Pachycerus simonae, Meregalli, 2009

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 : 316-319

PACHYCERUS SIMONAE SP. NOV.

Type locality: Southern Morocco, Cap Boudjour, 14°30′W, 25°08′N .

Holotype female: Morocco: ‘Rio de Oro, El Arch [= Cap Boudjour, 14°30′W, 25°08′N], X. Mateu’ ( MNHN, coll. De Peyerimhoff).

Paratypes: same data as above, 1 female ( MER); ‘Maghreb, wil. Tiznit, Ait ou Mribibele, Oued Massa [09° 41′W, 29° 52′N], 16.III.1997, E. Colonnelli’, 1 female ( CSNV) .

Diagnosis: A Pachycerus of large size, apparently related to P. segnis . It is characterized by the scales being bifid, and only connate at the base, with very divergent teeth, regularly covering the whole integument, by the relatively long rostrum, with sharp, narrow, slightly converging dorsolateral keels, a broad median elevation, and a narrow median keel, by the elytra with spaced small glossy granules on the intervals, and by the shape of sternite VIII of the female.

Measurements: Body length excluding rostrum: 14.31 mm. Rostrum: length, 2.56 mm; width, 1.49 mm; ratio, 1.71. Pronotum: length, 3.68 mm; width, 4.50 mm; ratio, 0.82. Elytra: length, 9.89 mm; width, 5.96 mm; ratio, 1.66. Ratio of elytral to pronotal length: 2.69 (holotype).

Description ( Figs 85–96 ): Body oval-elliptical, integument black, scarcely glossy, and densely covered with bifid scales ( Figs 85–86 ). Rostrum relatively long, nearly subquadrate in transverse section, dorsolateral margins very sharp, glossy, narrowly keeled, sublinear, and weakly convergent from base to apex, extended beyond antennal insertion; dorsum on middle with a broad obtuse very wide elevation, with narrow longitudinal glossy lines, and a narrow linear median keel, bifurcate at antennal insertion to delimit an oval fovea, linear again up to epistoma; epistoma subtruncate at apex, at centre convex, and with a narrow low keel continuing the median keel of rostrum; longitudinal furrows between the raised dorsolateral margins and the median elevation not deeply impressed, relatively broad; surface deeply sculptured, with short narrow irregular longitudinal wrinkles delimiting short and deep narrow impressions; in lateral view rostrum straight from base, upper margins slightly irregular, straight, median line visible, moderately and regularly convex; sides in front of eyes long triangular, glossy, with very dense irregular oval punctures, in part convergent and forming short rows; upper margin of scrobes not sharply delimited, moderately curved, flattened, barely distinct basally, and not reaching eyes, lower margin short, straight, reaching underside in basal part; scrobes short, deep, and glossy. Vestiture composed of long, bifid, dark ivory scales, connate at base and with long, divergent, acuminate teeth, inserted centripetally on the whole dorsum from base to antennae, relatively dense and partly hiding integument on all surface, including the central raised area, and of long, narrow, curved hair-like setae, sparse and barely visible on dorsum and more dense, replacing scales beyond antennal insertion up to basal part of epistoma ( Figs 87–88 ). Antennae short, robust, and densely covered with bifid scales and some slender acuminate setae; scape regularly thickened from base, straight; funicle as wide as scape at apex, segment I as long as wide, moderately conical, more densely scaly, segments II–VII short, transverse; club elliptical, as long as segments III–VII of funicle, finely and densely hairy, base of segment I moderately scaly, not glossy ( Fig. 93 ). Head slightly wider than rostrum at base, flattened, vertex flat, between eyes as wide as base of rostrum, sculpture and vestiture undifferentiated between base of rostrum and vertex; dorsolateral margins of rostrum extended to apex of vertex, slightly convergent behind, and not raised above, eyes; interocular pit round, deep, and clearly distinct; eyes nearly flat, narrowly elliptical. Pronotum large, base nearly linearly and obliquely prominent towards elytra, at centre acutely and shortly angular, sides weakly and regularly rounded, nearly parallel at base, and progressively more rounded towards apex, maximum width in basal third; apex slightly swollen above head, postocular lobes distinct; dorsum with a very thin median line in apical half and a shallow longitudinal impression in basal half; disc irregularly sculptured, with several scattered small glossy granules, more frequent at base, two larger granules near centre and some irregular glossy wrinkles delimiting sides of disc and forming a barely distinct, shallowly impressed curved figure, much narrowed forwards; dorso–lateral sides anteriorly shallowly impressed and with some minute granules; sides in their upper part with some isolated larger glossy granules; vestiture composed of bifid scales, connate at base, with narrow divergent teeth, dark ivory and relatively dense on the discal flat surface, amidst the granules, and not hiding the integument; lighter and more dense in a narrow curved dorsolateral stripe, convergent forwards, and in a lateral broad stripe, connected at middle of its length with the dorsolateral stripe, reaching apex in the upper part of postocular lobes and base in front of intervals 8–10 ( Fig. 90 ). Scutellum: not visible. Elytra oval-elliptical, at base narrower than pronotum base, moderately widened at humeri, sides nearly parallel, slightly compressed behind humeri, regularly and not sharply converging at apex, in lateral view regularly and weakly convex, and only slightly more curved on declivity; intervals flat, much wider than striae; odd intervals at base slightly more raised and densely granulose, and slightly larger than even intervals; surface with very small glossy spaced granules, more distinct on basal part of elytra, and usually more frequent and irregularly scattered on odd intervals, and sparse and aligned in a single row on even intervals, being less evident from middle of length to apex. Vestiture composed of relatively dense light-brown–yellowish bifid scales, connate at base, with very narrow divergent teeth, alternating with some slightly larger and lighter, either not or moderately bifid, scales, forming irregular and vaguely delimited patterns ( Fig. 89 ), the lighter scales being more frequent on striae and on two scarcely distinct round patches on intervals 3–4, one near base and one behind middle of length, this second patch followed by a slightly distinct patch with narrower and darker less dense bifid scales; apex of interval 5 followed by a small bare patch. Legs slender, with long, slightly prominent, bifid scales, including on tarsi, usually simple on fore tibiae, and with long, curved setae; femora very weakly thickened at middle; fore tibiae straight, broadened at apex, with a fringe of dark-orange apical denticles; fore tarsi short, segment I as long as wide and triangular, segment II transverse, segment III with lobes regularly developed; lateral margin of all segments with strong downward-directed setae, underside of segment III with small pad limited to anterior part; onychium as long as segments I–III, claws strong, connate up to mid-length, teeth robust, and scarcely divergent; hind tarsi slightly longer. Ventrites convex, intercoxal projection of ventrite I acute and long; ventrite I as long as ventrite II, ventrites III and IV short, suture slightly sinuate at margin, ventrite V narrow, depressed at apex; all ventrites with very dense coating of light-greyish bifid scales, connate at base, with very long teeth, and some long, curved narrow setae; bare spots scarcely visible ( Fig. 95 ). Sternite VIII with a short apodeme, arms narrow, regularly curved, moderately divergent, lamina oval, and fully sclerotized ( Fig. 91 ); spermatheca with a curved cornu, not narrowed apically; nodulus thick and tapering ( Fig. 92 ); hemisternites strong, parallel for most of their length, shortly converging at apex, styli slender, and cylindrical; symbiont pouches very long, twice as long as hemisternites ( Figs 94, 96 ).

Variation: The topotypical paratype is very similar to the holotype, excepting the smaller size (10.40 mm). The specimen from Tiznit has slightly more uniformly coloured vestiture of scales, but does not differ in the traits of taxonomic significance.

Affinities: This species seems to be related to the Mediterranean P. segnis (= P. scabrosus Brullé, 1832 ), from which it differs mainly in the bifid scales being connate at base, and with very narrow, often hair-like teeth, quite uniformly dispersed on the elytra, whitish alternating with light-brownish (scales larger, connate at mid-length, and with teeth comparatively broad, glossy white, irregularly dispersed on the elytra, and missing from two vague patches on the median part in P. segnis ). Pachycerus segnis , moreover, has dorsolateral margins of the rostrum scarcely raised, not sharply keeled, barely distinct near head, and, in lateral view, curved downwards; sides of pronotum with more prominent granules; elytra with maximum width in their basal third, sides slightly convergent behind the humeri; sternite VIII of the female more strongly sclerotized, with slightly angular arms, its apical plate nearly perfectly rectangular, and with a longer apodeme.

Etymology: I am pleased to name this species after my colleague Simona Bonelli, a lepidopterologist who patiently bears the disorder and confusion that I daily bring to the laboratory.

Distribution ( Fig. 108 ): Pachycerus simonae was found in the coastal deserts of southern Morocco, from the surrounding of Tiznit to Cap Boujdour (today’s name of “El Arch”). It seems to be a geographycal vicariant of P. segnis . No species of Pachycerus was reported by Kocher (1961) for Morocco.

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 85–96. Pachycerus simonae sp. nov., holotype: body (85, 86); rostrum (87, 88); pronotum (90); antenna (93); detail of elytral scales (89); ventrites (95); sternite VIII (91); hemisternites (94, 96); spermatheca (92). Scale bars: 85, 86, 5 mm; 94, 95, 2 mm; 87, 88, 90, 91, 93, 96, 1 mm; 92, 0.2 mm.