Tiarocera cornuta (Gory and Percheron, 1833)

Ratcliffe, Brett C., 2014, A Review of the Neotropical GeneraAstroscaraSchürhoff, 1937, ChiriquibiaBates, 1889, HadrostictaKraatz, 1892, JansoniaSchürhoff, 1937, MacrocraniusSchürhoff, 1935, andTiaroceraBurmeister, 1842 (Coleoptera: Scarabaeidae: Cetoniinae: Gymnetini), The Coleopterists Bulletin 68 (3), pp. 363-376 : 374-375

Tiarocera cornuta (Gory and Percheron, 1833) ( Figs. 26–31 )

Gymnetis cornuta Gory and Percheron, 1833: 69 (original combination). Holotype at RMNH, examined. Type locality: “ Cuba.”

Description. Length 17.2–25.0 mm; width across humeri 9.8–16.0 mm. Color mostly black, occasionally piceous, weakly shiny.

Males. Head: Frons and clypeus rugulose. Frons with longitudinal, narrow, forward projecting horn (majors) ( Fig. 26 ) or keel (minors); sides of horn/keel with moderately long, reddish brown setae; lateral margin above antennal insertion and eye elevated. Clypeus broadly subquadrate, sides rounded; apex with long, bifurcate (majors) or short, truncate (minors) horn projecting upwards and forward; base of horn on either side with moderately long, reddish brown setae. Eyes small, interocular width equals 8.0 transverse eye diameters. Antenna with 10 antennomeres, club subequal in length to antennomeres 2–7. Pronotum: Surface with punctures moderate in size and density, punctures becoming larger, denser, setigerous on sides; setae moderately long, reddish brown. Anterior margin at center weakly tumid. Sides with marginal bead for entire length. Elytra: Disc with 6 punctate striae; punctures large, ocellate, horseshoe-shaped; first interval with similar punctures, remaining intervals nearly impunctate; punctures behind humerus and on sides smaller, sparser. Sutural and 2 discal costae weakly elevated, discal costae terminating at prominent apical umbone. Apices at suture each with broad tooth. Pygidium: Surface concentrically strigulose, with short, moderately dense, reddish brown setae. In lateral view, surface weakly convex to nearly flat. Venter: Metasternite with large, dense, ocellate, setigerous punctures either side of broad, nearly impunctate center. Mesometasternal process, in lateral view, imperceptibly protuberant, subparallel

27) Female.

to ventral axis of body ( Fig. 28 ); in ventral view, process subparallel, apex broadly rounded. Abdominal ventrites 1–5, in lateral view, slightly concave to nearly flat. Legs: Protibia relatively slender, strongly tridentate. Parameres ( Figs. 30–31 ): In caudal view, form elongated, subrectangular, apices rounded, each with small, subapical tooth laterally.

Diagnosis. Tiarocera cornuta is distinguished by the form of the frontal and clypeal horns or keels in both sexes in combination with the following: robust body form (similar to that of Blaesia Burmeister species ); pronotum at the center apex in males slightly produced and females with an erect tubercle followed usually by a shallow fovea (a unique feature in New World Gymnetini ); densely punctate-striate elytra; and mesometasternal process in same plane as ventral axis of body and not protuberant.

Natural History. Nothing is known of the life history of this species. Chapin (1932) recorded larvae feeding on dry guano (from bats?) in a cave. Label data indicates two adults were taken in the nest of Atta species ( Hymenoptera : Formicidae ).

Females. As males except in the following respects: Body form more robust ( Fig. 27 ). Head: Frons and clypeus rugopunctate to rugose. Frons with narrow, longitudinal keel, apex barely free in large specimens, not free in small specimens. Clypeus with short, erect, subtruncate horn. Pronotum: Surface densely punctate; punctures moderately large to large, becoming larger on sides and setigerous; setae long on sides and anterior fifth, setae short and sparse on disc. Anterior margin at center with erect tubercle and shallow fovea behind tubercle, fovea occasionally obsolete. Pygidium: Surface less densely strigulose and setose, nearly flat in lateral view. Venter: Abdominal ventrites, in lateral view, slightly tumid. Legs: Protibia broader.

Distribution. Tiarocera cornuta is endemic in Cuba.

Locality Records. 57 specimens from AMNH, BCRC, BMNH, CASC, CNCI, FMNH, HAHC, HNHB, IRSNB, MCZC, MNHN, RMNH, USNM, and ZMHU. Some data from Chapin (1932). CUBA (63). CIEGO DE ÁVILA (2) : Baragua. CIENFUEGOS (3) : Cumanayagua, Soledad. GRANMA (1) : Sierra Maestra. GUANTÁNAMO (7) : Guantánamo. ISLA DE LA JUVENTUD (7) : La Cieba. Santa Fé. LA HABANA (5) : Sierra Amape, Habana, Marianao, Tapaste. PINAR DEL RIO (3) : Cerro Cabras, Rangel. SANTIAGO DE CUBA (7) : Santiago de Cuba , Turquino Peak. VILLA CLARA (3) : Corallilo. NO DATA (24).

Temporal Distribution. January (1), June (4), September (10), October (10), November (3), December (2).

Figures

Figs. 26–27. Tiarocera cornuta, habitus. 26) Male;

Figs. 28–31. Tiarocera cornuta. 28–29) Lateral and ventral views, respectively, of form of mesometasternal process; 30–31) Parameres.