Desicasta reichei ( Thomson, 1860 )

Ratcliffe, Brett C., 2013, A Revision of the Neotropical Genus Desicasta Thomson (Coleoptera: Scarabaeidae: Cetoniinae: Gymnetini), The Coleopterists Bulletin 67 (4), pp. 447-456 : 453-455

Desicasta reichei ( Thomson, 1860) ( Figs. 15–18 )

Stethodesma reichei Thomson 1860: 32 (original combination). Holotype male at MNHN, examined. Type locality: “ Colombia.”

Moscheuma laevicostatum Neervoort van de Poll 1886: 234 (original combination). Holotype female at RMNH, examined. Type locality: “ Panama.” New synonymy.

Description. Length 21.7–25.8 mm; width across humeri 12.5–14.2 mm. Color entirely black, shiny. Head: Lateral margins weakly elevated. Frons and base of clypeus weakly, longitudinally tumescent at middle. Surface glabrous with small, moderately dense punctures. Clypeus at apex with deep U-shaped emargination ( Fig. 15 ), not reflexed. Eyes moderately large, interocular width equals 4.5 transverse eye diameters in both sexes. Antenna with 10 antennomeres, club slightly longer than antennomeres 2–7 in both sexes. Pronotum: Surface with punctures moderate in density and size, punctures becoming larger and denser on lateral thirds; most punctures elongate, tapering and becoming shallower on posterior edge. Lateral margin with thick bead. Elytra: Surface moderately densely punctate, with 2 weak, parallel costae terminating at apical umbone; punctures on disc in distinct to indistinct rows, moderately large, moderately dense, ocellate, round to n-shaped. Surface behind and either side of apical umbone with sparse punctures or rugae. Apices at suture acutely produced. Pygidium: Surface concentrically strigose, setigerous, setae in males minute, acute, setae in females minute, black. In lateral view, profile weakly convex in both sexes. Venter: Setae black. Mesometasternal process in lateral view subrectangular to bluntly rounded, strongly protruding obliquely away from ventral axis of body ( Fig. 16 ), apex broadly rounded in ventral view. Abdominal ventrites nearly smooth in central third, lateral thirds with large, sparse to moderately dense punctures. Legs: Protibia slender in males, with 2 lateral teeth and small basal tooth. Protibia in females broader, strongly tridentate. Parameres ( Figs. 17–18 ): In caudal view, form elongate, apices broadly rounded, each with small, lateral spine.

Distribution. Desicasta reichei is known from Panama to Venezuela and Colombia. The Costa Rica record is suspect and was not listed by Solís (2004) as occurring in Costa Rica.

Locality Records. 69 specimens from AMNH, BCRC, CASC, CMNH, DCCC, FMNH, FSCA, IRSNB, MEFLG, MNHN, PKLC, RMNH, TAMU, UAIC, UNAL, UNSM, USNM, WBWC, and ZMHU. Some data from Suárez and Amat (2007) .

COLOMBIA (34). ANTOQUIA (7) Cañasgordas, Envigado, San Jerónimo, No data. BOYACÁ (5): Muzo. CUNDINAMARCA (2): Quetame. DISTRITO CAPITAL (4): Bogotá. MAGDALENA (1): Don Amo. SANTANDER (2): Barichara, No data. TOLIMA (7): Armero, El Espinal, Melgar, No data. VALLE DEL CAUCA (2): Ginebra, No data. NO DATA (3) .

COSTA RICA (1). GUANACASTE (1): No data.

ECUADOR (1). NO DATA (1).

PANAMA (31). CHIRIQUÍ (1): Cerro Colorado . COLÓN (3): Melia Panama Canal Hotel. PANAMÁ (26): Ancón, Arraiján, Balboa, Barro Colorado Island, Canal Zone, Cerro Campana, Cerro Jefé, Cunundu, El Llano Cartí Road, Ft. Gulick, Isla San José ( Pearl Islands ). NO DATA (1) .

VENEZUELA (1). DISTRITO CAPITAL (1): Caracas.

NO DATA (1).

Temporal Distribution. March (1), April (3), May (14), June (10), July (1), August (1), September (2), October (2), November (4), December (2).

Diagnosis. Desicasta reichei is distinguished by its entirely shiny dorsal surface in both sexes (males with elytra opaque and appearing “greasy” in D. lobata , while the elytra in D. purpurascnes are velutinous); by the absence of two distinctly elevated, longitudinal, elytral costae; a bulbous to subquadrate mesometasternal process ( Fig. 16 ); and by sparsely punctate (as opposed to rugulose) elytral apices behind the apical umbones.

Nomenclature. I examined the holotypes of both D. reichei and D. laevicostata and have concluded they are conspecific. Neervoort van de Poll observed that his D. laevicostata might just be a local variety of D. reichei . He was correct.

Natural History. The natural history of this species is largely unknown. Adults have been collected at banana bait at elevations of 320–1,300 m. Krell et al. (2002) found two larvae of D. laevicostata (= D. reichei ) in living stalk tissue of Vriesea sanguinolenta Cogn. and Marchal (Bromeliaceae) in Panama and surmised the larvae were feeding on the plant tissue. This is the only known occurrence of cetoniine larvae feeding on living plant tissue.

Figures

Fig. 15. Desicasta reichei.

Figs. 16–18. Desicasta reichei. 16) Lateral view of form of mesometasternal process; 17–18) Parameres.