Want to know more about beneficial bugs & dung beetles? Check out the new website Horses Bugs & Beetles! The website and fact sheets are supported by Horse SA Federation and Dung beetle Solutions Australia. The aim is to raise awareness amongst horse property managers, owners and agistees about sustainable horse keeping through providing a focus on promoting dung beetle health and reducing the use of chemicals.
Dung beetles in Australia
There are more than 400 different types of native dung beetles in Australia who have been here burying kangaroo and wallaby poo for millennia. Most of the native beetles are no good at getting rid of the dung of domestic stock, including horses.
The piles of unburied dung in Australian paddocks prompted scientists to introduce new types of dung beetles. These new beetles came from Africa and Europe, where they colonise the dung of horses and other domestic stock. In Australia, most of these beetles bury horse dung but none of them like the dung pellets produced by kangaroos and wallabies, so they don’t affect the food supply of native dung beetles.
Dung beetles for horse dung (South Australia)
In southern Australia there are introduced dung beetles that bury horse dung in all seasons. In South Australia we have only summer and winter beetles: the spring and autumn species are not yet present. The summer and winter beetles do a great job when they are active but they are scarce or dormant in spring and autumn. Once established, beetles don’t need to be introduced again, provided there is enough suitable dung and they are not killed by toxic chemicals.
Three native dung beetle species are found in low numbers in horse dung:
- Onthophagus mniszechi, in spring, summer and autumn
- Onthophagus australis, in spring and autumn
- Onthophagus pentacanthus, in winter.
- O. mniszechi breeds well in horse dung, especially in sandy soils.
Many beetles of all species often have small mites hitching a ride. These don’t harm the beetles but use them to travel between dung pads, where they are predators of insect eggs and larvae, as well as nematodes.
In winter, the southern European beetle Bubas bison does a great job on horse manure, but it is not yet widely distributed. Currently there are no introduced spring or autumn beetles active in the Adelaide Hills region although small numbers of the summer beetles are found during spring and summer.
The summer active species are:
- O. Taurus, a small black beetle
- E. fulvus, a small fawn beetle
- Onthophagus binodi, a small black one from South Africa
- Onitis aygulus, a largish tan beetle from South Africa
- Aphodius fimetarius, a small one with orange wing covers
Benefits of dung beetles
Dung beetles are a great way to achieve manure management. Adult beetles feed on the juices in dung and then bury it underground, taking infective stages of gut parasites and fly larvae with it. Shredded dung remnants remain on the surface in which little can survive.
The females lay eggs in the buried dung and these hatch into larvae which eat the dung and grow into adult beetles.
Allowing dung beetles to bury dung in paddocks is a natural way to get rid of the dung and let the grass grow.
Beetle activity provides a number of obvious benefits:
- improves soil health by burying nutrients and organic matter
- prevents dung from smothering pasture
- promotion of pasture growth
- helps to control parasitic gut worms and other pests
- improved soil biology (earthworms and microbes)
- increased soil carbon and organic matter
- restructuring the soil profile with tunnels and subsoil brought to the surface
- biological control of the infective stages of gut worms and dung-breeding flies
Why could dung beetles be scarce on your horse property?
Many horse properties appear to have low numbers of dung beetles with correspondingly low levels of dung burial. This can be due to a lull in the seasonal activity of dung beetles (such as in spring and autumn) but there can be a number of other causes, which include:
- the use of beetle-toxic pastes/drenches
- frequent collection of all manure, denying the beetles the opportunity to breed locally
- relatively unfavourable conditions for local breeding of established species
- dung beetle predators
- the absence of suitable species because established species have not yet arrived
Refer to the Horses, Bugs and Beetle fact sheet series and The Dung Beetle Dictionary for help in identifying which dung beetles may be active on your horse property.
You can find these fact sheets on the Horses Bugs & Beetles website: http://www.horsesbugsbeetles.org/
It also provide more information about reducing chemicals, pests and horse care.