Asterogethes 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 : 351-354

2. Asterogethes Audisio & Cline , gen. nov.

( Figs. 2 a–n )

Type species. Meligethes arcuatus Reitter, 1872: 252 (by present designation) [= Asterogethes arcuatus (Reitter, 1872) comb. nov.].

Generic description and diagnosis. Inclusive species vary greatly in size (1.7–3.6 mm length), and share the following combination of characters.

Body color and pubescence: pubescence golden to silvery-whitish, moderately elongate, suberect, partially obscuring the variably colored (yellowish, reddish, brown, blackish-brown, or brown with yellow spots on elytra: Figs. 2a, b ) dorsal body surface; pronotal and elytral sides strongly narrowed and flat, yellowish and frequently paler than pronotal disk. Lateral margin of pronotum and elytra with series of long, erect setae ( Fig. 2d ), each seta usually as long as those on elytral disc; posterior margin of pronotum comprising moderately long, usually distally trifid or tetrafid microsetae ( Fig. 2m ), microsetae also uniformly distributed on middle region anterior to scutellum.

Dorsal habitus: body moderately convex, variably shaped, moderately short and wide, oval, or more narrow and parallel-sided ( Figs. 2a, b ); dorsal punctures on pronotal disc larger than eye facets, usually deeply impressed and densely distributed; anterior margin of clypeus moderately arcuately emarginate, simple, i.e. without small distinct bulge at middle, and not bordered ( Figs. 2a, b, c ), with circum-ocular furrows (occipital sulci) on dorsal side of head absent ( Fig. 2c ); eyes large and usually moderately projecting laterally ( Figs. 2a, b, c ); pronotum with faintly distinct posterior angles, rounded to obtuse and never directed posteriorly ( Figs. 2a, b ); scutellum regularly punctate in most of exposed region; elytra with simple punctation, never transversely strigose; elytral humeral angle faintly distinct, not protruding laterally ( Figs. 2a, b ); elytral humeral striae not distinct; elytral pre-sutural striae visible, originating at scutellar vertex, terminating at elytral apex, and delimiting a faintly distinct, flat, not raised sutural border on each elytron, border widest at posterior third, slightly narrower than proximal width of 3 rd antennomere; elytral apices truncately rounded in both sexes ( Fig. 2a ); pygidium partially exposed, moderately convex, apically rounded in both sexes ( Figs. 2a, b ).

Ventral habitus: antennal furrows distinctly delimited, nearly parallel-sided, or slightly diverging posteriorly; mentum subpentagonal ( Fig. 2d ); antennal prosternal furrows on anterior margin of prosternum nearly obliterated ( Fig. 2d ); prosternal process relatively narrow, but subapical portion strongly dilated, 2.4–2.6× as wide as maximum width of 1 st antennomere, with arcuately convex apex ( Fig. 2n ); posterior margin of mesoventrite simple, never incised at middle ( Fig. 2n ); lateral borders of prosternal process not delimiting furrows, terminating at base of prosternal process ( Fig. 2n ); sexual dimorphism variable but usually distinctly manifested, frequently with more or less distinct impressions on metaventrite in males; first two visible abdominal ventrites simple in both sexes, without tufts of setae; caudal marginal lines of metacoxal cavities always simple, parallel and contiguous to posterior margin of metacoxal cavities, without deep arched impression of outer ‘axillary’ line ( Fig. 2f ); ‘axillary’ space on first abdominal ventrite moderately developed, ‘axillary’ angle widely obtuse ( Fig. 2f ); small, short, and shallowly impressed arched impressions on basal portion of last visible abdominal ventrite, frequently covered by distal portion of penultimate visible abdominal ventrite ( Fig. 2g ).

Appendages: male 1 st antennomere 0.7–0.9× as long as width of protibiae, excluding distal teeth ( Figs. 2a, b, d ); 3 rd antennomere in both sexes usually only 1.9–2.0× as long as wide, 0.7–0.8× as long but distinctly thinner than 2 nd antennomere ( Fig. 2d ); 4 th and 5 th antennomeres in both sexes subequal, short, nearly as long as wide; antennal club compact, small, simple, no sexual dimorphism present, comprising last 3 antennomeres in both sexes (8 th antennomere moderately widened, 0.6–0.7× as wide as 9 th antennomere) ( Fig. 2k ), much narrower than width of protibiae; labial palpi moderately long in both sexes ( Fig. 2d ), terminal segment 1.8–1.9× as long as wide; maxillary palpi moderately long and slender in both sexes ( Fig. 2d ), terminal segment 2.2–2.3× as long as wide; mandible usually small ( Figs. 2a, b ), ~1.2–1.3× longer than wide, comprising moderately acuminate apex, no sexual dimorphism present; tarsal claws simple, never toothed at base (as in Fig. 3d ); tarsi of variable size and shape, 0.6–0.8× as long as corresponding tibiae ( Figs. 2a, b ); protibiae with a series of usually large, basally widened, uneven, more or less sharp teeth on lateral margin ( Figs. 2a, b ; Figs. 126 a–e in KIREJTSHUK & AUDISIO 1995); meso- and metatibiae with lateral margin bearing a nearly double and usually uneven row of large and robust spurs ( Fig. 2h ), without U-shaped sinuosity at distal third; meso- and metatibiae moderately slender, flat ( Figs. 2a, b ), never distinctly subtrapezoidal or axe-shaped; sexual dimorphism variably expressed in metatibiae, i.e. simple or distinctly sinuate in males ( Figs. 2a, b ; Figs. 87–90 in KIREJTSHUK & AUDISIO 1995), and with tarsal plates of prolegs slightly wider in males; posterior margin of male metafemora with 2–3 minute tubercles ( Fig. 2e ; Figs. 101, 105 in KIREJTSHUK & AUDISIO 1995).

Male genitalia: processes along inner side of parameres absent ( Figs. 21–24 and 27–28 in KIREJTSHUK & AUDISIO 1995), distal margin nearly transversely truncate, and without deep median longitudinal desclerotization from proximal portion of tegmen to medial distal Vshaped excision; median lobe of aedeagus without lateral emargination, bluntly acuminate anteriorly, without distal minute emargination.

Female genitalia (ovipositor): variably shaped, usually small; styli usually short but distinct, simple, cylindrical, subtruncate, not distinctly pigmented, inserted at apex of nearly contiguous gonostyloids; lateral portion of basicoxites simple, never indentate (Figs. 52–54 in KIREJTSHUK & AUDISIO 1995), and faintly distinct arcuate area along lateral subdistal portion of gonostyloids. ‘Central point’ of ovipositor centrally located, proximally directed spicule absent.

Etymology. The generic name is derived from the host-plant family of all inclusive species, i.e. Asteraceae , and from ‘- gethes ’, emphasizing the association with this botanical family as well as its phylogenetic relationship with Meligethes . Gender masculine.

Biology. The three inclusive species are strictly associated for larval development with inflorescences (capitula) of Asteraceae , in particular Arctotis L., Osteospermum L., Dimorphoteca Vaill. ex Moench, Othonna L., and allied genera ( KIREJTSHUK & AUDISIO 1995; AUDISIO unpublished data).

Phylogenetic position. Asterogethes gen. nov. is closely related to Odontholariopsis gen. nov., Neolariopsis gen. nov., and Lariopsis , with which it forms the newly circumscribed Lariopsis - complex of genera. This complex is supported by evidence from both adult morphology and molecular data ( TRIZZINO et al. 2009). But phylogenetic relationships of Asterogethes gen. nov. with Acanthogethes , Clypeogethes , and other ancestral Meligethinae remain unclear.

Taxonomy and geographic distribution. Asterogethes gen. nov. includes three species with the following restricted distributions in Southern Africa ( KIREJTSHUK & AUDISIO 1995).

Asterogethes arcuatus (Reitter, 1872) comb. nov. South Africa: W Cape Asterogethes endroedyi ( Kirejtshuk & Audisio, 1995) comb. nov. South Africa: W Cape, S Namibia Asterogethes rufiventris (Reitter, 1872) comb. nov. South Africa: W Cape

Figures

Fig. 2. Asterogethes Audisio & Cline, gen. nov.: a – A. endroedyi (Kirejtshuk & Audisio, 1995); b–d, f–n – A. arcuatus (Reitter, 1872); e – A. rufiventris (Reitter, 1872). a, b – male habitus (a – length 3.2 mm; b – length 2.4 mm); c – dorso-lateral view of head; d – ventral view of head and anterior portion of prosternum; e – outline of male metafemur (length 0.5 mm); f – caudal marginal lines of metacoxal cavities; g – exposed portion of last visible abdominal ventrite; h – middle leg with illustrating outer margin of mesotibia; k – antenna; m – pronotal setae and microsetae on posterior margin of pronotum; n – prosternal process and mesoventrite. Scale bars: Figs. c, h, m, n = 20μm; Figs. d, f, g = 100 μm.

Fig. 3. Odontholariopsis Audisio & Cline, gen. nov.: a, g – O. haagii (Reitter, 1872); b–f, h – O. nebulosus (Reitter, 1872). a – male habitus (length 2.6 mm); b – dorsal view of head; c – ventral view of head and anterior portion of prosternum; d – middle leg illustrating outer margin of mesotibia; e – scutellum and microsetae on posterior margin of pronotum; f – prosternal process and mesoventrite; g – outline of male metafemur (length 0.5 mm); h – exposed portion of last visible abdominal ventrite. Scale bars: Figs. b, c, f, h = 100 μm; Fig. d = 30 μm; Fig. e = 20 μm.

Fig. 21. Paleogethes Audisio & Cline, gen. nov.: a–k – P. wollastoni (Easton, 1950). a – male habitus (length 1.9 mm); b – dorsal view of head; c – protibia; d – ventral view of head and anterior portion of prosternum; e – middle leg with outer margin of mesotibia; f – prosternal process and mesoventrite; g – anterior portion of scutellum and microsetae on middle of posterior margin of pronotum; h – exposed portion of last visible abdominal ventrite; k – ventral view of body. Scale bars: Figs. b, d, e, f, h = 100 μm; Fig. c = 20 μm; Fig. g = 10 μm; Fig. k = 200 μm.

Fig. 22. Rubiogethes Audisio & Cline, gen. nov.: a–k – R. newtoni (Kirejtshuk, 1990). a – female habitus; b – dorsal view of head; c – ventral view of head and anterior portion of prosternum; d – scutellum and microsetae on middle of posterior margin of pronotum; e – prosternal process and mesoventrite; f – exposed portion of last visible abdominal ventrite; g – caudal marginal line of metacoxal cavity; h – middle leg with outer margin of mesotibia; k – protibia. Scale bars: Figs. a, b = 200 μm; Figs. c, d, e, f, g = 100 μm; Figs. h, k = 20 μm.

Fig. 23. Lamiogethes Audisio & Cline, gen. nov.: a – L. paschalis (Spornraft, 1975); b – L. convexus (Boheman, 1851); c–e, g–h, m – L. ruficollis (Reitter, 1872); k, f, n – L. difficilis (Heer, 1841). a, b – male habitus (a – length 3.0 mm; b – length 2.7 mm); c – ventral view of head and of anterior portion of prosternum; d – dorsal view of head; e–f – scutellum and microsetae on middle of posterior margin of pronotum; g – ventral view of body; h–k – prosternal process and mesoventrite; m – last tarsomere of middle leg; n – outer margin of mesotibia. Scale bars: Figs. c, d, e, f, h, n = 100 μm; Fig. g = 1 mm; Fig. m = 20 μm.

Fig. 24. Chromogethes Kirejtshuk, 1989: a – C. formosus (Kirejtshuk, 1989); b–h – C. mastax (Audisio & De Biase, 2004); k – C. splendidulus (Reitter, 1873). a – male habitus (length 2.0 mm); b, k – dorsal view of head; c – scutellum and microsetae on middle of posterior margin of pronotum; d – ventral view of head and anterior portion of prosternum; e – exposed portion of last visible abdominal ventrite; f – tarsal claws of middle leg; g – outer margin of mesotibia; h – prosternal process and mesoventrite. Scale bars: Figs. b, d, e, g, k = 100 μm; Fig. c, f = 30 μm; Fig. h = 200 μm.

Fig. 27. Tarchonanthogethes Audisio & Cline, gen. nov.: a, c–i – T. rotundiclava (Kirejtshuk & Easton, 1988); b – T.sp.; k – T. martini (Grouvelle, 1899). a, b – male habitus (a – length 2.6 mm; b – length 2.0 mm); c–d – male genitalia (c – length 0. 43 mm; d – length 0.38 mm); e – major sclerites of male endophallus (length 0.20 mm); f – scutellum and microsetae on middle of posterior margin of pronotum; g – ventral view of body; h – male antenna (length 0.65 mm); i – dorsal view of head; k – distal portion of ovipositor (length 0.4 mm). Scale bars: Figs. f, i = 100 μm; Fig. g = 300 μm.

Fig. 28. Sebastiangethes Audisio, Kirk-Spriggs & Cline, 2008: a–i – S. anthystrixoides Audisio, Kirk-Spriggs & Cline, 2008. a – male habitus (length 2.7 mm); b – right maxilla and palpus; c – left mandible; d – labrum; e–f – male genitalia; g – major sclerites of male endophallus; h – distal portion of ovipositor; i – ventral view of head and anterior portion of prosternum. Drawings b–i: refer to AUDISIO et al. (2008) for scale.