Attractiveness of Scarabaeinae (Coleoptera: Scarabaeidae) to different baits in the Brazilian Amazon region

Abstract

Dung beetles (Coleoptera: Scarabaeidae: Scarabaeinae) are considered essential for enhancing the physicochemical characteristics of soils, principally by changing organic materials (e.g. dead animals, faeces, fruits e leaf litter). This study compared the species richness and abundance of dung beetles captured using various types of baits, to demonstrate attractiveness differences in variable habitats of the Brazilian Amazon. Samplings were carried out with pitfall traps baited with human faeces, rotten banana, rotten meat and a nonbaited trap, in February, March, June, September and October 2015. Habitats included native forests, agriculture areas, pastures and disturbed forests in different regeneration stages. A total of 13 736 Scarabaeinae beetles were captured, distributed over 98 species. Most individuals were captured using traps baited with faeces (76.7 % of individuals), followed by rotten meat baited traps (17.8 % of individuals), fermented banana baited traps (3.9 % of individuals) and finally by non-baited traps (1.6 % of individuals). A significant difference in attractiveness of the different baits used and habitats types was observed. Most of the captured assemblages were composed by coprophagous (42 %), generalist species (32 %), necrophagous (15 %) and none was classified as saprophagous. Approximately 54 % of the specimens were tunnelers, 25 % were rollers and 12 % were dwellers. The species of Scarabaeinae sampled in the region revealed qualitative and quantitative differences among their assemblages and the phytophysiognomies. The forest environments housed the greatest species richness observed, and a fraction of these is exclusive of those areas. We concluded that some species of Scarabaeinae have an important potential as disturbance indicators in the Amazonian ecosystem. Rev. Biol. Trop. 65 (3): 917-924. Epub 2017 September 01.

Are Small Dung Beetles (Aphodiinae) useful for monitoring neotropical forests’ ecological status? Lessons from a preliminary case study in the Brazilian Amazon

“…abundance and richness). The high coprophagy specialization in the SDB seems to be related to the regular and diverse availability of mammal dung (Cajaiba et al, 2017b). However, this preference was not linear for all habitats.…”

“…In each study site (PF, SF-15, SF-5, Ag and Pa), seven sample points were placed 100 m apart. We located the sampling points at a minimum distance of 100 m from ecotones, to ensure that most beetles captured were associated to the habitat monitored (Cajaiba et al, 2017b). Each sampling point contained four pitfall traps (75 mm diameter and 110 mm deep, filled with preservative liquid) including different baits (Human faeces-HF, Rotten meat-RM, Rotten banana-RB, to attract different species according to their feeding habits and non-baited pitfalls, used as control-Co), separated by 5 m. The distance between pitfall traps by location was determined in order to select individuals according to their preferential diet, as suggested by related studies (Almeida and Louzada, 2009;Campos and Hernández, 2015;Cajaiba et al, 2017b).…”

“…Small dung beetles (SDB) diversity (Abundance and Richness) was generally superior in the Primary forest (PF), which suggests SDB assemblages' dependence on complex and pristine habitats with more resources (e.g., carrion, faeces and even leaf litter; Driscoll and Weir, 2005;Cajaiba et al, 2017b). This result might also be associated with a range of environmental characteristics created by vegetation structure that are favorable for SDB survival and reproduction: e.g.…”

“…This process seems to be linked with the local availability of the habitats to provide food, i.e. when the preferred food is not available, many SDB may use other resources in similar state of decomposition (Cajaiba et al, 2017b). It is obvious that saprophages and coprophages adults have less specialized diets (Stebnicka, 2001b): for example, the adults of a given species imbibe the liquid that seeps from vegetable masses undergoing fermentation.…”

A preliminary list of beetles (Insecta: Coleoptera) of forensic importance from Peru

“…Consequently, more rigorous studies are required to establish preference or specialization for carrion. For Scarabaeinae, studies incorporating simultaneous collecting with different baits (carrion, dung, rotting fruits) and establishing their food preferences (relative abundance per bait) are required, like those performed by Ratcliffe (2013) and Cajaiba et al (2017). The forensic importance of Ataenius picinus Harold, 1868 has been suggested from cadaveric succession trials in which its abundance was higher during decomposition phase and positively related to duration for each stage (Ries et al 2016).…”