Smicronyx san, sp. nov.
Creators: name: Haran, Julien M.
Publisher: name: Zenodo
Year: 2021
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Curculionidae
Smicronyx
Smicronyx san

description: Smicronyx san sp. nov.
urn:lsid:zoobank.org:act: F652DB37-9106-483C-A89F-9F2375C52910
Figs 2 A–C, 4D, 5L, 6E; Table 1
Differential diagnosis
In the Republic of South Africa, S. san sp. nov. is closest to S. drakensbergensis sp. nov.; it can be distinguished from this species by the coating on the elytra (white and brown scales, grey in S. drakensbergensis sp. nov.), the ratio of its prothorax (isodiametric, slightly longer than wide in S. drakensbergensis sp. nov.), and its shorter penis body (Fig. 5 L–M).
Etymology
This species is dedicated to the San people, hunter gatherers whose first traces date back 44 000 years in southern Africa. They left remarkable marks of their presence along the coast in Western Cape Province, where S. san sp. nov. forms dense populations due to the local abundance of its host plants.
Material examined
Holotype REPUBLIC OF SOUTH AFRICA • 1 ♂; “Rep. of South Africa; Stellenbosch [Western Cape Province]; 33°56.566S, 18°52.402E; 156 m, 20.ii.2018; J. Haran leg.” / “on Chironia baccifera; JHAR00761_0101” / “HOLOTYPE; Smicronyx san; Haran 2021”; SAMC.
Paratypes REPUBLIC OF SOUTH AFRICA • 1 ♂, 1 ♀; same collection data as for holotype; BMNH • 2 ♂♂, 2 ♀♀; same collection data as for holotype; CBGP • 1 ♂, 1 ♀; same collection data as for holotype; MNHN • 1 ♂, 1 ♀; same collection data as for holotype; RMCA • 1 ♀; same collection data as for holotype; SAMC • 1 ♂, 1 ♀; same collection data as for holotype; SANC • 6 ♂♂, 7 ♀♀; Western Cape Province, Cape Peninsula; 34°20.300 S, 18°27.489 E; alt. 16 m; 24 Feb. 2018; J. Haran leg.; on Orphium frutescens; JHAR00769; CBGP • 4 specs; Stellenbosch, Bottelaryberg; 29 Jun. 2019; J. Haran leg.; on Chironia baccifera; JHAR02343; ethanol coll. CBGP • 14 specs; Helderberg; 34°0.88′ S, 18°53.533′ E; alt. 443 m; 19 Aug. 2018; J. Haran leg.; on Sebaea sp.; JHAR01367; ethanol coll. CBGP • 1 ♂, 1 ♀; Kapstyl; 24 Aug. 2018; J. Haran leg.; on Chironia baccifera; JHAR01438; CMNC • 20 specs; same collection data as for preceding; JHAR01438; ethanol coll. CBGP • 1 ♂, 2 ♀♀; Western Cape Province, R27 near Langebaan; 33°06.04 S, 18°07.71 E; 14 Nov. 2007; E. Colonnelli leg.; MCZ • 7 specs; Gansbaai, Grootbos private nature reserve; 11 Aug. 2018; J. Haran leg., on Chironia sp.; JHAR01317; ethanol coll. CBGP • 16 ♂♂, 13 ♀♀; Worcester; Jan. 1929; R.E. Turner leg.; BMNH • 1 ♂, 1 ♀; Table Mountain; 1906; W. Bevins leg.; BMNH • 1 ♀; Cape Town, Milnerton; 14–28 Dec. 1925; R.E. Turner leg.; BMNH • 1 ♀; Swellendam; 17 Dec. 1931 – 18 Jan. 1932; R.E. Turner leg.; BMNH • 4 specs; Somerset West, Helderberg Nature Reserve; 34.062212 S, 18.873992 E; 14 Oct. 2019; J. Haran leg.; sweeping Sebaea aurea; JHAR01367_02; ethanol coll. CBGP.
Description
BODY LENGTH. 1.8–2.0 mm.
COLOUR. Body integument entirely black, shiny; vestiture of elytra consisting of recumbent, elliptical, twice as long as wide, overlapping scales, pale brown with transverse shades of white scales, densely covering but not concealing the integument.
HEAD. Rostrum as long as head + prothorax in lateral view, moderately and regularly downcurved (Fig. 4D), in dorsal view punctate, covered with suberect brown scales in basal ⅓–½, glabrous in apical half; transverse furrow at base of rostrum shiny, bare of scales; head capsule glabrous; eyes flat, close to each other on ventral side, separated by a distance equal to width of 2–3 ommatidia; scape of antennae straight, slightly and regularly widening apicad, clavate in apical ⅓, segment 1 of funicle elongate, as long as 2 + 3, 4–7 wider than long.
PROTHORAX. Isodiametric (ratio w/l: 1), widest near middle of length, narrowed at apex, sides rounded; integument greatly punctuate and granulous, shiny; scales pale brown, overlapping, usually concentrated on sides, with a spot of white scales near humeri; disc usually bare of scales or with narrow scales not concealing integument, forming a broad longitudinal strip where integument remains visible; median line sometimes bearing a narrow band of brown scales, generally visible at base near scutellum.
ELYTRA. Sides rounded, widest near middle of length (ratio w/l: 0.76); humeri raised; striae narrow, interstriae flat, wide, integument slightly reticulate, apex of interstria 5 lacking declivital callosity; scutellum small, not visible through coating.
ABDOMEN. Underside mostly covered with overlapping pale brown scales, more condensed on metasternum and metanepisterna.
LEGS. Covered with pale brown semi-erect elongate scales; femora clavate, bearing a tiny ventral tooth usually concealed by scales; tibiae straight on external side, slightly bisinuate ventrally at basal third; claws equal in length.
GENITALIA. Body of penis very short (ratio w/l: 1), 0.8× as long as apodemes, sides sub-parallel or slightly expanding from base to apex in basal ¾, converging in apical ⅓, acuminate at apex, curvature in lateral view regular (Fig. 5L).
Sexual dimorphism
Females are distinguished from males by their rostrum, which is slightly longer, and less densely covered with scales in basal ½.
Life history
Smicronyx san sp. nov. develops on various Gentianaceae: Chironia baccifera Linnaeus, 1753, Orphium frustescens (L) E. Mey., 1838, Sebaea spp. including S. aurea (L. f.) Roem. & Schult. (Fig. 6 E–H). Adults were collected on the ground under its host plant or by beating the plant in February, June, August, October–December.
Distribution
Republic of South Africa (Western Cape Province).
Remarks
Smicronyx san sp. nov. belongs morphologically to the S. reichi (Gyllenhal, 1835) species group (Dieckmann 1990), which is associated with Gentianaceae, and shows a much shorter body of the penis than other Smicronyx species (Pericart 1957). S. san sp. nov. is a polymorphic species, specimens obtained from Orphium frustescens (Fig. 2B) are larger and have a less dense coating than specimens developing on Chironia (Fig. 2A). Specimens obtained from Sebaea have a more elongate body (Fig. 2C) than those on Chironia. However, the sequences of the gene COI revealed no genetic divergence between populations from each host plant.
description: Published as part of Haran, Julien M., 2021, The Smicronychini of southern Africa (Coleoptera, Curculionidae): Review of the tribe and description of 12 new species, pp. 34-73 in European Journal of Taxonomy 735 on pages 60-62, DOI: 10.5852/ejt.2021.735.1239, http://zenodo.org/record/5707947