Dr Umar Lubanga1, Dr Penelope Mills2, Mr Greg Lefoe1

1Agriculture Victoria, Bundoora, Australia, 2School of Biological Sciences, The University of Queensland, Brisbane, St Lucia, Australia

Biography:

Greg Lefoe is a Senior Research Scientist with the Department of Energy, Environment and Climate Action’s Agriculture Victoria Research Division, based at the AgriBio Centre in Bundoora. Greg has more than 25 years’ experience in the biological control of weeds and pest insects. He currently leads research into the biological control of the weed silverleaf nightshade and biological control of horticultural pests. Past research projects include biological control of gorse, invasive brooms, bridal creeper and wandering trad. Greg’s work encompasses the full range of classical biological control activities, including overseas exploration and field studies of new biocontrol agents, risk assessment and quarantine experiments, release of approved agents in conjunction with stakeholders such as farmers, public land managers and community-based natural resource management groups, integrated pest and weed management, and long-term impact assessment studies.

Abstract:

Giant pine scale (GPS), Marchalina hellenica is an exotic sap sucking scale insect that was detected feeding on a novel host (Pinus radiata) in Adelaide and Melbourne in late 2014. This scale insect is native to the eastern Mediterranean region (mainland Greece and Turkey) where it is considered an economically important insect in the apiculture industry. GPS is a concern in Australia because high population densities can lead to a decline in tree health and reduction in insect biodiversity. In addition, GPS is a threat to Australia’s soft wood industry (valued at $1.16 billion) as it attacks the dominant commercially grown species (P. radiata). There are currently no effective control options. Complete destruction of infested tress is currently being used to stop GPS from spreading into pine plantation.

A feasibility study carried out by Agriculture Victoria identified Neoleucopis kartliana (Diptera: Chamaemyiidae) as the most promising biological control agent of GPS. Recent studies in Greece involving molecular analyses have revealed that N. kartliana sensu lato is a species complex comprising three species; N. kartliana sensu stricto, N. n. sp. A. and N. n. sp. B., of which only N. kartliana sensu stricto has been described. It is likely that all three species play a role in suppressing GPS populations in Greece and therefore have high potential for use as biological control agents for GPS.

The aim of this research was to assess risks associated with the introduction of potential biological control agents of GPS and determine the agents’ suitability for long-term, sustainable management of GPS in Australia. Preliminary laboratory and field results from Greece indicate N. n. sp. B to be highly prey specific. If approved for release, N. n. sp. B, will complement other management practices to prevent or slow the spread of GPS into softwood plantations.