Mesoconius suzukii Marshall 2019, sp. nov.

Mesoconius suzukii sp. nov.

urn:lsid:zoobank.org:act: 5928413F-78D5-4E5B-AF94-C0B6240BE716

Figs 18–19

Etymology

The specific name was chosen in part as a patronym for the Canadian popular science writer and broadcaster David Suzuki and in part because the sexual dimorphism in wing pigmentation is coincidentally similar to that of the well-known Drosophila suzukii (Matsamura, 1931), the Spotted Wing Drosophila.

Material examined

Holotype

COLOMBIA • ♂; Magdalena, PNN Santa Marta, San Lorenzo; 10°48ʹ N, 73°39ʹ W; 2200 m a.s.l.; 27 Feb.–14 Mar. 2001; J. Cantillo leg.; Malaise trap; IAVH.

Paratypes

COLOMBIA • 1 ♀; El Libano, Magdalena Department; 1829 m a.s.l.; Apr. [around 1900?]; Herbert Huntingdon Smith leg. [?]; CMNH • 1 ♀; El Libano, Magdalena Department; 1829 m a.s.l.; May [around 1900?]; Herbert Huntingdon Smith leg. [?]; CMNH • 2 ♀♀; Magdalena, PNN Santa Marta, San Lorenzo; 10°48ʹ40ʺ N, 73°39ʹ32ʺ W; 2200 m a.s.l.; 11–25 May 2000; I. Uribe leg.; DEBUA306-17 sequenced for CO1; IAVH • 1 ♀; Magdalena, PNN Santa Marta, El Ramo; 10°48ʹ N, 73°39ʹ W; 2500 m a.s.l.; 15–31 Jul. 2000; J. Cantillo leg.; IAVH • 1 ♂, 2 ♀♀; Magdalena, PNN Santa Marta, San Lorenzo; 10°48ʹ N, 73°39ʹ W; 2200 m a.s.l.; 14–31 Mar. 2001; J. Cantillo and D. Rubi leg.; Malaise trap; IAVH.

Other material

COLOMBIA • 1 ♀; Magdalena, PNN Santa Marta, Betoma; 10°48ʹ N, 73°39ʹ W; 1700 m a.s.l.; 15–30 Aug. 2001; J. Cantillo leg.; Malaise trap; CO1 sequence DEBUA302-17; IAVH.

Description

LENGTH. 15–16 mm.

COLOUR. Head mostly orange-yellow, except for sharply contrasting black frontal vitta, shiny brown lunule, upper face and scape, and very pale yellow gena, postgena and parafacial; pedicel and first flagellomere brown and heavily setulose, first aristomere white. Thorax pale yellow to white laterally, dorsally orange-yellow with strong brown stripes laterally and a weak medial brown vitta. Fore coxa and base of fore femur white, grading to yellow and then to black distally, fore tibia black, tarsus white. Mid and hind femora yellow, except for a basal brown longitudinal streak and an incomplete brown band just beyond middle. Hind tibia pale brown, tarsomere 1 pale on basal ¾, black distally. Wing of females uniformly lightly infuscated, in males with a dark and discrete apical black spot. Abdomen pale, sclerites brown to yellow, except for black posterolateral corners of T2; membranes white.

HEAD. Epicephalon and paracephalon shiny and smooth; frontal vitta sharply delineated and tapered to an elongate, narrow, depressed point posterior to ocelli, broad anterior to ocelli, with lateral extensions and anteromedial point separated from anterior margin of frons. Ocellar triangle elevated and prominent, densely setulose; ocelli conspicuous. Inner vertical bristle strong, with four–five setulae near base. Two fronto-orbital bristles: an indistinct lower bristle inserted below level of anterior ocellus and a very small upper bristle well above level of posterior ocelli. Upper face prominent. Subantennal area shiny dark brown. Clypeus bare anteriorly, setulose laterally.

THORAX. Cervical sclerite with a vertical groove separating a large, convex microtrichose posterior portion from a small, bare anterior portion. Notum mostly finely and densely covered with black microtrichia, dorsocentral vittae bare; dorsocentral setulae weak but in a distinct row, acrostichal setulae apparently absent. Postpronotal lobe sparsely microtrichose, with several scattered small, pale setulae; posterior and anterior faces flat. Dorsocentral bristle black, subequal to scutellar length. Scutellum with long, closely spaced black apical bristles (longer than scutellum). Katatergite strongly convex but not conical, without a nipple-like apex. Notopleuron with two widely spaced black bristles. Vertical row of katepisternal bristles weak, pale. All coxae with golden anteroventral setae. Tarsomere 1 of all legs elongate and slightly swollen, longer than remaining tarsomeres combined.

ABDOMEN. Abdominal segment 1 petiolate; length of T1+2 double that of T3. T1 setose, with preapical long, thin lateral setae; constricted area between T1 and T2 bare.

FEMALE ABDOMEN. Oviscape shiny, with scattered setulae. Bursa large, conspicuously rugose, suboval; ventral receptacle prominent and on a large base arising from basal part of bursa; spermathecal ducts with a broad common common duct at distal margin of bursa. Paired spermathecal duct thick, basal half smooth-walled, distal half ringed with weak striae. Single spermathecal duct arising laterally before apex of common duct, almost as long as half width of paired duct; single spermatheca very small. Stems of paired spermathecae elongate, without swellings or protruberances, but with a spiculose or scaly surface. Spermathecae large, dense and suboval, with distinct oblong punctations; apex deeply invaginate.

MALE ABDOMEN. Segments 3–6 thin, parallel-sided; S5 reduced but with a tuft of about ten long golden setae along posterior margin of segment. Sternite 6 divided medially into two small shiny plates, separated by setose membrane. Synsternite 7–8 sparsely microtrichose, shiny, contrasting with dull, microtrichose preceding sclerites and microtrichose epandrium; S7 with narrow, pale ventral part, including a process extending under right plate of S6; S8 white and entirely bare, as long as epandrium. Epandrium very small, white and uniformly setose, constricted basally and greatly expanded distally, with posteroventral corners produced into broad processes as large as remainder of epandrium. Cercus very large, almost round. Hypandrium forming a short loop anteriorly. Basiphallus small, barely extending beyond base of distiphallus. Basal part of distiphallus broad and parallel-sided, phallic bulb large and elongate; distal part of distiphallus half as long as basal part (including phallic bulb), of uniform width except for expanded apex. Ejaculatory apodeme greatly reduced, slightly smaller than broad sperm pump.

Variation

One female specimen is not included as a paratype although its CO1 sequence (DEBUA302-17) is identical to that of typical specimens. It differs from typical specimens in having a dark brown thorax, darker legs and darker pigmentation on the head, as well as T1 and T2. Internal structures seem identical.

Remarks

This is a very unusual and distinctive species, easily recognized by the male wing pigmentation and characterized by the greatly reduced male terminalia, with a small but broad white epandrium. Mesoconius suzukii sp. nov. is treated as part of the M. eques group for diagnostic purposes because of the absence of postocellar bristles, but it was recovered outside the M. eques group on the CO1 tree (Fig. 50) and it lacks most of the defining characters of the group.