Mesoconius triunfo, Marshall, 2019

Marshall, Stephen A., 2019, A revision of the genus Mesoconius Enderlein (Diptera, Micropezidae, Taeniapterinae), European Journal of Taxonomy 548, pp. 1-126 : 71-73

Mesoconius triunfo sp. nov.

urn:lsid:zoobank.org:act:07C84F8E-C311-400C-B6BE-2DDC966D6B5D

Fig. 28

Etymology

The species name refers to the El Triunfo Biosphere Reserve, which protects the unique high elevation cloud forests in which this species lives.

Material examined

Holotype

MEXICO • ♂; Chiapas, El Triunfo , 49 km S of Yaltenango; 2000 m a.s.l.; 13–15 May 1985; A. Freidberg leg.; USNM.

Paratypes

MEXICO • 1 ♂, 3 ♀♀; same collecting data as for holotype; MYCRO064-15 sequenced for CO1; TAUI .

Description

LENGTH. 13–16 mm.

COLOUR. Burnt orange with narrow black vittae on notum; lunule, lower frons, epicephalon and corners of tergites darkened; mid and hind femora orange, with a black distomedian ring; distal part of fore femur and fore tibia black; fore tarsomeres and tarsomeres 1 and 2 of hind leg white, distal hind tarsomeres black. Antenna brown, with basal fifth of first flagellomere yellow to orange; parafacial silvery, palpus and clypeus yellow. Frontal vitta velvety black. Wing strongly infuscated, with clear areas in cell r 2+3, cell r 4+5 and distal to crossvein dm-cu.

HEAD. Epicephalon and paracephalon smooth and shiny, lower half of frons dull; frontal vitta posteriorly narrow but expanded into a microtrichose patch at level of postocellar bristles, broad and broadly tapered anteriorly, narrowly separated from frons margin. Antennae separated by width of antennal socket, upper face weakly carinate, lower face flat and microtrichose. Clypeus shiny medially, laterally microtrichose. Postocciput with sparse small setulae.

THORAX. Cervical sclerite small, unmodified, entirely microtrichose. Postpronotal lobe microtrichose with some scattered pale setulae, anterior margin vertical and bare on upper quarter.

ABDOMEN. Abdominal segment 1–3 petiolate (segment 4 also somewhat petiolate in male), length of T1+2 double that of T3.

FEMALE ABDOMEN. Ventral receptacle not observed; bursa small, terminating in a short, broad, striate common duct that splits into ducts leading to paired and single spermathecae. Paired spermathecae large, kidney-shaped and distally invaginate, distinctly striate, each on a separate narrow stem with a large ovate swelling near base; common duct of paired spermathecae long and indistinctly striate in basal half, smooth distally. Single spermatheca vestigial, barely differentiated from short duct.

MALE ABDOMEN. Sternites 5 and 6 greatly reduced, lightly sclerotized and very narrow, S6 slightly broadened at anterior margin. Sternite 7 narrow ventrally, but with an expanded, spatulate right apex. Sternite 8 shiny, longer than epandrium, with scattered setulae. Epandrium and cercus small, cercus and posteroventral corner of epandrium setose, anteroventral corner of epandrium forming a parallel-sided lobe articulating with hypandrium. Hypandrium with a very broad, twisted anterior plate. Postgonites small, broad and divergent, with small preapical setae. Basal basiphallus short and broad, about 3 times as long as broad and ending in a cup-like apex that extends over a large two-chambered phallic bulb, with lower chamber a simple globe and upper chamber saddle-like. Ejaculatory apodeme longer but narrower than epandrium.

Remarks

The most closely related species seems to be the Costa Rican species M. dianthus Marshall, 2015 , from which M. triunfo sp. nov. can be distinguished by its dark head and more extensive dark markings on the notum, as well as by characters of the male genitalia (differently shaped basal distiphallus and phallic bulb) and female spermathecal complex (features of the paired duct).

Figures

Fig. 28. Mesoconius triunfo sp. nov. A–B. Paratypes, ♀♀, TAUI. C. Spermathecae and associated structures. D. Phallic bulb. E. Male terminalia, left lateral view. F. Head and thorax, ♂. G. Abdomen, ♂. Abbreviations: bdp = basal distiphallus; ddp = distal distiphallus; e = epandrium; hy = hypandrium; pb = phallic bulb; ps = paired spermathecae; ss = single spermatheca.