Lalagetes Schoenherr, 1842

Borovec, Roman & Skuhrovec, Jiří, 2018, Revision of the species related to Lalagetes subfasciatus Boheman and transfer of remaining Lalagetes species to other genera of Embrithini (Coleoptera: Curculionidae: Entiminae), Zootaxa 4374 (1), pp. 71-90 : 73-78

Genus Lalagetes Schoenherr, 1842

( Figs 2C, D , 3A–E , 5A–F , 6A–F , 7A–F , 8A–E , 9A–F , 10A–F )

Lalagetes Schoenherr, 1842: 125 (original description).

Lalagetes: Lacordaire 1863: 193 (monography of Entiminae); Lona 1937: 357 (catalogue); Louw 1998: 10 (note); Alonso- Zarazaga & Lyal 1999: 172 (catalogue); Grobbelaar et al. 2000: 24 (note); Borovec et al. 2009: 843 (note); Borovec & Oberprieler 2013: 367 (note).

Type species: Lalagetes subfasciatus Boheman, 1842 , by original description.

Diagnosis. Very small Embrithini to 2.5 mm, with short-oval to globular elytra with mostly long, lancet-shaped, pointed erect setae and large, dense, rounded appressed scales; epifrons at base weakly or distinctly narrower than space between eyes; frons glabrous; epistome distinct; protibiae long and slender; metatibiae without corbel, amucronate with apical surface glabrous; claws fused; ventrites densely scaled with ventrite 2 longer than ventrites 3 and 4 combined and suture between ventrite 1 and 2 sinuose; tegmen with short and weakly sclerotised parameres; female sternite VIII with very long and slender apodeme terminating inside basal half of plate, its plate short and small, subtriangular, with clearly visible basal and apical margin, reaching fifth to sixth of apodeme length.

Redescription ( Figs 2C, D ; 3A–E, 5A–F, 6A–F, 7A–F, 8A–E, 9A–F, 10A–F).

Body length 1.8–2.5 mm. The whole body brownish to dark brownish, antennae and legs somewhat paler, only clubs in some species blackish. The whole dorsal part of body densely covered by moderately large, rounded appressed scales, 3–5 scales across width of one interval, completely covering integument, isolated to somewhat imbricate, leaving only very narrow elytral striae exposed; ventral side densely covered by slightly smaller rounded appressed scales, covering integument but somewhat isolated; boundary between gena and subgena with long-oval, transverse glabrous area. Scapes, femora and tibiae densely covered by rounded scales smaller than those on the elytra; funicles and tarsi glabrous; clubs densely and finely setose. The whole dorsal part of body with conspicuous, long, erect, lancet-shaped and pointed apicad setae, exceptionally narrowly subspatulate, creating one dense row on each elytral interval, longer in males than in females; pronotum and head with rostrum with identical setae, somewhat shorter than those on elytra, densely irregularly scattered; scapes and tibiae with semiappressed to semierect short to long, slender, lancet-shaped setae; femora with semiappressed short, parallel-sided setae. Body vestiture greyish white, unicolorous to spotted, elytra with transverse stripe on inner intervals or with small irregularly scattered spots from light to dark brownish scales, pronotum with two curved longitudinal bands on disc.

Rostrum ( Figs 5B–C , 6B–C , 7B–C , 8B–C , 9B–C , 10B–C ) more slender in males than in females, in both sexes 1.1–1.3 × as wide as long, at base 1.05–1.15 × as wide as at apex, with straight or slightly concave sides, weakly tapered anteriad. Epifrons wide to narrow, at apical half subparallel, at basal half weakly enlarged posteriad, at base narrower than distance between eyes, flat, in lateral view slightly separated from head by clearly defined transverse sulcus; when cleared of scales with very slender median and lateral longitudinal carina, median one interrupted by slender and short fovea, and with shallow, longitudinal, ill-defined depressions along the medina carina; in lateral view tooth-like separated from vertex by very slender and deep, arched to V-shaped, clearly defined sulcus; vertex densely finely longitudinally striate from anterior border of pronotum to transverse sulcus or only at anterior part. Epistome V-shaped, posteriorly sharply carinate, asquamose. Frons short, glabrous, leaving very narrow glabrous stripe along epistome, with 3–4 pairs of slender, long setae. Antennal scrobes ( Figs 5A , 6A , 7A , 8A , 9A , 10A ) dorsally narrowly pit-shaped or furrow-shaped, visible at anterior half; in lateral view furrow-shaped, slender, glabrous, dorsally placed, deflected from dorsal border of rostrum, weakly curved, directed to middle of eye, separated from it by squamose stripe somewhat shorter than diameter of eye, with ventral edge slightly more developed than dorsal one. Eyes moderately large, strongly convex and prominent from head, slightly asymmetric, widest behind midlength; in lateral view subcircular to short-oval, dorsally placed. Gena and lateral parts of subgena densely squamose, middle part of subgena sparsely squamose, narrow transverse stripe between gena and subgena glabrous. Mandibles trisetose, asquamose, small. Submentum with pair of long, slender setae.

Antennae ( Figs 5A , 6A , 7A , 8A , 9A , 10A ) slender; scapes 1.1 × as long as funicles, 4.6–6.1 × as long as wide, slightly exceeding anterior border of pronotum, almost straight, gradually enlarged apicad at apical quarter, at apex at most 1.2 × as wide as clubs; funicles 6–7 segmented; segments 1 and 2 slender and long, conical, funicle 1 longer and wider than segment 2; segments 3–7 longer than wide; at most segment 7 isodiametric; clubs spindleshaped, with segment 1 largest.

Pronotum ( Figs 5A , 6A , 7A , 8A , 9A , 10A ) 1.5–1.8 × as broad as long, in males more slender than in females, widest at posterior third, distinctly more tapered anteriad than posteriad, with rounded sides, weakly constricted behind anterior border. Disc regularly convex, without keels or furrows, in lateral view weakly convex, behind anterior border flattened. When cleared of scales disc matt, densely, finely and regularly punctured by small shallow punctures with very slender edges between them, narrow to wider stripe behind anterior border unpunctured, smooth, shiny, distinctly separated from punctured part. Base straight. Anterior border in lateral view straight, without ocular lobes or anteriad directed setae or scales. Procoxal cavities contiguous, round, nearer to anterior than posteriad border; procoxae subglobular. Scutellum dorsally not visible.

Elytra ( Figs 5A , 6A , 7A , 8A , 9A , 10A ) short-oval to globular, 1.05–1.2 × as long as wide, in males more slender than in females, widest at midlength with distinctly rounded sides, without developed, humeral or posthumeral calli, in lateral view distinctly convex, posterior declivity slightly overhanging apex. Base straight, equally wide as pronotal base; elytra 10-striate, intervals wide, slightly convex; striae very narrow. When cleared of scales intervals shiny, unpunctured; striae distinctly punctured, narrow. Mesocoxae semiglobular, narrowly separate, mesosternal process narrow, about as wide as fifth to sixth of mesocoxa diameter. Metacoxae short transverse, separated by distance shorter than their width.

Legs ( Figs 5A , 6A , 7A , 8A , 9A , 10A ). Femora unarmed, medialy slightly inflatted. Protibiae ( Figs 5D , 6D , 7D , 8D , 9D , 10D ) moderately slender, 5.5–6.6 × as long as wide, double sinuated at inner side and straight at lateral side, at short apical part mesally distinctly enlarged with very short mucro; apex rounded with fringe of very short and fine yellowish setae. Mesotibiae with oval, glabrous apical surface, with short mucro. Metatibiae with small, oval, glabrous apical surface, without corbels, fringed mesally by dense, short, fine yellowish setae and laterally by dense, long, fine, translucent yellowish setae, amucronate. Tarsi moderately slender; segment 1 conical, long and slender, but shorter than segment 2 and 3 combined; segment 2 isodiametric to slightly transverse; segment 3 bilobed, 1.3–1.7 × as wide as segment 2; onychium equally long to 1.1 × longer than segment 3, weakly enlarged distad. Claws fused at basal quarter, weakly divergent.

Abdomen ventrally subtriangular, isodiametric to 1.1 × longer than broad; ventrite 1 in middle shorter than ventrite 2–4 combined and less than twice as long as ventrite 2, laterally about as long as ventrite 2; ventrite 2 as long or longer than ventrites 3 and 4 combined; ventrite 5 apically short, subtruncate in males and longer and subtriangular in females; suture between ventrites 1 and 2 weakly arched, narrow and fine, other sutures straight, broad, and deep. Ventrites ( Fig. 2C ) densely covered by rounded, isolated appressed scales and several inconspicuous semiappressed, subspatulate short setae. Metaventral process obtuse, at most as wide as transverse diameter of metacoxa.

Sexual dimorphism. Males are externally distinguished from females by more slender rostrum, pronotum and elytra, longer erect elytral setae and also by shorter, subtrapezoidal ventrite 5.

Male genitalia. Penis ( Figs 3A–E , 5E , 6E , 7E , 9E , 10E ) small to medium sized, well sclerotised, temones 1.5– 2.8 × as long as body of penis and 1.6–2.3 × longer than tegminal manubrium; tegmen with manubrium 1.3–2.5 × longer than diameter of ring; ring complete, with short and weakly sclerotised parameres, distinctly connected at base. Sternite IX with spiculum gastrale moderately short and robust, posteriorly with fused basal arms, in species with long temones anteriorly enlarged to large, subrounded plate, in species with short temones anteriorly curved and tapered.

Female genitalia. Gonocoxites moderately long, regularly tapered apicad, with very short apical styli with tuft of 3–4 fine setae. Sternite VIII ( Fig. 2D ) with very long and slender apodeme, 4.7–5.6 × as long as length of plate, terminating inside basal half of plate, plate short and small, subtriangular, with clearly visible basal and apical margin, the later armed with very short, fine setae. Spermatheca crescentic, differing between the species.

Biology. Unknown, there are no notes about collecting methods on the locality labels. Reproduction of all species amphigonic.

Distribution. South Africa, known from Western and Eastern Cape, KwaZulu-Natal, Limpopo and Mpumalanga ( Fig. 4 ).

Included species. Two species originally described in genus Lalagetes and four species newly described below.

Remarks. The genus Lalagetes is distinguished from all other Afrotropical Embrithini genera by its small size up to 2.5 mm, rostrum and head separated by narrow transverse sulcus, frons short and glabrous, epistome large and distinct, clearly visible dorsally, posthumeral calli not developed, protibiae long and slender, 5.5–6.7 × as long as wide and metatibiae lacking corbels with apical surface glabrous. Lalagetes shares these characters only with the genus Phaylomerinthus . It is possible to distinguish both genera by the characters stated in the key. The following key includes the genus Glyptosomus , where we transfer several species originally described under the genus Lalagetes .

1. Frons densely squamose ( Fig. 1B ). Metatibiae with at least partly squamose apical surface and slender to wide corbels. Protibiae ( Fig. 1C ) short and robust, 3.9–5.2 × as long as wide, apically armed with 7–9 short spines. Posthumeral calli ( Fig. 1A ) differently developed, visible in dorsal or dorso-lateral view. Ventrite 1 in middle longer than ventrite 2–4 combined, ventrite 2 as long as ventrite 3 or 4 ( Fig. 2A ). Female sternite VIII ( Fig. 2B ) with umbrella shaped plate lacking pointed tip and sclerites, with ill-defined posterior border. Size 2.7–5.4 mm ....................................... Glyptosomus Schoenherr * * Note. We used for illustration type species of Glyptosomus , G. costipennis Schoenherr, 1847 . Ridge-shaped elevations on odd intervals is a conspicuous character of G. costipennis , but not a character typical for genus Glyptosomus as a whole.

1‘ Frons glabrous ( Figs 1E , 5B , 6B , 7B , 8B , 9B , 10B ). Metatibiae with glabrous apical surface, lacking corbels. Protibiae ( Figs 1F , 5D , 6D , 7D , 8D , 9D , 10D ) long and slender, 5.5–6.7 × as long as wide, apically fringed with short, fine setae. Posthumeral calli ( Figs 1D , 5A , 6A , 7A , 8A , 9A , 10A ) not developed. Ventrite 1 in middle shorter than ventrite 2–4 combined, ventrite 2 as long or longer than ventrites 3 and 4 combined ( Figs 2C, E ). Female sternite VIII ( Figs 2D, F ) with narrow plate either with clearly developed posterior border or lacking it, then with sharply pointed tip and longitudinal sclerites. Size at most 3.3 mm ..................................................................................................... 2

2. Epifrons at base distinctly narrower than space between eyes, between scrobes 0.40–0.55 × as wide as rostral width at the same place ( Fig. 1E ). Metatibiae with long and slender mucro. Ventrites glabrous to sparsely squamose, integument predominant ( Fig. 2E ). Ventrite 2 shorter than ventrites 3 and 4 combined, suture between ventrite 1 and 2 straight ( Fig. 2E ). Sternite VIII in females ( Fig. 2F ) with large, umbrella-shaped plate, reaching almost half of its length, with longitudinal sclerites and prominent sclerotised tip and with apodeme short and robust. Size 2.0– 3.3 mm .................. Phaylomerinthus Schoenherr

2‘ Epifrons at base slightly narrower than space between eyes, between scrobes 0.70–0.80 × as wide as rostral width at the same place ( Figs 5B , 6B , 7B , 8B , 9B , 10B ). Metatibiae amucronate. Ventrites densely squamose, integument completely covered by scales ( Fig. 2C ). Ventrite 2 longer than ventrites 3 and 4 combined, suture between ventrite 1 and 2 sinuose ( Fig. 2C ). Sternite VIII in females ( Fig. 2D ) with small, subtriangular plate, reaching fifth to sixth of its length, without sclerites and prominent sclerotised tip and with apodeme long and slender. Size 1.8–2.5 mm ............................ Lalagetes Schoenherr

Figures

FIGURE 1. Differential characters between genus Glyptosomus and genus Phaylomerinthus: G.costipennis Schoenherr, 1847: A—habitus, dorsal view, female; B—rostrum, female, dorsal view; C—protibia, male; P. cinereus Boheman, 1842: D— habitus, dorsal view, female; E—rostrum, female, dorsal view; F—protibia, female.Scales bar:1 mm (A, D).

FIGURE 2. Differential characters between genera Glyptosomus, Lalagetes and Phaylomerinthus: G. costipennis Schoenherr, 1847: A—ventrites, female; B—female sternite VIII; L. subfasciatus Boheman, 1842: C—ventrites, female; D—female sternite VIII; P. convergens (Voss, 1962): E—ventrites, female; P. cinereus Boheman, 1842: F—female sternite VIII; Scales bar:0.5 mm (B, D, F).

FIGURE 3. Apex of penis. A—Lalagetes andersoni sp. nov.; B—Lalagetes howdenorum sp. nov.; C—Lalagetes sarkae sp. nov.; D—Lalagetes subfasciatus Boheman, 1842; E—Lalagetes zitae sp.nov. Scales bar: 0.25 mm.

FIGURE 4. Distribution of Lalagetes species in South Africa; Lalagetes andersoni sp. nov. (green round); Lalagetes howdenorum sp. nov. (pink round); Lalagetes sarkae sp. nov. (yellow rounds); Lalagetes seminulum Fåhraeus, 1871 (red round); Lalagetes subfasciatus Boheman, 1842 (blue rounds); Lalagetes zitae sp. nov. (brown rounds).

FIGURE 5. Lalagetes andersoni sp. nov. A—habitus, dorsal view, female; B—rostrum, female, dorsal view; C—rostrum, female, lateral view; D—protibia, female; E—aedeagus; F—spermatheca.Scales bars:1 mm (A), 0.5 mm (E) and 0.3 mm (F).

FIGURE 6. Lalagetes howdenorum sp. nov. A—habitus, dorsal view, female; B—rostrum, female, dorsal view; C—rostrum, female, lateral view; D—protibia, female; E—aedeagus; F—spermatheca.Scales bars:1 mm (A), 0.5 mm (E) and 0.3 mm (F).

FIGURE 8. Lalagetes seminulum Fåhraeus, 1871. A—habitus, dorsal view, female; B—rostrum, female, dorsal view; C— rostrum, female, lateral view; D—protibia,female; E—spermatheca.Scales bars: 1 mm (A), and 0.3 mm (E).

FIGURE 9. Lalagetes subfasciatus Boheman, 1842. A—habitus, dorsal view, female; B—rostrum, female, dorsal view; C— rostrum, female, lateral view; D—protibia, female; E—aedeagus; F—spermatheca.Scales bars:1 mm (A), 0.5 mm (E) and 0.3 mm (F).

FIGURE 10. Lalagetes zitae sp. nov. A—habitus, dorsal view, female; B—rostrum, female, dorsal view; C—rostrum, female, lateral view; D—protibia, female; E—aedeagus; F—spermatheca.Scales bars: 1 mm(A), 0.5 mm (E) and 0.3 mm (F).

FIGURE7. Lalagetes sarkae sp. nov. A—habitus, dorsalview,female; B—rostrum,female,dorsal view; C—rostrum, female, lateral view; D—protibia, female; E—aedeagus; F—spermatheca.Scales bars: 1 mm(A), 0.5 mm (E) and 0.3 mm (F).