A simple technique to assess resource use in dung beetle breeding studies

1. Current methods for identifying resource preferences in dung beetles are based on above-ground trials. Although useful, these methods do not directly investigate resource provisioning of offspring below ground, missing an important part of dung beetle ecology.2. We tested the potential for UV-fluorescent and non-fluorescent coloured glitters to be used as markers for tracing the origin of dung incorporated into brood balls (dung shaped by parental beetles enclosing an egg), and so aid in a more complete understanding of resource use in dung beetles. We tested the effect of glitter addition on brood ball production in two species of tunnelling dung beetles, Onthophagus taurus and Euoniticellus fulvus.3. There was no effect of glitter addition on brood ball production during no-choice tests for each species: both species made a similar number of brood balls, regardless of glitter presence or glitter colour. In a separate choice trial, O. taurus showed no preference for dung when presented with four dung pats containing four unique glitter colours.4. Here we show that glitter can be used as an effective marker of individual brood ball origin in tunnelling dung beetles. This method provides a useful tool for tracking below ground resource use and larval provisioning experiments in dung beetles.