Sunday, 9 December 2012

Dung Beetles Now Active In Cattle Manure

In the past couple of weeks we've noticed quite a deal of dung beetle activity in the manure pats from our cattle. This link takes you to the Dung Beetle article on Wikipedia. The article explains that there are three main types of dung beetles:

  • 'Rollers' who are called such because they roll the dung into balls
  • 'Tunnelers' because they tunnel under the dung and bury it in the the tunnels they make in the soil
  • "Dwellers' because they basically live or dwell in the dung
In our dung we've observed two different species. One is quite small at about twice the size of a house fly or half the size of a blow fly. They other is much larger at around 2/3rds the size of Christmas Beetles. Based on the activity we can see in and below the dung at least one of these is a tunneler; which to be honest is our preferred type as we are very keen to see the beetles assist in the build up of organic matter in our soils.

Below is a sequence of photos showing different aspects of the beetles and the dung at different stages. NB: The photographs are not all of the same dung pat, but rather a range at different stages of dung beetle impact.

Untouched / fresh dung pat

From what we understand this is a pretty good 'shape' for a dung pat in that it contains good moisture whilst maintaining reasonable structure. Given that we are now in the non-growing season due to the extended dry period (we've not had a rainfall event of in excess of 25 mm since July) we recently recommenced giving our cattle daily Distillers Condensed Soluble as a supplement, together with a small quantity of some other minerals and grains.

It is important to note that whilst some of the sheep manure has dung beetle activity it is much less in percentage terms of the total number of deposits. Almost all of the cattle manure pats have some level of beetle activity which we deduce is as a consequence of the greater critical mass of the cattle pats. They take comparatively much longer to dry out and have a higher initial moisture content.

Early Stages of Dung Beetle Activity

Here you can see evidence of the tunneling activity on the edge of the cattle pat.

Tunneling Through the Dung

The above photograph was taken of the preceding cattle pat after most of the top was moved away. Clearly evident is one of the tunnels through the manure, as is one of the beetles (partially covered). We've been able to flip over some of the pats at this stage and have seen entrances to the tunnels that are in some cases every 2 to 3 cm or so, quite evenly spread.

Dung Tunnel Close-up

Here's a photo in macro of the same dung tunnel.

Dung Beetle in Close-up

Here's a better picture of one of the species of dung beetle. It's similar in appearance in some ways to a Christmas beetle and about 2/3rds the size.

Pat as Dung Beetle Activity Subsides

Here you can see that the cattle pat has lost most of its structure due to the dung beetle activity.

Pat After Dung Beetle Activity Has Ceased

Here you can see just how well the dung has been dispersed. Eggs will have been laid in the below-ground stores of dung. Aside from assisting in enhanced mineral cycling the beetles also dramatically reduce the scope for flies to lay eggs in the dung.


Anonymous said...

Phillip, I think the species of dung beetle in your photo is Onitis alexis. We often have that same species at this time of year. Regards Philip Barrett-Lennard, Gingin, WA.

Phillip Diprose said...

Thanks for the lead / information, Philip
A web search shows some information specific to the species you've mentioned at