Aristogethes Audisio & Cline, 2009

Audisio, Paolo, Cline, Andrew Richard, Biase, Alessio De, Antonini, Gloria, Mancini, Emiliano, Trizzino, Marco, Costantini, Lorenzo, Strika, Sirio, Lamanna, Francesco & Cerretti, Pierfilippo, 2009, Preliminary re-examination of genus-level taxonomy of the pollen beetle subfamily Meligethinae (Coleoptera: Nitidulidae), Acta Entomologica Musei Nationalis Pragae 49 (2), pp. 341-504 : 402-406

17. Aristogethes Audisio & Cline , gen. nov.

( Figs. 17 a–m)

Type species. Meligethes translatus Grouvelle, 1913: 393 (by present designation) [= Meligethes (Acanthogethes) atratus Reitter, 1872: 244 , 259, nec Nitidula atrata A. G. Olivier, 1790: 18); = Aristogethes translatus (Grouvelle, 1913) comb. nov.].

Generic description and diagnosis. Inclusive species vary greatly in size (1.8–3.7 mm length), and share the following combination of characters.

Body color and pubescence: pubescence silvery-whitish to golden, in most species strongly developed, long and dense, recumbent, frequently partially obscuring the variably colored dorsal body surface (black to reddish-brown); pronotal and elytral sides narrowly flattened, typically same color as disc. Lateral margin of pronotum and elytra fimbriate, each seta usually 0.5–0.6× as long as those on elytral disc; posterior margin of pronotum with moderately long, usually distally multifid microsetae, microsetae uniformly distributed on middle region anterior to scutellum ( Fig. 17g).

Dorsal habitus: body moderately convex, variably shaped ( Figs. 17a, b); dorsal punctures on discal portion of pronotum larger than eye facets, usually deeply impressed and densely distributed; anterior margin of clypeus truncate or moderately emarginate, narrowly bordered ( Figs. 17c, d), without small, faintly distinct, medial bulge; circum-ocular furrows (occipital sulci) on dorsal side of head in most species complete, narrow, and deeply impressed ( Fig. 17c), absent in a few species, (i.e. AUDISIO et al. 1998; Fig. 17d); eyes large and usually moderately projecting laterally ( Figs. 17a–d); pronotum with distinct obtuse posterior angles, never directed posteriorly ( Figs. 17a, b); scutellum regularly punctured on most of exposed portion ( Fig. 17g); elytra with punctures simple or completely transversely strigose; elytral humeral angle moderately distinct, not protruding laterally ( Figs. 17a, b); elytral humeral striae not distinct; elytral pre-sutural striae faintly distinct, originating at scutellar vertex, terminating close to elytral apex, and delimiting on each elytron a flat, poorly defined narrow sutural border, usually narrower than proximal portion of 3 rd antennomere; elytral apices truncately rounded in both sexes ( Fig. 17a); pygidium partially exposed, moderately convex, apically rounded in both sexes ( Figs. 17a, b).

Ventral habitus: antennal furrows markedly delimited, nearly parallel-sided, slightly convergent posteriorly; mentum subpentagonal, submental impression short and transverse ( Fig. 17e); antennal furrows on anterior margin of prosternum moderately to strongly raised but relatively short ( Fig. 17e); prosternal process relatively wide, subapical dilated portion 2.3–2.6× as wide as maximum width of 1 st antennomere, apex usually blunt ( Fig. 17f); lateral borders of prosternal process delimiting moderately deep and narrowly impressed furrows, distally terminating over predistal lateral expansions, nearly reaching the smooth posterior margin ( Fig. 17f); posterior margin of mesoventrite simple, never medially incised ( Fig. 17f); male impressions on metaventrite more or less strongly developed; first two visible abdominal ventrites simple in both sexes, without tufts of setae; caudal marginal lines of metacoxal cavities nearly simple, slightly and regularly deviating posterio-medially from posterior margin of metacoxal cavities ( Fig. 17k), with deep arched impression of outer ‘axillary’ line ( Fig. 17k); ‘axillary’ space on first abdominal ventrite reduced, ‘axillary’ angle usually subacute ( Fig. 17k); relatively wide and short, deeply impressed arched impressions on basal portion of last visible abdominal ventrite, frequently partially covered by distal portion of penultimate visible abdominal ventrite ( Fig. 17h).

Appendages: male 1 st antennomere 0.7–0.8× as long as width of protibiae excluding distal teeth ( Figs. 17a, b); 3 rd antennomere in both sexes usually 2.5–2.6× longer than wide, 0.9–1.0× as long as but distinctly thinner than 2 nd antennomere ( Fig. 17e); 4 th and 5 th antennomeres in both sexes subequal, short, slightly longer than wide; antennal club compact, small, simple, comprising last 3 antennomeres in both sexes (8 th antennomere scarcely widened, 0.5–0.6× as wide as 9 th antennomere) ( Fig. 17e), distinctly narrower than width of protibiae, sexual dimorphism absent; labial palpi moderately long in both sexes ( Fig. 17e), terminal segment nearly1.6–1.8× as long as wide; maxillary palpi long in both sexes ( Fig. 17e), terminal segment 2.6–3.0× as long as wide; mandible mid-sized ( Figs. 17a, b), apex acuminate, no sexual dimorphism present; tarsal claws simple, bluntly toothed, or strongly and acutely toothed at base ( Fig. 17m; Figs. 55–57 in AUDISIO et al. 1998); tarsi of normal size and shape, 0.5–0.7× as long as corresponding tibiae ( Figs. 17a, b); protibiae with a series of variably shaped, frequently uneven, and more or less sharply acuminate, perpendicular or oblique teeth on lateral margin ( Figs. 17a, b; Figs. 9–18 in AUDISIO et al. 1998), with or without a group of larger distal teeth; meso- and metatibiae on lateral margin bearing a single and usually even row of relatively long and robust spurs, without U-shaped sinuosity at distal third; meso- and metatibiae of variable width, usually slender and narrow ( Figs. 17a, b), never subtrapezoidal or axe-shaped; tibial sexual dimorphism present in a few species ( Fig. 19 in AUDISIO et al. 1998); tarsal plates of prolegs usually distinctly wider in males; posterior margin of metafemora in both sexes without tubercles, spines, or gibbosities.

Male genitalia: processes along inner side of parameres absent ( Figs. 22 –44 in AUDISIO et al. 1998), with more or less deeply incised or subtruncate distal margin, and always without deep median longitudinal desclerotization from proximal portion of tegmen extending to medial distal excision; median lobe of aedeagus variable, without lateral emargination, narrowed and variably shaped distally, most species with acuminate or truncate distal projections.

Female genitalia (ovipositor): variably shaped, usually large; styli moderately long or short, simple, cylindrical, usually unpigmented, inserted close to apex of contiguous gonostyloids (Figs. 45–52 in AUDISIO et al. 1998); each gonostyloid lightly sclerotized and occasionally moderately to darkly pigmented distally, with a simple, never indentate outer portion of basicoxites, and a single, narrow, lightly pigmented and sclerotized arcuate area along outer subdistal portion of gonostyloids. ‘Central point’ of ovipositor usually nearly centrally located, with or without proximad directed spicule.

Etymology. The generic name is derived from a combination of the Greek ‘ αριστος’ (= excellent, the best), to emphasize the usually long and elegant dorsal pubescence of most inclusive species, and from ‘- gethes ’, to emphasize its phylogenetic relationship with Meligethes . Gender masculine.

Biology. The biology of inclusive species is only partially known, but appears to be similar throughout the genus. Members of Aristogethes gen. nov. are likely all associated as larvae with flowers of Sterculiaceae . This specialization likely occurred in a single ecological shift followed by a marked radiation and morphological diversification. Members of the speciose genus Hermannia L. are the recognized larval host-plants of most described Southern African species ( AUDISIO et al. 1998, and unpublished data; AUDISIO & DE BIASE 2007).

Phylogenetic position. Available morphological and molecular ( TRIZZINO et al. 2009) datasets provide weak support for tentative placement of Aristogethes gen. nov. within Meligethinae , with potential relationships with Afrogethes gen. nov. and allied taxa, or with ‘ Meligethes ’ perfectus Easton, 1960 and allied species in the group of African-Indian species with uncertain generic affinities (see Afrogethes gen. nov.).

Taxonomy and geographic distribution. Aristogethes gen. nov. includes 19 described African species, which were attributed to three formerly recognized species-groups, i.e. the ‘ Meligethes pubescens / plumbeus ’, ‘ M. incognitus ’, and ‘ M. eremita ’ species-groups ( AUDISIO et al. 1998, and unpublished data; AUDISIO & DE BIASE 2007).

Aristogethes argentarius (Audisio, Kirk-Spriggs South Africa: E Cape, KwaZulu-Natal

& Kirejtshuk, 1998) comb. nov.

Aristogethes aurivestis (Audisio, Kirk-Spriggs South Africa: W Cape

& Kirejtshuk, 1998) comb. nov.

Aristogethes bisignifer (Kirejtshuk, 1996) comb. nov. N Namibia

Aristogethes colonnellii ( Audisio & De Biase, 2007) South Africa: W Cape comb. nov.

Aristogethes confertus (Reitter, 1872) comb. nov. South Africa: W and E Cape

Aristogethes eremita (Audisio, Kirk-Spriggs South Africa: W Cape, NW Province, S Namibia & Kirejtshuk, 1998) comb. nov.

Aristogethes fuerschi ( Spornraft & Audisio, 1995) South Africa: Mpumalanga, Free State, KwaZulucomb. nov. Natal

Aristogethes hermanniae (Audisio, Kirk-Spriggs South Africa: E Cape

& Kirejtshuk, 1998) comb. nov.

Aristogethes incognitus ( Grouvelle, 1910) comb. nov. Tanzania

Aristogethes marshalli ( Grouvelle, 1914) comb. nov. South Africa: E Cape, KwaZulu-Natal

Aristogethes massivus (Audisio, Kirk-Spriggs South Africa: Limpopo

& Kirejtshuk, 1998) comb. nov.

Aristogethes namaqwaensis (Audisio, Kirk-Spriggs South Africa: W Cape

& Kirejtshuk, 1998) comb. nov.

Aristogethes pecten (Audisio, Kirk-Spriggs South Africa: W Cape, Free State

& Kirejtshuk, 1998) comb. nov.

Aristogethes pilosus ( Easton, 1960) comb. nov. Kenya, Cameroon

Aristogethes plumbeus (Reitter, 1872) comb. nov. South Africa: W Cape

Aristogethes pubescens (Reitter, 1872) comb. nov. South Africa: W Cape

Aristogethes rufofuscus (Audisio, Kirk-Spriggs South Africa: Limpopo; Namibia

& Kirejtshuk, 1998) comb. nov.

Aristogethes translatus (Grouvelle, 1913) comb. nov. South Africa: W Cape

Aristogethes verniceus ( Kirejtshuk, 1990) comb. nov. Namibia