Paracyclidius axillaris ( Gory and Percheron, 1833 ), 2025

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 : 1104-1112

Paracyclidius axillaris ( Gory and Percheron, 1833) comb. n.

( Figures 1 (I), 23 –27, 32(H-L))

Cremastocheilus axillaris Gory and Percheron, 1833, p. 112 (original combination) Cryptodinus (Cyclidius) axillaris ( Gory and Percheron, 1833) (new combination) by MacLeay 1838: 17–18

Cyclidius axillaris ( Gory and Percheron, 1833) (new combination) by Burmeister and Schaum 1841: 260

Paracyclidius bennetti Howden, 1971: 227 (new junior subjective synonym)

Taxonomic history

Gory and Percheron (1833), p. 112 (original description). – MacLeay 1838: 17–18 (new combination). – Burmeister and Schaum 1841: 258–260 (taxonomic revision). – Schaum 1841: 258–260 (taxonomic revision). – Westwood 1874: 54 (taxonomic revision). – Schenkling 1921: 378 (catalogue). – Blackwelder 1944: 265 (catalogue). – Krikken 1976 (key to the genera of Cremastocheilini ). – Krikken 1984: 45 (catalogue of genera). – Krajčik 1999: 42 (catalogue). – Ratcliffe 2002: 39 (checklist). – Di Iorio 2013: 62–82 (catalogue, appendix). – – Rodrigues et al. 2023 (catalogue). – Schoolmeesters 2024 (catalogue).

Redescription

Size: length: 24.1– 19.2 mm; width: 12.4– 9.9 mm. Body: Elongate, dorsally flattened. Colour: Body dorsally with the pronotum and anterior region of the elytra orange-red, and the remaining parts black ( Figures 23 (A, E, F), 25(A, E, F)), or entirely black ( Figure 26 (A, E, F)), or entirely orange-red ( Figure 24 (A, E, F)). Ventral side is black, dark reddish brown, or orange in the abdomen region. Palps and antennomeres are either black or brownish. Eyes black or yellow, sometimes non-black, occasionally with black stains. Head: Clypeal projection bent upwards in the frontal view, evenly arched ( Figures 23 (C)–26(C), 32(H)). Frons rugose or confluently punctate on the surface, may have a central protuberance, without tubercles posteriorly ( Figure 32 (H)); antegenal protusion is evident, and the eye-canthus is superficially rugose; scape semitriangular; mentum almost right angle shaped, shallowly concave in the central four-fifths, then rounded and slightly convex to margins; posterior margin is broadly ‘V’-shaped, with a rounded apex, neither thickened nor perpendicular; surface of the mentum is finely tuberculate, with fine strigose texture near the margins, covering most of the mouthparts. Pronotum: Disc suborcular and convex ( Figures 1 (I), 23(A)–26(A)); surface is irregular sometimes, occasionally velutinous, and, if not, punctuated or inconspicuously punctated; without margin on lateral border. Scutellum: Triangular, velutinous, with flat and/or differentially punctate areas on the surface. Elytra: Disc elongated and evenly rounded, with one anteapical umbone in each elytron; velutinous surface, with punctures arranged in irregular rows, vaguely indicating intervals. The punctures are distinct at the base, with flat, very finely granular bottoms. Thoracic venter: Hypomerum: Shallowly concave below the procoxa; the surface is rugose or striate convergently. Prosternum : Narrow anteriorly, forming pointed projection, setose at the anterior base. Mesoventrite: Rugose or differently punctate. Mesepisternum: Rugose and/or punctate anteriorly. Mesepimeron: Rugose, barely visible dorsally. Metaventrite: Slightly punctate centrally, rugose along the posterior margin, with ‘c’-punctate shaped punctures or velutinous texture laterally. Metepisternum: ‘c’-punctate or velutinous. Metepimeron: ‘c’-punctate, rugose, or velutinous. Legs: The last tarsomere of the tarsus is the same length as the two preceding ones combined; protarsomeres are shorter than latter ones. Protibia: Ventrally flat and differently punctate dorsally, enlarged centrally; a non-pointed projection from which one spur emerges apically, along with three or four teeth: apical-lateral, ventro-apical, and lateral-proximal, occasionally with a minor among the major laterals ( Figures 23 (D)–26(D)). Profemur: The anterior margin is straight or nearly straight, rugose ventrally, and differently punctate and/or rugose dorsally. Mesotibia shorter than metatibia, both are dorsally flattened and rugose, ventrally differently punctate, with two pairs of apical teeth and one proximal tooth, with a concavity superficially opaque and rugose between the proximal tooth and one of the apical pairs; two spurs apically. Metafemur wider than Mesofemur both ‘c’-punctate or differently punctate. Procoxa and Mesocoxa rugose and/or punctate, occasionally with setae, same for trochanter. Metacoxa: Rugose or ‘c’-punctate, glossy, opaque, or velutinous. Abdomen: Ventrites are ‘c’-punctate, glossy, and opaque or velutinous laterally. The spiracle on last tergite is always visible and not elevated above the surface. Pygidium: Convex, ocellate-punctate, incompletely velutinous or opaque.

Sexual dimorphism

Female size: length: 20.3– 19.2 mm; width: 9.9– 9.8 mm. Males with strong concavity in the abdomen ( Figures 23 (F)–24(F)), which is absent in females ( Figures 25 (F)– 26(F)).

Morphological variation

Protibia with two lateral teeth of similar size, or three lateral teeth, and in these cases, the middle tooth is smaller than the others. There is some variation in the pronotum of two specimens, where the lateral margin does not form a border but instead forms a clear delimitation, unlike in the other specimens observed. On the sides of the pronotum in these two specimens, there is a very small concavity in the medial anterior region. The pronotum of one observed male is as wide as the elytra, unlike the others. A protuberance on the forehead is present in some specimens. One specimen exhibits elytral punctures centrally, with a crumpled impression just below the scutellum. The surface shows a combination of glossy and opaque areas.

Natural history

Paracyclidius axillaris is associated with arboreal ant nests ( Howden 1971).

Geographical distribution

Paracyclidius axillaris is known from Amazon Forest in Brazil, French Guiana, and Peru, also in Panamá ( Ratcliffe 2002) and Trinidad and Tobago, in the biogeographical provinces of Rondônia, Roraima, and Trinidad ( Figure 27 ).

Remarks

Due to the divergence in the diagnostic characters between Cyclidius and Cyclidius axillaris ( Gory and Percheron, 1833) , this species is transferred to the genus Paracyclidius , with which its characters match. Furthemore, the male genitalia of C. axillaris ( Figures 23 (E, F), 24(E, F)) differs from the common form present in Cyclidius and matches with Paracyclidius bennetti , which, due to all the characteristics analysed and compared, and by the priority principle [Article 23, ICZN [International Commission on Zoological Nomenclature] (1999)] will be synonymised with P. axillaris , Paracyclidius being still a monotypic genus. Both Gory and Percheron (1833) and MacLeay (1838) initially attributed the autorship of this species to Dupont. However, the authorship of C. axillaris was subsequently assigned to Gory and Percheron by later works, for presenting the first description of the species.

Type specimens examined (n = 2)

Holotype of Cremastocheilus axillaris . ( Figure 32 (I, K)) Labels [ FRENCH GUIANA] [1: handwritten text on cream label] ‘Cayenne’/[2: handwritten text on cream label] ‘Axillaris G. et P’./[3: printed text on cream label with black margin] ‘Ex Museo Mniszech’/[4: printed text on white label] ‘Paris: MNHN’/[5: printed text on red label] ‘Type’/[6: handwritten text on white label] ‘Photo [?]77’/[7: handwritten text on white label] ‘Photo [?]79’/[8: handwritten text on white label] ‘ Paracyclidius axillaris G.P. Holotype’/[9: handwritten text on cream label] ‘Schaum zeit [?] 1841 p 260’/[10: handwritten text on cream label] ‘Type Gory Mon Cetoin p 112 Pl 15 Figure 3 ’ (1. ♀ at MNHN).

Holotype of Paracyclidius bennetti : ( Figures 32 (J, L)) Labels [ TRINIDAD AND TOBAGO] [1: handwritten text on white label] ‘ Mayaro, Trinidad, W.I. VI.1964 ’/[2: handwritten and printed text on white label] ‘ Arboreal ant nest F. D. Bennett Collector’ /[3: handwritten text on white label] ‘ H. &A. Howden Collection’ /[4: printed and handwritten text on red label] ‘ HOLOTYPE Paracyclidius bennetti H. Howden’ /[5: printed text on white label] ‘ Canadiam Museum of Musée canadien de la NATURE CMNEN 00011948’ (1 ♂ at CMNC) .

Non-type specimens examined (n = 7) BRAZIL (6)

Amazonas: Itacoatiara , 15 .xi .2007, DBRibeiro (1 ♀ CEMT 00192402 ); Manaus, Campus Universitário-FUA, viii .2000 (1 ♂ CEMT 00192401 ); Manaus, Comune near Borba , iii .1931, Le Moult vendit (1 ♂ 2 ♀ IRSNB); Rio Preto da Eva , 28 .i .2017, Wanderson Malheiros Leg (1 ♀ INPA) . PERU (1): Junín: 30 km Satipo Rio Verde , 1100–1200 m, ii .2006, D. Ribeira (1 ♀ CERPE) .

Genus Quititinus Rodrigues, Grossi and Vaz-de-Mello gen. n.

http://zoobank.org/ urn:lsid:zoobank.org:act:F1E4F48C-4287-4C7D-9189-472F22023BBE

( Figures 1 (K), 28 –30, 31(F-K))

Type species

Genuchinus parvulus Krikken, 1981 , here designated.

Diagnosis

Quititinus gen. n. is recognised by the following combination of characters: Small size, very flattened and glossy body ( Figures 28 (A,B, E, F), 29(A,B, E, F)). Mentum circular ( Figures 28 (B)–29(B)). Pronotum with a concave anterior margin and convex posterior margin; lateral margin rounded, wide anteriorly, wider centrally, and narrow posteriorly, forming a short callus at the angle where it connects to the posterior margin ( Figures 1 (K), 28 (C)–29(C)). Protibia with one spur apically between two apical teeth, and three more teeth: a larger apical-lateral, a lateral-proximal, and a ventro-apical projecting from a keel ( Figures 28 (C)–29(C)). Parameres curving, each apex uniform width until thin at the tip, central membranous portion large ( Figure 28 (G–F)).

Description

Male. Size: length: 7– 6.5 mm; width: 3.5– 2.6 mm. Body: Elongate, applanate dorsally, very flattened ( Figures 28 (A, B, E, F), 29(A, B, E, F)). Colour: Body glossy black, glossy dark reddish brown, or glossy brown on both dorsal and ventral surfaces, with some sparse whitish velutinous spots; palps and antennomeres are black or brownish. Eyes are black, brown, or yellow, sometimes non-black with black spots. Hind wing is yellow-amber. Head: Clypeus evenly arched in frontal view, weakly bent upwards; clypeolateral declivity with rounded corners, the lateral transition of the clypeus gradually declivous. Frons almost flat, ocellate-punctate and/or differently punctate, sometimes with whitish velutinous spots. Antegenal protusion is evident, eye-canthus is superficially punctate; scape semitriangular; mentum is circular ( Figures 28 (B)–29(B)), superficially punctate. Pronotum: Surface very feebly convex; anterior margin concave and posterior convex. Lateral margin rounded, wider anteriorly, wider centrally, and narrow posteriorly, forming a callus at the angular connection to the posterior margin ( Figures 1 (K), 28 (C)–29(C)). Disc has whitish velutinous spots. Scutellum: Triangular, ocellate-punctate anteriorly with a ‘V’-shaped impression; occasionally with a central whitish velutinous spot. Elytra: Disc elongate and evenly rounded, with a short anteapical umbone on each elytron and a shallow posthumeral emargination. Surface glossy with ocellate punctures and whitish velutinous spots on the disc. Thoracic venter: Hypomerum: Shallowly concave below procoxa; surface striate convergently. Prosternum : Narrow anteriorly, forming a pointed projection, setose at the anterior base. Mesoventrite: Ocellate-punctate and/or differently punctate. Mesepisternum: Rugose anteriorly or not. Mesepimeron: Ocellate-punctate and occasionally rugose, barely visible dorsally. Metaventrite: Slightly punctate centrally, ocellate-punctate laterally, ocassionally with whitish velutinous spots. Metepisternum: Ocellate-punctate, with the outermost side thickened and smooth. Metepimeron: Punctate, or with whitish velutinous spots. Legs: Tarsus with setae on the tarsomeres. Protibia: Differently punctate and/or rugose dorsally and ventrally, with one spur apically between two apical teeth and three additional teeth, the largest being apical-lateral, lateral-proximal, and ventro-apical projecting from the keel ( Figures 28 (C)–29(C)). Profemur: Rugose and differently punctate. Mesotibia shorter than metatibia ( Figures 28 (C)– 29(C)), both are dorsally flattened and differently punctate, ventrally differently punctate, with two pairs of apical teeth and one proximal tooth. A concavity between the proximal tooth and one of the apical pairs is superficially rugose. Two spurs apically, occasionaly with short setae. Metafemur wider than mesofemur ( Figures 28 (C)–29(C)), both ‘c’-punctate or differently punctate. Procoxa and mesocoxa rugose and/or punctate, occasionally with setae, as are the trochanter. Metacoxa: Ocellate-punctate. Abdomen: Ventrites ocellate-punctate and slightly puntate ( Figures 28 (B)–29(B)). Fifth ventrite concave anterioriorly with a deep impression; elevation around the spiracle of the last tergite always visible, with whitish velutinous spots. Pygidium: Convex, ocellate-punctate and slightly punctate, occasionally with setae and whitish velutinous spots. Aedeagus: Parameres curved, wide until thin at the apex, with a large central membranous portion ( Figure 28 (G, H)).

Sexual dimorphism

Males with concave abdomen, observed on the first four ventrites.

Geographical distribution

Quititinus gen. n. is only known from Brazil ( Figure 30 ).

Etymology

The word ‘quititinho’ is a Brazilian informal and diminutive form of pequeno (meaning small in Portuguese); with the suffix ‘nus’ we form the name of the genus, Quititinus , a group like Genuchinus , but quite small, being a masculine noun in the nominative case.

Remarks

Upon reviewing Genuchinus from South America ( G. parvulus and G. sulcipennis ) and comparing them with Genuchinus from Central and North America (including the type species Genuchinus v-notatus Westwood, 1874 ), we observed differences among some characters significant enough to separate them into two distinct generic groups. Due to the presence of unique characters observed in Quititinus gen. n. (see the diagnosis), the description of a new genus is proposed here. Additionally, the pronotum is a key characteristic for differentiating the New World Cremastocheilini genera, which is one of the crucial features supporting this new proposal.

Key to the species of Quititinus Rodrigues, Grossi and Vaz-de-Mello gen. n

1. Elytra surface regular, flat centrally, with ocellate punctures without elevation, and ocellate-punctate laterally, without setae. Amazon Forest ( Figure 30 ) ............................. ................................................................................... Quititinus sulcipennis ( Westwood, 1874)

1’. Elytra surface irregular, with ocellate punctures surrounded by elevations on the disc and punctures laterally, with short setae. Atlantic Forest ( Figure 30 ) ............................... ............................................................................................... Quititinus parvulus ( Krikken, 1981)

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 3. Geographical distribution map of Cyclidiellus velutinus (Westwood, 1874). ‘?’ indicates the exact locality is not known.

Figure 23. Paracyclidius axillaris (Gory and Percheron, 1833) comb. n. Male at CEMT, variation elytra half reddish orange (Brazil, Amazonas, Manaus). (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 24. Paracyclidius axillaris (Gory and Percheron, 1833) comb. n. Male at IRSNB, variation all reddish-orange body (Brazil, Amazonas, Manaus). (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 25. Paracyclidius axillaris (Gory and Percheron, 1833) comb. n. Female at CEMT, variation elytra half reddish orange (Brazil, Amazonas, Itacoatiara). (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 26. Paracyclidius axillaris (Gory and Percheron, 1833) comb. n. Female at CERPE, variation all black body (Peru, Junín,Satipo). (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 27. Geographical distribution map of Paracyclidius axillaris (Gory and Percheron, 1833) comb. n. ‘?’ indicates the exact locality is not known.

Figure 28. Quititinus parvulus (Krikken, 1981) comb. n. Male at CERPE (Brazil, São Paulo, Salesópolis). (A) Habitus, dorsal view. (B) Habitus, ventral view. (C) Pronotum, dorsal view. (D) Protibia, dorsal view. (E) Habitus, dorsolateral view. (F) Habitus, lateral view. (G) Aedeagus, lateral view. (H) Parameres, dorsal view. (I) Pupal chamber. Scale bars = 1 mm.

Figure 30. Geographical distribution map of Quititinus parvulus (Krikken, 1981) comb. n. and Quititinus sulcippenis (Westwood, 1874) comb. n. ‘?’ indicates the exact locality is not known.

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).