History OF THE CSIRO Dung Beetle Project (1966-86)

Rationale for the project

European settlement has permanently changed the nature of the Australian landscape.
Key changes have been partial or total clearing of vegetated areas, coupled with the introduction of pastures plants, undesirable plants, cattle and other domestic animals.

Cattle are quite unlike our native marsupials, particularly in their grazing patterns and in the type of dung they produce. A large proportion of the annual dry matter production of a pasture is consumed by cattle and converted into dung.

Australia has its own unique fauna of dung beetles that evolved with the marsupials, which usually produce relatively dry and fibrous dung pellets.

These insects, with some exceptions, are not adapted to use cattle dung effectively, nor do most of them colonise dung in cleared open habitats. Hence cattle dung in most areas of Australia prior to the beetle introductions was not dispersed (i.e., buried and/or shredded) to any extent, except in a few areas where native beetles were able to have an impact.

This gave rise to various problems, of which the main ones were:

• Cattle dung is the only breeding medium for the introduced buffalo fly and is a major breeding site for the native bush fly and four species of Culicoides biting midges, some of which are known vectors of diseases such as ephemeral fever.

• Dung fouls pasture, obstructing plant growth and promoting rank unpalatable growth around the edge of dung pats.

• Plant nutrients are immobilised in undecomposed dung pats, retarding the recycling process.

• There is some loss of nitrogen to the atmosphere from unburied dung.

On other continents where large ruminants evolved, such as Africa, India and in Europe, there was a parallel evolution of diverse dung beetle faunas to utilize their dung for feeding and breeding. This ensured that much of the dung was buried or dispersed during the growing season.

There is considerable specialization among these beetles as to dung preference, time of activity, reproductive strategy and so forth. There are also clearly recognizable functional groups: dung ball rollers, large and small; tunnelling beetles of all sizes; and several other types.

Thus cattle arrived in Australia without any of the dung beetles that are adapted to bovine dung overseas. This fact was noted by Dr George Bornemissza, of the CSIRO Division of Entomology, who recalled that in his native Hungary it was commonplace to see dung beetles removing quantities of dung from cattle pats.

He proposed that foreign dung beetles be imported to disperse cattle dung in Australia, thus reducing the problems associated with unburied dung.


Introductions from Hawaii

In 1966 a pilot project commenced to import foreign dung beetles into northern Australia to assess prospects for the biological control of dung in this region. George Bornemissza travelled to Hawaii, where several foreign dung beetles were already established, products of an earlier and similar plan to rid the islands of the horn fly.

The Hawaiians had earlier brought in dung beetles from different parts of the world, including Africa and Mexico.

Seven species of dung beetles were selected and shipped to Australia from Hawaii. They were reared in quarantine in Canberra and then five species were mass-reared and released in 1968 at Townsville and soon after at several other sites north of Brisbane.

At Townsville one species, Onthophagus gazella, quickly became abundant and caused spectacular dung dispersal. Two other species also became established. The combined effect of these developments excited much interest and enthusiasm among cattlemen and there was a move to fund a further project, based in South Africa, to import a range of dung beetles for different climatic areas of Australia.


Introductions from Africa

In mid-1970 George Bornemissza travelled to South Africa to set up a research unit in Pretoria for a dung beetle introduction project funded by CSIRO and the Australian Meat Research Committee.

There followed almost a decade of work selecting and collecting beetles for shipment to Australia. Matters at the Australian end were co-ordinated in Canberra, where the quarantine and mass breeding work occurred. Consignments of the new beetles were shipped from Canberra to pre-arranged co-operators around Australia.

Two small dung beetle research groups were established in Australia to bring a focus to introduced beetles in different climatic areas: one at Rockhampton, charged with evaluating the effectiveness of the beetles in this summer rainfall area, and the other in Perth, with a winter-rainfall Mediterranean climate.

Another small group was established at Montpellier in southern France, as a base for collection of European beetles for southern Australia.


Impact of the introduced dung beetles

By 1980 there were up to six species of dung beetles established at a few release sites in Queensland, including Rockhampton. Here dung beetles often appeared in huge numbers, although their activity fluctuated considerably throughout the growing season.

Dung dispersal was spectacular at times and during such episodes, buffalo fly breeding in dung pats was much reduced. When intensive dung beetle activity persisted for more than a couple of weeks, longer than the lifespan of the flies, buffalo fly numbers on cattle declined, often to rise again as beetle activity decreased.

This was clear evidence that the beetles were having some impact on fly breeding, but the overall effect was not as great as had been hoped initially.

Anecdotal reports from western Queensland at that time indicated that bush fly populations had declined markedly since the beetles had become established.


Consolidation phase

At that time (1980) the dung beetle fauna comprised two basic groups of species: small dung ball rollers and small tunnellers. The former fashion balls of dung in the pat and roll them some distance away, where they are either buried or stowed in the base of vegetation.

The tunnellers work entirely within the dung pat, digging tunnels in the soil and packing them with dung masses called brood balls. In both cases eggs are laid in the dung balls and the larvae develop within them.

None of the larger species of ball rollers or tunnellers, which cause such spectacular dung removal in Africa, were released in Australia, mainly due to breeding problems.

Failure to achieve early sustained biological control of buffalo fly led to a change in approach. A decision was taken not to import further beetles until there was a better understanding of the interaction between dung beetles and the buffalo fly in Australia.

The dung beetles, other dung-inhabiting insects and related fauna such as predatory mites (“dung fauna”) on both continents then came under much closer scrutiny.

The Rockhampton group conducted field experiments to identify deficiencies in the activity of the dung fauna for controlling the buffalo fly. The South African group began to analyse the capacity of their dung fauna to control their local buffalo fly, which in most situations occurs only in low numbers.

A long series of comparative experiments in both countries measured the effect of the local dung faunas on buffalo fly breeding. In the period 1980-86, a large amount of additional information was collected on the distribution, abundance and ecology of dung beetles in southern Africa.

Progress was made towards understanding the affinities of species for different habitats as a basis for improving the process of selecting beetles for Australia. In addition, many of the breeding problems were solved. However, the project was terminated, prematurely in terms of its objectives, through withdrawal of funding in 1986.

Between 1968 and 1982, CSIRO imported 55 species of dung beetles for release in Australia. Of these, 37 were intended for summer rainfall regions of northern Australia.

Eight species were reared in insufficient numbers, but the remaining 29 species were liberated in at least one locality in northern Australia; 22 of these originated from southern
Africa.

Eight species are now well established and widespread in Queensland. Two of these, Onthophagus gazella and Euoniticellus intermedius, were considered to have reached their limits of distribution years ago, extending over most of northern Australia.

Seven other species are well established in at least one locality, from which they could be harvested and redistributed. The remainder have failed to establish.

Two were recovered within a few years of release in central Queensland but have not been seen since. The chances of establishment for some species was reduced by successive dry seasons following their release in the early 1980’s.

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This publication is intended to provide producers with information to enable them to choose parasiticides and parasite control strategies to minimise the impact on their dung beetles. The information is not intended to reflect upon the efficacy of any product as a parasiticide. The material is derived from CSIRO Contracted Report #56 by K. G. Wardhaugh (2000) : Parasiticides registered for use in cattle in Australia – an annotated bibliography and literature guide prepared for the National Dung Beetle Planning Forum and from the scientific literature either mentioned therein or located independently.

Trade names for each active constituent and composition of products were checked with the Australian Pesticides & Veterinary Medicines Authority and other sources prior to printing.

This Note is provided for general information only. For application to specific circumstances, professional advice should be sought. While AgForce Queensland and the Qld Dung Beetle Project Management Committee have taken all reasonable steps to ensure accuracy at the time of publication, no warranty is made as to the completeness of the information

Published: July/2003