Pasture Dieback Project

‘Pasture dieback’ has caused over a billion dollars in economic damage through widescale ‘death of grass’ across millions of hectares of grazing in Queensland and New South Wales. The cause was previously ‘unknown’.
Our research combined conventional and molecular entomology to identify the causal agent – a new incursion of the mealybug Heliococcus summervillei – and develop real world management solutions.

Click here to see video from Landline.


We used molecular and conventional systematics to show that the recent outbreak results from an incursion of a new variant of the mealybug, and transcriptomics to show how the mealybug shuts down the plant immune system by disrupting the jasmonic acid /salicylic acid pathways.

We conducted life history studies to find which instars of the mealybug cause the damage, and developed new methods for seasonal monitoring of the mealybug that graziers can use to identify and manage the critical, seasonal stages of mealybugs.

We developed rapid screening methods to identify resistant and tolerant pasture grass varieties and shared this with global seed companies.

Finally, we identified the fungal root endophytes in pasture soil, and showed how increasing diversity and abundance of these fungi reduces mealybug numbers and enhances pasture recovery.

Quote from MLA: “Collectively the work by QUT on these 3 projects has contributed more and most significantly to our understanding of pasture dieback than any of the other investments: much of the work has exceeded expectations… we can go confidently to industry with this information”.

Chief Investigators