Rainbow Scarab

• Its colours are not pigments: they come from microscopic layers of the cuticle that split the light, just as soap bubbles do.
• Instead of rolling balls across the surface, it digs vertical tunnels directly beneath the dung and takes the material down, a way of life known as tunnelling.
• The burial of dung by dung beetles recycles nutrients, aerates the soil and cuts down pasture flies, an ecological service valued at hundreds of millions of euros a year.
• Its metallic green, coppery and golden colours are structural colour, and they have earned it the name of rainbow scarab.
• The male bears a curved horn on its head; as in the bull-headed dung beetle, there are large long-horned males that fight and small hornless males that rely on sneaking.
• It is a tunneller, not a roller: it digs vertical tunnels beneath the food source and takes the dung down to the bottom, where the female builds brood balls.
• The pair cooperate in the digging and the provisioning.
• It is used in forensic entomology studies, because its presence beneath a corpse helps to narrow down the time elapsed.

Skeleton type

Invertebrate - chitin exoskeleton (insect)

Habitat and environment

Meadows, pasture and woodland edges of eastern North America

Gestation / incubation

The larva develops inside the dung ball and can remain in it for up to four months; the full cycle from egg to adult lasts between two and six months

Litter / clutch size

A single egg per brood ball; the pair makes and buries several balls in the system of galleries dug beneath the dung pat

Sources consulted: Universidad de Florida, Featured Creatures · Price (2009) · Hoback et al · NC State Extension, ficha Rainbow scarab · ficha de especie de Phanaeus vindex · Ninnescah Biology Field Station (Wichita State University), ficha Rainbow scarab beetle · Ninnescah Biology Field Station · NCBI PMC10317053 (muestreos en Michigan)

Best time: Adults active in the warm months, from May to October; in cold areas they stay in the burrows below the frost line