Spring active dung beetles New colonies of dung beetles at Red Cow Organics
During the spring of 2019, Cradle Coast Authority Natural Resource Management (NRM) team became involved in supporting the Dung Beetle Ecosystem Engineers (DBEE) project. This national project has the goal of introducing new species of dung beetles across southern Australia, to provide dung beetle activity year-round for grazing systems. Tunnelling dung beetles provide a range of benefits to livestock producers as well as the environment. One gap in dung beetle activity in Tasmania is spring, and so in 2019 nursery colonies of Onthophagus vacca, a spring active species of dung beetle, were established in 21 locations across southern Australia. Cradle Coast Authority provided support in setting up and caring for the nursery colony in our region, as well as collecting data on the reproductive rate of this species in Tasmania. The result was a 6-fold increase in the first generation of O. vacca beetles bred in Tasmania, a great result. Following this early success from the first field site near Burnie, the next phase was to spread O. vacca nursery colonies across additional grazing districts. Survival of the first couple of generations of a new species such as this is crucial to ensure establishment and proliferation, so aspects of site selection for new nursery colonies had to be carefully considered.
With a portion of O. vacca’s lifecycle occurring in summer, irrigated or higher rainfall cattle grazing properties were one such criteria. Irrigated dairy farms in Tasmania play a crucial role in survival of dung beetles which are active in the warmer months, essentially providing a stronghold for them by maintaining a level of soil moisture. Organic or lower input grazing enterprises were another desired element, providing a higher likelihood of dung beetle survival.
After much consideration, a second nursery colony was established during the 2019-20 summer on a commercial farm near Burnie. A further four nursery colonies were set up during the spring of 2020 on organic and lower input dairy and beef farms. Two of the four newer colonies were established at Oldina, one at Mawbanna, and one at Cressy. So far we can say with confidence that O. vacca can increase its population by at least 6-fold each generation in the temperate climate of north-west Tasmania, and that to date six nursery colonies have been established on farms by the Cradle Coast Authority. When more beetles are available to distribute, the intention is to build on this and set up more colonies each year across grazing districts and get more of these useful beetles working for farmers.
This project is supported by Cradle Coast Authority, through funding from the Australian Government’s National Landcare Program.
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