Synopsis and key to the genera of Dynastinae ( Coleoptera , Scarabaeoidea , Scarabaeidae ) of Colombia

An illustrated key to identify the adults at the generic level of Dynastinae known from Colombia is provided. A synopsis for each genus is given with updated information on the diversity and distribution of species in Colombia and worldwide.


Synopsis and key to the genera of Dynastinae
(Coleoptera, Scarabaeoidea, Scarabaeidae) of Colombia Introduction Th e subfamily Dynastinae is a cosmopolitan group of beetles widely distributed in most biogeographical regions of the world (except in the polar regions), and the majority of species are distributed in the tropics, especially in the Neotropics.Th ere are approximately 220 genera and 1500 species within the Dynastinae world wide (Ratcliff e 2003).Endrődi (1985) estimated about 2000 species world wide.Some authors (e.g., Baraud 1985;Dechambre 1986) referred to this taxon at the family level.In groups belonging to Scarabaeoidea, the phylogenetic relationships and taxonomic hierarchy are poorly studied.A comparative analysis including all known tribes and genera would provide a much needed evolutionary and taxonomic foundation in the Scarabaeoidea.
To date, however, many genera lack complete taxonomic revisions and most larvae remain undescribed (Morón et al. 1997).
Adult Dynastinae are characterized by exposed mandibles in dorsal view; small and thin labrum with the border usually not surpassing the clypeal margin; antennae with nine or ten segments with the base of the scape hidden by the clypeus; scutellum visible; mesepimeron hidden; pygidium exposed; procoxae transverse; middle and hind tarsal claws simple; and apex of the fi fth meso-and metatarsomeres lacking a longitudinal slit.Th e body shape is generally robust, and the color is generally dark brown, black or reddish, occasionally testaceous yellow, with maculae or dark symmetrical lines or spots.Body length ranges from 4 to 160 mm (including the head and pronotal projections in males).
Th e dynastine beetles are important in nutrient recycling.Th e larvae are able to fragment large amounts of wood during their feeding, greatly expediting decomposition time (Morón 1985).In the process, they produce detritus and excretions that facilitate the action of other decompositional agents in the microfauna and microfl ora.Th is ecological role makes them essential for nutrient recycling in tropical forest ecosystems (Morón 1985).
Adults of most species are nocturnal or crepuscular and are attracted to lights at night.Dynastines feed on foliage, sap secretions, fruits, fl owers, and pollen of plants.Larvae are saprophagous or phytophagous, feeding on roots, stems, decaying logs, or organic matter.Some species are economically important, causing damage to crops such as corn and sugarcane (Morón 2004).Males in several species (mainly in the tribes Dynastini, Agaocephalini, and Oryctini) possess prominent horns on the head and/or the thorax, which, because of their great size, give rise to vernacular names such as "rhinoceros beetle", "elephant beetle", "Hercules beetle" or "unicorn beetle" (Ratcliff e 2003).
In the last ten years in Colombia, the Dynastinae subfamily has been the subject of increasing interest.One of the most remarkable pioneering studies was Restrepo's (1998) undergraduate thesis that provided the fi rst contribution to the study of the phytophagous scarab beetles in Colombia.In this work, the author compiled and analyzed information about the phytophagous scarabs and presented an identifi cation key to 76 genera and a descriptive synopsis of important agricultural species.For the subfamily Dynastinae, Restrepo reported 40 genera and 195 species in Colombia, and seven species were of agricultural importance.From this study, and as a posthumous tribute, two important reference papers for the study of the Dynastinae were published that increased the number of species in Colombia to 200: Especies de Chisas (Coleoptera: Melolonthidae) de importancia agrícola en Colombia (Restrepo and López-Avila 2000) and Catálogo de Coleoptera Melolonthidae (Scarabaeidae: Pleurosticti) de Colombia (Restrepo et al. 2003).
Th is faunistic survey recorded 42 genera and 213 species of Dynastinae in Colombia.At the genus level, Colombia surpasses other countries with great diversity such as Mexico and Costa Rica.Colombia possesses approximately 20% of the generic richness in the world (Table 1).Ten genera are represented by a single species each, whereas genera such Haplophileurus Kolbe, Horridocalia Endrődi, Pucaya Ohaus, and Th ronistes Burmeister have all of the species comprising each genus.In recent years the monotypic South American genus Acrobolbia Ohaus was removed from the subfamily Rutelinae and transferred to the tribe Cyclocephalini (Jameson et al. 2002).According to the known geographical distribution (Ecuador, Peru and Venezuela), Acrobolbia should be found in Colombia.However, Acrobolbia has not yet been recorded in Colombia.Accordingly, Acrobolbia is not included in the identifi cation key below.
In this contribution we present an illustrated identifi cation key to the adults of the genera of Dynastinae found in Colombia.In addition, a diagnosis, world and national distributions, and the current species number in the world and in Colombia are included for each genus.

Table 1 .
Dynastinae generic diversity in the World, Colombia, and other regions of the Neotropics.