Dung beetles (Coleoptera: Scarabaeinae) mediate many ecological functions that are important to maintain the ecosystem functioning of terrestrial environments. Although a large amount of literature explores the dung beetle-mediated ecological processes, little is known about the individual contribution from distinct species. Here, we aimed to examine the intra and interspecific variations in dung burial rates performed by two roller dung beetle species (Canthon smaragdulus Fabricius, 1781 and Canthon sulcatus Castelnau, 1840). Furthermore, we evaluated the relationship between dung beetle biomass and dung burial rates. We set up a laboratorial experiment with three treatments (two males, two females, and a couple) and 10 replicates per treatment for each dung beetle species, and dung burial rates were measured after exposing 100 g of mixed pig and human excrement for 48 hours. Our results demonstrate that dung burial rates of males, females, and couples within each species do not differ. However, C. smaragdulus individuals performed a larger dung burial than C. sulcatus individuals did. In addition, we found no effect of individual biomass on the amount of dung burial on intra and interspecific levels. These findings highlight the need for further research considering that distinct species, even from the same genus, may perform different rates of ecological processes, as well as about the importance for considering the beetle biomass when measuring their ecological functions. We call for studies to fill in the knowledge gap about the individual species’ contribution to the maintenance of different dung beetle-mediated ecological processes.

While pillaging the brood of other ant colonies, Eciton army ants accumulate prey in piles, or caches, along their foraging trails. Widely documented, these structures have historically been considered as by-products of heavy traffic or aborted relocations of the ants' temporary nest, or bivouac. However, we recently observed that caches of the hook-jawed army ant, Eciton hamatum , appeared independently from heavy traffic or bivouac relocations. In addition, the flow of prey through caches varied based on the quantity of prey items workers transported. As this suggested a potential adaptive function, we developed agent-based simulations to compare raids of caching and non-caching virtual army ants. We found that caches increased the amount of prey that relatively low numbers of raiders were able to retrieve. However, this advantage became less conspicuous—and generally disappeared—as the number of raiders increased. Based on these results, we hypothesize that caches maximize the amount of prey that limited amounts of raiders can retrieve, especially as prey colonies coordinately evacuate their brood. In principle, caches also allow workers to safely collect multiple prey items and efficiently transport them to the bivouac. Further field observations are needed to test this and other hypotheses emerging from our study.

With urbanization increasing globally, conservation ecologists need to characterize the functioning of ecosystems embedded in urban landscapes. Ubiquitous and hyperdiverse, ants are an ideal model taxon for this purpose. Here we compared diversity, richness, and abundance of ants in a forest fragment and a green urban area within the City of São Paulo, characterizing relationships among ant species. We found higher species abundance and richness in the urban area, whereas diversity was greater in the secondary forest fragment. Transect sampling revealed higher heterogeneity in the more urban area, with a number of species not found in the secondary forest. Bait sampling suggested that, in the urban area, dominance of one or a few species was stronger than in the secondary forest, possibly because dominant species outnumbered other species at resources and behaved aggressively. We found that a limited number of species dominated in both the forest and the urban area. Although this study only relies on a limited sample size taken in relatively narrow geographic and climatic conditions, it suggests that ant community traits in urban environments vary depending on human-related disturbance.

Potential negative effects of the synthetic veterinary pharmaceutical, Ivermectin, on non-target fauna have generated a search for less-toxic alternatives. Thus, Neem plant extract (Azadirachta indica A. Juss) has been used as a natural alternative to replace Ivermectin worldwide. However, little is known about the effects of this natural veterinary pharmaceutical’s residues on the behaviour and physiology of adult dung beetles (Coleoptera: Scarabaeinae), which use livestock dung as a feeding and nesting resource. To understand such effects, we performed a non-choice experiment using Dichotomius nisus Oliver, 1798. We evaluated effects of Neem and Ivermectin residues on the ecological functions of dung burial and soil bioturbation performed by dung beetles. Additionally, we performed Soxhlet extraction of dung beetle body fat content to evaluate physiological stress in response to ingestion of Ivermectin or Neem. Our results showed that D. nisus do not alter their behaviour in the presence of Neem and Ivermectin residues in dung when contrasted with the control after 48 hours. However, individuals feeding on dung with Ivermectin residues for a period of twenty days had 5% more body fat content than those from control and Neem treatments. Our findings provide the first evidence that Neem can be a less toxic alternative to non-target fauna than Ivermectin.