Common name: spear thistle
[Spear thistle](http://www.environment.gov.au/cgi-bin/biodiversity/invasive/weeds/weeddetails.pl?taxon_id=9636) adversely impacts agriculture by competing with pasture species, inhibiting stock movement, contaminating wool, and causing injury to animals.
[Three biocontrol agents](https://biocollect.ala.org.au/biocontrolhub/project/index/c5b3564b-b170-4105-9e37-6c3de8219e7b?hub=biocontrolhub) have been released in Australia:
1. Spear thistle crown weevil *Trichosirocalus horridus*
2. Spear thistle gall fly *Urophora stylata*
3. Spear thistle receptacle weevil *Rhinocyllus conicus*
Further information is required on the establishment, spread and impact of these agents.