Scoping the development of a best practice manual for managing pesticide use while maintaining healthy dung beetle populations

Summary

Producers do not have a single source of reliable information to guide their choices about healthy dung beetle population management on their farms whilst not compromising profitable decisions about key animal pests (for example worms, lice and ticks). They are interested in the production
and ecological benefits of dung beetles on their farms, however learning that common pesticides can damage dung beetle populations.

This report maps out the research required to create a Best Practice Manual (BPM) for cattle and sheep producers to minimise adverse impacts on dung beetles through pesticide use in livestock production.

An extensive review was undertaken to examine the interactions between dung beetles and the main groups of chemicals used for livestock parasite management, before a proposed structure and template for the BPM guidelines was developed.

Objectives

The main objectives of this project were to:

• clearly define the research questions that will need to be answered in order to underpin future BPM guidelines through solid science
• determine what information producers would like to see in relation to the project findings and how to best communicate to enable adoption
• begin a process of developing protocols for the independent assessment of new pesticides and their formulations and uses to assess their impact on dung beetles, in order to ensure the industry can safely incorporate new products into their farming practices.

Key findings

The literature review identified several key findings that will be important in planning and conducting research on the impact of pesticides on dung beetles:

• Commonly used veterinary pesticides can have a negative impact on dung beetles. The severity of this impact, which might include death, depends on the class of chemical and level of residue in dung, and the timing of chemical exposure in the beetle life cycle.
• Eco-toxicological information on the effect of the key active ingredients and the excretion curve in dung is not available. This severely limits accurate evaluation of the toxic effect of these products on dung beetles specifically and on ecosystem functions more broadly.
• Published field evidence has shown that moderate levels of dung burial by beetles can achieve a degree of biological control of the infective stages of gut parasites.
• Substantially greater levels of dung burial occurs when soil is damp (a key time for gut parasites). The impact of such substantial dung burial on field populations of intestinal parasites needs to be studied in more detail, especially in sheep.
• Information about pesticides effect on dung beetles is highly dispersed and difficult to find. Without a central point to access such information, it is difficult for producers to make informed decisions.

Benefits to industry

Identifying and understanding the research questions required to underpin new best practice guidelines with solid science will enable producers to make informed decisions around safe and appropriate use of pesticides.

Developing protocols for the consistent and objective assessment of new pesticides, their formulations and uses through specific assessment of their impact on dung beetles, will ensure the industry is able to safely incorporate new products into their farming practices.

Providing producers with clear guidelines via a BPM on how to balance responsible chemical pesticide use with healthy dung beetle populations, will create long-term animal productivity and environmental benefits.

MLA action

MLA is seeking expressions of interest from providers to undertake five areas of future R&D identified by this project.

Future research

Additional research is needed if comprehensive and accurate BPM recommendations are to be provided for on farm chemical use that benefits dung beetle populations. Areas include:

• predicting the potential amount of chemical active in dung and the margins of safety for dung beetles
• developing dung beetle information packages for current key providers of pesticide recommendations
• developing guidelines to test the off-target effects of new actives on dung beetles
• determining the impact of buffalo fly ear tags on dung beetle populations
• researching the role of dung beetles in controlling helminth populations.