Afromuelleria , a new genus of Trachyphloeini from Limpopo , with descriptions of four new species ( Coleoptera : Curculionidae : Entiminae )

A new genus, Afromuelleria gen. n., assigned to the tribe Trachyphloeini Lacordaire, 1863, is described for four South African species of weevils: A. awelani sp. n., A. baobab sp. n., A. limpopo sp. n. and A. venda sp. n. All species are illustrated and keyed. Taxonomic status of the new genus is discussed and compared with similar genera of Trachyphloeini and Embrithini Marshall, 1942. ZooBank Article LSID: 02D78E92-405C-4C8B-A670-ABC65E561AB6 * Corresponding author; e-mail: jirislavskuhrovec@gmail.com INTRODUCTION The Cape Floristic Region is by far the smallest in the world, characterized mainly by a very high species diversity of angiosperms, with about 8,700 species in 165 families, which is about 20% of all African angiosperms (Hendrych, 1984). The phytophagous superfamily of weevils (Curculionoidea), the largest superfamily of living organisms with about 62,000 described species (Oberprieler et al., 2007), should be very speciose in this botanically rich region, but at present, we know only a very small fragment of this weevil fauna. This is true also of the Entiminae Schoenherr, 1823, the largest weevil subfamily with about 12,000 described species (Oberprieler et al., 2007). First genera and species of South African entimines were described by Boheman (in Schoen herr, e.g., 1842, 1845) or Schoenherr (e.g., 1843, 1847) in Schoenherr’s monumental monograph of world weevils. Continuation of this study based on material collected mainly during the fi rst botanical expedition to South Africa (Gunn & Codd, 1981) were descriptions by Fåhraeus (1871). The extensive work by G.A.K. Marshall, who published between 1902 and 1962 about 110 articles focused on Afrotropical and particularly South African weevils, contain descriptions of a number of genera and species of Curculionoidea, as well as several revisions providing keys. Additional studies were later Eur. J. Entomol. 115: 668–683, 2018 doi: 10.14411/eje.2018.066


INTRODUCTION
The Cape Floristic Region is by far the smallest in the world, characterized mainly by a very high species diversity of angiosperms, with about 8,700 species in 165 families, which is about 20% of all African angiosperms (Hendrych, 1984).The phytophagous superfamily of weevils (Curculionoidea), the largest superfamily of living organisms with about 62,000 described species (Oberprieler et al., 2007), should be very speciose in this botanically rich region, but at present, we know only a very small fragment of this weevil fauna.This is true also of the Entiminae Schoenherr, 1823, the largest weevil subfamily with about 12,000 described species (Oberprieler et al., 2007).First genera and species of South African entimines were described by Boheman (in Schoen herr, e.g., 1842, 1845) or Schoenherr (e.g., 1843Schoenherr (e.g., , 1847) in Schoenherr's monumental monograph of world weevils.Continuation of this study based on material collected mainly during the fi rst botanical expedition to South Africa (Gunn & Codd, 1981) were descriptions by Fåhraeus (1871).The extensive work by G.A.K. Marshall, who published between 1902 and1962 about 110 articles focused on Afrotropical and particularly South African weevils, contain descriptions of a number of genera and species of Curculionoidea, as well as several revisions providing keys.Additional studies were later wide as interocular space, with median longitudinal furrow; frons densely squamose; epistome very short, not projecting anteriorly; antennal scrobes in dorsal view visible along the whole length, in lateral view triangular, reaching above and below posterior margin of eye; eyes small, hardly projecting beyond the outline of head in dorsal view; head in ventral and lateral views partly fi nely densely longitudinally striate (striae well visible in glabrous transverse stripe); tibiae short and robust, amucronate, metatibiae without corbels; ventrite 1 in middle slightly shorter than ventrite 2, suture between them distinctly sinuate; ventrites glabrous; tegmen with ring expanded into tegminal plate bearing elongated membraneous parameres; female sternite VIII with long and slender apodeme and small, widely oval, slightly wider than long plate, terminating at base of plate, plate with slender basal margin.
Description.Body length 1.5-2.1 mm.Integument of body brownish to blackish, legs and antennae unicolourous, reddish brown or brownish.Vestiture on body consists of dense appressed rounded scales; scales on elytra fl at, 2 across one elytral interstria, leaving very slender glabrous striae; scales on pronotum slightly imbricate, with distinct deep puncture in centre.Antennal scapes, femora and tibiae covered with dispersed appressed scales with punctures in centres, with indistinct structure, funicles and tarsi without appressed scales; clubs fi nely and densely setose.Elytra covered with one dense mostly conspicuous regular row of semiappressed to erect, subspatulate to spatulate setae; pronotum and head with rostrum with similar, but shorter, densely irregularly scattered setae, rostrum moreover with regular row of these setae laterally projecting from outline and border its outline.Antennal scapes, femora and tibiae covered with slender, subspatulate, semierect setae; tarsi and funicles with short semierect bristles.
Rostrum (Figs 1B, C, 7B, C, 10B, C, 11B, C, 12B, C) extremely short and wide, 1.5-1.9× wider than long, widest at base or just before the base, evenly tapered apicad with straight or slightly rounded sides, apically widely rounded, at base as wide as head with eyes or wider, continuous with head; in lateral view weakly convex to almost fl at, at the same level as head, anteriorly abruptly declivous beyond antennal insertion.Epifrons fl at and wide, distinctly and evenly tapered apicad with straight sides, at base as wide as interocular space and evenly directly continuing posteriorly to posterior margins of eyes; space of epifrons with slender, median longitudinal furrow along the whole length, evanescent shortly before epistome and with shorter furrow very nearly parallel with margin of epifrons; when cleared of scales, shiny, smooth, regularly continuous with head, with long, fi ne and slender longitudinal ridges along the whole length, converging towards slender median furrow and multiplied by shorter and fi ner ridges on vertex.Frons not differentiated, densely squamose.Epistome small and very short, glabrous, posteriorly slightly carinated, hidden from above by a pair of large spatulate transverse scales.Mandibles not squamose, trisetose, weakly projecting anteriad.Prementum with a pair of long setae.Subgena (ventral part of rostrum) moderately densely covered by However, there is a lot of unidentifi ed material collected mainly in recent decades and deposited in European as well as South African museums and private collections, mainly among unsorted material.The ratio of undescribed to described species is very high (Oberprieler et al., 2007) and many of the undescribed species belong also to undescribed genera.We describe herein a small genus including four species, known only from Limpopo province, which is easily distinguished from all other known genera not only by its external morphological characters (e.g., extremely short and wide rostrum) but also by unique characters of the males and unusual characters of female genitalia.We also discuss its taxonomic position and relation to other genera of small, terricolous entimines.

MATERIAL AND METHODS
Body length of all specimens was measured in dorsal view from the anterior border of the eyes to the apex of the elytra, excluding the rostrum.Width/length ratio of the rostrum was calculated using the maximum width at the base and maximum length to the base of the mandibles.Width/length ratios of pronotum, elytra, antennal segments and tarsomeres were based on the maximum width and length of the respective parts in dorsal view; length of onychium refers to the part protruding beyond the outline of tarsal segment 3. Dissected male and female genitalia were studied in glycerine.Female genitalia were afterwards embedded in Solakryl BMX (epoxy resin soluble in toluene; Medika, Prague); male genitalia were mounted dry on the same card as the respective specimen, with tegmen and sternite IX embedded in Solakryl BMX.Photographs of adults were taken with a Canon EOS 700D camera with an MP-E 65 mm macro lens and combined using Zerene Stacker and GIMP2 software.Details of adults (rostrum -dorsal and lateral view, protibia, ventrites) and genitalia were taken and enhanced using a HIROX RH-2000 digital microscope.The terminology used to describe the details of the rostrum, antenna and genitalia follows Oberprieler et al. (2014).
Exact label data of type specimens are cited: separate labels are indicated by a slash (/).Authors' remarks and comments are in square brackets.
Specimens are deposited in the following museums and private collections: NHMUK -Natural History Museum, London, United Kingdom (formerly British Museum of Natural History) (Maxwell Barclay); JSPC -Jiří Skuhrovec collection, Praha, Czech Republic; MMTI -Massimo Meregalli collection, Torino, Italy; BMSA -National Museum, Bloemfontein, South Africa (Burgert Muller); NMPC -National museum Praha, Czech Republic (Jiří Hájek); RBSC -Roman Borovec collection, Sloupno, Czech Republic; TMSA -Ditsong National Museum of Natural History (formerly Transvaal Museum), Pretoria, South Africa (Ruth Müller).Diagnosis.Very small Entiminae, up to 2.1 mm; rostrum extremely short and wide, at base as wide as head with eyes or wider, continuous with head; epifrons at base as appressed subspatulate scales.Gena as long as subgena, glabrous, fi nely, densely, longitudinally striate; borderline between gena and subgena arched.Scrobes in dorsal view visible along the whole length as a narrow furrow, distinctly constricted in anterior third and then evenly enlarged posteriad, reaching base of rostrum before eyes; in lateral view short, slightly curved, triangular, sharply set off from densely squamose lateral part of rostrum, distinctly enlarged posteriad, reaching eye, with well defi ned edges and reaching posterior margin of eye, dorsal border aligned with dorsal border of eye, ventral border below eye, leaving slender glabrous furrow between it and eye.Head very wide and fl at, with slender longitudinal stria in middle and next to borders, continuing into striae on epifrons.Eyes very small, convex, but not or only slightly projecting beyond outline in dorsal view, in lateral view subcircular, positioned approximately in the middle of head height.Head in lateral and ventral part with glabrous transverse stripe, fi nely densely longitudinally striate (except a subtriangular squamose spot in lateral view and a narrow anterior stripe in ventral view).
Pronotum (Figs 7A, 10A, 11A, 12A) short and wide, 1.5-1.8× wider than long, sides rounded, widest at midlength or before, behind anterior border slightly constricted with anterior border slightly narrower than posterior border; disc regularly convex without furrow or depression; base straight.Anterior border in lateral view straight, without ocular lobes or setae.
Male terminalia.Penis (Figs 8A-D) moderately long, slender, differing between species in shape; temones short, as long as penis and longer than tegminal manubrium.Tegmen ( Figs 8E-H) very exceptional in Entiminae, with tegminal plate; ring moderately small, enlarged at base of manubrium, which is short, longer than diameter of ring; ring incomplete, interrupted in middle, expanded to form a large membranous, not diversifi ed tegminal plate, almost as long as diameter of ring, lateral edges slightly more sclerotized and elongate forming two differently long, slender, membraneous parameres, distant at base.Sternite IX with spiculum gastrale moderately long, anteriorly perpendicu-  C) with long and slender apodeme, 5.8-7.7 × longer than plate; plate small, oval, nearly isodiametric, with basal half slightly sclerotized, apical margin sparsely fringed with short and fi ne setae, apodeme terminates at base of plate, basal margin developed.Gonocoxites (Figs 9D, E) long and slender, subtriangular, weakly sclerotised, with slender and moderately long apical styli with apical setae.Spermatheca (Figs 9F-I) with slender, pointed, regularly curved cornu and short but differentiated ramus and nodulus, differing between species.
Derivation of name.This newly described genus is dedicated to our German colleague and friend, born in Angola and living in South Africa, Ruth Müller, curator of Ditsong National Museum of Natural History in Pretoria.She is extremely enthusiastic and keen about nature and has helped many specialists working on beetles in South Africa.Moreover, Ruth during many fi eld trips collected a remarkable amount of important material for the mu-seum and science, for example, two of the four new species of this newly described genus.
Distribution.The genus contains four newly described species; all are known only from the northern part of Limpopo province in South Africa.
Biology.Afromuelleria awelani sp.n. was sifted from forest litter in mopane type forest, below a big Ekebergia sp.(Meliaceae), in partly rocky terrain (Fig. 2).Afromuelleria limpopo sp.n. was collected using ground traps baited with banana.Species of this genus seem to be inhabitants of forests, living in litter below trees in more humid habitats.
Taxonomical remarks.Afromuelleria gen.n. belongs to the tribe Trachyphloeini Lacordaire, 1863 based on the following morphological characters: rostrum wider than its length; scrobes located subdorsally, laterally directed towards eyes; epifrons with well defi ned margins along the whole length, at base as wide as the space between anterior eye margins; elytra without humeral calli, fused at suture; the entire dorsal part of body densely squamose and metatibiae lacking corbels.In the tribe Trachyphloeini, Afromuelleria gen.n. is very exceptional in having the following set of characters: rostrum extremely short and wide, at base as wide as head with eyes or wider, with regular row of spatulate setae; antennal scrobes in lateral view triangular, reaching posterior margin above and below the eyes; tibiae without mucro, tegmen with ring expanded into a tegminal plate elongated into membraneous parameres, and female sternite VIII with a slender and long apodeme, 5.8-7.7 × longer than small oval plate, terminating at slender basal margin.Among Trachyphloeini genera with connate claws, Afromuelleria  10A, 11A, 12A).Tibiae short and robust, without a mucro; protibiae 3.2-3.8×longer than width at apex (Fig. 7A, D).Ventrites with conspicuous spatulate setae, ventrite 1 in middle slightly shorter than ventrite 2, ventrite 2, 1.5 × as long as ventrites 3 and 4 combined (Fig. 1A).Suture between ventrites 1 and 2 distinctly sinuate, between 2-5 straight (Fig. 1A).Tegmen with ring extending to the tegminal plate ( Figs 8E-H).Sternite VIII in females with apodeme 5.8-7.7 × as long as a plate, ending at basal margin; plate small, oval, without apical process (Figs 9A-C).Spermatheca with differentiated nodulus and ramus (Figs 9F-H).
Among Trachyphloeini with free claws, Afromuelleria gen.n. is only similar in general habitus (small size with extremely short and wide rostrum) to "Trachyphloeosoma" brevicolle Voss, 1974, known from the Western Cape (this species was described by Voss by mistake in his original description of the genus Trachyphloeosoma Wollaston, 1869, see Borovec & Skuhrovec, 2017a).This species belongs to an undescribed genus including 14 undescribed species native primarily to Western Cape, Eastern Cape, but we also know two species from KwaZulu-Natal, (Borovec & Skuhrovec, 2017a).Both genera share not only short and wide rostrum but also rostrum continuous with head, short and slender antennae, tegmen with parameres and female sternite VIII with long and slender apodeme.In having free claws "Trachyphloeosoma" brevicolle belongs to a group of species and genera related to Nama Borovec & Meregalli, 2013, native to Western and Northern Cape and southern Namibia."Trachyphloeosoma" brevicolle and its allies will be described in a forthcoming revision dedicated to all Trachyphloeini with free claws.However, both genera can be distinguished by the following characters:   8E-H).Female sternite VIII with small, oval plate (Figs 9A-C).
The presence of corbels on the metatibial apex is, in fact, the only character separating the Trachyphloeini and Embrithini Marshall, 1942.The mutual relationship between these two tribes is unclear at present because the separation of these two tribes is based on only one character, which appears to be unstable.This fact becomes more apparent when the fact that metatibial corbels have several different forms and could also be variable inside one tribe, for example, Oosomini Lacordaire, 1863, which currently contains genera with different forms of corbels and even genera lacking corbels.On the other hand, the very speciose genus Naupactus Dejean, 1821 (Naupactini Gistel, 1856) from South America even contains species with and without corbels (Del Río et al., 2018).Clarifi cation of this situation is not a topic of the present paper, but it is the reason why we compare the newly described genus with the tribe Embrithini.It includes also small terricolous forms, although most are still undescribed.Except for the metatibiae, it is only possible to compare Afromuelleria gen.n. with two embrithine genera, Afrophloeus Borovec &Oberprieler, 2013 andGlyptososmus Schoenherr, 1847, with which it shares mainly a densely squamose frons and short and robust protibiae.These two characters separate all three genera from other genera including small, terricolous entimines, such as Phaylomerinthus Schoenherr, 1842 and Lalagetes Schoenherr, 1842.Afromuelleria gen.n. can be easily distinguished from Afrophloeus Borovec & Oberprieler by the following characters:  10D, 11D, 12D).Metatibiae without corbel.Ventrites glabrous, ventrite 1 at middle slightly shorter than ventrite 2 (Fig. 1A).Tegmen with tegminal plate lengthened into parameres (Figs 8E-H).Female sternite VIII with apodeme terminating at basal margin of the small oval plate (Figs 9A-C).
tween ventrites 1 and 2 arched (Fig. 6G).Tegmen with a slender complete ring but without parameres (Fig. 6E).Female sternite VIII with apodeme 1.9-2.7 × longer than the plate, terminating just inside plate, plate umbrella-shaped, with basal margin ill-defi ned (Fig. 6F).shortly before base.In having a 7-segmented funicle, it is similar only to A. baobab sp.n., but is distinguishable from it by having a penis with short pointed tip and spermatheca with equally long and wide ramus and nodulus.
Description.Body length 1.59-1.84mm, holotype 1.63 mm.Elytra with conspicuous row of spatulate, semierect setae, slightly longer than half the width of one interstria.
Rostrum (Figs 1B, C, 7B, C) 1.88-2.03× wider than long, short basal part enlarged anteriad, then evenly tapered apicad with straight sides, at base wider than head with eyes; eyes hardly projecting beyond outline in dorsal view.
Male terminalia.Penis (Fig. 8A) in basal half subparallel-sided, in apical half evenly tapered apicad with slightly concave sides, tip bluntly pointed.Tegminal plate short, parameres about as long as half of diameter of ring (Fig. 8E).
Female terminalia.Spermatheca (Fig. 9F) with ramus and nodulus equally large and long, parallel-sided, rounded.Differential diagnosis.This new species is similar to A. awelani sp.n. in its 7-segmented funicle, but distinguishable from it by having a penis with long tip with concave sides and spermatheca with long ramus and short angular nodulus on its opposite side.Description.Body length 1.66-2.14mm, holotype 1.66 mm.Elytra with conspicuous row of spatulate, semierect setae, slightly longer than half the width of one interstria.
Rostrum (Figs 10B, C) 1.53-1.67× wider than long, widest at base, evenly tapered apicad with straight sides, at base as wide as head with eyes; eyes weakly projecting beyond outline in dorsal view.
Male terminalia.Penis (Fig. 8B) moderately long and slender, widest at base, with slightly concave sides along the whole length, apex distinctly tapered with elongated tip with concave sides.Ring of tegmen slender (Fig. 8F), tegminal plate and parameres long, almost as long as diameter of ring.
Female terminalia.Spermatheca (Fig. 9G) with ramus longer than wide, tapered apicad and nodulus short, angular, staying on its opposite side.Remarks.One female from Messina was not listed among type specimens due to its more slender pronotum and nodulus of spermatheca rounded.
Description.Body length 1.51-1.81mm, holotype 1.51 mm.Elytra with inconspicuous row of semiappressed, slender, subspatulate setae, as long as half the width of one interstria.11B, C) 1.73-1.81× wider than long, short basal part enlarged anteriad, then evenly tapered apicad with straight sides, at base wider than head with eyes; eyes slightly projecting beyond outline in dorsal view.
Male terminalia.Penis (Fig. 8C) widest at base, at midlength distinctly constricted with concave sides, apex subtriangular, tip narrowly rounded.Parameres about as long as half of diameter of ring (Fig. 8G).
Derivation of name.Patronymic, dedicated to the province, where this genus and this newly described species were collected.Description.Body length 1.47 mm.Elytra with conspicuous row of slender subspatulate, semierect setae, slightly longer than half the width of one interstria.

Afromuelleria venda sp. n.
Rostrum (Figs 12B, C) 1.86 × wider than long, widest at base, evenly tapered apicad with straight sides, at base as wide as head with eyes; eyes slightly projecting beyond outline in dorsal view.
Type locality.South Africa, Limpopo, Mopane.Derivation of name.The name venda is dedicated to the Venda people, Southern African people living mostly near South African -Zimbabwean border, in the same region as this genus and newly described species occur.
Key to the species of Afromuelleria gen.n.