Dung beetle populations in the UK are struggling, according to farmer and entomologist Sally-Ann Spence.
These insects play a vital role in livestock systems with dung management, soil health and pest control.
Cattle produce 6% of their body weight in faeces each day, or 9 t / year, and sheep produce 8% of their body weight in faeces daily, or 800 kg / year.
Dung beetles help break this down – but over 50% of UK species are threatened to some extent, according to a report from Natural England (NECR224, 2016).
Types of dung beetles
There are around 60 species of dung beetle in the UK and they fall into three groups.
Aphodiines are “dwellers”, living in manure, while geotrupidae – the largest of the three – and onthophagi are “tunnel boring machines”, pulling balls of manure through the ground.
They are all herbivores, can fly, and have clubbed antennae to maximize their ability to smell feces.
Threats against dung beetles
Dung beetles face many challenges:
- Climate change – particularly periods of sudden unusual heat, which can trigger the emergence of dung beetles in large numbers when livestock may not yet be grazing so that there is no manure for feed or breed in
- Removal of livestock from farms
- Land use change, for example, for a golf course
- Soil disturbance – tines and harrows expose dung beetles to predation
- Chemical treatments – treating livestock for parasites kills dung beetles.
Sally-Ann Spence’s tips for encouraging dung beetles
- If you have cattle, you are already helping dung beetles
- If you have a breeding mix, even better
- If they go out all year round (even if little), it’s even better
- Treat your livestock for parasites selectively rather than systematically
See more on the Dung beetles for farmers information center.
Benefits of dung beetles
Although their main function is to dry and remove dung, dung beetles provide many other services. They:
- Reduce the need for harrowing, saving costs
- Cut populations of parasites and harmful flies by disturbing the eggs in the feces and breaking their life cycle
- Carry mites on your back from pat to pat and drop them to hunt down maggots
- Reduce greenhouse gas emissions – dung beetle’s unrecomposed droppings remain on the ground, where they continue to ferment and produce methane
- Increase the fertility of pastures
- Increase soil organic matter
- Redistribute fungi and bacteria
- Improve soil aeration
- Improve water quality
- Improve rain infiltration
- Increase biodiversity above and below ground
- Are a vital source of food.
“Think of manure as habitat,” says Ms. Spence. “Manure dung with high ridges – neither too wet nor too dry – is ideal.
“Dung beetles don’t like ‘splash’ – they aren’t deep enough for dung beetles to move away from predators, they can’t pull manure into the ground and they can drown.”
Encourage dung beetles
To encourage dung beetle activity, Ms. Spence advises adopting a sustainable management plan:
- Perform fecal egg counts or blood tests to assess the parasite load and only treat animals that need to be treated
- Kill animals susceptible to parasite loads and breed selectively for natural resistance
- Develop a parasite control plan with your veterinarian using low toxicity treatments
- Keep animals out of clean pastures for at least a week after any treatment
- Be aware that long-acting products will also affect dung beetles for a longer period.
- Avoid under-dosing, as this can speed up resistance of the parasites, and weigh animals accurately to determine the dosage rate
- Rotation of animal species around pasture – stock / pasture rotation can help break pest cycles and reduce pest resistance
- Include high-fiber grasses and natural pest control species like chicory, sainfoin, plantain, and trefoil in grass mixes.
Sally-Ann Spence was speaking at Groundswell, which took place on June 22-23 at Lannock Manor Farm, Hitchin, North Hertfordshire.