Paterson's Curse biocontrol on the rise

01 Sep 2021

Beetle numbers are increasing

Tablelands Telegraph - September 2021

Marita Sydes, Senior Land Services Officer - Weed Action Program

About this time last year we published an article on the effects crown weevils (Mogulones larvatus) and root weevils (Mogulones geographicus) were having on the control of Paterson’s Curse in the region as their population numbers continued to recover after the drought.

In the article we asked landholders to keep an eye out for the shot hole damage on the leaves of their Paterson’s Curse plants – this damage was evidence of established populations of the crown and root weevils.

Local council weed biosecurity officers from across our region have reported that these weevils are building in numbers again this year and we should expect to see more damage to plants across the region.

Recently, Senior Research Scientist (Weed Biocontrol) for NSW Department of Primary Industries, Dr Andrew McConnachie, has also spotted another biocontrol active on Paterson’s Curse around Orange. This time adult flea beetles (Longitarsus echii) were spotted out in full force.

Adults of this flea beetle emerge in winter. The adults feed on rosette leaves and larvae feed inside the main root. Andrew suggested now was a good time to collect and redistribute adult flea beetles, before conditions start to warm up.

The flea beetle and the weevils that feed on Paterson’s Curse are only a few of the six biocontrol insects that are established in the field in Australia. Mitta to Murray Landcare in partnership with Agriculture Victoria have made a series of videos on Paterson’s Curse Biocontrols which are worth watching.

• Biocontrol with Paterson's Curse
• Biological control agents for Paterson's Curse
• Collecting and releasing biocontrol for Paterson's Curse

Biocontrol insects like the flea beetle and the crown or root weevils are an important component of the integrated weed management of Paterson’s Curse - other methods of weed control that can be used include:

• competitive crops and pastures
• grazing management
• a range of herbicide groups
• spray grazing
• slashing
• hand weeding

For more information on the best methods for controlling Paterson's Curse please contact your local council weed officer or visit NSW WeedWise.