Barclayanthus Borovec & Skuhrovec, 2019

Borovec, Roman & Skuhrovec, Jiří, 2019, Two new genera of Trachyphloeini with a key to the genera of small terricolous South African Trachyphloeini and Embrithini (Coleoptera: Curculionidae: Entiminae), Zootaxa 4695 (5), pp. 451-476 : 452-454

Barclayanthus Borovec & Skuhrovec , gen. nov.

( Figs 1 A–F, 2A–E, 3A–E) http://zoobank.org/ urn:lsid:zoobank.org:act:87B3690D-3D5B-4EC1-9302-65C68632CC44

Type species: Barclayanthus micros Borovec & Skuhrovec , sp. nov., by present designation.

Diagnosis. Very small Trachyphloeini , less than 2 mm, with very short and wide rostrum and epifrons; frons densely squamose; rostrum and head not separated by any stria; gena and subgena mostly glabrous; glabrous antennal scrobes reaching as furrow above and below eyes just behind them; antennal scape and legs robust and very short; anterior border of pronotum laterally toothlike, tapered posteriad; protibiae armed with laterally prominent spines, reaching midlength; meso- and metatibiae with sparse spines reaching apical third of their length; metatibiae with apical surface squamose and without corbels; claws connate at base.

Description ( Figs 1 A–F, 2A–E, 3A–E). Body length 1.2–1.7 mm. Body ( Figs 1A , 2A , 3A ) brownish to darker brownish, only spines on tibiae blackish. Vestiture on body created by very dense, moderately large, appressed scales, regularly covering dorsal and ventral part of body except ventral part of head, antennal funicles with clubs and tarsi; clubs finely moderately densely setose. Head laterally in dorsal half densely squamose ( Figs 2B , 3B ), in ventral half glabrous with sharp borderline between; ventrally gena glabrous and subgena densely squamose only in lateral parts ( Fig. 1D ), scaled area subtriangular. Scale-like setae on body including antennae and legs inconspicuous to hardly visible, semiappressed, on elytra shorter than on pronotum and head with rostrum, equally long or slightly longer than diameter of one appressed scale. Colour pattern of scales greyish light brown with small irregularly scattered darker brown spots on pronotum and elytra.

Rostrum very robust and short in dorsal view ( Figs 2B , 3B ), 1.9–2.0 × as wide as long, in dorsal view ventral borders of rostrum visible, below eyes abruptly enlarged, then regularly distinctly tapered anteriad, with straight sides, at base 1.2–1.3 × as wide as at apex; in lateral view ( Figs 2C , 3C ) weakly vaulted, almost flat, not separated from distinctly vaulted, large vertex. Epifrons very wide and short, at base equally wide as distance between eyes, occupied majority of dorsal rostral space, subparallel-sided with weakly convex sides, flat, with very slender median longitudinal stria along the whole length, reaching anterior border of pronotum. When scraped without any transverse stria or sulcus, finely and densely punctate, matt, with median longitudinal stria and two short, shallow and narrow, longitudinal striae along lateral borders ( Figs 1B, C ). Frons densely squamose, without any apical setae. Epistome very small and slender, U-shaped, hardly visible, indistinctly posteriorly carinate, asquamose. Antennal scrobes not visible dorsally; laterally furrow-shaped, glabrous and well edged along the whole length, in anterior half slender, subparallel-sided, in posterior half distinctly enlarged and goes round the eyes, with sinuate edges, reaching above and below eyes just behind them. Dorsal border above eyes turned up and goes transversally inside, forming short transverse keel behind eyes. Head large and wide, distinctly vaulted. Eyes very small, subcircular, weakly vaulted, dorsally hardly visible, laterally placed in the middle of head. Mandibles trisetose, small, asquamose. Submentum without visible setae, which might have been broken off.

Antennae short and robust ( Figs 2A , 3A ). Scapes short, 1.1 × as long as funicles, 2.5 × as long as wide, distinctly dorso-ventrally flattened, basal half distinctly enlarged apicad, than subparallel-sided, at apex 1.5 × wider than clubs. Funicles 6-segmented, with segment 1 enlarged, longer than segments 2 and 3 combined; segments progressively wider towards club. Club with segment 1 conspicuously largest.

Pronotum short and transverse ( Figs 2A , 3A ), 1.3–1.8 × as wide as long, sides roundly inflated, distinctly tapered anteriad with anterior border distinctly narrower than posterior one, anteriorly significantly constricted. Disc distinctly vaulted, with shallow longitudinal median furrow connected behind anterior border with transverse constriction and divided disc to two low, wide bumps. Base V-shaped, arched. Anterior border laterally straight, in middle distinctly toothlike tapered posteriad, forming large indentation for eyes and dorsal border of antennal scrobes. Procoxal cavities contiguous, touching anterior border of pronotum; procoxae subglobular. Scutellum not visible.

Elytra ( Figs 2A , 3A ) subquadrate, 1.1–1.2 × as long as wide, with slightly rounded sides, apically broadly rounded, with regularly rounded shoulders; base V-shaped arched; posthumeral calli developed, not visible dorsally; 10-striae, striae narrow, intervals slightly vaulted; in lateral view posterior declivity distinctly overhanging apex. Mesocoxae ( Fig. 1A ) semiglobular, widely separate, mesosternal process about as wide as half of diameter of mesocoxa, not reaching posterior margin of metacoxae. Metacoxae ( Fig. 1A ) shortly transverse, separated by about 1.5 × their width. Tergite VII in males short and wide, translucent, with sclerotised very narrow margins, apically subtruncate; tergite VIII bowl-shaped, with sclerotised narrow margins, apically truncate or concave.

Femora unarmed, medially inflated, distinctly flattened. Tibiae very short and robust. Protibiae 3.6–4.2 longer than wide at widest part ( Figs 2E , 3E ), widest at midlength or apical third, at apex narrow, armed by 5 blackish spines of unequal size and mesally curved, yellowish mucro. Inner portion and anterior border with the smallest spines, lateral edge with three long, distinct, laterally prominent spines, anterior and subanterior spine largest, conspicuous, the last one smaller, placed about at midlength. Lateral edge between three spines with two shallow indentations. Mesotibiae apically with 2 long, slender and 2 short blackish spines and yellowish slender mucro. Metatibiae with 3 moderately big, short and wide brownish spines and 2 small, slender, blackish ones and one mucro. Spines in meso- and metatibiae reaching to about third of their length; apical surface of meso- and metatibiae densely squamose; metatibiae without corbels. Tarsi long and slender; segment 1 long and slender; segment 2 isodiametric to slightly wider than long; segment 3 indistinctly wider than segment 2 and bilobed; onychium distinctly longer than segment 3, cylinder form, parallel-sided. Claws short, at base connate, only slightly divaricate.

Abdominal ventrites ( Fig. 1E ) about 1.1 × as long as wide; ventrite 1 in middle about as long as ventrites 2–4 combined, behind metacoxa slightly longer than ventrite 2; ventrite 2 in middle slightly longer than ventrite 3 or 4, ventrite 5 large, subtrapezoidal, longer than ventrites 3 and 4 combined. Suture between ventrites 1 and 2 distinctly arched; other sutures straight; all sutures narrow and fine. Ventrites densely squamose with irregularly scattered, semiappressed, very short, slender and hardly visible setae. Metaventral process obtuse, 1.5 × as wide as transverse diameter of metacoxa.

Sexual dimorphism. Sexes externally indistinguishable.

Male genitalia. Penis moderately long ( Figs 2D , 3D ), well sclerotised, temones 1.2 × as long as body of penis and distinctly longer than tegminal manubrium; endophallus short, inside only very finely spiculate. Tegmen with very slender ring without parameres. Sternite IX moderately long and slender, anteriorly curved and tapered, posteriorly with fused basal arms; apical plate absent.

Female genitalia. Gonocoxites not examined. Sternite VIII with moderately long, slender apodeme, Y-shaped terminating just at the base of plate, plate short and wide, crescent-shaped, with basal and apical margin slender, apically armed with fringe of short, fine setae. Spermatheca ( Fig. 1F ) large, crescent shaped, with slender cornu and corpus and developed ramus and nodulus.

Derivation of name. The newly described genus is dedicated to our friend and colleague Maxwell V. L. Barclay (British Museum, London), for his kind assistance and co-operation in our study, for his hospitality during visits of first author to the British Museum of Natural History, London and also for the loans of the very important material for ongoing study of South African Entiminae. The name is a combination of his surname and Greek word anthos, which means glory, splendour.

Biology. Unknown. Reproduction amphigonic.

Distribution. Known only from South Africa, Western Cape.

Species included. The genus includes two newly described species.

Remarks. Barclayanthus Borovec & Skuhrovec , gen. nov. is similar only to several species of Pentatrachyphloeus with the antennal scrobes not visible dorsally, but is easily distinguishable mainly by the following set of characters: rostrum and head not separated by any stria ( Pentatrachyphloeus has rostrum separated by slender tranverse V-shaped stria); gena and partly subgena glabrous ( Pentatrachyphloeus has gena and subgena densely squamose); head laterally at dorsal half squamose, at ventral half glabrous with sharp borderline between ( Pentatrachyphloeus has head laterally densely squamose); glabrous antennal scrobes reaching above and below eyes behind posterior border of eyes ( Pentatrachyphloeus has antennal scrobes not reaching eyes or dorsal border of scrobes reaching eyes, then scrobes squamose); anterior border of pronotum laterally toothlike, tapered posteriad ( Pentatrachyphloeus has anterior border of pronotum straight); profemora at anterior border with furrow for keeping of tibiae ( Pentatrachyphloeus has only short furrow on profemora); protibiae armed with laterally prominent spines, reaching midlength, with shallow indentations between them ( Pentatrachyphloeus has apex of protibiae rounded, armed with very short and fine spines, lateral edge without spines and indentations); meso- and metatibiae with sparse spines reaching third of their length ( Pentatrachyphloeus has apical surface armed with short fringe of fine, short spines, reaching one sixth of their length).

Barclayanthus Borovec & Skuhrovec , gen. nov. in general habitus, shape of densely squamose rostrum, pronotum and elytra and also short and robust antennae and protibiae is similar to Palaearctic Trachyphloeus Germar, 1817 species, but it differs from Trachyphloeus by gena and subgena mostly glabrous ( Trachyphloeus has gena and subgena densely squamose); head laterally in dorsal half squamose, in ventral half glabrous with sharp borderline between ( Trachyphloeus has head laterally densely squamose); antennal scrobes in lateral view subtriangular, reaching posterior margin above and below the eyes ( Trachyphloeus has antennal scrobes not reaching eyes); anterior border of pronotum laterally toothlike tapered posteriad ( Trachyphloeus has anterior border of pronotum straight); profemora at anterior border with furrow to receive tibia ( Trachyphloeus has only short furrow on profemora); protibiae armed with laterally prominent spines, reaching its midlength, with shallow indentations between them ( Trachyphloeus has apex of protibiae lobed, armed with spines and indentations, but lateral edge without spines); meso- and metatibiae with sparse spines, last lateral spine situated at about a third of length of tibiae from apex ( Trachyphloeus has apical surface armed with short fringe of short spines, last lateral spine situated at most at sixth of length of tibiae from apex); claws at base fused ( Trachyphloeus has claws free); suture between ventrite 1 and 2 arched ( Trachyphloeus has suture between ventrite 1 and 2 sinuose); metaventral process 1.5 × as wide as transverse diameter of metacoxa ( Trachyphloeus has metaventral process as wide as transverse diameter of metacoxa).

Figures

FIGURE 1. Barclayanthus micros sp. nov. A—habitus, ventral view, male; B—rostrum without scales, dorsal view, male; C—rostrum without scales, lateral view, male; D—head, ventral view, male; E—ventrites, male; F—spermatheca. Scale bar: 0.25 mm (F).

FIGURE 2. Barclayanthus micros sp. nov. A—habitus, dorsal view, male; B—rostrum, dorsal view, male; C—rostrum, lateral view, male; D—aedeagus; E—protibia, male. Scale bars: 1 mm (A), 0.5 mm (D).

FIGURE 3. Barclayanthus cooteri sp. nov. A—habitus, dorsal view, male; B—rostrum, dorsal view, male; C—rostrum, lateral view, male; D—aedeagus; E—protibia, male. Scale bars: 1 mm (A), 0.5 mm (D).