Stenocyphus Marshall, 1922

Guadalupe del Rio, M. & Lanteri, Analia A., 2013, Taxonomic revision of the genus Stenocyphus Marshall (Coleoptera, Curculionidae) from Brazil, ZooKeys 357, pp. 29-43 : 30-32

Stenocyphus Marshall, 1922 Figs 1-26

Stenocyphus Marshall, 1922: 183; Dalla Torre et al. 1936: 8 (catalogue); Emden 1944: 512 (in key); Hustache 1947: 6 (in key); Blackwelder 1947: 792 (checklist); Wibmer and O’Brien 1986: 51 (checklist); Alonso-Zarazaga and Lyal 1999: 165 (catalogue).

Type species.

Cyphus bituberosus Gyllenhal in Schoenherr 1833: 622.

Diagnosis.

Species medium-sized (LB: 10-16 mm long; LS: 8.4-13.0 mm long); body elongate, slender; integument densely covered with dull whitish, cream, or tan vestiture, composed of overlapping scales and scattered seta-like scales or setae (Figs 1-6). Rostrum short, with distinct lateral carinae (Fig. 7). Antennae slender, setose, moderately long; scape exceeding posterior margin of eyes. Pronotum slightly truncate-conical, impressed on disc and flanks. Elytra humped, with strongly bisinuate base and prominent humeri, bearing conical tubercles on elytral intervals 5, or 3 and 5, or 3, 5 and 7 (Figs 1-6). Metatibial apex with broad, squamose corbel, and apical comb about 2 × longer than dorsal comb. Aedeagus with long, curled flagellum.

Redescription.

Species medium-sized to large (LB: female 12.7-16.0 mm long, male 10.6-13.5 mm long; LS: female 10.1-13.0 mm, male 8.4-9.8 mm).

Integument black, densely covered with dull whitish, cream or tan vestiture; scales subcircular and striate; seta-like scales pale, short, decumbent on rostrum, pronotum and elytra, and moderately long on elytral tubercles, venter and legs (longer and denser on inner and outer face of tibiae).

Rostrum (Fig. 7) short (LR/WR: 1.00-1.21), sides slightly convergent toward apex (WF/WR: 1.20-1.50); dorsum strongly depressed; rostral carinae strong, subparallel, reaching anterior margin of eyes; median groove linear, exceeding hind margin of eyes; epistome broad, impressed, covered with subcircular small scales; scrobes scarcely visible from dorsum, slightly curving downwards, ending below eyes; gular angle very open (about 140-160°).Mandibles covered with creamy dispersed scales and coarse yellowish setae on external face; prementum subcordiform or subcircular, without long setae.

Antennae (Figs 8-10) (LB/LA: 2.47-3.00) slender, setose; scape exceeding posterior margin of eyes, slightly shorter than funicle; funicular article 2, 1.50 –1.79× longer than article 1, articles 3 to 7, 2 –3× longer than wide; club acuminate oval (LC/WC: 2.14-2.80).

Head. Eyes moderately convex; preocular impression distinct; postocular constriction slight. Forehead flat; vertex slightly convex.

Pronotum (Figs 1-3) moderately transverse (WP/LP: 1.16-1.32), with subparallel flanks on posterior 2/3, converging towards apex on anterior 1/3; pronotal disc and flanks longitudinally and/or irregularly impressed; anterior margin slightly curved backwards; hind margin moderately to strongly bisinuate, with posterior angles projected backwards.

Scutellar shield subtriangular or suboval, covered with cream or whitish scales.

Elytra (Figs 1-6) elongate, with maximum width behind midlength (LE/WE: 1.54-1.79; LE/LP: 2.13-3.27); base strongly bisinuate, projecting towards pronotum; humeri slightly to strongly prominent, without tooth; disc flat to slightly convex, elevated towards declivity; punctures of striae shallow to moderately deep, with one small oval scale on bottom; surface of intervals transversely undulate; intervals 5, or 3 and 5, or 3, 5 and 7 with tubercles; apical declivity abrupt, with distinct subapical callus; apex entire (not bifid), subacute. Metathoracic wings present, well developed.

Legs. Fore coxae tangent, slightly closer to anterior margin than to posterior margin of prosternum; protibiae curved inwards near apex, with distinct mucro and 6-8 small denticles on inner face (except in Stenocyphus tuberculatus , lacking mucro and denticles); metatibial apex distinctly expanded; corbels broad, densely covered with scales; apical comb about 2 × longer than dorsal comb; tarsomeres 1 and 2 elongate.

Abdomen (Figs 11-13). Intercoxal portion about 1.75 × as wide as cavities of metacoxae; ventrite 2 about 1.20 × as long as ventrites 3+4.

Female genitalia. Sternite VIII (Figs 14-16) subrhomboidal, slightly to moderately sclerotized, apex bearing long setae; apodeme 2 –3× as long as plate. Ovipositor (Figs 17-19) slender, long (about 2/3 of abdomen), slightly curved on lateral view, with or without coarse setae along external sides of posterior 2/3 of baculi; coxites slightly sclerotized with short setae; baculi subparallel to slightly divergent towards base; styli well developed. Spermatheca (Figs 20-22) with subcylindrical or subglobose body, conical nodulus, indistinct or slightly developed ramus and short to moderately long cornu (not or reaching opening of gland); spermathecal duct membranous, narrow, as long as half length of ovipositor; spermathecal gland 2 × as long as spermatheca.

Male genitalia. Penis (Figs 23-26) as long as ventrites 1-5, about 1.45 –1.50× as long as temones, slightly curved in lateral view, with rounded apex and large ostium. Endophallus with curled flagellum.

Sexual dimorphism.

Males slenderer and smaller than females; antennae slightly longer; pronotum less transversal and longer in relation to elytral disc (LE/LP: 2.13-3.05 in males; LE/LP: 2.90-3.27 in females); elytra more elongate (LE/WE: 1.62-1.79 in males; LE/WE: 1.54-1.57 in females), with tubercles slightly smaller than in females.

Distribution.

Stenocyphus is distributed along the coastal hills of eastern Brazil, in Espirito Santo, Rio de Janeiro and São Paulo states. This area corresponds to the Atlantic province of the Neotropical region sensu Cabrera and Willink (1980), or Brazilian Atlantic Forest according to the biogeographic scheme of Morrone (2002, 2006). It is characterized by a pluvial forest of trees of 30-40 meters high, with a lower stratum rich in palms, lianas and epiphytes.