Common Dumble Dor

Commonly known as earth-boring dung beetles, the Common Dumble Dor (Geotrupes spiniger) is one of the eight species of dor beetle found in the UK.

The Common Dumble Dor is a large, native, heavily built beetle with a convex body shape and parallel looking sides of its body. It has a faint metallic sheen to the upper surface and usually a blue margin around the wing cases (the elytra) and the thorax (the section between the head and abdomen and known as a pronotum). The underside of the beetle is a beautiful bright metallic blue in colour.

These beetles are very similar in appearance to the Common Dor Beetle (Geotrupes stercorarius).  However, they tend to be less shiny in appearance and also lack hairs in the middle of each of the abdominal segments on their undersides. There are also very subtle differences in the shape of the hind legs.

Despite recent decline in the population, the Common Dumble Dor remains one of our most common dor beetles. It can be found across the UK, although appears to be more common across southern England and Wales.  It has been recorded on grazed pastures, moorland, woodland and dunes.

• Size: 16-26mm
• Life span: Possibly 2-3 years
• Diet: Both adults and their larvae feed on the dung of large herbivores including sheep, cattle, horses and deer.
• Reproduction: The adults mate in spring and early summer.  Females dig a vertical burrow under a dung pat and then excavate horizontal branches from it.  In each horizontal branch she will place a cylindrical piece of dung into which a single egg is laid, and then cap the chamber with soil.  Larvae develop through the summer and will then either pupate in the burrow during the autumn or, overwinter and then pupate during spring.
• When to see: Adults emerge around May and will continue to be active until October. They are often seen on warm spring and summer evenings flying over dung pastures.
• Population Trend: Thought to be declining
• Threats: Earth boring dung beetle populations are affected by the loss of permanent pasture and livestock being removed from pasture for long periods.  They are also affected by the use of broad spectrum veterinary worming products.
• Fun Fact:  By late spring most adult beetles will be carrying large numbers of mites over the undersides of their bodies. These mites cause the beetles no harm but merely use them to hitch a lift to fresh dung pats.

How you can help: 

Buglife is working to increase awareness of invertebrates and the Common Dumble Dor Beetle through specific projects and campaigns, but we need your help!

Join a recording scheme and log your finds – send any records/sightings to the British Scarab Recording Scheme who work to promote the recording of dor beetles and other species of scarabs or download the iRecord app and get recording!

Do remember that we rely on donations to continue our work.  If you have searched, found and learnt about our incredible invertebrates on our website, please do consider Making a Donation, Becoming a Member or maybe even making a purchase in our shop.  For more ideas on how to support our work find out how to Get Involved.  Thank you 🕷

You might also be interested in

Brush-horned Sand Beetle

Orthocerus clavicornis

Strandline Beetle

Eurynebria complanata