Low dung beetle populations could be limiting grass production on many livestock farms in the UK by reducing the grazing area as the season progresses.
However, farmers could soon rectify the problem by purchasing dung beetles and reintroducing them to their fields.
Dung beetle expert Sarah Beynon is breeding native dung beetles to release on to UK farms and hopes to supply them within a year. In the meantime, she answers some questions submitted by FWi users.
What is the ideal environment for dung beetles?
Dung beetles thrive in unimproved, permanent pasture. What they like less is improved land with short-term leys.
However, with more than 40 species of dung beetle native to the UK, some will thrive in these systems too.
What’s a healthy population of dung beetles?
There are many different species of dung beetle active at different times of the year. Therefore, the numbers of dung beetles and rates of dung removal will vary across seasons.
However, if you have a healthy population, I would estimate that you should see more than 500 dung beetles a cow pat in spring and autumn, about 30-50 or more in early summer and then about 50-100 in late summer (now), which should include up to five to 10 large tunnelers.
You should also see large tunnels under dung at this time of year (at least 2/dung pat). Most dung should be removed within one to three weeks during the summer.
It should disappear more quickly than this in spring and autumn, as the species active at those times of year can shred dung and remove it in a matter of days.
There are very few species of dung beetles which are active in winter, so dung removal is much slower during the winter. However, it is often accelerated by heavy rain/weathering.
In a healthy dung beetle community, there should always be multiple different species present.
The best way to find out is to take a look. Flip a dung pat and look for beetles on the grass, in the pat-grass boundary and also in the crust.
What numbers are you finding, are there fields with none?
Yes, I am finding fields where there are no dung beetles, which is really very worrying.
Often these fields contain livestock that are routinely and regularly wormed with a product containing doramectin, ivermectin or eprinomectin – all of which are toxic to dung beetles.
The difference between farms that follow different worming regimes is really very striking.
I am also finding very good numbers of dung beetles on agricultural land across the UK, so it shows that productive agriculture and healthy populations can go hand-in-hand
How would farmers reintroduce purchased beetles?
We have a waiting list for dung beetle packages, so people can ask to be added to this list. As soon as they are supplied to us they will be sent through the post and can be released directly onto dung on pasture – it is as simple as that.