Red Headed Pasture Cockchafers

Summary of Project

 

The redheaded cockchafer (RHC) is a native insect species that has become a significant pest of ryegrass-based dairy pastures in Victoria. Farms with heavy infestations can lose up to $200,000 per annum.  Currently there is no effective management method other than to regularly rip and resow pastures which is unprofitable for dairy farm businesses. 

The project has advanced the aim of providing dairy farmers with cost-effective techniques to manage red headed cockchafers. It has achieved this through its research deliverables. These included quantifying RHC infestations across Gippsland which showed the pest was widespread.  Pilot studies using EM38 electrical conductivity field surveys indicate a relationship between electrical conductivity and RHC spatial distribution and abundance.  This is important as it is a major step towards early detection of RHC infestations which will help farmers to make earlier informed decisions about how to treat and use the affected area. These surveys were not designed to provide definitive distribution data across the state. They were designed to test if EM38 would be a useful tool for further studies. The cockchafer sampling conducted in conjunction with EM38 field surveys gave a snapshot of RHC distribution in some key dairy production areas of the state. A new project has been submitted to build on these findings.

Phone surveys provided a good indication of cockchafer issues across Victoria as well as revealing that identification of RHC is not always done accurately by farmers or consultants. An essential first goal in future work is to develop tools to assist farmers identify pasture grubs so they can use appropriate management methods. Preliminary work undertaken during the cockchafer sampling in the current project suggests that confirmation of the diagnostic characters used by the project team to distinguish between the common cockchafer species present as larvae in pastures could be packaged for use by farmers and advisory service providers.

The strong collaborative relationships within the skilled project team has meant all research and delivery objectives have been achieved in less than one year.  This is despite very extreme weather conditions delaying field research and increasing its difficulty.  The project has resulted in a leap in understanding of the incidence of RHC and is therefore valuable to the longer term goal of being able to better assist farmers trying to manage the problem.

Research outputs included two scientific papers.  One has been accepted for publication in Agricultural Systems. The paper explains the trans-disciplinary research approach of the project.  Another paper will be submitted to the Australian Journal of Entomology.  It provides an update of issues associated with the management of the RHC in south eastern Australia. 

The project also resulted in development of future research study priorities, some of which are the subject of a new application to the Gardiner Foundation. This came after the project’s  multi-disciplined group engaged other experts at a forum where information was shared and methodology suited to analysing complex problems was used. The approach allowed multiple interactions to be considered before prevention measures were implemented. This is important as missed interactions may have long term environmental effects. Another benefit is that the next phase of work submitted for consideration by the Gardiner Foundation fits within a larger perspective understood by members of the taskforce who are across research into RHC being done by the DPIV, University of New England and some private contractors.

This preliminary project has found that farmers face two issues: (1) problems in identifying which species of cockchafers are damaging their pastures; and (2) inability to readily detect the underground stages of cockchafers before they have matured, bred and spread resulting in severe loss of pastures. The work undertaken in the last nine months has indicated that (1) accurate identification of cockchafers is possible, and (2) remote sensing technologies can provide guidance on the most useful areas for sampling to detect cockchafers in the soil. Both these areas will be addressed in a new application under consideration by the Gardner Foundation in order to provide farmers with appropriate tools to detect and identify cockchafers more rapidly and easily.