Awel Y Grug Project update - August 2024

Awel y Grug is undertaking a project to investigate targeted selective treatment of sheep to improve their endoparasitic worm control. Anthelmintic treatments, particularly the ivermectins, can have a detrimental effect on dung beetle populations and to complement the project, dung beetle surveys have been carried out. Dung beetles can offer a variety of benefits from increasing soil nutrient cycling to actively deterring livestock pests.

Due to the set up of the management system and the project, we will not be able to test whether the project is having an impact on dung beetle numbers because the treatment groups are all running together. There are also other confounding factors such as the fact that beetles are very mobile (they fly) and can move between locations very easily. Different species are present at different times of the year and hence population numbers naturally fluctuate and the weather can also have an impact.

However, due to the enormous service that dung beetles provide on livestock farms, this project will provide a valuable platform to discuss their role and the measures that farmers can take to protect them.

Three fields were surveyed on 15 July 2024 at the parcel of land by Tan y Foel Quarry. The three fields are indicated in figure 1. Dung beetles can take 24 – 48 hours to move into fresh dung and therefore it is best not to survey very fresh dung. The timings of when the sheep were grazing the field in relation to the survey are also indicated on the image below. The fields were being grazed by ewes and lambs that had been treated with a wormer approximately 1 week prior to the survey.

Figure 1. Image indicating sampling sites

Ten dung pats were collected from each field into a plastic bag as shown in figure 2. A zig zag was walked across each field to collect the pats randomly.

Figure 2. Samples being collected

The ten pats were then emptied into a bucket of clean water and the pats were broken up. This releases the dung beetles and they float to the surface.

Figure 3. Breaking up the pats to release beetles

Figure 4. Beetles floating in the water bucket following being released from the pats

Figure 5. Beetles and other insects floating in the water bucket following being released from the pats

The beetles from the three fields were collected into separate sample pots and taken away for further identification. The images shown below are the beetles found in each field. It is important to note that this type of survey is only indicative of their presence and species and the actual counts should not be read as an indication of abundance.

The beetles in figure 6 were collected from the field where the sheep were grazing on day of sampling
 

Figure 6. Dung beetles collected from the field where the sheep were grazing on day of sampling

The beetles in figure 7 were collected from the field where the sheep had been removed 1 day prior to sampling.

Figure 7. Dung beetles collected from the field where the sheep had been removed 1 day prior to sampling

The beetles in figure 8 were collected from the field where the sheep were removed 4 days prior to sampling.

Figure 8. dung beetles collected from the field where the sheep were removed 4 days prior to sampling

Some of the beetles in figure 8 have phoretic mites attached to them and this is shown more clearly in figure 9. These mites hitch a lift on the beetles and cause the beetles no harm at all. However, they also have an important role to play as they feed on the larvae of parasitic flies in the dung

Figure 9. Close-up of phoretic mites attached to dung beetles

There are also beetles other than dung beetles that live in dung. Some examples of these are shown in figure 10. These are also predatory beetles that eat the larvae of other insects and therefore also play a role in controlling parasitic flies.

Figure 10. Examples of beetles other than dung beetles that live in dung, found at Awel y Grug