Scarabaeinae, Latreille, 1802

Ratcliffe, Brett C., 2013, The Dung- and Carrion-Feeding Scarabs (Coleoptera: Scarabaeoidea) of an Amazonian Blackwater Rainforest: Results of a Continuous, 56 - Week, Baited-PitfallTrap Study, The Coleopterists Bulletin 67 (4), pp. 481-520 : 510

Scarabaeinae : Dichotomiini

Aphengium Harold is a small South American genus with only three species. Only two specimens of Aphengium cupreum Shipp were collected at Reserva Ducke, one each at dung and carrion ( Table 1). Virtually nothing is known of these rare beetles.

Ateuchus ( Fig. 44 ) contains about 92 species distributed from the USA to Argentina ( Gill 2002; Larsen 2012a). This large genus is in great need of revision, and identification for many of the species is difficult. Ten species were taken at Reserva Ducke, but only four could be reliably identified ( Table 1). All but three species came exclusively to dung. Ateuchus murrayi (Amazon basin of Brazil, Colombia, Ecuador) was collected in large numbers in dung (96%), but some individuals also were collected in the carrion traps (4%).

Canthidium is comprised of approximately 170 species found from southern Arizona to South America ( Gill 2002). Like Ateuchus , this genus is in great need of revision, and it is currently difficult to identify many species with any reliability. Fourteen species were collected at Reserva Ducke, mostly in the dung traps; Canthidium sp. #2 was the exception with nearly five times more individuals collected in the carrion traps ( Table 1). Canthidium bicolor Boucomont ( Fig. 45 ) ( Brazil, Colombia, Peru, Bolivia) and Canthidium sp. near gigas Balthasar (French Guiana, Brazil) are coprophages (this study), whereas Canthidium gerstaeckeri Harold ( Fig. 46 ) ( Brazil, Peru, Colombia, Venezuela, Guyana, Bolivia) feeds primarily on dung but also less frequently on carrion, dead invertebrate animals, fruit, and fungi ( Larsen 2012b).

Dichotomius is a large genus of 150–200 species found from the USA to southern South America ( Gill 2002).The genus is in great need of revisionary studies, and many species probably remain to be described. Most of the species are large, nocturnal coprophages. Four species were collected at Reserva Ducke, and the vast majority were taken throughout the year in the dung traps ( Table 1). Dichotomius boreus (Olivier) ( Fig. 47 ) ( Brazil, Suriname, French Guiana, Colombia, Ecuador) (99% on dung) and Dichotomius sp. near mamillatus (Felsche) ( Fig. 48 ) (Amazon basin of Brazil, Colombia, Ecuador, Peru, Bolivia) (98% on dung) were the two most abundant species in the study.

Ontherus Erichson has 58 species that occur from Mexico to Argentina ( Génier 1996). Only one species, Ontherus carinifrons Lüderwaldt ( Brazil, one record for Peru; Génier 1996), was found at Reserva Ducke ( Table 1), exclusively on dung.

Trichillum Harold has, depending on the authority one consults, 50–100 species (e.g., Vaz-de-Mello 2003) distributed in the Neotropics. Two species were collected at Reserva Ducke. Trichillum boucomonti Saylor ( Brazil, Colombia, Bolivia, Paraguay) was found almost exclusively in the carrion traps (99%), and Trichillum hirsutum Boucomont ( Brazil, Colombia, Bolivia, Paraguay) was divided between the dung and carrion traps (62% on dung versus 38% on carrion) ( Table 1).

Uroxys is comprised of about 60 species that are found from Mexico to Argentina. Three species were collected at Reserva Ducke, and two of these were represented by singletons taken in dung traps ( Table 1). One of these, Uroxys besti Ratcliffe (Amazonian Brazil), is known to inhabit the fur of sloths ( Ratcliffe 1980) and may not normally come to dung in pitfall traps. Uroxys pygmaeus (Amazonian Brazil) ( Fig. 49 ), on the other hand, was taken in huge numbers throughout the year (7,721 specimens), primarily on dung (98% versus 2% on carrion).

Figures

Figs. 41–46. Reserva Ducke dung beetles. 41) Deltochilum carinatum. Photograph by Jim McClarin; 42) Deltochilum septemstriatum. Photograph by Denis Faure; 43) Deltochilum pseudoicarus. Photograph by Trond Larsen; 44) Ateuchus sp. Photograph by Jim McClarin; 45) Canthidium bicolor with phoretic mite. Photograph by Trond Larsen; 46) Canthidium gerstaeckeri. Photograph by Trond Larsen. All images used by permission.

Figs. 47–52. Reserva Ducke dung beetles. 47) Dichotomius boreus. Photograph by Trond Larsen; 48) Dichotomius mamillatus. Photograph by Trond Larsen; 49) Uroxys pygmaeus. Photograph by Trond Larsen; 50) Coprophanaeus lancifer. Photograph by Trond Larsen; 51) Oxysternon conspicillatum. Photograph by Doug Emlen and Mark Rowland; 52) Phanaeus chalcomelas. Photograph by Trond Larsen. All images used by permission.