The volatile organic compounds of introduced and native dung and carrion and their role in dung beetle foraging behaviour

Abstract

1. The decomposition of biological material produces a plethora of volatile organic compounds (VOCs), which are implicated in the foraging behaviour of coprophagous and necrophagous insects. Dung beetles (Coleoptera: Scarabaeidae: Scarabaeinae) have an acute olfactory system used to locate food resources. Accordingly, identification of food resource VOCs potentially used in food location is integral to understanding dung beetle foraging ecology.2. In this study, volatile emissions from dung and carrion of native and introduced animals in New Zealand were analysed using solid-phase microextraction (SPME) and gas chromatography-mass spectrometry (GC-MS). Volatile profiles were compared via principal component analyses (PCAs) and cluster solutions based on attractiveness using canonical discriminant analysis (CDA).3. A total of 115 compounds were detected from 21 food types. Statistical analyses showed that dung and carrion volatile profiles clustered according to attractiveness to the dung beetle Saphobius edwardsi, and that different dung types formed distinct clusters and grouped separately from carrion.4. This study suggests that volatile profiles emitted by food resources used by dung beetles are complex, producing distinct odours, which potentially mediate foraging decisions.

Attractiveness of baits to dung beetles in Brazilian savanna and exotic pasturelands

“…cattle dung vs horse dung; Louzada & Carvalho e Silva 2009) or clearly distinct (human feces vs rodent dung; Puker et al 2013) have attracted distinct dung beetle communities. This probably occurred, in the first instance, because the dung beetles are able to select a specific food type using olfactory cues (Dormont et al 2004(Dormont et al , 2010Stavert et al 2014).…”

“…, ; Stavert et al . ). Therefore, volatile compounds released by the food source are important components in determining the dung beetle niche, and this can vary depending on the vegetation structure of a given habitat.…”

“…, ) and the odor emitted by each bait type is different (Stavert et al . ). We believe that tunneler beetles are dominant in the two ecosystems studied, given that they are usually large (≥10.0 mm, Arellano et al .…”

“…Dung beetles typically use an odor plume to locate food sources (Dormont et al 2004(Dormont et al , 2010Stavert et al 2014).…”

“…Davis 1994;Tshikae et al 2008;Whipple & Hoback 2012;Puker et al 2013). We expect that there are differences in the species composition attracted to each bait type because dung beetles are able to select a specific food type based on olfactory cues (Dormont et al 2004(Dormont et al , 2010 and the odor emitted by each bait type is different (Stavert et al 2014). We believe that tunneler beetles are dominant in the two ecosystems studied, given that they are usually large (≥10.0 mm, Arellano et al 2005), and because of their nutritional need and/or ability they may colonize a large quantity of the available resources.…”