Field-scale dispersal ofAphodiusdung beetles (Coleoptera: Scarabaeidae) in response to avermectin treatments on pastured cattle

Abstract

Very few studies have examined, at the field scale, the potential for faecal residues in the dung of avermectin-treated cattle to affect dung-breeding insects. The current study examined populations of dung beetles (Scarabaeidae: Aphodius) using pitfall traps baited with dung from untreated cattle on 26 fields across eight farms in southwest Scotland. The fields were grazed either by untreated cattle or by cattle treated with an avermectin product, i.e. doramectin or ivermectin. During the two-year study, significantly more beetles were trapped in fields grazed by treated cattle (n=9377 beetles) than in fields where cattle remained untreated (n=2483 beetles). Additional trials showed that beetles preferentially colonised dung of untreated versus doramectin-treated cattle. This may explain the higher captures of beetles in traps baited with dung of untreated cattle, which were located in fields of treated cattle. Given that Aphodius beetles avoided dung of treated cattle in the current study, the potential harmful effects of avermectin residues in cattle dung could be reduced through livestock management practices that maximise the availability of dung from untreated livestock in areas where avermectins are being used.

Merging Wildlife and Environmental Monitoring Approaches with Forensic Principles: Application of Unconventional and Non-Invasive Sampling in Eco- Pharmacovigilance

“…However, ecologically important insect assemblages and other already vulnerable species may be exposed to such residues, with as yet unknown consequences (e.g., the Egyptian vulture, which is coprophagous [179][180] and rapidly declining in some parts of its range [181,182]. Residues of antiparasitic agents (e.g., endectocides like ivermectin) in the dung of livestock animals can be harmful to a number of coprophagous insects [183][184][185][186] that perform similar ecosystem services to vultures, but on a less obvious microscale. Consequently, the presence of NSAID residues and other relevant harmful compounds -and their persistence in fecal matter -should be better established.…”

“…We are unaware of any studies that have investigated the potential exposure of scavenging insects to nonsteroidal anti-inflammatory drugs, or possible secondary exposure/effects to the species that feed on them. In contrast to scavenging insects, a substantial number of studies have examined the repercussions of veterinary agents excreted in livestock animal dung to coprophagous insect species [186,228] which play a key role in maintaining pasture hygiene [229] and productivity, and in cycling nutrients [183]. However, to our knowledge, the potential exposure of these species to NSAIDs has not yet been evaluated.…”

How to test nontarget effects of veterinary pharmaceutical residues in livestock dung in the field

“…Numerous studies have assessed the effects of VMPs on dung organisms, both in the laboratory and in the field, using different methods (reviews by Floate et al 2005;Lumaret and Errouissi 2002;Wardhaugh 2005;also Floate 2007;Floate et al 2008;Hempel et al 2006;Iwasa et al 2007Iwasa et al , 2008Kryger et al 2005Kryger et al , 2007Lumaret et al 2007;Rö mbke et al 2007Rö mbke et al , 2009Suárez et al 2009;Webb et al 2007Webb et al , 2010. Collectively, these studies support the following conclusions: 1) there has been a strong bias for research on endectocides, primarily ivermectin but also doramectin, eprinomectin, and moxidectin; 2) most of the research studies have been performed in Europe, Canada, and Australia, and to a lesser extent in Japan, South Africa, South America, and the United States; 3) the lethal effects of residues on species of dungbreeding flies and beetles in cattle dung are most often measured; 4) because insect activity can accelerate dung pat degradation, the effect of residues on the rate of dung decomposition also is often measured in field-based studies; 5) the lack of standard test methods and reporting protocols largely prevents direct comparisons among studies; and 6) the interpretation of results is generally hampered and easily confounded by a lack of knowledge about the local biological aspects of the study system, i.e., the dung pat and its associated organisms, which may vary considerably among geographic regions.…”

Dung removal by dung beetles (Coleoptera: Scarabaeidae) and macrocyclic lactone use on cattle ranches of Yucatan, Mexico

“…Residues of ML, particularly ivermectin, are excreted in dung and there is increasing evidence of their lethal and sublethal effects on the immature stages (eggs and larvae) of dung beetle species (Errouissi & Lumaret, 2010;Floate, 2011;Wall & Beynon, 2012;Webb, Beaumont, Nager, & McCracken, 2010). The intensive use of ML to treat parasites in cattle can lead to drastic reductions in Scarabaeinae population abundance, especially if this type of endectocide is used during the beetle reproduction period, when eggs and larvae are exposed to the chemical compound (Errouissi & Lumaret, 2010).…”

“…Dung removal was compared between both types of ranches at the beginning, in the middle and at the end of the rainy season, when dung beetle richness and abundance were the highest in the region (Basto-Estrella et al, 2012;Reyes-Novelo, Delfín-González, & Morón-Ríos, 2007). If the behavior and biology of dung beetles in ML sites is negatively affected by the endectocide (Errouissi & Lumaret, 2010;Floate, 2011;Wall & Beynon, 2012;Webb, Beaumont, Nager, & McCracken, 2010), we hypothesize that the quantity of removed dung will be higher in non-ML sites than in ML using sites. Additionally, we hypothesize that tunneler beetles should remove more dung than telocoprid beetles at sites level, and that the maximum dung removal is expected to occur in the middle of the rainy season in accordance with the abundance of these beetles reported by Basto-Estrella et al (2012).…”