Macrostomus nigriventris (Macquart)

Rafael, José Albertino & Cumming, Jeffrey M., 2012, Revision of the genus Macrostomus Wiedemann (Diptera, Empididae, Empidinae). III. The limbipennis species-group, Zootaxa 3361, pp. 45-55 : 50-51

Macrostomus nigriventris (Macquart)

( Figs. 26–31 )

Rhamphomyia nigriventris Macquart, 1846: 224 ; Bezzi, 1905: 457 (citation); Bezzi, 1909: 322 (keyed); Melander, 1928: 199 (geographical distribution).

Macrostomus nigriventris: Collin, 1933: 210 ; Smith, 1961: 53; 1962: 242 (description transcription); 1967: 30 (catalogue); Rafael, 2001: 45 (citation); Rafael & Cumming, 2004: 446 (citation); Yang et al., 2007: 145 (catalogue).

Diagnosis. Postgenal and antepronotal setae weaker than dorsal thoracic setae. Tergite 8 with wide median projection at distal margin. Hypandrium distinctly wider at apex.

Re-description. Holotype male. Body length 3.4 mm; wing length 4.1 mm. The type of M. nigriventris was not located by Rafael (2001). Fortunately it was found in the Hope Entomological Collections of the University Museum in Oxford (OUMNH). The original description was transcribed by Smith (1962) and is useful. The wing and the terminalia are intact and it is now possible to add the following characters: posterior leg with coxa, trochanter and femur yellow, except apex of femur light brown; tibia light brown with extreme base yellow; tarsus yellow; tibia ( Fig. 26 ) with six slender dorsal setae; tarsomere 1 with 1 longer dorsal seta at middle and short spinelike setae ventrally. Wing ( Fig. 27 ) hyaline, light brown infuscated at costal and distal margins with pterostigma darker; cell dm somewhat truncate; veins M1, M2 and A1 evanescent. Halter lost. Abdomen shining black after dissection. Sternites concolorous with tergites. Terminalia black. Tergite 8 ( Fig. 29 ) with somewhat wide projection inside median distal sulcus. Epandrium ( Fig. 30 ) with anterodorsal and posterodorsal lobes of same height with somewhat deep sinus. Anterior cercus very large with dorsal sinus; posterior cercus elongate, bifid; median lobe ( Figs. 28, 30 ) with long setae. Hypandrium ( Fig. 31 ) with 6 slender setae along posterior margin (broken on dissected piece), with wider apex. Ejaculatory apodeme with short lateral lamella.

Female. Unknown.

Geographical distribution. Brazil (Minas Gerais).

Type Material. HOLOTYPE ɗ: “ Rhamphomyia nigriventris Macq. Male, n. sp., Brasil, Minas Gerais, Macq. D. 9r. Nvn” (sic) [handwritten white rectangular label, black bordered] // “ Holotype ” [printed rounded label red bordered] // “ R. nigriventris ex Coll. Bigot” [printed rectangular white label] ( OUMNH).

Holotype condition. Pinned specimen in poor condition. Body covered with a secretion (?glue). Right anterior leg with no tarsus. Left anterior leg lost. Left mid tibia glued to the pin, tarsus mounted on microslide. Right mid leg (except coxa) and posterior legs (except coxae) mounted on microslide. Wings mounted on microslide; mounted right wing with basal third lost; left wing ( Fig. 27 ) almost entire. Abdomen in good condition, in microvial with glycerin. Microslide and microvial on pin with specimen.

Figures

FIGURES 26 – 31. Macrostomus nigriventris (Macquart), holotype. 26, right mid leg, posterior view; 27, left wing; 28, apex of medial lobe of cercus; 29, tergite 8, dorsal view with right setae omitted; 30 terminalia, lateral view, setae omitted; 31, hypandrium and phallus, lateral view, setae broken, insertion indicated. Scales: 26 = 0.5 mm; 28 – 31 = 0.2 mm.