Mesoconius nono, Marshall, 2019

Marshall, Stephen A., 2019, A revision of the genus Mesoconius Enderlein (Diptera, Micropezidae, Taeniapterinae), European Journal of Taxonomy 548, pp. 1-126 : 84-86

Mesoconius nono sp. nov.

urn:lsid:zoobank.org:act:772D3B1E-23B7-4221-AC4D-4C57AB9A5195

Fig. 34

Etymology

The species name is a noun in apposition partially inspired by the name of a town near the type locality, and partially reflecting my response to the confounding variation in leg colour.

Material examined

Holotype

ECUADOR • ♂; Pichincha, Nono-Mindo road, 15 km NW of Nono; 2000 m a.s.l.; 25 Oct. 1999; S.A. Marshall leg.; on log; QCAZ.

Paratypes

ECUADOR • 9 ♂♂; same collecting data as for holotype; MYCRO072-15 sequenced for CO1; DEBU • 1 ♂; Pichincha, 11.7 km SE of Tandayapa, road to Nono , near stream; 28 Oct. 1999; S.A. Marshall leg.; litter/wood; DEBU • 1 ♂; Pichincha, Bellavista Reserve ; 2200 m a.s.l.; 28 Oct. 1999; S.A. Marshall leg.; DEBU .

Description (males only)

LENGTH. 14 mm.

COLOUR. Mostly black; anterior margin of clypeus brownish, palpus black; parafacials, gena and lower face strongly silvery microtrichose. Fore femur variable in colour, usually black with a small basal orange band, but sometimes entirely orange ventrally; fore tarsomere 1 yellow to orange; mid and hind femora entirely bright orange in holotype and most other specimens, but sometimes all or partially black, mid and hind tibiae black to orange, densely covered with black setulae; mid and hind tarsomeres mostly black, tarsomere 1 variably reddish brown. Silver pollinosity of scutum broken by a broad median brown vitta and narrow lateral brown vittae. Wing lightly infuscated on basal ⅔, darkly infuscated on distal third, except for apical margin, thus with a large, diffuse, dark subapical band.

HEAD. Epicephalon and paracephalon mostly shiny but rugose, epicephala separated by a narrow, microtrichose medial groove; orbits rugose and shiny; frontal vitta microtrichose, tapered to dorsal and ventral points, width of frontal vitta half of frontal width. Postocellar bristles closely spaced and strongly divergent, inner and outer vertical bristles well developed and inserted in microtrichose areas; upper fronto-orbital inserted at level of ocelli; one large lower frontal orbital bristle (doubled on left side on one of type specimens only). Frons contiguous with antennal socket, antennae separated by width of antennal socket, face weakly carinate; subantennal areas shiny, middle of face flat and microtrichose. Clypeus directed anteriorly, meeting face at an angle of about 100°, shiny medially, laterally microtrichose. Postocciput with uniformly small setulae.

THORAX. Notum, including postnotum, dull, microtrichose; scutum, prescutum and postscutum strongly differentiated. Dorsocentral bristle very short and inconspicuous, about half as long as scutellum. Scutellum with minute discal setulae and one pair of long apical bristles (longer than scutellum). Katatergite prominent, swollen, but without median process. Postpronotal lobe dull, with fine bristles along outer margin only; notopleuron with two widely spaced bristles. Propleuron with four ventro- lateral setae. Vertical row of katepisternal bristles brown, other katepisternal bristles (including long ventral bristles) pale. All coxae with an anteroventral tuft of black setae. Postmetacoxal area partly black, but not sclerotized.

ABDOMEN. At least abdominal segments 1–2 petiolate, T3–4 also narrow; length of T1+2 double that of T3. Sternites 1–5 very narrow, S5 and S6 unmodified, almost linear, pale. Sternite 7 with a dark ventral and left lateral linear band; S7 fused broadly with large, unmodified S8. Epandrium with short anteroventral arms (1/5 of epandrial length); ventral part of epandrium strongly incurved, with prominent ventral lobes at anterior and posterior margin of incurved areas. Hypandrium looped, with a broad, horizontal, scoop-like anterior margin. Pregonites finely setulose, inconspicuous, without prominent ventral lobes. Ejaculatory apodeme and phallapodeme large, with broad posterior parts; central body of sperm pump with finely spinulose surface. Basiphallus small, frame-like; basal part of distiphallus unusually broad, sclerotized dorsally and spinulose-membranous ventrally; broad apex encircling distal bulb, distiphallus ending at distal bulb.

Variation

One specimen taken with the type series (see Fig. 34B ) has entirely black mid and hind legs, but is otherwise identical to other paratypes. Another fly, photographed at the type locality but not collected, had the apex of its hind femur red and the base black.

Remarks

Most of the type series was taken on a log serving as a makeshift bridge across a small stream along the Nono-Mindo road, Ecuador. Two females of Mesoconius auristrigatus Enderlein, 1922 (a species in the M. eques group) were found on the same log at the same time as the type series of ten male Mesoconius nono sp. nov.

Figures

Fig. 34. Mesoconius nono sp. nov., ♂♂. A. Holotype, QCAZ. B. Atypical black specimen. C. Another colour form from the type locality. D. Typical form from the type locality. E. Head, holotype. F. Male terminalia and apex of abdomen. G. Male terminalia. H. Phallus, showing broad basal distiphallus with twisted ejaculatory duct terminating in phallic bulb.