|Publication Type:||Journal Article|
|Year of Publication:||2007|
|Authors:||L. Dormont, Rapior, S., McKey, D. B., Lumaret, J. - P.|
|Keywords:||Dung beetles, dung volatiles, herbivore faeces, olfactometer, trophic preferences, –|
Most dung beetles colonize the faeces of several vertebrate species without much discrimination, and are thus often considered as polyphagous. Recent studies have provided evidence for clear feeding preferences in scarab beetles colonizing dung of herbivore species, but little is known about these insects’abilities to discriminate among odours from faeces of various herbivores. In this study, trophic preferences were examined using blocks of pitfall traps baited with dung from four different herbivore species, i.e., sheep, cattle, horse, and red deer, in a moun- tainous area of south-central France. 4941 coprophagous scarabs, belonging to 27 species, were captured. Beetles were more attracted to dung of sheep (2257 individuals) than that of cattle (1294 individuals), followed by deer dung (768 individuals) and horse dung (622 individuals). Eleven of the 27 beetle species collected had significant feeding preferences for one of the four dung types. For each insect species, trophic habits did not vary between the two differ- ent sites of trapping, an open pasture and a wooded habitat. In laboratory olfactometer bioassays, scarab beetles orien- tated preferentially towards the dung volatiles from the dung type they preferred in the field. Trypocopris pyrenaeus, Anoplotrupes stercorosus, andAphodius rufipeswere more attracted to volatile compounds from sheep dung, Onthophagus fracticornissignificantly preferred horse dung volatiles, and Aphodius haemorrhoidalis responded posi- tively to deer dung odours. The role of dung olfactory cues in the process of resource selection by dung beetles is discussed.