Dor beetle  (Geotrupes stercorarius)

The biggest threat to these beetles is the use of invermectin-based worming treatment for grazing animals. This chemical is used to treat intestinal worms in the animals’ gut but persists in their dung when it is deposited on the ground. The ivermectin effectively kills the developing larvae long after it has passed through the larger animal.

Although the dor beetle is not thought to be threatened as a species, they are linked to another animal which is the subject of several conservation projects. Dor beetles and their cousins, the chafers, are the main prey of greater horseshoe bats, a species that has been declining in numbers for many years. The cause of this is believed to be the use of the ivermectin-based wormers used in the intensive rearing of cattle. A reduction in the available insect food has affected greater horseshoe bat populations across the UK, and the bats are now limited to parts of the West Country and South Wales. Conservation projects to restore the fortunes of this mammal include limiting the use of ivermectin treatments and re-creating habitats suitable for the bats. As with so many endangered species, the solution to one problem frequently benefits other associated animals.