Macrostomus grallatrix ( Bezzi, 1909 )

Rafael, José Albertino & Marques, Dayse Willkenia Almeida, 2019, Five new species of Macrostomus Wiedemann and a checklist of Empididae (s. str.) (Diptera) from Bolivia, Zootaxa 4567 (2), pp. 251-275 : 256

Macrostomus grallatrix ( Bezzi, 1909)

( Figs 4 A–E)

Rhamphomyia grallatrix Bezzi, 1909: 326 (syntypes ♂, ♀). Melander, 1928: 194; Collin, 1933: 211 (cit).

Macrostomus grallatrix: Smith, 1961: 53 ; 1967: 30 (cat.); Rafael & Cumming, 2004: 446.

Diagnosis. Slender, shiny, thorax yellow, darker on mesonotum; hind femur slightly clavate (male); hind tibia with longer setae (male); legs mainly yellow; wing elongate, narrow basally, slightly brown infuscate on costal and apical margins, anal lobe very narrow; abdomen shiny black.

Redescription. Lectotype male. From original description: “body length 3.5–4.5 mm; wing length 4.5 mm ”. Frons shiny black, slightly narrower than anterior ocellus width. One pair of proclinate ocellar setae. Face shiny black, slightly narrower than frons. Inner vertical seta stouter than outer vertical seta, latter subequal in length to uniseriate postocular row of setae; only 1 pair of dorsal occipital setae. Antenna dark brown to black with postpedicel setulose. Proboscis yellow. Thorax shiny yellow, brown on scutum, scutellum and mediotergite; slightly gray pruinose on disc of scutum and scutellum. Thoracic chaetotaxy: 2 antepronotals; 1 postpronotal stout, 1–2 weak; 4 dorsocentrals; 1 presutural supra-alar; 0 postsutural supra-alar; 1 postalar; 2 small proepisternals; 1 notopleural stout; 2 pairs of scutellars, inner pair stouter, slightly convergent; 4–6 laterotergitals. Legs yellow with apex of mid tibia, apex of hind femur, entire hind tibia and all tarsi brown. Hind femur slightly clavate. Legs longer setae: hind femur with 1 short anteroventral seta on distal third; hind tibia with 4 longer dorsal setae with one at basal fifth and three on distal two thirds; hind tarsomere 1 with longer dorsal median setae. Wings lost, described as “ alis elongatis, basi cuneatis alula et lobo alari nullis, cinereo hyalinis fuscedine marginali et apicali, cellulae analis angulo supero minus acuto ” [wing elongate, base narrow, light brown infuscated on costal and apical margins, anal cell with dorsal angle less acute]. Abdomen lost, described as “ genitalibus maximis erectis nigro pilosus ” [terminalia upwardly directed with black setae].

Female (paralectotype). Head lost. Wing ( Fig. 4A ) elongate, slightly brown infuscated along costal margin; anal lobe narrow; veins M 1, M 2 and CuA+CuP evanescent distally; last section of vein M 4 slightly longer than vein dm–m; cell dm rather truncate. Halter light yellow to light brown. Abdomen shiny black with longer setae on posterior margins of tergites. Tergite 8 ( Figs 4B, C ) elongate, wider at base, with narrow sub-basal sclerotized band and distinct basal and distal sinus. Sternite 8 ( Figs 4B, D ) sandal-shaped in lateral view, higher on posterior half and narrower at basal third, with two more sclerotized spots laterally. Genital fork ( Fig. 4E ) well sclerotized, small, wider distally. Genital chamber membranous.

Geographical records. Bolivia (La Paz).

Type material examined. LECTOTYPE ♂ (here designated): “ BOLIVIA [La Paz], Mapiri, Sarampioni , 21.ii.1903 ” (SMTD). PARALECTOTYPES: Same data as lectotype (1♀, SMTD, damaged) ; BOLIVIA, Mapiri , San Carlos, 10.i. 1903, 800 m (1♀, SMTD, damaged) .

Lectotype condition. Both wings, left mid leg and abdomen lost.

Remarks. Lectotype designated accordingly to fix and stabilize the current concept of the name.

Figures

FIGURE 4. Macrostomus grallatrix (Bezzi, 1909), paralectotype ♀. A. Wing; B–D setae omitted; B. Tergites 8, 9+10; sternites 8 and 10, lateral view; C. Tergite 8, tergite 9+10 and cerci, dorsal view; D. Sternite 8 and sternite 10, ventral view; E. Genital fork, ventral view. Scale bars, figures A = 1 mm; B–D = 0.2 mm; E = 0.1 mm.