Dor beetle

Anoplotrupes stercorosus

About

The Dor beetle is the same convex black-blue beetle that slowly crosses the path in beech and spruce forests. Its body length is 12–20 mm. It is black with a blue or greenish metallic sheen on top, and if you turn the beetle over, you can see a bright blue or purple underside. The elytra have longitudinal grooves.

In the Carpathians, this is one of the most common beetles of the forest belt — in observations by naturalists from the Ukrainian Carpathians, it is the most frequent among insects that were not yet in our catalog. Adult beetles can be seen from late spring to autumn, most often in summer and early autumn, especially during the mushroom season.

Dor beetles feed on animal droppings, decaying leaves, and old mushrooms. For their offspring, the male and female together dig a deep burrow with side chambers under a pile of food, fill them with nutrients, and the female lays an egg in each chamber. The larvae develop in the soil for about a year.

Thus, the beetles bury organic matter in the soil, fertilizing and aerating it — hence they are called the sanitarians of the forest. If you take a beetle in your hand, it quietly squeaks, rubbing its abdomen against its elytra.

On the body of the Dor beetle, small reddish mites often sit. These are not human parasites and not Ixodes ticks: they simply 'ride' on the beetle to a new food source. The beetle does not bite and is not poisonous. Do not step on it on the path — it is going about its business.

Where in the Carpathians

fewermore461 records in the Carpathians

The map shows where naturalists recorded the species (GBIF, CC0 and CC BY records), not every place it lives. The Ukrainian Carpathians are less studied, so a blank area does not mean the species is absent.

Countries: Ukraine · Hungary · Slovakia · Poland · Romania · Czechia
Mountain ranges: Rivna Polonyna, Gorgany, Bükk, Mátra, High Tatras, Skole Beskids, Zemplén Mountains, Făgăraș Mountains, Börzsöny and Cserhát, White Carpathians
Altitude belts: Foothills (below 600 m) · Beech forests (600–1200 m)

When to see it

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Sightings

From naturalists’ observations in the Carpathians (iNaturalist, research grade): the darker the cell, the more often the species is seen that month.

Protection and rules

Not listed in the Red Book of Ukraine.

FAQ

What is the blue-black beetle crawling on the paths in the Carpathians?

Most likely, it is the Dor beetle. It is black with a blue sheen, with a bright blue or purple underside, and measures 12–20 mm in length.

Are the mites on Dor beetles dangerous?

No. These are small mites that use the beetle as 'transport'. They do not attack humans and are not related to Ixodes ticks.

Similar species

Rose chaferCetonia aurataA metallic green beetle sitting on the flowers of rose and elderberry. It flies with its elytra lowered; larvae live in decaying wood.

Red Data Book of UkraineEuropean stag beetleLucanus cervusThe largest beetle in Europe with deer-like 'antlers'. It lives in old oak forests of the Carpathian foothills; a rare species in the Red Book of Ukraine.

Castor bean tickIxodes ricinusThe most common tick in the Carpathians, a carrier of Lyme disease and tick-borne encephalitis. How to protect yourself and what to do after a bite.

Where to meet it

Trails and peaks near which naturalists recorded the species (GBIF, iNaturalist), matched by altitude and habitat. Sightings are not guaranteed.

Sources

GBIF · iNaturalist · Wikidata · Distribution data: GBIF.org (CC0 and CC BY records), iNaturalist; names and identifiers: Wikidata (CC0). Text: Karpaty.rocks, checked 11.11.2026.