Baldorhynchus ( Di Marco & Osella, 2002 )

Bello, Cesare, Osella, Giuseppe & Baviera, Cosimo, 2016, A taxonomic revision of the genus Baldorhynchus (Di Marco & Osella, 2002) stat. n. (Coleoptera, Curculionidae, Entiminae), Zootaxa 4070 (1), pp. 1-101 : 10-11

Baldorhynchus ( Di Marco & Osella, 2002) stat. n.

( Figures 1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H, 1I, 1L, 1M, 1N, 1O, 1P, 1Q, 1R, 1S )

Troglorhynchus Czwalina, 1875: 121 ; Bertolini, 1872 (!): 167; Stierlin, 1883: 581; Halbherr, 1896: 15; Bertolini, 1899b: 89; Daniel, 1903: 260; Holdhaus, 1903: 257; Ganglbauer 1906: 35; Solari A. & Solari F., 1907: 471; Reitter, 1912: 1 –23; Luigioni, 1929: 1 -1159; Porta, 1932: 56; Lona, 1937: 1431; Solari, 1955: 78; Conci, 1956: 7 -8; Osella, 1966: 389-390; Osella, 1968: 141- 56; Osella, 1983: 95-123; Abbazzi & Osella, 1992: 301; Abbazzi et all., 1994: 21; Caoduro et all., 1994:74; Osella & Zuppa, 1998: 1123 -1130.

Otiorhynchus (Troglorhynchus) : Magnano, 1998: 60, 71; Monguzzi, 1999: 233 -234.

Otiorhynchus (Baldorhynchus) : Di Marco & Osella, 2002: 257 -262; Colonnelli, 2003: 39; Davidian & Savitsky, 2006: 49, 73; Abbazzi & Maggini, 2009: 53; Hlaváč, 2011: 190; Magnano & Alonso Zarazaga, 2013: 309.

Type species. Troglorhynchus baldensis Czwalina, 1875 by Di Marco & Osella, 2002. Gender masculine.

Diagnosis. Curculionidae, Entiminae , Otiorhynchini . Easily distinguishable among Otiorhynchini by club with basal segment flat. Elytra convex, elongate-oval or oval, ogive-shaped on declivity and more or less unpigmented. Punctation of elytra and pronotum more or less deep and sparse. Rostrum elongate with ear-shaped dorsally scrobes. Eyeless; if vestigial, eyes flat. Femora edentate (except Baldorhynchus chiarae ). Tooth-like tubercles on inner edge of tibiae (except Baldorhynchus settei hoc opus). Lamina of sternite VIII with apical margin normally fused.

Description. Body elongate with size from 3.63 to 6.00 mm, maximum width of elytra from 1.15 to 1.70 mm. Cuticle from reddish-brown to dark-brown, seldom yellow, generally shining, rarely dull. The degree of maturity is related with color, because paler specimens are also less sclerotized. Integument glabrous, with sparse, more or less erect setae on head, pronotum and elytra, almost always with more or less dense golden-yellowish or grey pubescence on rostrum, around eyes areas and on apex of elytra. Head short, conical, smooth and shining. Eyeless. Vestigial flat eyes, more or less covered by pubescence. Rostrum subconical, finely punctured, more or less covered by pubescence, about twice longer than head and separated immediately behind vertex by transverse impression, scarcely and regularly curved from base to apex; dorsum more or less convex and in the middle sometimes with a short keel; mesorostrum more or less gibbous; epistoma with ten/sixteen setae thin, curved, semierect. Vertex width/mesorostrum width: ratio 1.30-2.10. Genae elongate, finely punctured. Scrobes ear-shaped, lateral, deep, completely visible dorsally. Antennae slender and elongate, with long, semi-erect, thin setae. Scape clavate and as robust as funicle regularly thickened from base to apex, curved on the basal third. Funicle 7- segmented. Scape length: 0.66–1.10 mm; funicle length: 0.72–1.20 mm. Scape length/funicle length ratio: 0.70– 1.13. Funicle with club ratios as follows: 10/15: 6/9: 4/8: 4/9: 4/6: 4/8: 4/6. Club, fusiform, elongate, with basal segment flat, longest of last four/seven funicle segments, at least twice wider than funicle, with golden pubescence and some sparse elongate setae similar to those funicle segments. Pronotum convex; in dorsal view tubulate or subexagonal; constricted and impressed in basolateral region; longer than wide; widest in or near the middle; variously and irregularly punctate; punctation more or less deep and isodiametric, differently wide, sparse, normally not uniformly arranged; each puncture bearing a short, golden, erect seta; smooth at central area more or less extended on disc. Length: 0.80–1.23 mm; width: 0.75–1.10 mm; ratio: 1.10–1.25. Scutellum small, excavated, triangular. Elytra fused with suture more or less evident, more or less flanged; convex, strongly rounded on sides; wider on basal third or on the middle; elongate-oval or oval in dorsal view; more or less twice as long as wide; narrowing and ogive-shaped on declivity. Wings absent. Humeri inconspicuous. Length: 1.96–3.02 mm, width: 1.15–1.70 mm, ratio: 1.54–2.07. Each elytra with eight/ten striae more or less complete. Striae with punctation more or less deep and isodiametric but of different width; each with a minute seta; interspaces between strial punctation more or less wide. Interstriae barely wider than striae, flat, smooth, with long semi-erect golden setae. Legs more or less thin and elongate, with rather long golden erect setae. Femora edentate (feebly dentate only in B. chiarae ) more or less clubbed in the middle and narrowing to apex. Tibiae setose with five–eight tooth-like tubercles and acute spines on inner edge; mucro more or less evident on inner edge of apical angle; corbels simple. Protibia and mesotibia more or less curved in side view, metatibia sinuous. First tarsal segment elongate, conical; segment second short and transverse; segment three strongly bilobed; all segments with long thin golden setae. Onychium robust and claws free, elongate. Abdominal ventrites shining, slightly rugose, finely punctured, each point bearing a short seta. Ventrite 5 slightly shorter than 3+4 and, apically with fringe of long sparse setae. Sutures evident and strongly curved between ventrites 1 and 2, between ventrites 2 and 3 slightly curved, between ventrites 3–5 straight. Procoxae large, conical, connate. Mesocoxae large, separated by a space about as their diameter. Metacoxae rather flattened, separated by a space about three times the diameter of one of it. Male genitalia. Penis lengthened, sub-parallel seen from above and regularly and moderately curved in lateral view. Tegmen sclerotized. Internal sac present with evident sclerites in all species. Apex of penis more or less rounded. Sternite IX sinuous at apex with manubrium as in Fig. 1N . Female genitalia. Sternite VIII with sides sub-parallel or slightly curved; lamina subcircular with apical margin more or less fused, bearing short setae. Spermatheca sclerotized with cornu, ramus and nodulus more or less developed. Ovipositor weakly sclerotized, gonocoxites tapered, with short styli and several more or less long setae.

Sexual dimorphism. To date, 21 species of 37 are surely or probably amphigonic. Males can be recognized by their smaller size and less slender appearance, the legs stronger with a more noticeable apical mucro and ventrites 1 and 2 slightly hollowed ( Figs 2, 2 ’, 4, 4’, 17, 17’).

Ecology. All Baldorhynchus species are eyeless or have vestigial eyes. Adults are usually collected in caves or wooded environments, in limestone mountains and hills (from 100 to 1840 m at the summit of Avez) with considerable humidity. Baldorhynchus , like Solariola ( Baviera 2015) , can be considered “old forest dwellers” and could so be considering useful bioindicators for relatively natural and stable habitats. All weevils are phytophagous or rhizophagous insects, so it is hardly possible to consider them true troglobionts, even when they are only known from this environment ( Osella & Zuppa 1998). Their hygrophyly and rhizophagous diet might be the reasons for the colonization of soil and caves. Therefore, for these species, the caves act as “traps”.

Distribution. The current distribution of Baldorhynchus is limited to Northern Italy mainly in the hills or mountains between the Brembo River (Lombardia) and the Piave River (Veneto) ( Fig. 127 ). The main soils are those with pedogenetic structure in depth and weakly differentiated profile (Eutric and Calcaric Cambisols), but also on shallow soils of highest elevations (Lithic Cryosols), more or less shallow soils with organic matter accumulation on the surface (Lithic, Mollic, Eutric, and Rendzic Leptosols) and alluvial soils (Eutric Fluvisols) ( FAO/IIASA/ISRIC/ISSCAS/JRC, 2012).

Figures

FIGURES 1 E – 1 S— Genus Baldorhynchus: details of B. baldensis neotype ♂ from “ Bocca di Navene, Monte Baldo ”: 1 Eelytra, dorsal view and punctuation; 1 F—pronotum and rostrum, dorsal view and puntuation; 1 G—side view of eyes area; 1 H—femora and tibia; 1 I—toothed femora of B. chiarae; 1 L—tibia of B. settei; 1 M—internal sac; 1 N—tegmen and IX sternite; 1 O—VIII sternite; 1 P—spermatheca; IQ—gonocoxites; 1 R—sternites 3 – 4 – 5; 1 S—sternites 6 – 7.

FIGURE 127 — Distribution in Northern Italy of genus Baldorhynchus. FIGURE 128 — Distribution of the B. baldensis group.

FIGURES 2 – 2 f — Baldorhynchus amicalis (Osella, 1983) holotype ♀ from “ Grotta di Case Vecie, Grezzana, Verona ”: 2 — habitus, dorsal view (scale bar: 1 mm); 2 a—habitus, lateral view; 2 b—rostrum, lateral view; 2 c—pronotum; 2 d—elytra punctuation; 2 e—funicle and club; 2 f—spermatheca.