Allorrhina Burmeister, 1842,

Ratcliffe, Brett C., 2015, A Revision of the Neotropical GenusAllorrhinaBurmeister, 1842 (Coleoptera: Scarabaeidae: Cetoniinae: Gymnetini), The Coleopterists Bulletin 69 (1), pp. 91-113: 91-113

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http://doi.org/ 10.1649/0010-065X-69.1.91

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scientific name

Allorrhina Burmeister, 1842
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Allorrhina Burmeister, 1842 

Allorrhina Burmeister 1842: 251  . Type species: Gymnetis concolor Gory and Percheron 1833: 76  , here designated. Burmeister (1842) stated he knew only this species based upon actual specimens, while the second species in his new genus, Gymnetis menetriesii Mannerheim  , he knew only from the description. Accordingly, the former is designated as the type species. Gymnetis concolor  is a junior synonym of Cetonia scabriuscula Swederus. Burmeister (1842: 806)  belatedly recognized that C. scabriuscula Swederus  belonged in Allorrhina  .

Diagnosis. Form elongate, subparallel, slender to robust, slightly dorso-ventrally flattened. Length 11–29 mm. Color dorsally shiny dark green, reddish brown or piceous, or opaque light to dark reddish brown, plum, dark greenish gray, dark greenish black, or blackish gray, occasionally with weak metallic reflections. Venter most commonly shiny reddish brown or dark green, occasionally black. Cretaceous marks present or not on pronotum, lateral margins of elytra, pygidium, femora, and thoracic and abdominal sternites. Head: Shape subrectangular, frons of males longitudinally tumescent or with short, dorso-ventrally flattened horn projecting forward over clypeus, horn free at apex or not; clypeus with or without short, subrectangular or subtriangular horn at apex. Females with low, longitudinal tumescence on frons, apex occasionally barely free; clypeus with low, rounded or subrectangular, reflexed prominence at center or simply broadly rounded. Antenna with 10 antennomeres, club subequal to or distinctly longer than antennomeres 2–7. Pronotum: Shape subtrapezoidal, widest near base, gradually convergent to anterior angles, basomedian lobe strongly produced posteriorly, lobe covering all but tip of scutellum. Sides with slender, short or complete, marginal bead. Lateral margin usually strongly emarginate between middle and basal angle. Elytra: Widest at base, posthumeral emargination distinct. Complete or partial bead present on lateral margins. Apices usually slightly produced at suture. Pygidium: Surface with transverse, vermiform punctures or strigulae, setigerous; setae minute to short, most tawny, some black. Venter: Mesometasternal process, in lateral view, moderately protuberant, subparallel to ventral axis of body, apex broadly rounded ( Figs. 5View Figs, 10View Figs, 32View Figs). Abdominal ventrites 1–5 impunctate to sparsely punctate on central third, lateral thirds with moderately dense to dense, moderately large punctures. Legs: Protibia slender, unidentate, bidentate or weakly tridentate in males, tridentate in females. Parameres: Form (e.g., Figs. 3View Figs, 28View Figs), in caudal view, subrectangular, apices usually broadly rounded with subapical tooth on lateral edge or acuminate and curving mesad.

Distribution. Species of Allorrhina  are known from Venezuela and the Guianas in northern South America south to Argentina.

Diagnosis. As is the case with many other New World gymnetines, there seem to be few morphological characters, other than unreliable color and pattern, to circumscribe taxa, especially considering the similarity of the form of the parameres within genera. At least with Allorrhina  and Cotinis  , the armature of the head provides additional characters, although these should be used cautiously since this armature is subject to allometric growth exemplified by minors and majors. The characters of most taxonomic value for Allorrhina species  are: dorsal color; absence or presence of cretaceous marks on the pronotum, elytral margins, pygidium, and ventrites; length; form and/or armature of the frons and clypeus; sculpturing of the pronotum and pygidium; and form of the parameres. The mesometasternal process is similar in all the species and is slightly elongate, parallel to the ventral axis of the body in lateral view, and with subparallel sides and a broadly rounded apex in ventral view (e.g., Fig. 5View Figs). One species is noticeably pubescent on the process ( Fig. 10View Figs), while in the remaining species the process is glabrous or nearly so (e.g., Fig. 32View Figs).

Allorrhina  is closely allied to Cotinis  in character states. Goodrich (1966) revised Cotinis  and suggested Allorrhina  and Cotinis  were easily separated by the uniformity of the developed head armature (clypeal and occipital horns or projections) in both sexes of Cotinis species  but not in Allorrhina species.  Goodrich thought that males of Allorrhina  all had well-developed clypeal horns and occipital horns with a free apex. My observations demonstrate this is not true for all Allorrhina species.  Moreover, some Allorrhina species  have similar, albeit reduced, clypeal projections in both sexes, and some Cotinis species  have little or no armature on the head but merely prominences. Allorrhina species  occur only in South America, while Cotinis species  occur from the central USA southwards to northern South America.

Bates (1872) described Allorhina (sic) anomala  , but this species is in the genus Argyripa Thomson (Ratcliffe 1978)  . Westwood (1874) described Allorhina (sic) hypoglauca  from Nicaragua, and Janson (1877) placed it in junior synonymy with Allorhina (sic) lansbergei Sallé. This  species is in the genus Argyripa (Ratcliffe 1978)  . Janson (1888) described Allorhina (sic) insignis  from Panama, but this species is in the genus Chiriquibia Bates (Ratcliffe 2014)  . The genus Allorrhina  now contains nine species, including the new species described herein from Argentina.

Natural History. Species of Allorrhina  are diurnal. Unlike some species of Amithao Thomson, I  have seen no records of any Allorrhina species  being occasionally attracted to lights at night. The adults are found from near sea level to 1,800 m and are usually attracted to ripe fruits placed in traps. There are rare observations of species being found on a particular tree or flower, but their life history remains unknown. None of the larvae have been described.