetae dark reddish brown, scattered.

Thorax. Macrosetae 3 np, 1 sa, 1 pa, 0 dc, 1–2 sc. Mesonotum dark reddish brown, pruinescence light gray; vitta indistinct; setae black, erect, elongate intermixed with white, appressed setae. Pleuron dark reddish brown, pruinescence white, dense; setae white on propleuron, anepisternum, laterotergite, metanepisternum, and scutellum, absent on katepisternum. Wing. Length 3.7–4.5, 4.2 mm, length/width 2.7–2.9, 2.8; membrane opaque; veins brown; pterostigma dark brown. Halter dark brown. Legs. Femora dark brown, pruinescence white; setae white, elongate ventrally on fore­ and midfemora; av 2– 5:1:4–5, pv 0:0:1–3. Fore­ and hindtibiae dark brown, midtibia dark yellowish brown, apex dark brown. Tarsi dark brown.

Abdomen. Cuticle dark reddish brown, pruinescence white; dorsal setae white, lanceolate, appressed; lateral setae white, erect. Terminalia . Dark brown. Epandrium ( Fig. 1 ) quadrate, anterior margin broadly emarginate, posterolateral margin short broadly pointed. Hypoproct ( Fig. 1 ), posterior margin truncate, ending below apex of cercus. Gonocoxite ventral view ( Fig. 2 ) quadrate, rounded laterally, tapering posteriorly to short point, medial area with elongate concavity bearing dark yellow setae directed medially; dorsal view ( Fig. 3 ), gonocoxal bridge large; lateral view ( Fig. 4 ) tapering to thick dorsoposterior point. Gonostylus ( Fig. 5 ) lacking basodorsal lobe; ventral margin rounded, setae dark yellow. Aedeagus with dorsal apodeme ( Fig. 6 ) oblong, sides slightly rounded, anterior margin truncate; ventral apodeme ( Fig. 7 ), anterior margin deeply emarginate, tapering laterally to narrow point, ventral surface lacking pair of ventromedial projections; distiphallus ( Fig. 6 ) tapered posteriorly, lateral view ( Fig. 8 ), sinuate; ejaculatory apodeme ( Fig. 6 ) dark yellow, anterior half moderately expanded, anterior margin truncate, extending to anterior margin of dorsal apodeme.

Redescription of female.

Similar to male except for following.

Morphometric variation (n=10).

Body length 5.7–8.8, 6.5 mm.

Head. Length 0.70–0.88, 0.81 mm. Ocellar tubercle dark reddish brown, pruinescence gray. Frons ( Fig. 9 ) dark reddish brown, glossy, pruinescence silver ventrolaterally; setae absent. Antenna dark brown, scape occasionally dark yellow; Antenna/HL 0.64–0.98, 0.74; scape length 0.16–0.22, 0.19 mm, length/width 1.5–2.2, 1.8, scape/pedicel length 1.8–2.8, 2.3, scape/flagellum width 0.5–1.0, 0.8; pedicel length 0.07–0.09, 0.08 mm, length/width 0.6–1.0, 0.8; flagellum length 0.30–0.56, 0.37 mm, length/width 1.7–4.0, 2.9, flagellum/scape length 1.7–2.8, 2.0. Parafacial pruinescence silver gray. Maxillary palpus dark brown, occasionally apical third dark yellow; length 0.29–0.36, 0.32 mm, length/ width 3.8–6.0, 5.2. Genal setae white. Occipital setae white becoming yellowish brown, appressed, lanceolate dorsolaterally; macrosetae dark reddish brown, scattered.

Thorax. Macrosetae 2–4 np, 1–2 sa, 1 pa, 0 dc, 1–2 sc. Mesonotum with vittae dark brown, pruinescence light gray, separated by broad band of gray pruinescence; setae white to pink, appressed, lanceolate. Pleuron dark reddish brown, glossy on anterior threefourths of anepisternum, pruinescence silver, dense over remainder of pleuron. Wing. Length 4.0–5.3, 4.4 mm, length/width 3.0–3.7, 3.3; membrane opaque with broad pale brown margin along veins and crossveins; veins and pterostigma dark brown. Legs. Femora dark brown, pruinescence white; av 2–4:1:2–6, pv 0:0–1:1–2. Tibiae brown, occasionally dark brown. Tarsi dark brown.

Abdomen. Cuticle black, glossy, tergite 5 with posterior band of gray pruinescence; dorsal setae dark reddish brown, appressed, tergites 1–4 with white setae across posterior margin. Terminalia . Furca ( Fig. 10 ), length 0.38 mm, width 0.28 mm; spermathecal sac long, broad, spermatheca spherical ( Fig. 10 ).

Biology. Nigranitida costata has been hand netted or collected in Malaise traps in moist habitats or dry canyons from 15 September to 2 March.

Specimens Examined. Type Specimens. The neotype female of Psilocephala costata Wulp was designated by Metz (Metz et al. 2003:241) utilizing the holotype female of the Psilocephala atra Kröber (1911:512) , a junior synonym of Nigranitida costa ( Metz et al. 2003:239). This neotype (MEI 140761) was collected in Poterillos [Potrerillos], Prov. Mendoza, Reimoser, Argentina and deposited in the NHMW. Other Specimens. ARGEN­ TINA. BUENOS AIRES. San Blás [­40.58, ­62.24], 22.III.1983, 1 female MEI 0 30237 (MACN). CATAMARCA. 10 km W Chumbicha [­28.834, ­66.309], 590 m, 15.IX.1999, Irwin, M. E., Parker, F. D., 1 male MEI 147293 (INHS), 3 females 121666 ­8 (MEI), Malaise trap in moist habitat; Sierra de Ambato, 13 km NW Chumbicha [­28.833, ­66.408], 700 m, 13–15.IX.1999, Irwin, M. E., Parker, F. D., 1 female MEI 146414 (USNM), Malaise trap near water in side canyon; 18 km NW Chumbicha, Highway 60 [­28.803, ­ 66.389], 950 m, 5.IX.1999, Irwin, M. E., Parker, F. D. 1 female, MEI 121665 (MEI). COR­ DOBA. Bajo Grande, 6.II.1939, Maldenado, R., 1 female MEI 0 30239 (MLPA). LA PAMPA. 120 km N Rio Colorado on Highway 154 [­38.000, ­63.5131], 11.I.1984, J. Pettis, 1 male MEI 136908 (UGCA). LA RIOJA. 25 km N Chepes, Sierra de Arganaraz, El Rocillo [­31.203, ­66.712], 850 m, 11–16.IX.1999, Irwin, M. E., Parker, F. D., 2 females MEI 106768, 121768 (MEI), Malaise trap; Departamento de Rosaro V. Peñaloza, Sierra de Argañaraz, 1 km W El Rocillo [­31.207, ­66.714], 716 m, 11–22.X.1997, Irwin, M. E., Parker, F. D., Roig, S., 2 females MEI 106765, 106767 (MEI), Malaise trap in dry canyon; 22.X.1997, 2 females MEI 106764 (INHS), 106766 (MEI); El Rocillo [­31.207, ­66.713], 722 m, 11.X.1997, Irwin, M. E., Parker, F. D., Roig, S., 1 female MEI 106762 (INHS); 22.X.1997, 1 female MEI 106763 (MEI), Malaise trap. MENDOZA. Cacheuta [­33.038, ­ 69.103], 22.I.1950, Aczél, M., 1 male MEI 134862 (IMLA); Uspallata [­32.583, ­69.333], 16.II.1996, Stange, L., 1 male MEI 0 48204 (IMLA). TUCUMAN. Amaichá, 27.XI.1967, L. Stange, 1 female MEI 0 30238 (IMLA).

Figures

FIGURES 1 – 10. Nigranitida costata 1. Tergite 8, epandrium, cerci, hypoproct, dorsal view (MEI 048204). 2. Sternite 8, hypandrium, gonocoxite, ventral view. 3. Gonocoxite, hypandrium, dorsal view. 4. Gonocoxite, left lateral view. 5. Gonostylus, left lateral view. 6. Aedeagus, dorsal view (inset: ejaculatory apodeme cross­section). 7. Aedeagus, ventral view. 8. Aedeagus, left lateral view. 9. Female head. 10. Female internal reproductive organs (MEI 106765). Scale = 0.1 mm. Abbreviations: C = cercus, CD = common duct, DA = dorsal apodeme, Dp = distiphallus, EA = ejaculatory apodeme, Ep a = epandrium, F = furca, GA = gonocoxal apodeme, Gs = gonostylus, Gx = gonocoxite, GxB = gonocoxal bridge, H = hypandrium, Hp = hypoproct, Sp = spermatheca, SpD = spermathecal duct, SpS = spermathecal sac, SS = sensory seta, S 8 = sternite 8, T 8 = tergite 8, VA = ventral apodeme, VL = ventral lobe. Figure 9 modified from Metz et al, 2003.