Mesoconius infestus Enderlein, 1922

Marshall, Stephen A., 2019, A revision of the genus Mesoconius Enderlein (Diptera, Micropezidae, Taeniapterinae), European Journal of Taxonomy 548, pp. 1-126 : 62-66

Mesoconius infestus Enderlein, 1922

Figs 24–25

Mesoconius infestus Enderlein, 1922: 179 .

Mesoconius enderleini Frey, 1927: 72 . syn. nov.

Material examined

Lectotype of M. infestus (here designated)

PERU • ♂; Cusco, Callanga, Piñipiñi Valley ; 1500 m a.s.l.; 1900; O. Garlepp leg.; MNBG .

Paralectotypes of M. infestus

PERU • 2 ♀♀; same collecting data as for holotype; MNBG .

Enderlein also lists a specimen of M. infestus from Songo, Bolivia in the HMNH (not examined).

Holotype of M. enderleini

COLOMBIA • ♀; Aguatal; ZMUH.

Paratype of M. enderleini

COLOMBIA • ♀; San Antonio; ZMUH .

Other material

BOLIVIA • 1 ♂; La Paz, Cumbre Alto Beni, 28 km E of Caranavi; 15°40ʹ31ʺ S, 67°29ʹ21ʺ W; 1400 m a.s.l.; 14 Apr. 2001; S.A. Marshall leg.; cloud forest; MYCRO065-15 sequenced for CO1; DEBU • 1 ♂, 1 ♀; Coroico ; 1200 m a.s.l.; “ Coll. Fassl ”; “ C.T. Trechman bequest to BMNH1964–549 ”; BMNH . COLOMBIA • 1 ♀; “ Qu. Filandia - Granja Experimental Bengala - U. del Quindio ”; 04°41ʹ10ʺ N, 75°37ʹ2ʺ W; 2020 m a.s.l.; 13–16 Nov. 2009; Grupo Entomologia leg.; MYCRO0335 sequenced for CO1; CEUA 68655 • 1 ♂; Pereira, SFF Otun-Quimbaya ; 2890 m a.s.l.; 8 May 2001; Bosque nativo; mounted on sewing needle, 3 legs missing; CEUA • 1 ♀; Rio Tocola , “ W. Colombia ”; 10 Jun. 2008; BMNH • 1 ♂; same collecting data as for preceding but 20 May 1908; “Fassl 1–12”; BMNH • 1 ♂; “Villa Elvica, W. Colombia ”; 6 Jul. 1908; “Fassl 1.12”; BMNH • 2 ♂♂, 1 ♀; Cordillera Occidental, Rio Aguacatal ; 2000 m a.s.l.; “ Coll. Fassl ”; “ C.T. Trechman bequest to BMNH1964–549 ”; BMNH .

ECUADOR • 1 ♂, 1 ♀; Napo, Baeza ; 2000 m a.s.l.; 1–10 Mar. 1979; S.A. Marshall leg.; DEBU • 1 ♂; Napo, Baeza ; 2000 m a.s.l.; 1 Mar. 1979; S.A. Marshall leg.; MYCRO-066-15 sequenced for CO1; DEBU • 1 ♂; Napo, SierrAzul Reserve , 14 km W of Cosanga; 00°41ʹ S, 77°56ʹ W; 10 Oct. 2002; S.A. Marshall leg.; DEBU • 2 ♂♂; Napo, 14 km W of Cosanga, SierrAzul Lodge ; 2200 m a.s.l.; 8–11 Oct. 2002; S.M. Paiero leg.; dung on leaf; MYCRO332-18 sequenced for CO1; DEBU .

Redescription

Based on dissected specimens from Baeza, Ecuador; variation noted below.

LENGTH. 15–16 mm.

COLOUR. Mostly black, except as follows: head with silvery gena and parafacial; palpus brown on distal half; T5, T6 and terminalia of male orange, oviscape orange except at tip; fore tarsus and hind tarsomere 1 white to yellow, trochanters orange; fore femur orange on basal half, mid femur orange with broad distal black band, hind femur with basal and distal black bands; hind tibia of female black, hind tibia of male yellow-orange on basal half. Wing strongly infuscated on distal half, with large clear areas in cell r 2+3, cell r 4+5, and distal to crossvein dm-cu. Oviscape orange with a dark tip. Epandrium dull orange.

HEAD. Epicephalon and paracephalon shiny but finely striate, lower frons microtrichose. Frontal vitta posteriorly tapered and ending at postocellar bristles; broad and sharply tapered anteriorly, not reaching frons margin. Antennae separated by width of antennal socket, upper face strongly carinate. Clypeus shiny medially, laterally microtrichose. Lower back of head densely setulose.

THORAX. Cervical sclerite with a vertical groove separating a mostly microtrichose, subquadrate posterior portion from a small bare anterior portion. Fore tibia broad, flattened, sulcate on outer face. Notum with three silvery vittae anterior to suture; postpronotal lobe microtrichose with some scattered small setulae, anterior margin forming an almost vertical, shiny face.

ABDOMEN. Abdominal segments 1–3 petiolate on male, segment one petiolate in female. Length of T1+2 double that of tergite 3.

FEMALE ABDOMEN. Bursa broad and rugose; ventral receptacle large, with a distinct, nipple-like apical part; spermatheca with a short, broad, striate common duct before splitting into ducts leading to paired and single spermathecae. Paired spermathecae large striate, cup-shaped, each on a separate narrow and convoluted duct, deeply invaginated apically; common duct of paired spermathecae long and broad, divided into distinct parts, including wrinkled basal half that abruptly expands into a darker striate distal half. Single spermatheca elongate, narrow basally and expanded distally, only slightly wider than duct; single duct less than half as long as paired duct and wrinkled, weak basal section very short.

MALE ABDOMEN. Sternites 5 and 6 lightly sclerotized, unmodified. Sternite 7 sinuate, with a broad anterior apodeme and an expanded, bare, spatulate right apex; S8 bare, shiny orange. Epandrium with prominent, setose posteroventral angles, cercus large and distinct. Hypandrium with a very broad, twisted anterior plate with distiphallus apex coiled into its right side. Basal part of distiphallus broadly tubular, gradually expanding to form a distinctive dorsal hood over a broad phallic bulb with two broad, basal condyle-like loops, distal part of phalic bulb broadly cylindrical with a circular perforation. Ejaculatory apodeme elongate but narrow, longer than epandrium.

Variation

The Bolivian specimens differ from the other specimens in having T1 black and the abdomen otherwise entirely reddish, with no contrast in colour between T5 and the terminalia. Some of the Ecuadorian specimens (SierrAzul) have an entirely black abdomen, including the terminalia; one of these specimens was sequenced for CO1 and had almost the same sequence as an Ecuadorian specimen with red terminalia (Baeza). These species also seem to differ widely in size (the specimens from SierrAzul are much smaller), but the number of specimens available is inadequate to clarify whether this is a real difference or a sampling artifact. The Colombian specimens, corresponding to the type of M. enderleini , are characterized by a combination of a narrow femoral band, a black hind tibia and an orange abdomen. They are also larger larger than the Ecuadorian specimens.

Remarks

Mesoconius infestus is characterized by a strong katatergal process with an elongate apex, mostly dark wings with the discal pale band divided into diffuse spots below R 2+3 and R 4+5, fore tarsus entirely white or yellow, face black, mid tibia with one black band, hind femur with one or two black bands, and S8 bare and shiny. The species as recognized here is highly variable in colour and includes two previously described species ( M. infestus and M. enderleini ) as well as distinctive colour forms from Ecuador and Bolivia. All of these differently coloured specimens form a single cluster on a CO1 tree, with the Bolivian and Ecuadorian specimens separated by a specimen that matches the type of M. enderleini . The clade treated here as M. infestus is either a species complex including M. enderleini , M. infestus and two–three undescribed species, or a single variable species. It is tentatively treated as a single species pending examination of more material, despite the extensive variation.

Figures

Fig. 24. Mesoconius infestus Enderlein, 1922 (species complex), external characters and colour variation. A. Thorax and base of abdomen, ♂, showing prominent katatergite. B. ♂, DEBU, Baeza, Ecuador. C–D. ♂, DEBU, SierrAzul Lodge, Eucador. E. Head, specimen from SierrAzul. F. Lectotype, ♂, MNBG, Piñipiñi Valley, Peru. G. Holotype of M. enderleini Frey, 1927 (junior synonym of M. infestus), ♀, ZMUH, Colombia. H. ♂, specimen from Colombia. I. ♀, specimen from Colombia. J. Head and thorax, specimen from Bolivia. K. Habitus, ♀, BMNH, oviscape removed, specimen from Bolivia. Abbreviations: e = epandrium; iv = inner vertical bristle; poc = postocellar bristle; ufo = upper fronto-orbital.

Fig. 25. Mesoconius infestus Enderlein, 1922 (species complex), internal characters. A. Spermatheca and associated structures, specimen from Bolivia. B–C. Epandrium, hypandrium and associated structures, dorsal and lateral views, specimen from Colombia. D. ♂, apex of abdomen, specimen from Bolivia. E. Epandrium and associated structures, specimen from SierrAzul, Ecuador, DEBU. F. Male terminalia, including S8, specimen from Baeza, Ecuador, DEBU. G. Detail of basal distiphallus and phallic bulb, specimen from Ecuador, DEBU. Abbreviations: bdp = basal distiphallus; c = cercus; ddp = distal distiphallus; e = epandrium; ea = ejaculatory apodeme; ed = ejaculatory duct; hy = hypandrium; p = phallapodeme; pb = phallic bulb; pg = postgonite.