Predatory Behavior ofCanthon virens(Coleoptera: Scarabaeidae): A Predator of Leafcutter Ants

Abstract

We present a detailed description of the predatory behavior of the beetle Canthon virens Mannerheim, 1829, on the leafcutter ant Atta sp. We observed 51 acts of predation, which were also recorded on film and subjected to behavioral analysis. Canthon virens exhibited 28 behaviors while predating upon Atta sp. queens. Adult beetles search for queens while flying in a zigzag pattern, 15 to 20 cm above the ground. After catching a queen, the predator stands on its back and starts cutting the queen cervix. Once the prey is decapitated, the predator rolls it until an insurmountable obstacle is reached. The distance from the site of predation to the obstacle can vary widely and is unpredictable. The beetle rolling the queen also buries it in a very peculiar way: first, it digs a small hole and pulls the queen inside, while another beetle is attached to the prey. The burial process takes many hours (up to 12) and may depend on the hardness of the soil and the presence of obstacles. In general, one or two beetles are found in a chamber with the queen after it is buried. They make the brood balls, which serve as food for the offspring. This study contributes to the knowledge of the predatory behavior of Canthon virens, a predator poorly studied in Brazil and widespread in the country.

First report on dung beetles in intra-Amazonian savannahs in Roraima, Brazil

“…Although most species are considered as copro-necrophagous, other feeding habits, including fungi and debris feeders (Vaz-de-Mello 1999b) and ant predation (Hertel & Colli 1998, Vaz-de-Mello et al 1998, Villalobos et al 1998) were also recorded. The subgenus Canthon (Canthon) Hoffmannsegg, 1817 includes mainly coprophagous or necrophagous dung beetles, despite species preying on ants (Cantil et al 2014, Forti et al 2012, Villalobos et al 1998) and feeding on dead insects and millipedes (Villalobos et al 1998). Canthon (Canthon) aff.…”

“…scrutator Balthasar, 1939 ( Figure 1B) belongs to the Canthon virens species-group (Halffter & Martínez 1977), which is distributed throughout the northern Amazon Basin, Guyana and Atlantic Forest region. This species-group comprises copro-necrophagous dung beetles, also recorded consuming insect carcasses (Forti et al 2012) or sampled with carrion-baited pitfall traps (Salomão & Iannuzzi 2015). We believe the species Canthon (Canthon) aff.…”

CONTROLE BIOLÓGICO DE FORMIGAS-CORTADEIRAS: O CASO DA PREDAÇÃO DE FÊMEAS DE Atta SPP. POR Canthon virens

“…São insetos cosmopolitas, que se alimentam primariamente de fezes (coprófagos). A maioria deles tem por hábito, enterrar porções de fezes, carcaças e frutos em decomposição (SILVA et al, 2010) em túneis escavados próximos ao depósito de recursos, com os quais se alimentam e produzem suas progênies (FORTI et al, 2012). Os mais característicos são aqueles que fazem porções "pílulas" de fezes de bovinos depositadas em áreas de pastagem (com auxílio de suas pernas anteriores) e as rolam até o ninho (com auxílio de suas pernas posteriores) (LIMA, 1953).…”

“…Particularmente, para C. virens, além de tanajuras, Vaz- de-Melo et al (1998) mencionaram que os insetos adultos também se alimentam de fezes de mamíferos, como as do lobo guará (Chrysocyon brachyurus Illiger, 1815) e, frutos maduros. Hertel & Colli (1998), Silveira et al (2006), Araújo et al 2011e Forti et al (2012) descreveram o comportamento de predação C. virens, desde a aproximação da presa, a típica maneira de "monta" na região notal do tórax, a preparação para decaptação e a decaptação da presa, o transporte "rolamento" da presa abatida até o ninho e, o enterrio da mesma no ninho. Uma vez que a maioria dos casos de predação era realizada pelo macho solitário, Silveira et al (2006) mencionaram a possibilidade de ele usar, também, a tanajura abatida como atrativo de fêmeas para a cópula.…”

First observation on the predation of a non-arthropod species by a dung beetle species: The case of Canthon chalybaeus and the snail Bulimulus apodemetes

“…Among those strict necrophagous species, only few cases of predation of dung beetles on other arthropods have been observed, being the cases of Canthon virens Mannerheim, 1829 and C . dives Harold, 1868, preying on the leafcutter ant Atta laevigata (Smith, 1858), the first and most documented [ 4 – 9 ]. In this case, since both Canthon species lack the mouthparts to kill such as cutter mandibles [ 10 ], they use the same acute denticles of their clypeus that is used to cut carrion to decapitate ants [e.g.…”