Aristobatina metamelasma, Marshall, 2014

Marshall, Stephen A., 2014, A review of the Afrotropical genus Aristobatina Verbeke (Diptera: Micropezidae: Taeniapterinae), with descriptions of four new species from the Eastern Arc Mountains of Tanzania, African Invertebrates 55 (1), pp. 143-143 : 146-147

Aristobatina metamelasma sp. n.

Figs 1–6

Etymology: From the Greek words meta (near) and melasma (black spot), referring to the distinctive discal macula on the wing of this and the closely related A. melasma .

Description:

Length (head to wing tip): 13–15 mm.

Colour: Head orange anteriorly, reddish brown posteriorly, swollen part of frontal vitta dark reddish brown; thorax dark reddish brown; abdomen shiny blue­black; fore femur orange in basal ⅔, brown distally; mid and hind femur uniformly orange except for a small dark area at apex; mid tarsus dark brown or black; basal ½ of tarsomere 1 of hind leg pale, tarsus otherwise dark brown to black; abdominal pleurae grey on pinned types. Head: Scape bare except for marginal ring of short setae; pedicel short and setose, with some longer ventral apical setae; frontal vitta with strongly convex elongate oval area surrounding ocelli and extending half the distance from anterior ocellus to anterior margin of frons; 2 pairs of fronto-orbital setae, 1 large and above level of ocelli, 1 smaller below; postocellar, outer and inner vertical setae well­developed.

Thorax: Cervical sclerite flat, dull, microtrichose; proepisternum with a few long marginal ventral setae on posterior ½; katepisternum with double row of thin black setae, anterior row with only 5 setae, barely overlapping with lower end of posterior row; scutellum with 1 pair of marginal setae only, 1 small to minute seta between postalar and dorsocentral setae.

Wing: CuA 2 virtually at right angle to and in line with bm­cu, wing membrane with a distinctly infuscated tip and a small, circular discal macula extending from just anterior to R 4+5 to M; tegula, basicosta and stem vein brown, similar to adjacent wing base, stem vein dorsally microsetulose at base; wing base with 3 long costagial setae, inner one very long and inclinate.

Female abdomen: Paired spermathecae elongate egg­shaped, 1.9× as long as wide, with a constriction in basal ⅓, surface otherwise smooth, spermathecal duct densely covered with knob­like processes beyond the division of the common duct into 2 straight branches ( Fig. 1 ). Single spermatheca on a much shorter and smaller duct, body densely covered with processes much like the paired spermathecal ducts.

Male abdomen: Pleuron with large dome­like differentiated area on segment 4 (occupying approximately ventral ¾ of pleuron 4); hypandrium with a very short anterior plate and strong posterodorsal arms connecting to phallic plate, dorsolateral margin of posterodorsal arm with a prominent lobe ( Fig. 5 ). Basiphallus elongate and tapered posteriorly, extending well beyond base of distiphallus; postgonites equal, small and finely spinulose ventrally; distiphallus with tubular basal part bifurcating before transition into strongly dextrally recurved membranous distal part, apex with a finely spinulose glans ( Fig. 6 ); ejaculatory apodeme slightly larger than epandrium; genital fork (sternite 5) with gap Y­shaped at base ( Fig. 4 ), inner surfaces of arms densely spinose and with a right-angled bend in the middle.

Holotype ♂ and 3♀ paratypes: TANZANIA: Uluguru Mountains : “Tanganyika, Ulguru Mts, 1500–1800m ” ( CNCI).

Comments: This species is closely related to A. melasma , from which it differs in spermathecal shape and sculpturing and in the pigmentation of the hind tarsus.

Figures

Figs 1–6. Aristobatina metamelasma sp.n.: (1) spermathecae and bursa copulatrix; (2) female, dorsal view; male: (3) lateral view; (4) sternite 5; (5) terminalia, dorsolateral view; (6) terminalia, ventral view. Not to scale.