If these FAQs don’t answer your questions, please contact Bernard and he may be able to help you further.
Q: Why do I need dung beetles?
A: Dung beetles can provide a self-renewing environmentally friendly solution to dung accumulation while at the same time improving pasture production, water quality and carbon storage in the soil. In addition, dung beetles reduce the need for chemical fertilisers and so offer increasing cost savings as fertiliser costs escalate.
Q: How many dung beetles do I need?
A: A starter colony of winter-active beetles is about 1000 beetles; colonies of summer-active beetles number between 3000 and 5000. One colony is adequate for a small herd of cattle (up to 50 head). We recommend one starter colony per 50 head of cattle (or 1000 head of sheep) to speed the development of large numbers of beetles and so gain the pasture production benefits more quickly.
Q: How quickly will my dung beetles become established? How long after releasing a starter colony can I expect to see dung beetle activity on my property?
A: On some rare occasions, beetles (e.g. B. bison) have been recovered in the year following their release, but normally it takes at least several years before beetles become common and obvious in dung pads.
Q: How long will it take for B. bison to breed up to numbers that bury most of the dung produced during the winter?
A: It depends… In one instance on cattle country on Kangaroo Island, beetles were obvious and burying much dung five years after the release of 2000 B. bison. After 7–8 years, nearly all the dung in the paddocks surrounding the release area was being buried during the beetle’s active season. Other introductions have established more slowly. If you begin with several starter colonies large numbers will build up more quickly.
Q: How does the 2-year life cycle of B. bison affect establishment?
A: B. bison has a 2-year life cycle in many cool locations, e.g. Central Victoria, means that starter colonies need to be released in two successive years to ensure that beetles are active each winter. Beetles released in winters of 2008 and 2009, for example, will emerge in winters of 2010 and 2011 respectively. In warmer regions beetle populations show a mixture of 1- and 2-year life cycles.
Q: How do dung beetles spread?
A: Dung beetles spread by flying between dung pads but they only colonise fresh dung pads: they do not colonise old pads (older than a day or so) even though they can continue to bury dung from older pads for weeks after arriving. Adult B. bison and G. spiniger fly for about 20 minutes just on dark and again just on light in the morning. During a season an individual beetle may visit many (possibly 10 or more) dung pads.
Q: How fast do dung beetles spread?
A: It depends… At one test site on the Fleurieu Peninsula SA, B. bison appeared to be concentrated over about 4 hectares in the year following release and then to be dispersed over 200 hectares the following season. Eight years after release of B. bison on KI, small numbers were recovered 6 km from the release site. However, if dung is not available or is rare in an area, it is likely that beetles could travel some kilometres in a season. Other species are known to spread many kilometres per year.
Q: Can dung beetles become a problem?
A: Dung beetles have highly specific food preferences and feed only on dung: they do not feed on other materials such as compost. Their abundance is limited by the dung supply and so over time a natural balance develops between dung beetle populations and the local dung supply. Remove the dung supply and the beetles become locally extinct.
Q: Are there dangers associated with the introduction of foreign dung beetles; for example, disease dispersal?
A: There is no known history of transfer of dung-borne stock diseases (such as Johnes’ disease) associated with dung being transported from one property to another (eg by stock transport vehicles) and so it seems unlikely that dung beetles could act as disease vectors.
Q: Is toxic dung a serious problem for dung beetles?
A: Again it depends… Dung containing beetle-toxic chemicals kills adult dung beetles, reduces their egg-laying capacity and kills their young, and can decimate your dung beetle populations. Beetle-friendly chemicals are available and should be used when dung beetles are active.
Q: Are there dung beetles that deal with dog dung?
A: Unfortunately we know of no beetle species that predictably and consistently bury dog dung, although there is clearly a great demand for such creatures, especially for the domestic back yard. There are times in some regions where dung beetles do effectively dispose of dog dung for a short period each year but they do not do it consistently or across all seasons.
Q: Do dung beetles have predators?
A: Yes. Ibis, crows, foxes and other vertebrates find dung beetles to be both delicious and nutritious. But these predators are unlikely to have a significant effect on your beetle populations once they are well established.
Q: How often should I clean up horse manure in my paddocks?
A: When dung beetles are active, it is best to leave fresh manure in your paddock and pick up only the older and drier piles. If there are tunnels under the dung, leave it there; if there are no tunnels, pick it up. Remember that dung beetles need fresh dung in order to breed. If you manually remove it when the beetles are active, they will have no food and you will quickly lose them.
Q: Can I use dung beetles to clean up piles of old horse manure?
A: Probably not. Beetles fly to fresh dung but not to old dung, so they will not colonise piles of old dung. You could catch and manually introduce beetles to piles of dung, and they will bury it if it is moist, but not if it is dry.