Merodon lotus Vujic & Radenkovic 2021, sp. nov.
Creators: name: Vujić, Ante
name: Radenković, Snežana
name: Zorić, Ljiljana Šašić
name: Likov, Laura
name: Tot, Tamara
name: Veselić, Sanja
name: Djan, Mihajla
Publisher: name: Zenodo
Year: 2021
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Diptera
Syrphidae
Merodon
Merodon lotus

description: Merodon lotus Vujić & Radenković sp. nov.
urn:lsid:zoobank.org:act: 4FA6E871-8E78-418E-89EA-B4A334742811
Figs 1, 4E, 5E, 6E, 9E, 10E, 11E, 12E, 14D, 15D, 16D, 17, 18A, 22A–C, 26
Diagnosis
Black, medium sized species (8–9 mm), with shiny face, posterior half of scutum and terga without pollinosity (except a pair of indistinct pollinose fasciae on tergum 4 in female) (Fig. 14D); male genitalia with S-forming posterior lobe of surstyle, gradually narrowing toward tip (Fig. 17A, D: pl), anterior margin of surstyle rounded in lateral view (Fig. 17A, D: ams). Similar to Merodon nasicus from which differs in less prominent oral margin (Fig. 11E), and terga without clear pollinosity (Figs 5E, 14D), while in M. nasicus oral margin distinctly protruded (Fig. 11F) and terga 2–4 with distinct pollinose fasciae (Figs 5F, 14E, 20D).
Etymology
The specific epithet ‘ lotus ’ is a Latin adjective meaning ‘elegant, fine’, also ‘washed/clean’, implying clean, non pollinose terga, as the main diagnostic character of this species.
Material examined
Holotype REPUBLIC OF SOUTH AFRICA • 1 ♂; Ceres, Ceres 3; 33.364° S, 19.289° E; 546 m a.s.l.; 10 Nov. 2018; A. Vujić and S. Radenković S. leg.; FSUNS ID ZA6_039; NMSA.
Paratypes REPUBLIC OF SOUTH AFRICA • 1 ♂; Ceres, Ceres 2; 33.365° S, 19.289° E; 547 m a.s.l.; 9 Nov. 2018; A. Vujić and S. Radenković Sanja leg.; FSUNS ZA6_021; FSUNS • 4 ♂♂, 1 ♀; same collection data as for holotype; FSUNS ZA6_048, ZA6_049, ZA6_052, ZA6_060, ZA6_066; FSUNS • 1 ♀; same collection data as for holotype; FSUNS ID ZA6_067; NMSA.
Additional material
REPUBLIC OF SOUTH AFRICA • 1 ♂; Cape Province, Ceres; 1500 ft; Dec. 1920; R.E. Turner leg.; Merodon appendiculatus Hull unpublished name; BMNH.
Description
Length: medium sized species, body 8–9 mm, wing 5–6 mm (n = 8).
Male
HAD (Figs 4E, 9E, 11E, 12E). Antenna (Fig. 4E) brown; pedicel slightly shorter than basoflagellomere (relation scape:pedicel: basoflagellomere =1.0: 2.1: 2.5); basoflagellomere concave dorsally, with acute apex; arista thickened basally, yellowish at basal third, the rest blackish, 2.2 times as long as basoflagellomere. Face shiny black, covered with whitish or yellowish pile, except on bare medial vitta that occupies half width of face. Oral margin slightly protruded (Fig. 9E). Frons shiny black, inflated, covered with whitish-gray pile and gray pollinosity along eye margins. Vertical triangle isosceles (Fig. 12E), dark, predominantly covered with long, yellowish pile, except some black ones on ocellar triangle in some specimens. Ocellar triangle usually equilateral. Eye pile gray, except upper fourth with black pile, slightly longer than scape. Eye contiguity about 14–16 ommatidia long. Occiput blackish, mostly pollinose, except behind vertical triangle, covered with yellow pile.
THORAX (Figs 6E, 10E). Mesonotum black, covered with reddish-yellow pile; scutum without pollinose longitudinal vittae, but postpronotum and anterior part of scutum pollinose (Fig. 10E). Pleuron black, covered with sparse gray pollinosity and the following parts with whitish to yellow pile: anterior part of proepimeron, posterior part of anterior anepisternum, most of the posterior anepisternum except anterior end, antero-ventral and postero-dorsal part of katepisternum, anepimeron, metasternum. Wing brownish, hyaline, with dense microtrichia and dark brown veins. Calypter yellowish. Halter with yellowish pedicel and capitulum. All three femora dark brown to black; tibiae mostly reddish, medially black to dark brown; tarsi reddish, except blackish apical segment (Fig. 6E). Metatrochanter without calcar. Metafemur moderately thickened, with less developed apicoventral triangular lamina, more or less denatate, the apical dens more or less distinct (Fig. 6E). Pile on legs predominantly yellowish.
ABDOMEN (Fig. 5E). Black, covered with yellow to whitish pile on lateral sides. Tergum 1 covered with short whitish to yellow pile; terga 2 and 3 medially with shorter black pile, except two medial fasciae with whitish pile and some whitish pile at posterior margin; anterior half of tergum 4 covered with short black pile, posterior half with longer yellowish pilosity, medially with two oblique fasciae covered with whitish pile. Sterna dark brown, covered with yellowish pile.
GENITALIA (Figs 17, 18A). Posterior lobe of surstyle broad, bent, S-shaped, gradually narrowing toward tip (Fig. 17A, D: pl); anterior lobe of surstyle undeveloped (Fig. 17A, D); anterior margin of surstyle rounded in lateral view (Fig. 17A, D: ams); cercus square like (Fig. 17A, D: c). Hypandrium with theca medially distinctly narrowed (Fig. 17C, F). Lateral sclerite of aedeagus small (Fig. 18A: s).
Female (Figs 14D, 15D, 16D)
Similar to the male except for normal sexual dimorphism: Frons shiny, non pollinose, except along eye margins (Fig. 15D); tergum 4 with a pair of indistinct narrow oblique pollinose fasciae.
Period of flight and distribution (Fig. 1)
Merodon lotus sp. nov. occurs in RSA in the Ceres Mountain Fynbos Nature Reserve; the flight period is in November and December. This species appears in Mediterranean evergreen forest-hard-leaf scrub in the south of the African continent (Sayre et al. 2013).
Flower visited
During our fieldwork, adults of M. lotus sp. nov. were observed as regular visitors of flowers of the genus Coleonema Bartl. & H.L.Wendl. (Rutaceae) in Ceres (Fig. 25).
description: Published as part of Vujić, Ante, Radenković, Snežana, Zorić, Ljiljana Šašić, Likov, Laura, Tot, Tamara, Veselić, Sanja & Djan, Mihajla, 2021, Revision of the Merodon bombiformis group (Diptera: Syrphidae) - rare and endemic African hoverflies, pp. 88-135 in European Journal of Taxonomy 755 (1) on pages 99-103, DOI: 10.5852/ejt.2021.755.1401, http://zenodo.org/record/5013000