Case Study: British dung beetles – here to help
Author: Ceri Watkins, Co-Founder of Dung beetle UK Mapping Project
Species: Dung beetles
Why is farmland important for these species?
There are approximately 60 species of dung beetle in the UK. They are not the ‘ball rollers’ seen in warmer countries and on TV, instead they live inside the dung pile (dwellers) or in the soil beneath it (tunnellers). Livestock grazing provides much of the dung required for the survival of these beetles, although other animals such deer and badgers also contribute. Some species are rather specialised and require exacting conditions. For example, Volinus sticticus prefers horse or sheep dung in the shade and Onthophagus joannae is a sun loving beetle that favours sheep dung on light soils. Others are less fussy and have few specific requirements.
It is possible to find dung beetles at work all year round. Several species are winter active, although the vast majority are found in the spring, summer and autumn. Given the right conditions, dung beetles can decimate a pile of horse poo or a cow pat in just a couple of days.
Volinus sticticus (c) Katherine Child
Onthophagus joannae (c) Katherine Child
How do dung beetles benefit farms?
Dung beetles provide a wide range of ecosystem services that help to maintain healthy pastures and soils. These include the most obvious, the consumption of dung thereby removing it from the fields thus reducing pasture fouling, but also some that you may not have considered. As the beetles tunnel down through the soil, burying the dung for breeding purposes, essential nutrients are recycled within the soil profile. This improves grass growth and provides a direct benefit to grazing animals. The larger species such as the Minotaur beetle (Typhaeus typhoeus) can tunnel a metre or more, this action breaks up the ground and improves drainage, especially useful on clay soils.
In addition, dung beetles also reduce nuisance fly populations by transporting phoretic mites that eat fly eggs and help control intestinal parasites by reducing dung suitability for worm larvae. The beetles are also an important food source for many other farmland favourites such as bats and birds.
Onthophagus similis with phoretic mites (c) Ceri Watkins
Continuity of the dung supply and diversity of habitat are key factors in supporting a diverse range of dung beetle species on the farm. If possible, maintain some outdoor grazing year-round, even if only a few animals. Planting a group of trees and grazing within them will provide variety of forage and shelter for livestock and support the shade loving dung beetles too.
Broad spectrum livestock wormers such as avermectin are detrimental to beneficial dung invertebrates. These chemicals are excreted in the dung for many weeks after treatment and a range of lethal and sub-lethal effects occur depending on the concentration. Such effects include slowing beetle larvae development, reducing the size attained at adulthood and reduced breeding capacity.
Cutting down the use of chemicals on the farm with a sustainable worm control policy that includes monitoring with faecal egg counts will help. Treating animals only when necessary will save money and also slow the rate of anthelmintic resistance. As a natural alternative in a rotational system, consider using herbal leys. Sainfoin, birdsfoot trefoil and chicory all have anthelmintic properties. The latter has been shown to reduce worm burden in sheep by as much as 40%. In permanent grasslands, mixing up cattle and sheep grazing works by reducing the stocking density of the parasite host – cattle and sheep worms are different species.
Supporting dung beetles on your farm not only helps keep pasture and livestock healthy, it also represents good economic sense. It has been estimated that dung beetles save the UK cattle industry £367 million per annum through the provision of ecosystem services (Beynon et al., 2015). So, it really does pay to look after these useful little creatures.
For further information and dung beetle identification resources, please visit the Dung beetle UK Mapping Project website or get in touch via email or twitter.
Hi. I have some friends who keep horses. I’ve never seen any dung beetles or their larvae in their paddocks or manure heaps. I would like to obtain some dung beetles to introduce them into their paddocks. Is introducing certain dung beetles a good thing to do, and if so how?
Thanks for your question. The dung beetles might not be obvious, unless you or your friend have had a good look inside the dung pile. They aren’t often found in manure heaps as they prefer the soil/dung interface out in the paddock. Does your friend ‘poo pick’? If so, leaving some dung in the field would be of benefit and the dung beetles will colonise from the local area providing there is livestock nearby. It can take a while though depending on the local dung beetle population level. If you email firstname.lastname@example.org, we can discuss specifics further.
Many Thanks Ceri
Hello. I keep 4 ponies and regularly pick up the poo. I have seen several dung beetles, from small black ones to large ones with a bright blue underside. If I spot them in a poo pile I leave them to carry on with their job, but I wondered if they are harmed if they end up on the muck heap.
Please email Ceri direct with any further dung beetle questions (email@example.com). If you find a dung beetle, please add it to the Biological Records Centre website iRecord (www.brc.ac.uk/irecord).
Thank you for your interest. Good to hear that you have some of the different dung beetle species in your pastures. Dung beetles don’t really like the change of conditions that occurs in dung heaps – the heap will heat up too much and the interface with the soil is lost. However, if you inadvertently scoop a few up and they end up in the manure heap, they should extricate themselves and fly off to something more suitable. It sounds as if you are leaving the odd pile of poo in the field which is brilliant as this will give them something to go to.
Hi, I am two years in to regenerative/mob grazing sheep in Bedfordshire- currently very little summer rain and pasture is open field with shade structures moved with the sheep. We are on heavy clay that cracks and is very barren over summer! I am planting trees into the fields for shade but this will obviously take years to happen. We don’t use any wormers or fly treatment. Are there any dung beetles that work on sheep poo on heavy concrete/clay in full sun or do I need to wait for tree shade to see dung beetles moving in? Thanks!