Mesoconius garyi, Marshall, 2019

Marshall, Stephen A., 2019, A revision of the genus Mesoconius Enderlein (Diptera, Micropezidae, Taeniapterinae), European Journal of Taxonomy 548, pp. 1-126 : 81-83

Mesoconius garyi sp. nov.

urn:lsid:zoobank.org:act:1CAC3CDC-AFB9-4C95-AB4B-DE8037300D90

Fig. 33

Etymology

The species name is a patronym, honoring University of Guelph entomologist Gary Umphrey.

Material examined

Holotype

PERU • ♀; Cusco, Wayqecha Biological Station , 9 km NE of Challabamba; 13°10ʹ20ʺ S, 71°35ʹ00ʺ W; 2600–2700 m a.s.l.; 1–6 Dec. 2011; S.A. Marshall leg.; MUSM.

Paratypes

PERU • 1 ♂, 3 ♀♀; same collecting data as for holotype; one of each sex in alcohol; MYCRO116-15 and MYCRO337-18 sequenced for CO1; DEBU .

Description

LENGTH. 16 mm.

COLOUR. Mostly bright orange, except as follows: frontal vitta velvety black, except for partially orange ocellar triangle, contrasting with pale lower frons; vitta characteristically shaped with anterior portion broadly tapered and reaching or almost reaching frontal margin, posterior portion elongate triangular; broadest part of vitta continuous with a narrow transverse black band almost meeting eye. Face pale, parafacial, gena and postgena silvery microtrichose. Postpronotal lobe often yellow, but females usually with postpronotal lobe dark brown, sharply contrasting with orange notum and pleuron (postpronotal lobe relatively pale on holotype female). Fore tibia black with apex narrowly orange, fore tarsus bright yellow; hind and mid tarsi brown. Hind femur with a broad black band just beyond base. Wing entirely yellowish, without clear bands. Abdominal pleuron yellow, with orange areas on upper half of segments 4 and 5 (entire pleuron discoloured on pinned specimens).

HEAD. Epicephalon smooth and shiny, with scattered minute setulae and inconspicuous microtrichosity posteriorly; paracephalon minutely black setulose, slightly elevated above epicephalon. Frontal vitta only slightly elevated, narrow, at widest 0.4 × as wide as frons. Lower frons bare, depressed at middle. Palpus narrow, slightly tapered to a rounded apex. 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 distinct, inserted at level of upper ocellus; lower frontoorbital minute or absent.

THORAX. Scutum inconspicuously but evenly microtrichose, acrostichal setulae minute but forming a row; dorsocentral setulae long and in a distinct row above postpronotal lobe, otherwise minute. Cervical sclerite subquadrate, with a vertical groove separating a large microtrichose posterior section from a minute, constricted and bare anterior portion. Postpronotal lobe unusually wide, sparsely microtrichose and very sparsely setulose. Dorsocentral bristle short, inconspicuous, barely larger than dorsocentral setulae. Scutellum microtrichose but without macrosetae, apical bristles absent. Vertical row of katepisternal bristles golden. Katatergite not swollen, without median process, evenly convex and microtrichose. Fore coxa with black anteroventral setae, mid and hind coxae with an anteroventral tuft of long golden setae.

ABDOMEN. Strongly petiolate, T1+2 twice as long as T3, basally narrow, with a strong constriction between T1 and T2, apically as wide as base of T3.

FEMALE ABDOMEN. Bursa small, not strongly differentiated, with a short but very broad ventral receptacle. Single and double spermathecal ducts arising independently from bursa, both ducts smooth and of similar diameter and length; paired and single spermathecae similar, unusually elongate; paired spermathecae somewhat larger and more twisted.

MALE ABDOMEN. Sternite 5 small and narrow, S6 large, wide, slightly wider posteriorly and weakly posteromedially notched. Ventral part of S7 narrow, without sclerotization on right side. Sternite 8 twice as large as epandrium, bare in contrast with setulose epandrium. Epandrium saddle-shaped, long-setose posterodorsally; cercus greatly reduced, inconspicuous. Sperm pump unusually robust and ejaculatory apodeme larger than epandrium; hypandrium with a symmetrical, broad, scoop-like anterior margin. Basal part of distiphallus narrow but heavily sclerotized over basal ⅔, then greatly expanded to a characteristically shaped apex with anterodorsally directed arms partly enclosing a large phallic bulb; distal distiphallus apparently represented only by a very short preapical ventral process.

Remarks

The loss of scutellar bristles, confirmed in all type specimens and on photographs of living flies, is very unusual and makes this species easy to recognize. The elongate triangular shape and dark pigmentation of the frontal vitta is similar in M. garyi sp. nov. and M. ottoi nom. nov., but the anterior part of the frons of the latter species is pale and separates the frontal vitta from the anterior margin of the frons.

Figures

Fig. 33. Mesoconius garyi sp. nov. A–C. Paratypes prior to capture, ♀♀, DEBU. D. Pleuron and base of abdomen. E. Male terminalia. F. Head. G. Spermathecae and associated structures. Abbreviations: bdp = basal distiphallus; e = epandrium; ea = ejaculatory apodeme.