Pachycerus badeni, (FAUST, 1888)

Meregalli, Massimo, 2009, Revision of the Indo-African Pachycerus Schoenherr, 1823, with a description of four new species (Coleoptera: Curculionidae: Lixinae), Zoological Journal of the Linnean Society 157 (2), pp. 295-325 : 309-312

PACHYCERUS BADENI ( FAUST, 1888)

Gonocleonus Badeni Faust, 1888: 288 .

Pachycerus spinipennis Fairmaire, 1897: 168 . Pachycerus Badeni: Faust, 1904: 222 .

Cleonus (Pachycerus) Badeni: Csiki, 1934: 52 .

Lectotype male (designated here): 1. square blank gold label; 2. Madagascar Baden (Faust’s hw); 3. Badeni Faust (Faust’s hw) (note: 1–3 were glued on a new label); 4. Coll. J. Faust, Ankauf 1900 (pr, light blue); 5. Staatl. Museum für Tierkunde Dresden (pr); 6. Type (pr, red); 7. Gonocleonus badeni Faust, 1888 , Lectotypus, 2007 Meregalli des. (pr, red) (SMTD).

Paralectotypes: 2 ♀. Same labels as 1–6 of the lectotype; 7. Gonocleonus badeni Faust, 1888 , Paralectotypus, 2007 Meregalli des. (pr, red) ( SMTD) .

Type: Three syntypes are preserved in Faust’s collection, all with the same indication: ‘ Madagascar, Baden’. The male is designated here as the lectotype , the two females are designated as paralectotypes.

Measurements: Body length excluding rostrum: 8.28 mm. Rostrum: length, 1.62 mm; width, 0.95 mm; ratio, 1.71. Pronotum: length, 2.10 mm; width, 2.87 mm; ratio, 0.73. Elytra: length, 5.57 mm; width, 3.52 mm; ratio, 1.59. Ratio of elytral to pronotal length: 2.65 (lectotype).

Redescription ( Figs 57–69 ): Body elliptical, of small size, integument glossy, and blackish on rostrum, pronotum, and elytral sides, dark reddish on median part of elytra, legs, and antennae, covered with lanceolate simple scales ( Figs 57–58 ). Rostrum short and robust, subquadrate in transverse section, dorsolateral margins keeled, finely punctured, slightly sinuate, and moderately convergent from base to antennal insertion, outward curved from antennal insertion to apex, median keel obtusely raised, punctured, broadened anteriorly, and interrupted at antennal insertion, all keels sharply interrupted before head, dorsum with two deep furrows, delimited by median and dorsolateral keels, apex depressed, epistoma triangular, prominent at centre; surface minutely wrinkled and punctured, finely sculptured; rostrum in lateral view straight up to antennal insertion and strongly curved downwards at apex, thickened apicad, dorsolateral keels straight, linear; upper margin of scrobes obtuse, linearly directed towards lower part of eyes, and touching eyes, lower margin parallel with upper margin, reaching underside at basal third; scrobes deep, glossy, surface in front of eyes roughly sculptured. Vestiture composed of dense white-greyish lanceolate acuminate scales, usually forward-directed in the furrows and outward-directed at apex, also present and less dense on punctures of keels, epistoma with long, moderately erect golden hair-like setae; sides with sparse, narrower scales in front of eyes, and slender, longer scales on pregenae ( Figs 59–60 ). Antennae relatively short, sparsely scaly, scape moderately curved forwards, regularly thickened from base to apex; funicle of nearly uniform thickness; segment I subcylindrical, slightly longer than wide, and slightly narrower than apex of scape, segments II–VII weakly transverse, progressively slightly widened; club long and elliptical, acuminate, finely hairy, excepting on scaly base of segment I ( Fig. 66 ). Head large, finely punctured, vertex flat, with a narrow scarcely distinct central pit; eyes large, moderately convex, in dorsal view upper margins subparallel, weakly convergent behind; vestiture composed of sparse setae, thickened along upper margin of eyes. Pronotum transverse, base oblique, shortly prominent at middle towards scutellum, sides straight, parallel from base to apex, with a strongly prominent cylindrical lateral bulge beyond middle of length, and an obtuse subapical hump, apex straight, not prominent over head, postocular lobes round, weakly distinct; dorsum on disc with a rhomboidal pattern shallowly impressed, delimited by narrow, moderately raised ridges, distinctly angular at middle, curved and not joined at apex, joined at base, central part roughly sculptured, with a very narrow middle line, higher forward, flattened and broadened at middle, nearly indistinct in basal half; surface in rhomboidal impression with irregular large punctures, barely delimited, anterior part with two large glossy granules, median part with a few other irregularly delimited granules; dorsolateral surface, by side of margins of discal impression, slightly impressed anteriorly, with some irregular granules, and a narrow, raised vertical ridge joining the angle of discal ridges with lateral bulges; base flattened, more glossy, with dense regular punctures; sides smooth, flattened, regularly punctured. Vestiture composed of elongate glossy whitish scales, sparsely disposed on discal impression, reaching base near median keel, absent from basal dorso–lateral plate, and larger, thickened on anterior dorso–lateral impression and on upper part of sides, forming a lateral stripe broadly curved towards dorsum on middle ( Fig. 62 ). Scutellum strongly prominent, elongate, bare, glossy. Elytra elongate, in lateral view dorsum weakly and regularly curved, declivity very feeble, nearly indistinct; at base narrower than base of pronotum, sharply broadened at humeri, maximum width shortly behind humeri, sides nearly parallel up to middle and regularly curved to apex; apex with an acute, distinct short projection in front of interval 3; surface smooth, finely punctured, without granules; intervals barely convex, odd intervals slightly wider than even, as wide as striae, particularly intervals 3 and 5, these distinctly more raised and slightly curved at base, interval 5 interrupted in a slightly raised hump followed by a transverse impression before apex, interval 7 more raised in basal quarter, flattened behind; striae deeply impressed, with seriate round punctures. Vestiture composed of glossy elliptical simple scales, relatively dense and uniformly disposed, not hiding integument, absent from an irregular median stripe between intervals 4 and 8, but usually with a round densely scaly spot on interval 6, and absent from impression behind apex of interval 5; setae extremely short, indistinct, except on lateral margin near apex. Legs slender, with elliptical acuminate simple scales on femora, tibiae and tarsi and sparse setae on internal side of tibiae and tarsi; femora slender, scarcely thickened at middle; fore tibiae rectilinear, scarcely broadened at apex, with apical denticles; middle and hind tibiae slightly more robust; tarsi with segment I triangular, segment II moderately transverse, segment III as long as wide, broadly lobed; hind tarsi with all segments longer; underside of segment III with nearly complete pad of orange scales, also present in a small patch on segment II; onychium longer than tarsal segments on fore tarsi, as long as tarsal segments on hind tarsi; claws very weakly divergent, thick, connate at middle. Ventrites convex, I and II of equal length and together longer than III–V together, III and IV very short, convex, V short, transverse; vestiture composed of very long, lanceolate whitish simple scales and, on ventrite V, semierect hair–like setae ( Fig. 64 ). Aedeagus tubular, median lobe scarcely curved, shortly narrowed at apex, apical lamella not expanded ( Figs 61, 63, 68 ). Sternite VIII of female with basal apodeme shorter than length of lamina, arms broadly widened, sclerotization dense in apical half of lamina; spermatheca with thick cornu, curved at 90° with respect of nodulus, this large, thick ( Fig. 67 ); hemisternites broad, with distinct subapical angle, regularly tapering at apex, styli apical, elongate ( Fig. 65 ).

Variation: The three specimens examined all have rather uniform sculpture and vestiture: one of the females is smaller, 7.0 mm long, and has the pronotum with a slightly less raised sculpture, and with the vestiture of scales on the pronotum and elytra more dense. The other female has the sternite VIII with a longer apodeme, as long as the lamina.

Affinities: Pachycerus badeni is closely related to P. sahelicus sp. nov. The differences between them are detailed in the description of the latter species. These two species, probably together with P. efflatouni , form a monophyletic group, differentiated from the other taxa of the genus by the small size, the simple scales, the absence of a prominent hump above the eyes, and the more or less prominent lateral humps on the pronotum.

Distribution ( Fig. 108 ): Known so far only from the three type specimens collected by Baden in an unknown locality of Madagascar, and by those used by Fairmaire for his description of P. spinipennis .

Figures

Figure 108. The Indo-African species of Pachycerus. Distribution map. Map taken from Encarta World Atlas 2000 (Microsoft Corporation), refined with Photoshop 7.0.

Figures 57–69. Pachycerus badeni (Faust, 1888), lectotype: body (57, 58); rostrum (59, 60); pronotum (62); antenna (66); ventrites (64); aedeagus (61, 63, 68). Pachycerus badeni, paralectotype: sternite VIII (69); hemisternite (65); spermatheca (67). Scale bars: 57, 58, 5 mm; 64, 2 mm; 59, 60, 62, 66, 1 mm; 63, 65, 68, 69, 0.5 mm; 61, 67, 0.2 mm.