Using 3D printing as a tool to study nesting behaviours of paracoprid dung beetles (Coleoptera: Scarabaeidae)

Abstract The dung-burying activities of paracoprid dung beetles such as Onthophagus nuchicornis Linnaeus (Coleoptera: Scarabaeidae) are known to improve nutrient cycling, decrease greenhouse gas emissions, and reduce parasite transmission. These benefits are closely associated with the quantity of dung buried and the depth at which the nest is built; however, comparatively little research has focused on the role of underground nest architecture in underpinning ecosystem function. The use of three-dimensional (3D) printing has facilitated the use of innovative models, tools, and methods in recent ecological studies. Although past attempts have been made to construct paracoprid beetle observation chambers from wood, to our knowledge, 3D printing has not yet been used for this purpose. We designed a 3D-printed observation chamber that allowed us to view the placement and rate of brood-ball production. Initial trials of our design indicate that, with adjustment of the chamber interpane width, tunnelling and brood-ball activity can be monitored without limiting the activity of the captive beetles. Noninvasive observation of underground activity using 3D-printed observation chambers is cost and time effective, and it offers a number of practical advantages over traditional wooden designs. These improvements may facilitate observations and contribute to our understanding of ecosystem functions provided by paracoprid dung beetles.