Solariola Flach, 1908

Baviera, Cosimo, 2015, A review of the genus Solariola Flach, 1908 (Coleoptera: Curculionidae: Entiminae, Peritelini), Zootaxa 3920 (3), pp. 401-430 : 404-405

Solariola Flach, 1908

Solariella Flach, 1905: 318 not S. Wood, 1842

Solariola Flach, 1908: 56 ; Reitter, 1914: 111; Solari & Solari, 1923: 51; Hustache, 1923: 35; Luigioni, 1929: 871; Porta, 1932: 57, 58; Lona, 1937: 233, 234; Hoffmann, 1950: 151; Osella, 1976: 194; Osella, 1979: 312, 313; Abbazzi, Bartolozzi & Osella, 1989: 321, 322; Abbazzi & Osella, 1992: 302; Abbazzi et al., 1995: 22; Osella & Di Marco 1996: 349 –355; Alonso Zarazaga & Lyal, 1999: 170; Osella et al., 2004: 101, 108; Osella et al, 2005; Abbazzi & Maggini, 2009: 58; Magnano & Alonso Zarazaga, 2013: 80, 346.

Type species. Troglorhynchus paganettii Flach, 1905 .

Diagnosis. Curculionidae , Entiminae , Peritelini , with single tarsal claw. Rostrum distinctly longer than head, scarcely and regularly curved from base to apex. Scrobe lateral, deep, completely visible from above. Eyes absent, although the ocular area is composed of a longitudinally raised oval stemma. Frontal area often with an elongate dimple between eyes. Prothorax widest at or near the middle, with large punctures, each of which shows a minute eccentric bulging point at which a seta is located. Elytra oblong, more or less elongate oval, about two times longer than their maximal width, narrower at base than maximum width of prothorax. Elytron each with ten striae, strial punctures generally large to very large, almost subquadrate with margins often touching one another. Vestiture on elytral intervals and on pronotum formed by sparse short to long setae more or less curved and raised from the integument (more raised at elytral base and apex), microscopic setae transversally inserted in the punctures of elytral striae. Lower surface of rostrum, under the scrobe, with more or less minute spatulate setae, sometimes present also dorsally around eyes and on elytral apex. Femora and tibiae normally edentate. Aedeagus with sides more or less broadened on basal half, sides often parallel from base to middle, and thereafter widened, apex very often slightly arched, regularly curved; usually with well developed triangular lamella, very often covered on sides. Sclerites of the internal sac of the aedeagus absent. Spermatheca weakly sclerotized, relatively long, nodulus more or less slightly broadened and ramus very short, cornu long, somewhat pointed.

Description. Body size from 2 to 4 mm, maximum width of elytra from 0.5 to 1.5 mm. Cuticle from reddishbrown to dark-brown, rarely yellow, often with antennae and legs light reddish, generally dull, seldom glossy (color variation is probably related to maturity, as the paler specimens are always weakly sclerotized). Integument glabrous, with sparse setae on head, longer setae on prothorax and elytra, seldom with slender, lanceolate scales on underside of rostrum, around eyes and apex of elytra.

Head. Transverse, short, punctured; eyes atrophied, composed of only one longitudinally oval, more or less raised, stemma, dorsally separated by more than width of base of rostrum; interocular fovea small, barely distinct. Rostrum distinctly longer than head, from 0.8 to 1.2 times wider than long, very scarcely, and generally regularly curved from base to apex; dorsum confusedly and slightly wrinkled, with more or less wide rostral furrow, and differently arched and distant to each other rostral carinae, often convergent at base. Under sides of rostrum under the scrobe more or less densely covered with whitish-yellowish spatulate setae, often also partially visible to very dense dorsally, around eyes. Apex and base of rostrum with short and sparse setae more or less recumbent, pointing backward. Setae present on both sides and on upper surface of rostral carinae. Scrobe lateral, deep, completely visible from above. Frontoclypeal suture indistinct, clypeus short, transverse. Genae elongate, very scarcely punctured. Antennae long and slender, 11-segmented; scape from 4 to 6 times longer than wide, slightly curved in the proximal third, regularly thickened from base to apex which is curved in the basal third; funicle seven segmented. Club normally short, oval.

Pronotum. Nearly as long as wide, strongly convex, widest around the middle, base and apex straight. Apex generally slightly shorter than base, with large irregular deep punctures bearing a long (average length from 0.07 to 0.09 mm) recumbent seta originating from a minute bulging point at each puncture. Points are more distant from each other on disc than on sides, interspaces between punctures often matte, microreticulate, centripetal discal setae strongly inclined. Base of pronotum with row of confluent punctures forming shallow, poorly defined antibasal sulcus bearing flat bristles whose multifide apex is visible only at very high magnification. Scutellar shield invisible.

Elytra. Elongate oval, narrower at base than maximum width of prothorax, often nearly twice longer than wide. Sides sub-parallel, regularly convergent to apex, scarcely and very regularly curved, maximum width around the mid length, narrowing apically, sutural interval flat; humeri obliquely rounded, dorsum with ten striae of more or less deep and robust punctures, each with a short transverse seta (often ≤ 0.03 mm). Often the punctures of first two striae are more widely separated than the others. Interstriae normally clearly demarcated by striae, flat, with small punctures whose number is less than that of the points of striae, each bearing a seta almost curved and more or less inclined on elytral surface. Setae at elytral base and apex always more raised than others. Near elytral apex some setae are often spatulate and recumbent on elytral surface.

Legs. Thin, elongate, with rather long flattened setae, half-lifted on tarsi; femora edentate (dentate or subdentate only in S. paganettii ), more or less clubbed in the middle and narrowing to apex; tibiae setose, barely curved at apical third in side view, more so in males than in females, meso- and metatibiae with small to very small tooth-like tubercles on inner edge; apex of tibiae more or less mucronate and with a fringe of thick golden setae; tarsi with long thin setae, first tarsal joint elongate, subtriangular; joint 2 short, transverse; joint 3 strongly bilobed; single claw robust and long. Procoxae connate, mesocoxae separated by space about equal to their diameter, metacoxae separated by space about three times their diameter.

Sternites. Shining, slightly rugose, finely punctured, each point bearing a strongly flattened short seta. Urosternite 5 slightly longer than 3+4; sutures evident and strongly curved between urosternites 1 and 2, whereas they are straight between 2 and 3, 3 and 4, 4 and 5. In males urosternites 1 and 2 are more or less hollowed.

Male genitalia. Aedeagus long and curved, sides with sclerotisation often broadened in basal half, very often with medially more or less convergent sides. Lamella subtriangular, often partially covered by sides. Internal sac very weakly sclerotized

Female genitalia. Spermatheca very weakly sclerotized, often relatively long, with nodulus short more or less broadened, ramus very reduced, cornu thin and strongly elongate or thick and short, more or less falcate and elongate.

Ecology. Species of this genus are flightless, probably root-associated weevils. According to Osella (1979), Solariola , like the Otiorhynchus of the subgenus Lixorrhynchus are found in wooded environments of low, limestone mountains and hills (from 300 to 1900 m) with considerable humidity, so that they can be considered “old forest dwellers” ( Brandmayr & Pizzolotto, 1990). During this research Solariola specimens were collected also in sandy soil ( S. vitalei and S. angelae n. sp.) for the first time.

Distribution. The current distribution of Solariola is limited to southern Italy (Campania and Calabria) and Sicily.

Taxonomic notes. Based on morphological affinities, members of this genus can be divided in two groups, the S. gestroi species group, and the S. doderoi species group. The first group, characterized by small to medium body length, slightly rounded sides of pronotum, long elytral setae and aedeagus with narrow apex, is comprised of S. gestroi , S. hirtula , S. fraterna n. sp., and S. paganettii from southern Italy, and S. vitalei and S. pesarinii n. sp. from Sicily. The second group, characterized by medium to large body length, strongly rounded sides of pronotum, more or less short, curved and flattened elytral setae, seldom glossy tegument, and aedeagus often with a wide apex, includes the Sicilian S. doderoi , S. ruffoi and S. angelae n. sp..