Stenobelus Zimmerman

Oberprieler, Rolf G., Thompson, Richard T. & Peterson, Magnus, 2010, Darwin’s forgotten weevil, Zootaxa 2675, pp. 33-46 : 35-36

Genus Stenobelus Zimmerman

Stenobelus Zimmerman in Alonso-Zarazaga & Lyal, 1999: 39; Legalov 2009: 302, 308.

Leptobelus Zimmerman, 1994: 356 (non Stål, 1866); Alonso-Zarazaga & Lyal, 1999: 39; Legalov 2009: 308.

Type species: Belus tibialis Blackburn, 1893 .

Diagnosis. For description see Leptobelus in Zimmerman (1994: 356–357). Distinguishable from Rhinotia and other genera of Australian Belinae by the following suite of characters: vestiture dorsally sparse, consisting of fine, white, single setae inserted in wall of large shallow punctures ( Figs. 7–8), except denser on midline of pronotum and sutural elytral interstriae in S. tibialis to form a white median stripe (vitta), pronotal setae directed forwards, elytral ones backwards; lateral and ventral vestiture much denser, white; scutellum broad, densely clothed in white setae; rostrum ( Figs. 1–6) dark, strongly downcurved, as long as or longer than head + prothorax, inserted on ventral side of head, finely punctate; antennae inserted subbasally, about an eye diameter or less in front of eye, with scape about as long as first 2 funicle segments together, distal 4 segments forming a loose club, the apical one with a distinct cone; femora moderately inflated, with subapical spine, which on front femora is large and often flanked by a smaller, outer one ( Figs. 9–10), middle and hind femora with dorsal edge distally armed with a row of few (2–7) isolated, small, black teeth; tibiae with 2 spurs (2-2-2) and preapical mucro, front tibiae with inner edge basally strongly excised to end in strong single spine ( S. testaceus , Fig. 9) or series of 2–4 smaller spines ( S. tibialis , Fig. 10) shearing against femoral spine when leg is closed, inner edge distally with row of smaller teeth; middle and hind tibiae with outer edge sharply crenulate; tarsi slender, longer than tibiae, basal tarsite inflated, especially in front tarsi where it is sexually dimorphic (elongate in male, shorter to subquadrate in female, Figs. 11–14), claws divaricate, appendiculate; abdomen with apex of ventrite 5 roundly emarginate in male, subtruncate in female; aedeagus (see Zimmerman 1994, fig. 235) short, apex acute, tectum with long, broad anterior apodemes, endophallus with long, single, basal flagellum and a pair of short, dentate sclerites inside aedeagal body, tegmen short, lateral arms continued into ventral apodeme; ovipositor (see Zimmerman 1994, fig. 236) with long gonocoxites, spermatheca with 2 processes, gland very large.

Distribution. South-western and south-eastern Australia into southern Queensland ( Fig. 15).

Remarks. As described and delineated by Zimmerman (1994), Stenobelus is a well-characterised genus and contains only 2 species, S. testaceus and S. tibialis . Legalov’s (2009) recent placement of 6 species of Rhinotia in it, R. acaciae (Lea) , R. angustata (Lea) , R. aphthosa (Pascoe) , R. elegans (Blackburn) , R. exilis (Lea) and R. sparsa (Germar) , and his erection of a distinct new subgenus, Germaribelus , for the last one of these are totally unjustified as none of them share the diagnostic (apomorphic) characters of Stenobelus . Legalov (2009) gave no reason for including these species in Stenobelus , and for R. acaciae , R. angustata , R. elegans and R. exilis this seems only based on the fact that Zimmerman (1994) placed these in a species group of Rhinotia in which he also keyed out, for convenience, the two species of Stenobelus (as Leptobelus ) as they similarly have dentate, short femora. Zimmerman was, however, explicit that the Stenobelus species do not belong in this species group of Rhinotia and were only included in the key in case they were confused with Rhinotia (as he did with Isacanthodes ganglionica (Pascoe) and the three species of Araiobelus Zimmerman ). The other two species, R. aphthosa and R. sparsa , were placed among many others in Zimmerman’s next species group (characterised by dentate, long femora), and it is inexplicable why Legalov picked out these two species from the group to include in Stenobelus since they are not, in fact, as narrow as Stenobelus (couplet 7 in Legalov’s key). Legalov’s erection of the new subgenus Germaribelus for R. sparsa is equally untenable since the front femora of the male are not appreciably “wider” in this species than they are in some others, especially in R. acaciae . Zimmerman (1994: 363) clearly stated that his species groups of Rhinotia were artificial and only intended as an identification aid, and Legalov’s (2007, 2009) division of Rhinotia into several genera and subgenera (10 of them new) as largely based on Zimmerman’s species groups is without any basis and best ignored until the genus is comprehensively revised. Since we cannot, however, accept a subgenus Germaribelus for Rhinotia sparsa in Stenobelus and also cannot sanction it as a valid subgenus of Rhinotia , we here formally synonymise only the name Germaribelus Legalov, 2009 with that of Rhinotia Kirby, 1819 (syn. n.).