Cionus concavifrons, Caldara & Košťál, 2023

Caldara, Roberto & Košťál, Michael, 2023, A Taxonomic Revision Of The Afrotropical Species Of The Weevil Genus Cionus (Coleoptera: Curculionidae), Zootaxa 5288 (1), pp. 1-98 : 59-60

31. Cionus concavifrons sp. n. ( Figs 31a–f )

Type locality. Katberg Pass env. (Eastern Cape, South Africa) .

Type series. Holotype, male. “ SOUTH AFRICA EASTERN CAPE c. Katberg Mts. Michael Košťál leg. / Katberg Pass env. 1300 m S 32°28.1’ E 26°40.3’ 26.xi.2018 ” ( NMPC) . Paratypes: same data of holotype (22, MKCS; 4, RCCM); “ SOUTH AFRICA EASTERN CAPE c. Katberg Mts. Michael Košťál leg. / Katberg Pass env. 1500 m S 32°27.5’ E 26°39.4’ 1.xii.2018 ” (4, MKCS) ; “ SOUTH AFRICA EASTERN CAPE c. Katberg Mts. Michael Košťál leg. / Katberg env. 3 km S 1050 m S 32 28.9 E 26 40.9 26.xi.2018 ” (8, MKCS) ; “ E. Cape Prov., Katberg , 4,000 ft., 1– 15.1.1933 / S. Africa, R.E. Turner, Brit. Mus. 1933–79” (2, BMNH) .

Diagnosis. Rostrum elongated, especially in female, its upper outline basally slightly concave, distinctly curved in apical half. Head between eyes considerably narrow. Pronotum with four transversely arranged protuberances emphasized by tufts of erect scales, median ones very small. Ventrites with elongated scales, in male slightly more elongated, hair-like at midline, forming a distinct tuft on V2. Claws distinctly asymmetrical in male.

Description. Male ( Figs 31a–b ). Body: short, globose. Head: rostrum moderately stout, elongated (Rl/Rw 6.20–6.27, Rl/Pl 1.63–1.67), dark brown; in lateral view in basal third straight, in apical half somewhat curved, of same width from base to apex, basally slightly concave at upper outline; in dorsal view from base to antennal insertion almost parallel-sided, striate-punctate, with several subtle, irregular, more or less long carinae, from base to near apex with sparse, recumbent elongated (l/w 6–8) grayish yellow scales. Head between eyes narrow, 0.3× as wide as rostrum at base, with dense, recumbent yellowish scales forming tufts around eyes. Eyes flat. Antennae reddish with dark brown club, inserted just behind middle; scape long (l/w 10); funicle distinctly shorter than scape, S1 more robust and distinctly shorter than S2, 1.2× as long as wide, S2 2.5 × as long as wide, S3 slightly longer than wide, S4–5 as long as wide; club oblongly oval, 0.8× as long as funicle, pubescent. Pronotum: dark brown, with moderately irregular, very small, indistinct, very shallow punctures completely hidden by recumbent, dense, elongated (l/w 5–8), grayish yellow scales forming two large, very slightly darker maculae at base; conical, distinctly transverse (Pw/Pl 1.50–1.55), widest at base, with rectilinear sides, slightly convex on disc, with four transversely arranged “false” protuberances, median ones very small. Prosternum: with anterior margin distinctly emarginated. Scutellar shield: heart-shaped, densely covered with grayish yellow scales similar to those on elytra. Elytra: dark brown, short (El/Ew 1.12–1.16), moderately globose, humeri rounded, sides in basal half subparallel, widest at middle, distinctly wider than pronotum (Ew/Pw 1.36–1.44), almost flat on disc; interstriae almost flat, distinctly sinuate in basal third, with moderately irregular, very small, indistinct, very shallow punctures completely hidden by dense recumbent (only a few very slightly raised) grayish yellow scales, partly obliquely arranged, with few spots formed by dark brown scales; striae not visible, with irregular, moderately deep punctures, slightly narrower than interstriae, intervals between punctures situated at same level as interstriae. Venter: mesosternal process moderately convex, emarginated. Metasternum densely covered with grayish scales being wider at sides and more elongated but not hair-like in middle. Abdomen with slightly irregular, very small, indistinct, very shallow punctures hidden by moderately dense, elongated grayish scales being denser, more elongated, hair-like in middle of V1 and especially of V2 where forming a distinct tuft; V1 1.9× longer than V2; V1+V2 3.6× longer than V3+V4, which are as long as V5. Legs: densely covered with elongated grayish scales; femora blackish with small teeth; tibiae brown; tarsi brown, with onychium as long as segments 1–3 combined; claws distinctly asymmetrical, one claw 1/3 as long as other. Penis: Figs 31d–f , its body subparallel-sided, tip blunted. Flagellum moderately thin, long, slightly narrowed from base to apex.

Female. Rostrum distinctly longer (Rl/Rw 7.7; Rl/Pl 2.17), in lateral view distinctly arcuate and more concave at base ( Fig. 31c ), claws only slightly asymmetrical, V1 convex also along midline, V2 flat, without tuft of hair-like scales.

Variability. Length 2.6–3.1 mm. Sometimes dorsal vestiture unicolorous varying from grey to yellowish. There are no other significant differences among specimens of the type series.

Etymology. The name of the species refers to its frons which is concave at the rostrum base.

Remarks. This species is characterized by the long rostrum especially in the female, which is concave at its base. A similar rostrum is present in C. tenuepilosus , which however has elytra longer and narrower in comparison with the pronotum. Moreover, this species lacks dark spots on elytra and the comb of scales around the upper margin of eyes.

Biological notes. The second author collected most of specimens by beating shrubby Buddleja sp.

Distribution. South Africa (Eastern Cape).

Figures

FIGURES 31–32. FIGURE 31. Cionus concavifrons sp. n. 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. FIGURE 32. Cionus longinasus sp. n. 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.