Cyclidius MacLeay, 1838

Rodrigues, Diego F., Grossi, Paschoal C. & Vaz-de-Mello, Fernando Z., 2025, Taxonomic revision of Cremastocheilini (Coleoptera: Scarabaeidae: Cetoniinae) from South America and an updated key for the genera of the New World, Journal of Natural History 59 (17 - 20), pp. 1063-1125 : 1078-1081

Genus Cyclidius MacLeay, 1838

( Figures 1 (E), 7–20, 32(A–H))

Type species

Cetonia elongata Olivier, 1789 , by subsequent designation here.

Taxonomic history

Cryptodinus (Cyclidius) MacLeay 1838, p. 17 (original description).

Cyclidius : Burmeister and Schaum 1841: 258–260 (taxonomic revision). – Schaum 1841: 258–260 (taxonomic revision). – Blanchard 1850: 42 (catalogue). – Lacordaire 1856: 553–554 (redescription). – Thomson 1860: 37–38 (new species). – Westwood 1874: 54–55 (taxonomic revision). – Kolbe 1893: 211–212 (new species). – Ohaus 1909: 73 (natural history). – Schenkling 1921: 378 (Catalogue). – Blackwelder 1944: 265 (catalogue). – Howden 1971 (key to the genera of Cremastocheilini ). – Krikken 1976 (key to the genera of Cremastocheilini ). – Krikken 1984: 45 (catalogue of genera). – Martínez 1992: 44 (distribution). – Krajčik 1999: 42 (catalogue). – Suárez-G. and Amat-García 2007 (catalogue). – Mynhardt and Wenzel 2010: 134 (phylogeny). – Carvajal et al. 2011: 297 (catalogue). – González-Hernández and Navarrete-Heredia 2011: 477 (checklist). – Di Iorio 2013: 62–82 (distribution and references). – Drechsel 2014: 61–63 (distribution). – Ratcliffe et al. 2015: 203 (checklist). – Alves-Oliveira et al. 2016 (natural history). – Rodrigues et al. 2023 (catalogue). – Schoolmeesters 2024 (Catalogue).

Diagnosis

Cyclidius is recognised by the following combination of characters: Clypeal projection bent upwards in frontal view, not evenly arched ( Figures 7 (C)–18(C), 32(G)); frons with two posterior tubercles ( Figure 32 (G)); pronotum suborbicular ( Figures 1 (E), 7(A)–18(A)), with a lateral border margin; and profemur with a central emargination ( Figure 14 (D)).

Redescription

Size: length: 27.2– 19 mm; width: 13.4– 9.1 mm. Body: Elongate, dorsally flattened. Colour: Body dorsally black or black with orange-red in the mediodiscal region of the elytra; ventrally black or dark reddish brown; palps and antennomeres black or brownish. Eyes black, brown, or yellow, with black spots if not completely black. Hindwing black with dark-blue or purple reflection. Head: Clypeal projection bent upwards in frontal view, not evenly arched ( Figures 7 (C)–18(C), 32(G)); frons rugose, with a central protuberance and two posterior tubercles ( Figure 32 (G)), non-rugose at the posterior edge of the tubercles. Antegenal protusion evident, eye-canthus rugose superficially; scape semi-triangular. Mentum almost right angle shaped, with the posterior margin broadly ‘V’-shaped and thickened, rounded anteriorly and slightly convex, largely covering the mouthparts ( Figures 7 (C)–18(C)). Pronotum: Disc suborcular, convex; surface irregularly velutinous in places ( Figures 1 (E), 7(A)– 18(A)); margin with a lateral border. Scutellum: Triangular, with rugose and/or differentially punctate areas on the surface. Elytra: Elongate and evenly rounded, with one anteapical umbone on each elytron; often with punctures centrally; crumpled impression below the scutellum; surface with a combination of glossy and opaque areas, entirely velutinous in some parts, often velutinous on the sides of the elytra but not along the border. Thoracic venter: Hypomerum: Shallowly concave below the procoxa; surface rugose or convergently striate. Prosternum : Narrow anteriorly, forming a pointed projection, setose at the anterior base. Mesoventrite: Rugose or punctate. Mesepisternum: Rugose and/or punctate anteriorly. Mesepimeron: Rugose, barely visible dorsally. Metaventrite: Slightly punctate centrally, rugose along the posterior margin, being often ‘c’-punctate and opaque or velutinous laterally. Metepisternum: Often ‘c’-punctate, opaque or velutinous. Metepimeron: ‘c’-punctate, rugose, opaque, or velutinous. Legs: Tarsus with tarsomere V equal in size to the combined length of two tarsomeres; protarsomeres shorter than meso- and metatarsomeres. Protibia: Ventral surface rugose, differently punctate or striate dorsally, enlarged centrally, may have a medial-proximal tooth; one apical spur and three teeth: apical-lateral, ventro-apical, and lateral-proximal ( Figures 7 (D)–18(D)). Profemur: Rugose ventrally and differently punctate and/or rugose dorsally, with a central emargination. Mesotibia shorter than metatibia, both dorsally flattened and rugose, ventrally differently punctate, with two pairs of apical teeth and one proximal, showing a concavity superficially opaque and rugose between proximal tooth and apical pairs; two spurs apically. Metafemur wider than mesofemur, both ‘c’-punctate and differently punctate. Procoxa and mesocoxa rugose and/or punctate, occasionally with setae, same for the trochanter. Metacoxa: rugose or ‘c’-punctate, glossy or opaque or, velutinous. Abdomen: Ventrites often ‘c’-punctate, glossy and opaque or velutinous laterally; variation in elevation around the spiracle of the last tergite, always visible. Pygidium: Convex, ocellate-punctate, completely or incompletely velutinous. Aedeagus: Parameres curving dorsally, each apex rounded, with a callus proximally, just before the central membranous portion ( Figures 7 (G, H), 9 (G, H), 13 (G, H)–14(G, H), 17(G, H)).

Sexual dimorphism

The fifth ventrite is reduced in males compared to females, giving the abdomen a concave appearance ( Figures 7 (F), 9 (F)–10(F), 13 (F)–14(F), 17(F)), which is not observed in females ( Figures 8 (F), 11 (F)–12(F), 15 (F)–16(F), 18(F)).

Morphological variation

The body surface can be entirely velutinous dorsally, sometimes covering the punctures. The frons may have a raised longitudinal rigde in the centre, which can connect to the front part of the clypeus in some specimens. The size and shape of posterior tubercles on the frons can vary. The margin along the border of the pronotum is not always complete. The elytral disc can be entirely velutinous or opaque, with a glossy centre and velutinous or opaque border. Some specimens may show a slight lateral-proximal tip, but it does not form a second tooth.

Geographical distribution

Cyclidius is known from Argentina, Bolivia, Brazil, Colombia, Ecuador, French Guiana, Guyana, Paraguay, Peru, Suriname, and Venezuela ( Figures 19–20 ).

Key to the species of Cyclidius MacLeay

1. Protibia with medial proximal tooth ( Figures 9 (D)–10(D), 13(D)–17(D)) ................ 2

1’. Protibia without medial proximal tooth ( Figures 7 (D)–8(D), 11 (D)–12(D), 18(D)) 4

2(1). Clypeus bifurcate ( Figures 15 (C)–16(C)) or bilobed ( Figures 13 (C)–14(C)) anteriorly. Western Amazon ( Figures 19 ) .......................................... Cyclidius lacordairei Thomson

2’. Clypeus not bifurcate or bilobed anteriorly ( Figures 9 (C)–10(C), 17(C)) ................ 3

3(2’). Clypeal area anteriorly raised in semicircular form ( Figure 17 (C)); disc of mentum flattened . Cerrado, Chaco and Western Atlantic Forest ( Figure 20 ) .............................. ............................................................................................................. Cyclidius rohdei Kolbe (♂)

3’. Clypeal area anteriorly raised in trapezoidal form ( Figures 9 (C)–10(C)); disc of mentum concave. Eastern Amazon ( Figure 19 ) .. Cyclidius elongatus (Olivier) (♂)

4(1’). Clypeus anteriorly bidentate ( Figures 11 (C)–12(C)). Eastern Amazon ( Figure 19 ) ... ................................................................................................. Cyclidius elongatus (Olivier) (♀)

4’. Clypeus anteriorly not bidentate ( Figures 7 (C)–8(C), 18(C)) ........................................ 5

5(4’). Clypeal area anteriorly raised in semicircular or trapezoidal form ( Figure 18 (C)); disc of mentum flattened . Cerrado, Chaco and Western Atlantic Forest ( Figure 20 ) ............................................................................................................ Cyclidius rohdei Kolbe (♀)

5’. Clypeal area anteriorly raised in trapezoidal form, with a slight concavity at the apex ( Figures 7 (C), 8(C)); disc of mentum concave. Atlantic Forest ( Figure 20 ) ........ ...................................... Cyclidius atlanticus Rodrigues, Grossi and Vaz-de-Mello sp. n.

Figures

Figure 1. Pronotum shapes of Cremastocheilini genera from the Americas. (A) Centrochilus Krikken, 1976. (B) Cremastocheilus Knoch, 1801. (C) Cyclidiellus Krikken,1976. (D) Cyclidinus Westwood,1874. (E) Cyclidius MacLeay, 1838. (F) Genuchinus Westwood, 1874. (G) Krikkenjanius Rodrigues, Grossi and Vazde-Mello gen. n. (H) Lissomelas Bates, 1889. (I) Paracyclidius Howden, 1971. (J) Psilocnemis Burmeister, 1842. (K) Quititinus Rodrigues, Grossi and Vaz-de-Mello gen. n.

Figure 7. Cyclidius atlanticus sp. n. Holotype. Male at CEMT (Brazil, Rio de Janeiro, Santa Maria Madalena). (A) Habitus, dorsal view. (B) Habitus, ventral view. (C) Head, frontal view. (D) Protibia, dorsal view. (E) Habitus, dorsolateral view. (F) Habitus, lateral view. (G) Aedeagus, lateral view. (H) Parameres, dorsal view. (I) Labels. Scale bars = 1 mm.

Figure 8. Cyclidius atlanticus sp. n. Paratype. Female at CEMT (Brazil, Santa Catarina, Corupá). (A) Habitus, dorsal view. (B) Habitus, ventral view. (C) Head, frontal view. (D) Protibia, dorsal view. (E) Habitus, dorsolateral view. (F) Habitus, lateral view. Scale bars = 1 mm.

Figure 9. Cyclidius elongatus (Olivier, 1789). Male at CMN (French Guiana, Cayenne, Wayabo). (A) Habitus, dorsal view. (B) Habitus, ventral view. (C) Head, frontal view. (D) Protibia, dorsal view. (E) Habitus, dorsolateral view. (F) Habitus, lateral view. (G) Aedeagus, lateral view. (H) Parameres, dorsal view. Scale bars = 1 mm.

Figure 11. Cyclidius elongatus (Olivier, 1789). Female at MFNB (Guyana). (A) Habitus, dorsal view. (B) Habitus, ventral view. (C) Head, frontal view. (D) Protibia, dorsal view.(E) Habitus,dorsolateral view. (F) Habitus, lateral view. Scale bars = 1 mm.

Figure 13. Cyclidius lacordairei Thomson, 1860. Male at CEMT (Brazil, Mato Grosso, Rosário Oeste). (A) Habitus, dorsal view. (B) Habitus, ventral view. (C) Head, frontal view. (D) Protibia, dorsal view. (E) Habitus, dorsolateral view. (F) Habitus, lateral view. (G) Aedeagus, lateral view. (H) Parameres, dorsal view. Scale bars = 1 mm.

Figure 14. Cyclidius lacordairei Thomson,1860. Male at CMN, red variation on elytra (Ecuador,Orellana, Loreto). (A) Habitus, dorsal view. (B) Habitus, ventral view. (C) Head, frontal view. (D) Protibia, dorsal view. (E) Habitus,dorsolateral view. (F) Habitus, lateral view. (G) Aedeagus,lateral view. (H) Parameres, dorsal view. Scale bars = 1 mm.

Figure 15. Cyclidius lacordairei Thomson, 1860. Female at CEMT (Peru, Loreto, Maynas, Iquitos). (A) Habitus, dorsal view. (B) Habitus, ventral view. (C) Head, frontal view. (D) Protibia, dorsal view. (E) Habitus, dorsolateral view. (F) Habitus, lateral view. Scale bars = 1 mm.

Figure 17. Cyclidius rohdei Kolbe, 1893. Male at CMN (Bolivia, Santa Cruz, Ichilo, Rio Ichilo). (A) Habitus, dorsal view. (B) Habitus, ventral view. (C) Head, frontal view. (D) Protibia, dorsal view. (E) Habitus, dorsolateral view.(F) Habitus, lateral view. (G) Aedeagus,lateral view. (H) Parameres,dorsal view. Scale bars = 1 mm.

Figure 18. Cyclidius rohdei Kolbe, 1893. Holotype. Female at MFNB (Brazil, Mato Grosso, Acorizal). (A) Habitus, dorsal view. (B) Habitus, ventral view. (C) Head, frontal view. (D) Protibia, dorsal view. (E) Habitus, dorsolateral view. (F) Habitus, lateral view. (G) Labels. Scale bars = 1 mm.

Figure 19. Geographical distribution map of Cyclidius elongatus (Olivier, 1789) and Cyclidius lacordairei Thomson, 1860. ‘?’ indicates the exact locality is not known.

Figure 20. Geographical distribution map of Cyclidius atlanticus sp. n. and Cyclidius rohdei Kolbe, 1893.

Figure 32. (A) Habitus of lectotype of Cetonia elongata Olivier, 1789 at MNHN. (B) Type figure of Cyclidius lacordairei Thomson, 1860 (from Lacordaire 1856, Pl. 39; Figure 3). (C) Habitus of lectotype of Cyclidius acherontius Kolbe,1893 at MFNB.(D) Labels of lectotype of Cetonia elongata. (F) Identification of Lacordaire of Cyclidius lacordairei. (G) Dorsal view of head. Arrows point to the anterior margin of clypeus, and to the two tubercles posteriorly on the frons above in Cyclidius elongatus (Olivier, 1789).