Chrysina Kirby, 1828

Moore, Matthew R., Jameson, Mary L., Garner, Beulah H., Audibert, Cedric, Smith, Andrew B. T. & Seidel, Matthias, 2017, Synopsis of the pelidnotine scarabs (Coleoptera, Scarabaeidae, Rutelinae, Rutelini) and annotated catalog of the species and subspecies, ZooKeys 666, pp. 1-349 : 1

Chrysina Kirby, 1828 Figs 1A , 8 , 9 , 10 , 11 , 12

Type species.

Chrysina peruviana Kirby, 1828.

Species.

113 species; length 19-40 mm.

Species in the genus Chrysina are commonly known as the "jewel scarabs" for their spectacular metallic and iridescent coloration and large size. Species range from metallic green, pink, purple, gold, and silver, and their elytra may be adorned with metallic gold or silver pin stripes or polka dots. The males of some species have enlarged metafemora (e.g., Chrysina macropus [Francillon]). Morón (1990) reviewed the 73 species of Chrysina (then referred to as Plusiotis , Chrysina , and Pelidnotopsis ). Since that time, an additional 40 species have been described, and no updated revision or monograph is available for the group. The following characters serve to diagnose species in the genus: clypeal apex rounded, with or without emargination; all claws simple; male protarsal claw with or without inner tubercle; mandibles rounded externally; pronotum with bead incomplete apically and basally (complete laterally) ( Chrysophora with bead complete on all margins); elytral epipleuron shelf-like (not rounded); fifth meso- and metatarsomeres with internomedial tooth; metatarsi shorter than tibia (longer than tibia in Chrysophora and Chalcoplethis ); apex of the metatibia with or without corbel; meso- and metatarsomere 5 with internomedial tooth; mesosternal keel surpassing mesocoxae.

The genera Plusiotis and Chrysina were historically separate genera. Morón and Howden (1992) noted an apparent grade of characters within the taxa. Based on molecular and morphological data, Hawks (2001) synonymized Plusiotis as well as Pelidnotopsis with Chrysina . Soula (2008) resurrected the genus Pelidnotopsis , asserting that the genus was “closer” to Pelidnota than to Chrysina . Moore and Jameson (2013) again synonymized Pelidnotopsis within Chrysina . In an effort to develop identification tools for species of conservation importance, Moron and Noguiera (2016) advocated for the use of both Plusiotis and Chrysina . Although they acknowledge that several species possess "transitional characters", they argue that the evidence for synonymy of Plusiotis was based on unpublished data ( Hawks 2001). Characters, they assert, clearly differentiate the two genera, but they do not provide a list of these characters nor a diagnosis for each genus. In our view, the transitional characters provide support for one clade, thus we advise the unity of these genera into the senior name, Chrysina . An analysis in preparation by Morón will elucidate the relationships of the genera ( Morón and Noguiera 2016).

Species in the genus are distributed from the southwestern United States to Ecuador with the greatest diversity of species occurring between 1000-2000 m elevation ( Morón 1991). Many species have narrow habitat requirements and are negatively impacted by unfaltering deforestation that serves to reduce and isolate populations, thus placing species at risk ( Morón and Nogueira 2016). Species are found in primary forests (pine, juniper, and pine-oak) between 50-3800 m. Species feed on the foliage (adults) or rotting logs (larvae) of various trees including species in the genera Abies, Alnus, Arbutus, Heliocarpus, Juglans, Juniperus, Liquidambar, Pinus, Platanus, Quercus, and Turpinia ( Morón 1991). Representative larvae have been described in the genus ( Ritcher 1966, Morón 1976, 1985). Adults are frequently attracted to lights, and larvae live in rotten logs.

Figures

Figure 1. Clypeal shape varying from rounded, parabolic, trapezoidal, subquadrate (A-D), and emarginate (E-F). Lateral edge of mandibles with no reflexed teeth (lacking teeth in A, but the mandible is reflexed rather than flattened in A, two reflexed teeth (B, E, F), or one reflexed tooth (C )). Apical bead of pronotum varying from obsolete (A) to complete medially (B, C, D, F). Disc of frons with V-shaped depression (E) or frons planar, smooth, lacking V-shaped depression (A-D, F) A Chrysina beyeri Skinner B Epichalcoplethis velutipes velutipes (Arrow) C Parhomonyx fuscoaeneus (Ohaus) D Chipita mexicana (Ohaus) E Sorocha sp. F Homonyx elongatus (Blanchard).

Figure 8. Chrysina baileyana Monzon paratype male from MSPC. A Dorsal habitus B Lateral habitus C Specimen labels and male genitalia D Male genitalia, lateral view E Male parameres, dorsal view.

Figure 9. Chrysina benesi Pokorny and Curoe holotype male from NMPC. A Dorsal habitus B Lateral habitus C Specimen labels and male genitalia D Male genitalia, lateral view E Male parameres, caudal view.

Figure 10. Plusiotis cunninghami (Curoe) (valid name Chrysina cunninghami [Curoe]) paratype male from MSPC. A Dorsal habitus B Lateral habitus C Specimen labels and male genitalia D Male genitalia, lateral view E Male parameres, caudal view.

Figure 11. Chrysina giesberti Monzon paratype male from MSPC. A Dorsal habitus B Lateral habitus C Specimen labels and male genitalia D Male genitalia, lateral view E Male parameres, caudal view.

Figure 12. Plusiotis orizabae H. W. Bates (valid name Chrysina orizabae [H. W. Bates]) holotype from BMNH. A Dorsal habitus B Lateral habitus C Specimen labels.