Canthidium (Eucanthidium) darwini Kohlmann & Solís, 2009

Kohlmann, Bert & Solis, Angel, 2009, New species of Ateuchus and Canthidium (Coleoptera: Scarabaeidae: Scarabaeinae) from Costa Rica, Zootaxa 2219, pp. 31-37 : 34-36

Canthidium (Eucanthidium) darwini Kohlmann & Solís , sp. nov.

( Figs. 3–4)

Diagnosis: This species is distinguished from other Costa Rican species by the following combination of characters: Frontoclypeal region with three conical tubercles; clypeal indentation V-shaped; pygidium minutely punctate; elytral striae fine, superficially impressed; protibia with two clearly developed lateral teeth, and third weakly developed; head, pronotal, and elytral surface clearly and evidently shagreened.

Holotype description: Male ( Figs. 3–4). Total length 4.0 mm. Elytral width 2.7 mm. Body slightly globose, head and pronotal surface green with golden reflections, elytra reddish brown with golden reflections, dorsum shagreened; venter dark brown.

Clypeal margin anteriorly wrinkled and V-shaped, tooth on each side rounded, margin arcuate; dorsal surface of head finely punctate and shagreened; frons with three conical tubercles forming a triangle, area between the tubercles depressed; eye dorsally small (15x the interocular distance).

Pronotum finely punctate and uniformly and evidently shagreened, midline not impressed. Proepisternum finely wrinkled proepimeron granular.

Elytral surface uniformly shagreened; elytral striae broad, dark, smooth, and very slightly impressed; surface dotted with small, polished lunules. Pygidium smooth, shiny, uniformly and minutely punctate, slightly shagreened at base.

Protibia with two developed external teeth, the third weakly developed; protibiae long and slender (same in female), protibial anterior internal angle elongated as a broad, strong spine; mesotibiae and metatibiae clearly dilated apically.

Allotype: Female. Total length: 4.2 mm. Elytral width: 2.9 mm. Differs from the holotype by the following characters: protibial anterior internal angle elongated as a fine, slender spine; protibia slightly shorter (0.8 mm).

Variation: Total length: 3.9–4.1 mm. Elytral width: 2.5–2.7 mm. Pronotal reflections can be green, red, or dark brown.

Material Examined (48 specimens): Holotype, male: COSTA RICA: Limón. P.N. La Amistad. Punto #5. 1500–1600 m. 24–25 OCT 2007. B. Gamboa, M. Monge. Tp. Foso. L N 198990 627455 #92828. Allotype, female: ibidem. Paratypes. ibidem, 6 specimens; ibidem, Z.P. Río Banano, Campamento base, 1300–1400 m. 25–26 OCT 2007. L N 199938 627615 #92827, 5 specimens; ibidem, P.I. La Amistad Caribe. Camp. 2: Río Coén, Transecto 1. 1700–1800m. 21–23 FEB 2007. B. Gamboa, M. Moraga. Tp. Foso. L_S_370381_549794 #90734, 12 specimens. Cartago. La Unión. Z.P. C. Carpintera. Cima. 1870m. 23–25 JUL 2008. J. Azofeifa, B. Hernández, M. Moraga, M. Zumbado. Tp. Malaise/ Intersección. L_N_207500_538000 #94456, 11 specimens; ibidem, Z.P. C. Carpintera. Q. Chirraca. 1750m. 22–25 JUL 2008. Azofeifa, Hernández, Moraga, Zumbado. Tp. Malaise/ Intersección. L_N_208250_539000 #94458, 12 specimens; ibidem, Z.P. C. Carpintera. Fca. Istarú. 1840–1860m. 22–25 JUL 2008. Azofeifa, Hernández, Moraga, Zumbado. Tp. Malaise/ Intersección. L_N_207300_539000 #94463, 6 specimens.

Habitat: The species has been collected in February, July, and October between 1300 and 1870 m with Malaise/interception and hog dung-baited traps in cloud forest mixed with Quercus and Lauraceae .

Geographical distribution ( Fig. 4 ): Known only from the Caribbean slope of the Talamanca mountain range.

Chorological affinities: The new species is basically occupying a similar altitude (1000–1600 m) in the Caribbean slope of the Talamanca mountain range, as its sister species, C. marianelae , does in the Central, Tilarán, and Guanacaste mountain ranges.

Taxonomic relationships: This species is hypothesized to be the sister species of C. marianelae based on shared morphological characters. These species can be easily separated because the new species is heavily shagreened on the thorax and elytra; whereas C. marianelae is only slightly shagreened on the thorax. Moreover, the new species has evident broad, dark, flat, and superficial elytral striae; whereas, C. marianelae has broad, flat, and superficial elytral striae, that are very difficult to discern.

Etymology: “ Darwini ”, is the genitive form of Darwin. This species is primarily dedicated to the eminent biologist and evolutionist, Charles Darwin. It is additionally dedicated to the UK Darwin Initiative for their contribution to the preservation of tropical biodiversity and as an acknowledgement for financing the project “Basic Tools for Managing the La Amistad ( Costa Rica – Panama) International Park.” This project supported the expeditions that resulted in the collection of the specimens used in this study.

Figures

FIGURE 4. Known distribution of the new species in Costa Rica: A. earthorum (․) and C. darwini (˔).