Cionus griseus Har. Lindberg, 1958

Košťál, Michael & Caldara, Roberto, 2019, Revision of Palaearctic species of the genus Cionus Clairville (Coleoptera: Curculionidae: Cionini), Zootaxa 4631 (1), pp. 1-144 : 98-99

59. Cionus griseus Har. Lindberg, 1958

Figs 59 a–f.

Cionus griseus Har. Lindberg, 1958: 74 . Machado & Oromí, 2000: 228. Caldara, 2013: 123. Alonso-Zarazaga et al., 2017: 186.

Type locality. Canary Islands . Type series. In coll. Lindberg ( MZHF), despite of kind assistance of Museum staff, we could not find the type

material of C. griseus . However, according to the relatively precise original description stating “Körper schwarz, dicht mit anliegenden grauweissen schmalen Schuppen bekleidet. Halschild klein, schwarz, fast dreieckig...” it was possible to assign the description of C. griseus to the taxon as currently understood.

Synonyms. None. Based on sequencing of solely one mitochondrial DNA fragment COI, Stüben & Behne (2015) assumed that C. griseus could be a junior synonym of C. variegatus without having established a taxonomic act of synonymization. This is in contradiction with several clear morphological differences and different ecology of both species. Therefore, we do not agree with their proposed synonymy.

Redescription. Male. Body medium stout, suboval. Head: rostrum medium stout, medium long (l/ w 5.5, Rl/Pl 1.33), black; in lateral view slightly, evenly curved, in basal part of same width from base to antennal insertion, then very slightly tapered to apex; in dorsal view as in C. variegatus except slightly laterally constricted basal part; texture and vestiture as in C. variegatus . Head between eyes and eyes as in C. variegatus . Antennae as in C. variegatus except much shorter, hardly twice as long as wide spindle-shaped club. Pronotum: black, somewhat wider than long (Pl/Pw 0.67), densely punctured, punctures subrotund, of moderately unequal size, spaces between punctures smaller than puncture diameter; on sides and along midline in entire length densely covered with subrecumbent, elongate (l/w 4–6), yellowish scales, light scaled areas forming two irregularly delimited lateral and one medial bands, rest of pronotal surface covered with subrecumbent, short elongate black scales; widest at base, conically moderately narrowed to shortly before half of its length, then more distinctly narrowed to anterior margin, with shallow indistinct constriction, in lateral view in basal half flat, then moderately falling to anterior margin. Prosternum: as in C. variegatus . Scutellum: as in C. variegatus . Elytra: black, shaped as in C. variegatus (El/Ew 1.22), at base somewhat wider than pronotum (Ew/Pw 1.62), humeri subrotund, slightly prominent, with shallow posthumeral impression; moderately convex on disc; interstria 1 shortly before 1/3 of medial length moderately broadened, in preapical area very slightly broadened, interstria 2 on dorsum slightly narrowed and constricted laterally, in preapical area of same width, straight, encompassing small subrotund dorsal macula and almost concealed preapical black tomentous area without differently colored scale border; interstriae except perimacular areas of approximately equal width; odd interstriae without patches of scales; striae as in C. variegatus ; entire surface completely covered in major part with densely arranged, overlapping, recumbent, elongate (l/w 3–5) yellowish scales, in minor part with recumbent, shortly elongate black scales forming irregular black pattern on dorsum and humeri, both types of scales fully concealing elytral integument. Venter: as in C. variegatus except transversally ribbed part of metasternum and markedly more dense scales on sides. Legs: as in C. variegatus except always complete transverse band on profemora and more abundant yellow scales. Penis: Figs 59 d–f, as in C. variegatus except tipped and sinuate apex in lateral view.

Female. Rostrum longer (Rl/Pl 1.63), antennal insertion at 0.6 of rostrum length. Ventrites 1 and 2 without impression. Claws of approximately equal length.

Variability. Length ♂♂ 3.55–4.29 mm, ♀♀ 3.79–4.40 mm. Cionus griseus shows an enormous variability in the scale pattern on pronotum and elytra. The elytra can be almost completely yellow, with no dorsal and preapical maculae, or black spotted to black marbled with about 10% black portion of the entire elytral surface. The preapical macula in many specimens is absent or strongly reduced. The shape and the texture of pronotum, elytra and legs are not markedly variable.

Diagnosis. Cionus griseus is easily recognizable by completely concealed elytral integument, short, spindleshaped antennal club, elongate pronotum, reduced or missing femoral teeth, and penis shape.

Comparative notes. This species is most closely related to C. variegatus , from which it differs by markedly shorter antennal club, hardly twice as long as wide, longer pronotum, reduced black elytral pattern, shorter and broader yellowish scales on elytra, and tipped and sinuate penis in lateral view.

Biological notes. This is a common but endemic montane to subalpine species living on Scrophularia glabrata at elevations of approximately 1,500 to more than 2,000 m a. s. l. The first author collected a series of specimens on S. glabrata at elevations of 1,600 –2,000 m a. s. l. in Tenerife.

Distribution. Cionus griseus is endemic to the island Tenerife (Canary Islands).

Non-type specimens examined. We examined 75 specimens from Tenerife.

Figures

FIGURES 59–60. FIGURE 59. Cionus griseus. a: body in dorsal view (male), b: body in lateral view (male), c: rostrum in lateral view (female), d: penis in ventral view, e: penis in lateral view, f: apex of penis in dorsal view. Not to scale. FIGURE 60. Cionus latefasciatus. a: body in dorsal view (male), b: body in lateral view (male), c: rostrum in lateral view (female), d: penis in ventral view, e: penis in lateral view, f: apex of penis in dorsal view. Not to scale.