Horakia Jelínek, 2000

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 : 467-469

35. Horakia Jelínek, 2000

( Figs. 35 a–p )

Horakia Jelínek, 2000: 413 .

Type species. Horakia kubani Jelínek, 2000: 414 (by original designation).

Generic redescription and diagnosis. The single known species (2.5–2.6 mm length; 1.5 mm width) exhibits the following combination of characters.

Body color and pubescence: pubescence moderately long and fine, recumbent, golden on head and pronotum, darker on elytra, not obscuring the variably colored dorsal body surface (head and pronotal disk dark brown; elytra, pygidium and metaventrite blackish with faint metallic greenish iridescence on pronotal disc and pygidium), flattened sides of frons, and two diverging spots on posterior half of elytra ( Fig. 35a ) yellowish-brown; pronotal and elytral sides relatively widely flattened. SEM observations of microsetae on lateral margins of elytra and posterior margin of pronotum are unavailable.

Dorsal habitus: body slightly convex, wide and oval ( Fig. 35a ); dorsal punctures on discal portion of pronotum smaller than eye facet, shallowly impressed and sparsely distributed; anterior margin of clypeus emarginate, simple, i.e. without small distinct medial bulge, fused with frons; frons with lateral margins moderately bulging over antennal insertions ( Fig. 35a ); circum-ocular furrows (occipital sulci) on dorsal side of head (occipital sulci) absent; eyes small-sized and moderately projecting laterally ( Fig. 35a ), pronotum with markedly distinct posterior angles, subrectangular to slightly acute, slightly directed posteriorly ( Fig. 35a ); scutellum densely punctate on most of exposed portion; elytral punctation almost completely finely transversely strigose; elytral humeral angle obtuse, not protruding laterally; elytral humeral striae indistinct; elytra apically truncately rounded in males ( Fig. 35a ), female unknown; pygidium partially exposed, moderately convex, apically rounded in males ( Fig. 35a ).

Ventral habitus: antennal furrows delimited by moderately bulged genae, arcuately convergent posteriorly ( Fig. 35b ); mentum subpentagonal; prosternal antennal furrows on anterior margin of prosternum absent ( Fig. 35b ); prosternal process flat, moderately narrow, shallowly arcuately emarginate apically ( Fig. 35d ), subapical dilated portion ~1.5× as wide as maximum width of 1 st antennomere; lateral borders of prosternal process not delimiting impressed furrows, distally terminating at predistal lateral expansions ( Fig. 35d ); posterior margin of mesoventrite simple, not medially incised; sexual dimorphism likely absent in impressions on metaventrite, absent in males; first two visible abdominal ventrites simple in males, without tufts of setae; caudal marginal lines of metacoxal cavities simple, parallel and contiguous to posterior margin of metacoxal cavities; arched impressions on basal portion of last visible abdominal ventrite absent.

Appendages: male 1 st antennomere ~1.0× as long as width of protibiae ( Fig. 35a ); 3 rd antennomere long and thin in males, ~5× longer than wide, 3.5× longer and much thinner than 2 nd antennomere ( Fig. 35p ); 4 th antennomere relatively short, 2× longer than wide, 5 th antennomere long and thin in males, ~4× longer than wide; antennal club compact, long, moderately loose, comprising last 4 antennomeres in males (unknown, but presumably 3- segmented in females), wider than protibiae; labial palpi long and slender in both sexes ( Fig. 35b ), terminal segment ~2.7× as long as wide; maxillary palpi long and slender in both sexes ( Fig. 35b ), terminal segment ~3.4× as long as wide; mandibles mid-sized, apex arcuate and acuminate with subapical tooth; tarsal claws simple, not toothed at base; tarsi of normal size and shape, 0.6–0.7× as long as corresponding tibiae ( Fig. 35a ); protibiae with a series of small, fine, sharp teeth on apical portion of lateral margin ( Fig. 35k ), almost rectilinear outer margins and flatly arcuate inner margins; lateral margin of meso- and metatibiae bearing a single and regular row of long thin pegs ( Figs. 35m, n ), without U-shaped sinuosity at distal third; meso- and metatibiae moderately long and slender, not markedly subtrapezoidal or axeshaped; tarsal plates of prolegs moderately wide in males; posterior margins of metafemora simple in males, without tubercles or projections.

Male genitalia: processes along inner side of parameres absent ( Figs. 35e–f ), with deep and wide V-shaped excision along distal margin, without deep median longitudinal desclerotization from proximal portion of tegmen extending to medial distal V-shaped excision; median lobe of aedeagus long, without lateral emargination, sharply acuminate distally, without distal minute excision or emargination; main sclerites of internal sac small, narrow, lyriform, moderately sclerotized, ~4–5× shorter than aedeagus ( Fig. 35g ).

Female genitalia (ovipositor): unknown.

Etymology. Horakia was named for a Czech entomologist, Jan Horák (Prague), who collected the type specimens in Thailand ( JELÍNEK 2000a). Gender feminine.

Biology. The biology of the single inclusive species is unknown ( JELÍNEK 2000a). Both specimens in the type series were collected in indigenous mountain forests of northern Thailand on inflorescences of large trees of a local species of Castanopsis (D. Don) Spach (Fagaceae) , which is attractive to beetles in general. Horakia larvae may be associated with male inflorescences of a mountain forest palm ( Arecaceae ), as analogously observed in the two related genera Kabakovia and Cryptarchopria known from the region. The specific host is probably the Mountain fishtail palm, Caryota gigas W. J. Hahn ex Hodel , which is a large, endangered species that inhabits middle altitude (1200–1800 m a.s.l.) indigenous forests of northern Thailand and northeastern India, Myanmar ( Burma), southern China, and Laos ( RIFFLE 2008). However this assumption is speculative and requires further fieldwork to substantiate.

Phylogenetic position. Available morphological data provide good evidence of a sister-group relationship of Horakia and Cryptarchopria , with Kabakovia being likely sister to this clade ( JELÍNEK 2000a). A weaker relationship to members of Meligethinus could also be postulated. No molecular data is currently available.

Taxonomy and geographic distribution. This genus includes a single species from northernwestern Thailand ( JELÍNEK 2000a).

Horakia kubani Jelínek, 2000 NW Thailand

Figures

Fig. 35. Horakia Jelínek, 2000: a–p – H. kubani Jelínek, 2000. a – male habitus; b –ventral view of head and prosternum; c – dorsal view of head; d – prosternal process; e–f – male genitalia; g – major sclerites of endophallus; h – labrum; k – male protibia; m – male mesotibia; n – male metatibia; p – male antenna. Drawings a–p modified from JELÍNEK (2000a)). Refer to JELÍNEK (2000a) for scale.