Mesoconius albitergum, Marshall, 2019

Marshall, Stephen A., 2019, A revision of the genus Mesoconius Enderlein (Diptera, Micropezidae, Taeniapterinae), European Journal of Taxonomy 548, pp. 1-126 : 16-19

Mesoconius albitergum sp. nov.

urn:lsid:zoobank.org:act:AD7675B2-46CD-4AA0-B4AE-6F041FB80DD8

Fig. 3

Etymology

The specific name refers to the pale and lightly sclerotized T3–6, which contrast with the fully sclerotized orange T1–2.

Material examined

Holotype

COLOMBIA • ♂; Boyacá, SFF Iguaque, La Planada ; 05°25ʹ N, 73°27ʹ W; 2850 m a.s.l.; 4– 21 Dec. 2001; P. Reina leg.; IAVH.

Paratypes

COLOMBIA • 3 ♀♀; same collecting data as for holotype; IAVH • 2 ♀♀; Boyacá, SFF Iguaque, La Planada ; 05°25ʹ12ʺ N, 73°27ʹ24ʺ W; 2850 m a.s.l.; 17 Aug. – 1 Sep. 2000; P. Reina leg.; IAVH • 1 ♀; Boyacá, SFF Iguaque, La Planada ; 05°25ʹ N, 73°27ʹ W; 2850 m a.s.l.; 6– 23 Oct. 2000; P. Reina leg.; Malaise trap; UGIC 178-15/ MYCRO 079-15 sequenced for CO 1; IAVH • 2 ♀♀; Boyacá, SFF Iguaque, La Planada; 05°2512ʺ N, 73°27ʹ24ʺ W; 2850 m a.s.l.; 25 Jun.–13 Jul. 2000; P. Reina leg.; Malaise trap; IAVH • 2 ♀♀; Boyacá, SFF Iguaque ; 05°25ʹ12ʺ N, 73°27ʹ24ʺ W; 2850 m a.s.l.; 1–19 Apr. 2000; P. Reina leg.; Malaise trap; IAVH • 1 ♀; Boyacá, SFF Iguaque, Cabaña Carrizal ; 05°25ʹ N, 73°27ʹ W; 2850 m a.s.l.; 27 Mar.–16 Apr. 2001; P. Reina leg.; Malaise trap; IAVH • 1 ♀; Boyacá, SFF Iguaque, Quebrada Carrizal ; 05°25ʹ N, 73°27ʹ W; 3350 m a.s.l.; 7–21 Jan. 2001; P. Reina leg.; IAVH • 2 ♀♀; Boyacá, SFF Iguaque, Cerro Pan de Azucar ; 05°25ʹ N, 73°27ʹ W; 3300 m a.s.l.; 10–28 Jun. 2001; P. Reina leg.; Malaise trap; IAVH • 2 ♀♀; Boyacá, SFF Iguaque, Cerro Pan de Azucar ; 05°25ʹ N, 73°27ʹ W; 3300 m a.s.l.; 12 Sep.–13 Oct. 2001; P. Reina leg.; Malaise trap; IAVH • 1 ♀; Boyacá, SFF Iguaque, La Planada ; 05°25ʹ N, 73°27ʹ W; 2856 m a.s.l.; 13–30 Jul. 2001; P. Reina leg.; IAVH • 1♀; Boyacá, SFF Iguaque, La Planada ; 05°25ʹ N, 73°27ʹ W; 2850 m a.s.l.; 30 Jul.–17 Aug. 2000; P. Reina leg.; IAVH • 1 ♀; Boyacá, SFF Iguaque, La Planada ; 05°25ʹ N, 73°27ʹ W; 2850 m a.s.l.; 23 Sep.–11 Oct. 2000; P. Reina leg.; IAVH • 1 ♂; Boyacá, SFF Iguaque, Cerro Pan de Azucar ; 05°25ʹ N, 73°27ʹ W; 3300 m a.s.l.; 27 Mar.– 16 Apr. 2001; P. Reina leg.; Malaise trap; IAVH • 1 ♂; Boyacá, SFF Iguaque, La Planada ; 05°25ʹ12ʺ N, 73°27ʹ24ʺ W; 2850 m a.s.l.; 2–19 Aug. 2000; P. Reina leg.; IAVH • 1 ♀; Nariño, RP Planada Via Hondon ; 01°15ʹ N, 78°15ʹ W; 1930 m a.s.l.; G. Oliva leg.; Malaise trap; IAVH .

Description

LENGTH. 17–19 mm.

COLOUR. Burnt orange, except as follows: parafacial, postgena and most of gena silvery microtrichose, middle part of gena shiny brown ventrally; palpus and clypeus yellow; lower face white; frontal vitta anterior to ocelli velvety black striate, frons with black transverse area at lower margin of vitta, which is widely separated from anterior frons margin; upper frons paler than lower frons. Cervical sclerite entirely orange and subshining. Katepisternum and anepisternum with black patches ventrally; scutum with two narrow central black vittae on anterior ⅔ and broader sublateral black bands broken by deep transverse suture and ending well before scutellum. Fore tibia and all tarsi dark brown to black, mid femur with a white band before middle and hind femur with a white band at middle (band sometimes indistinct on mid femur). Wing evenly and lightly infuscated. Abdomen white or very pale and lightly sclerotized between darker, fully sclerotized syntergite 1+2 and oviscape (female) or S8 (male); posterior corners of tergite 2 black.

HEAD. Epicephalon and paracephalon very finely striate, dull; lower margin of epicephalon and upper parafacial microtrichose, forming a pruinose patch visible at some angles. Frontal vitta not visibly extending posterior to ocelli; ocellar triangle distinctly elevated. Lower fronto-orbital bristle strong, inserted well anterior to ocellar triangle in microtrichose patch near lower margin of epicephalon. Upper face broadly raised, flat or very weakly convex at middle, subantennal areas shiny.

THORAX. Cervical sclerite with a vertical groove separating a large subquadrate posterior portion from a small anterior portion. Notum with central area almost bare; acrostichal and dorsocentral setulae sparse and minute, but in distinct rows. Postpronotal lobe subshining, very sparsely microtrichose, with some scattered small pale bristles, anterior margin bare and almost vertical, posterior margin setulose and only slightly less vertical than anterior margin. Dorsocentral bristle very small, similar in size to discal scutellar setulae and ⅓ as long as supra-alar bristle. Scutellum with four small discal setulae and long, closely spaced apical bristles (longer than scutellum). Katatergite very prominent, with a long, nipplelike, microtrichose pointed process. Notopleuron with two (rarely three) widely spaced black bristles. Vertical row of katepisternal bristles black. Fore coxa with black anteroventral setae, mid and hind coxae with golden anteroventral setae.

ABDOMEN. Abdominal segment 1 and base of segment 2 petiolate; 1+2 slightly more than twice as long as tergite 3. T1 with a ring of long thin preapical setae.

FEMALE ABDOMEN. Oviscape pale brown, darker at apex, bare except for scattered setulae. Bursa only slightly swollen, twice the diameter of common spermathecal duct at base; ventral receptacle small and inconspicuous. Single spermathecal duct branching off a very short common duct that tapers slightly to the much longer, paired spermathecal duct, which is divided into distinct parts, including a long rugose basal ⅔ that abruptly transforms into a slightly narrower, relatively smooth (indistinctly striate) distal third. Paired spermathecae expanded distally, apex invaginated, surface reticulate, stem (beyond division of paired duct) broad and conspicuously coiled and tuberculate. Single spermathecal duct similar in texture to distal part of paired spermathecal duct, but much smaller; single spermatheca vestigial, very small and tuberculate, on a long, thick stem separated from main part of duct by a constriction.

MALE ABDOMEN. Sternite 5 small; S6 large, pale, lightly sclerotized, with evenly spaced equal small setae, broadest posteriorly. Sternite 7 ventrally broad; S7 and S8 sparsely microtrichose with few setulae, contrasting with pale, setulose T3–6. Sternite 8 marginally larger than epandrium, pale and bare; epandrium with stout dark setae on dorsal half, but with only a few scattered setae ventrally; cercus large and strongly projecting posteriorly, in contrast with most congeners. Hypandrium elongate and slender, forming an anterior loop extending beyond anterior margin of T6, anterior apex small and thin. Basiphallus well developed, broad, extending laterally and posteriorly to base of distiphallus. Basal part of distiphallus very broad, but strongly flattened, distally abruptly expanding to enclose a phallic bulb, which sperm duct enters through a distinct, condyle-like basal process flanked by a similar lobe; distal distiphallus tapered and whip-like. Ejaculatory apodeme very small, smaller than attached sperm pump.

Remarks

This species shares many distinctive features with the Ecuadorian M. cosanga sp. nov., including the unusual pale T3–6 and pale femoral bands. Mesoconius cosanga sp. nov., however, has white fore tarsi, lacks black notal and pleural markings, and lacks the raised ocellar triangle. These two species make up a single branch on the CO1 tree ( Fig. 50 ), but they are widely separated on that branch. Mesoconius albitergum sp. nov. is apparently characterized by a number of characters in the male genitalia, such as the unusual distiphallus, projecting cercus and extremely elongate hypandrium, but males of the closely related M. cosanga sp. nov. remain unknown and only 3 of the 31 examined specimens of M. albitergum sp. nov. are males. The Venezuelan species M. anchitarsus sp. nov. is closely related, but easily distinguished by its greatly swollen female fore tarsomere 1 and its darkly pigmented and sclerotized male T3–6.

Figures

Fig.3.Mesoconiusalbitergumsp.nov.A.♀.B.Holotype,♂,IAVH.C.Spermathecaandassociatedstructures. D. Abdominal apex, ♂, lateral view. E. Male terminalia, lateral view but with phallus twisted (basiphallus 90° left, distiphallus 180°). F. Head and thorax, ♀. Abbreviations: b = basiphallus; bc = bursa copulatrix; bdp = basal distiphallus; c = cercus; ddp = distal distiphallus; e = epandrium; iv = inner vertical bristle; pb = phallic bulb; pd = paired spermathecal duct; pst = paired spermathecal duct; sd = single spermathecal duct; ss = single spermatheca.

Fig. 50. Maximum likelihood tree from CO1 barcodes. Sequences were aligned using BOLD (amino acid based HMM) and then manually corrected. Maximum likelihood analysis was performed in RAxML (ver. 8.2) using GTR-G with 100 replicates.