Smicronyx fallax (Gyllenhal, 1863)

Haran, Julien M., 2021, The Smicronychini of southern Africa (Coleoptera, Curculionidae): Review of the tribe and description of 12 new species, European Journal of Taxonomy 735, pp. 34-73 : 55-57

Smicronyx fallax (Gyllenhal, 1863)

Figs 1J , 4B , 5I , 6A; Table 1

Micronyx fallax Gyllenhal, 1836: 427 .

Smicronyx fallax ( Gyllenhal, 1836) [ Schoenherr 1843].

Differential diagnosis

Of the southern African Smicronychini , Smicronyx fallax is closely related to S. albosquamosus , which may be found in sympatry with this species. They can be distinguished by the shape of their prothorax (isodiametric in S. fallax , wider than long in S. albosquamosus ) and their claws (equal in length in S. fallax , unequal in S. albosquamosus in most specimens). These species show an interspecific genetic distance of 12.3% for the barcode fragment.

Material examined

Neotype (here designated) REPUBLIC OF SOUTH AFRICA • 1 ♂; “ Rep. of South Africa; Underberg [KwaZulu-Natal Province]; 29°346′37.42″S 29°30′00.44″E; 1579 m, 25.xii.2018; J. Haran leg.” / “Beating Cuscuta sp. parasite of Artemisia afra ; JHAR01694_0101” / “NEOTYPE; Smicronyx fallax ( Gyllenhal, 1836) ; Des. Haran 2021”; NHRS.

Other material

NAMIBIA • 14 specs; Oanob lake ; 23°19.242′ S, 17°1.008′ E; 7 Dec. 2018; J. Haran leg.; beating and at base of Cuscuta campestris parasite of Asteraceae ; JHAR01630 ; ethanol coll. CBGP.

REPUBLIC OF SOUTH AFRICA • 1 ♂; same collection data as for neotype; SAMC; • 1 ♂; same collection data as for neotype; SANC • 1 ♂; same collection data as for neotype; CBGP • 9 specs; same collection data as for neotype; ethanol coll. CBGP • 1 ♂; Limpopo Province, Tzaneen Mokgolobotho; 23°51.967′ S, 30°16.776′ S; alt. 561 m; 7 Feb. 2019; J. Haran leg.; beating and at base of Cuscuta sp. parasite of Asteraceae ; JHAR02166 ; CBGP • 2 ♂♂, 1 ♀; Mpumalanga Province, Kruger Park, Skukuza ; 12–14 Dec. 1985; S. & J. Peck leg.; thorn scrub forest, evening car netting; MCN • 5 ♂♂, 5 ♀♀; Kruger National Park, Skukuza ; 24.59 S, 3138 E; 8 Mar. 1996; Endrödy-Younga leg.; UV light; TMSA • 8 ♂♂, 6 ♀♀; Kruger National Park , Pafuri rest camp ; 22.25 S, 31.12 E; 30 Jan. 1994; Endrödy-Younga leg.; UV light trap; TMSA • 1 ♀; Limpopo Province, Little Muck ; 22.15 S, 29.16 E; 8–9 Dec. 2008; R. Müller leg.; at light; TMSA • 1 ♂; Kareepoort, near Sonop; 25.38,3 S, 27.39,4 E; alt. 1150 m; 1 Oct. 1996; Millar, Stals and Stiller leg.; beating Acacia nilotica ; SANC • 1 ♂; KwaZulu Natal Province, South West Magudu ; 27.3 S, 31.35 E; alt. 480 m; 4 Jan. 2009; P. Schüle leg.; light trap; SANC • 1 ♂; Gauteng Province, Rivonia ; 23 Oct. 1967; M.I. Russell leg.; BMNH • 1 ♂; Orange Free State, Hendrik- Verwoeddam, Gariep dam ; 30.40′ S, 25.30′ E; alt. 1300 m; 6 Nov. 1988; E. Colonnelli leg.; MCZ.

ZIMBABWE • 1 ♂; Matopo , Maleme Dam ; 30 Jan. 1963; J. Weir leg.; BMNH .

Redescription

BODY LENGTH. 2.0– 2.1 mm.

COLOUR. Body integument entirely black, shiny; vestiture of elytra consisting of whitish and brownish, recumbent, elliptical scales, twice as long as wide; whitish scales forming two ill-defined, oblique bands from humeri to apical ¾ of elytral suture and a spot on declivital callosities.

HEAD. Rostrum longer than head + prothorax in lateral view, almost straight ( Fig. 4B ), dorsal face punctate, covered with suberect whitish scales forming four distinct series in basal ¾ and two spots near eyes, apical ⅓ bearing scattered white setae; transverse furrow at base of rostrum shiny, bare of scales; head capsule glabrous; eyes flat, sub-contiguous on ventral side; scape of antennae slightly bisinuate, slightly and regularly widening toward apex, not clavate at apex, segment 1 of funicle elongate, longer than 2 + 3, 2 square, 3–7 wider than long.

PROTHORAX. Isodiametric (ratio w/l: 1), widest near middle of length, sides moderately rounded, not greatly narrowed at apex; integument punctuate and granulous, punctures forming weak concentric circles in basal ½; scales whitish and brownish, elongate, mostly condensed along the median line and on the sides.

ELYTRA. Sides subparallel in basal ¾ of length, rounded in apical ⅓, widest near middle of length (ratio w/l: 0.70); humeri raised; striae narrow, interstriae flat, wide, 4× as wide as striae, integument shiny, slightly reticulate, apex of interstria 5 with a very slight declivital callosity; scutellum small, bare of scales.

ABDOMEN. Underside mostly covered with non-overlapping greyish scales, not condensed on metanepisterna.

LEGS. Covered with whitish, semi-erect, elongate scales; femora clavate, armed with a tiny ventral tooth, usually concealed with scales; tibiae straight on external side, slightly bisinuate ventrally; claws equal in

length. Genitalia. Body of penis elongate (ratio w/l: 0.33), 1.3 × as long as apodemes, sides sub-parallel, broadly rounded at apex, curvature in lateral view moderate and regular, tapering at apex ( Fig. 5I ).

Sexual dimorphism

Females are distinguished from males by their rostrum, which is slightly longer, and covered with scales only in basal ¼ (in basal ⅓ in males).

Life history

All recently collected specimens of this species were found on dodders ( Cuscuta spp.) including the introduced weed Cuscuta campestris Yunck, 1932 ( Fig. 6 A–B). Labels indicate that this species might be collected with light traps (UV light). Adults were collected from October to March.

Distribution

Smicronyx fallax is widely distributed in the subtropical and desert areas of southern Africa. It has been recorded from Namibia to Zimbabwe, and in the Gauteng, KwaZulu-Natal, Limpopo, Mpumalanga and Orange provinces of the Republic of South Africa.

Remarks

The type specimen of S. fallax was deposited by Gyllenhal in the collection of Ecklon & Zeyer ( Gyllenhal 1836), currently lost. In the absence of further information about this type, and in order to stabilize the taxonomy in this genus, a neotype was designated based on the description of this species. Gyllenhal described S. fallax as a species very closely related to the Palaearctic taxon S. jungermanniae Reich, 1797 . This description corresponded very well to the specimens used to re-describe this species, both regarding external and internal morphology. In addition, COI sequences obtained from these specimens (JHAR01630_0101-1694_0101 [GB accession: MT370316 -17]) showed that they are closest to S. jungermanniae out of all the species of Smicronyx for which a barcode sequence is available (uncorrected p-distance of 7.0%). The neotype (here designated) was designated for a male specimen from a population from the western side of KwaZulu-Natal Province in the Republic of South Africa, which is close to the original type locality of S. fallax (“Caffraria”, probably corresponding to the Eastern Cape Province). Three male and nine unsexed specimens stored in ethanol from this series were deposited in the institutions CBGP, SAMC and SANC.

Figures

Fig. 1. Habitus of species of Smicronychini from southern Africa (Part 1). A. Sharpia madibai sp. nov., ♂, holotype (SAMC). B. Afrosmicronyx cycnii sp. nov., ♂, holotype (SAMC). C. Afrosmicronyx louwi sp. nov., ♂, holotype (SAMC). D. Afrosmicronyx marshalli sp. nov., ♂, holotype (SANC). E. Afrosmicronyx nebulosipennis sp. nov., ♂, holotype (BMNH). F. Smicronyx gracilipes sp. nov., ♀, holotype (SAMC). G. Smicronyx similis sp. nov., ♂, holotype (SANC). H. Smicronyx pseudocoecus sp. nov., ♂, holotype (SAMC). I. Smicronyx paucisquamis sp. nov., ♂, holotype (SAMC). J. Smicronyx fallax (Gyllenhal, 1836), ♂, neotype (NHRS). K. Smicronyx australis sp. nov., ♂, holotype (SAMC). L. Smicronyx pauperculus Wollaston, 1864, ♂, specimen from Tanzania. Scale bars: 1 mm.

Fig. 4. Head and prothorax in lateral view of species of Smicronyx from southern Africa (Part 2). A. Smicronyx paucisquamis sp. nov., ♂, holotype (SAMC). B. Smicronyx fallax (Gyllenhal, 1836), ♂, neotype (NHRS). C. Smicronyx australis sp. nov., ♂, holotype (SAMC). D. Smicronyx san sp. nov., ♂, bred from Chironia baccifera L., holotype (SAMC). E. Smicronyx drakensbergensis sp. nov., ♂, holotype (TMSA). F. Smicronyx lutulentus Dietz, 1894, ♂ (CBGP). Scale bars: 0.5 mm.

Fig. 5 (opposite page). Penis of Smicronyx from southern Africa, in dorsal (left) and lateral (right) view. A. Sharpia madibai sp. nov., ♂, holotype (SAMC). B. Afrosmicronyx cycnii sp. nov., ♂, holotype (SAMC). C. Afrosmicronyx louwi sp. nov., ♂, holotype (SAMC). D. Afrosmicronyx marshalli sp. nov., ♂, holotype (SANC). E. Afrosmicronyx nebulosipennis sp. nov., ♂, holotype (BMNH). F. Smicronyx similis sp. nov., ♂, holotype (SANC). G. Smicronyx pseudocoecus sp. nov., ♂, holotype (SAMC). H. Smicronyx paucisquamis sp. nov., ♂, holotype (SAMC). I. Smicronyx fallax (Gyllenhal, 1836), ♂, neotype (NHRS). J. Smicronyx australis sp. nov., ♂, holotype (SAMC). K. Smicronyx pauperculus Wollaston, 1864, ♂, specimen from Tanzania. L. Smicronyx san sp. nov., ♂, holotype (SAMC), bred from Chironia baccifera L. M. Smicronyx drakensbergensis sp. nov., ♂, holotype (TMSA). N. Smicronyx zonatus Haran, 2018, ♂, paratype (CBGP), specimen from the Western Cape Province of the Republic of South Africa. O. Smicronyx lutulentus Dietz, 1894, ♂ (CBGP). P. Smicronyx namibicus Haran, 2018, ♂, holotype (MNHN), specimen from Tanzania. Scale bars: 100 μm.

Fig. 6. Habitus in natura, host plants and habitats of Smicronyx of southern Africa. A. S. fallax (Gyllenhal, 1863) on Cuscuta campestris Yunck, 1932. B. Cuscuta campestris. C. S. pseudocoecus sp. nov. on Cuscuta sp. D. Cuscuta nitida E. Mey ex Choisy, host of S. pseudocoecus sp. nov. and S. australis sp. nov. E. S. san sp. nov. on Chironia baccifera L. F. Sebaea Sol. ex R.Br. sp., host of S. san sp. nov. G. Orphium frutescens L. (E. Mey), host of S. san sp. nov. and surrounding fynbos vegetation. H. Chironia baccifera, host of S. san sp. nov. I. S. zonatus Haran, 2018, in copula. J. Orobanchaceae Vent., host of S. zonatus growing in a marshy environment at the base of Cyperaceae Juss.