Hydrotaea tantula, Couri, Márcia & Pont, Adrian C., 2014

Couri, Márcia & Pont, Adrian C., 2014, New species of Afrotropical Muscidae (Diptera: Muscoidea), Zootaxa 3852 (3), pp. 301-320 : 310-312

Hydrotaea tantula sp. nov.

Figs 20–25 .

Type material. Holotype ♂, REPUBLIC OF SOUTH AFRICA: KwaZulu-Natal, Ndumo Game R., main road at: 26°54.288′S, 32°17.974′E, Malaise traps, sand & broad-leafed deciduous forest, 4–8.xii.2009 (A.H. Kirk-Spriggs), BMSA (D)17764 ( BMSA).

Paratype 1♀. REPUBLIC OF SOUTH AFRICA: same data as holotype, except: BMSA (D)19080 ( MNRJ).

Diagnosis. H. tantula sp. nov. is a very small shining green species, which is a unique colour outside Madagascar for Hydrotaea . Fronto-orbital plate, frontal triangle and parafacial glossy black; vein M curved forward towards vein R4+5.

Description. General coloration. Ground-colour dark green metallic, fronto-orbital plate, parafacial, gena and female ocellar triangle shining dark brown with some reddish reflections; antenna, arista and palpus dark brown; anterior spiracle dark brown; calypters brown in male and white in female; wing clear with some areas hyaline and devoid of microtrichia, especially in the basal part of the wing cells; haltere yellow; legs dark brown with dark green metallic reflexions.

♂. Measurements. Body length: 3.1 mm; wing length: 3.0 mm

Head. Eye bare, large, eyes very closely approximated, frons at vertex as broad as diameter of ocellar triangle; fronto-orbital plate narrow; vertical seta very short and fine; ocellar triangle short, with a pair of moderately long ocellar setae; frons with 7 very fine and short pairs of frontal setae; antenna inserted a little below mid-level of eye, postpedicel about 2 × as long as pedicel; arista bare, enlarged at base; gena slender, narrower than the width of postpedicel; palpus filiform.

Thorax. Ground-setulae relatively developed and all setae fine; acrostichals 0 + 1; dorsocentrals 2 + 4, the first two postsutural setae short and the last two long; 2 postpronotals; 2 postsutural intra-alars; 1 presutural and 1 postsutural supra-alars; prealar absent; 2 postalars. Notopleuron with two setae, similar in size. Anepisternum with a series of 6 long and thin setae. Katepisternals 1 + 1, the posterior one longer. Anepimeron and meron bare. Posterior spiracle with margins bare. Scutellum with a sub-basal and an apical pair of long setae.

Legs. Fore femur without a preapical ventral process; a complete row of dorsal and ventral setae; the ventral ones longer; fore tibia with no developed setae, except for one dorsal preapical that is hardly distinct from the ground-setulae and a ventral apical; mid femur with short setulae on ventral surface and 2 preapical dorsal setae; mid tibia with 2 posterodorsal setae on middle third, without anterodorsals; hind femur with a complete anterodorsal row of setae, longer on basal third; a series of well-spaced setae on apical half of ventral surface; hind tibia with 1-2 anteroventral setae on middle third; one posterodorsal on apical third, only a little longer than diameter of the tibia, one dorsal preapical and one ventral apical.

Wing. Lower calypter about 1.5 × as long as upper one. Wing veins bare; vein M curved forward towards R4+ 5 in apical part, at wing-tip cell r4+5 no wider than length of crossvein r-m.

Abdomen. Ground-setulae moderately long and dense, especially at sides and on margins of tergites 4 and 5 and disc of tergite 5. Sternite 5 as in Fig.20 .

Terminalia . Cercal plate and surstylus as in Figs 21–22 . Aedeagus in frontal and lateral views an in Figs 23–24 .

♀. Measurements. Body length: 2.5 mm; wing length: 2.4 mm.

Differs from ♂ as follows: frons about ⅓ of head-width at level of anterior ocellus; ocellar triangle long and wide, reaching lunule; crossed interfrontal setae absent; 3 pairs of inclinate frontal setae and 2 pairs of reclinate orbitals. Ground-setulae of notum not developed as in male, short and sparse.

Terminalia . Ovipositor and spermathecae as in Fig. 25 .

Distribution. Republic of South Africa (KwaZulu-Natal).

Etymology. The name is from the Latin word tantulus (“small”), referring to its very small size, and is an adjective in agreement with the feminine noun Hydrotaea .

Remarks. H. tantula sp. nov. and H. bella Couri, Pont & Penny, 2006 (endemic to Madagascar) are the only known Hydrotaea species to have a metallic green colour. The new species can be easily separated by its tiny size, dark brown palpus, and forward curvature of vein M.

Figures

FIGURES 20 – 25. Hydrotaea tantula sp. nov.: 20. sternite 5, dorsal view; 21. cercal plate and surstyli, dorsal view; 22. cercal plate and surstylus, lateral view; 23. aedeagus, dorsal view; 24. aedeagus, lateral view; 25. ovipositor, dorsal and ventral views and spermathecae.