Mesoconius aurantium, Marshall, 2019

Marshall, Stephen A., 2019, A revision of the genus Mesoconius Enderlein (Diptera, Micropezidae, Taeniapterinae), European Journal of Taxonomy 548, pp. 1-126 : 75-78

Mesoconius aurantium sp. nov.

urn:lsid:zoobank.org:act:238AAAF3-3136-4822-BAC7-F0B51316C7B3

Fig. 31

Material examined

Holotype

PERU • ♀; Cusco, Wayqecha Biological Station , 9 km NE of Challabamba; 13°11ʹ18ʺ S, 71°35ʹ06ʺ W; 3100 m a.s.l.; 7–8-Dec. 2011; S.A. Marshall leg.; MUSM.

Etymology

The name, from the Latin noun for ʻorangeʼ, refers to the generally orange colour of this species.

Description

LENGTH. 18 mm.

COLOUR. Mostly bright orange, except as follows: lower frons dark; face pale, parafacial, gena and postgena silvery microtrichose, except for a shiny gap on posterior part of gena; palpus yellow. Postpronotal lobe, tegula and subalar sclerite dark brown to black, sharply contrasting with orange notum and pleuron. Fore femur black at apex; fore tibia all black; fore tarsus white, with tarsomere 1 black ventrally on basal half. Mid tarsus and apex of mid tibia brown with black setulae, thus appearing black. Hind tarsus with tarsomere 1 with black setulae only at apex, tarsomeres 2–5 all appearing as black due to black setulae. Wing entirely yellowish, without clear bands.Abdominal pleuron discoloured on unique type, but apparently dark dorsally, pale ventrally.

HEAD. Epicephalon minutely striate, shiny, with scattered minute setulae posteriorly. Frontal vitta fusiform, indistinct, narrow but almost parallel-sided behind ocelli, broader in front but still relatively narrow, 0.4 × as wide as frons at widest point. Lower frons bare, broadly depressed at middle. Postocellar bristles closely spaced and slightly divergent, inner vertical and outer vertical bristles well developed, with scattered setulae anterior to base of inner vertical; upper fronto-orbital bristle very large, inserted at level of upper ocellus; lower fronto-orbital minute or absent.

THORAX. Scutum densely golden microtrichose, laterally black microtrichose.Acrostichal setulae minute, but forming a row; dorsocentral setulae minute, in a row. Thoracic pleuron mostly bare, katepisternum with long white microtrichia and scattered white setulae. Cervical sclerite elongate, shiny dorsally with an incomplete vertical groove separating a large mostly dull posterior section from a minute, constricted and bare anterior portion. Postpronotal lobe unusually wide, dull, with white microtrichia on anterior and posterior faces. Posterior notopleural bristle much stronger than anterior one, on a distinct swelling. Dorsocentral bristle longer than scutellum. Scutellum sparsely microtrichose, shiny; apical bristles strong, almost erect. Vertical row of katepisternal bristles black. Katatergite slightly swollen, without median process, evenly convex and microtrichose; subalar swelling (posterodorsal corner of anepimeron) black, prominent. Fore coxa with black anteroventral setae, mid and hind coxae with an anteroventral tuft of long, golden setae.

ABDOMEN. Strongly petiolate, T1+2 1.2× as long as T3, basally narrow, with a strong constriction between T1 and T2, apically as wide as base of T3, T1 with a preapical ring of golden setae.

FEMALE ABDOMEN. Bursa small, broad, with an inconspicuous ventral receptacle. Single and double spermathecal ducts arising from apex of a very short (shorter than wide) common duct; both ducts smooth and of similar diameter, paired duct slightly longer, with pipe-shaped distally swollen spermathecae on exceptionally long stems (stems ⅔ as long as duct before split); spermathecae similar, unusually elongate, narrow, parallel-sided and of similar diameter to the duct.

Remarks

Mesoconius aurantium sp. nov. differs from all congeners in having an orange (not black or dark brown) frontal vitta. Additionally, it stands out for its black subalar sclerite and postpronotal lobe, which contrast with the otherwise orange body.

Figures

Fig. 31. Mesoconius aurantium sp. nov., holotype, ♀, MUSM. A–B. Habitus. C. Spermathecae and associated structures. D. Pleuron and abdominal base. E. Head. Abbreviations: iv = inner vertical bristle; ov = outer vertical bristle; poc = postocellar bristle.