Ragwort is an noxious pasture weed that threatens native flora biodiversity and poisons grazing animals. It can also be found invading roadsides, forests and woodlands, where it competes and suppresses growth of other vegetation. Four biocontrol agents have been released in Australia to combat the spread of ragwort.
1. Ragwort cinnabar moth *[Tyria jacobaeae](https://bie.ala.org.au/species/urn:lsid:biodiversity.org.au:afd.taxon:17ed7058-7aed-48e9-a3cd-e40228b4bda2)*
2. Ragwort flea beetle *[Longitarsus](https://bie.ala.org.au/species/urn:lsid:biodiversity.org.au:afd.taxon:ce6404da-3e02-4a09-80cd-d324ef481ce1#overview) flavicornis*
3. Ragwort plume moth *[Platyptilia isodactylus](https://bie.ala.org.au/species/urn:lsid:biodiversity.org.au:afd.taxon:2ef8799b-1b19-4617-8b01-fe223d556021#overview)*
4. Ragwort stem and crown boring moth *[Cochylis atricapitana](https://bie.ala.org.au/species/urn:lsid:biodiversity.org.au:afd.taxon:304a3ff9-fab6-4b03-a6ed-cb742fd97cad)*
The combined effects of these biocontrol agents is expected to reduce ragwort growth and seed-set, thus limiting the spread of this invasive weed. The ragwort plume moth was first released in Tasmania in 2000, where it is now well established and spreading. The ragwort flea beetle has established in some areas of Victoria and Tasmania, however there are yet to be reports of them significantly impacting ragwort populations. The ragwort stem and crown boring moth is also widely established and has been reported to reduce the height and vigour of ragwort. The ragwort cinnabar moth has been released at many field sites however is yet to establish a large enough population to impact the target weed.
![Ragwort cinnabar moth](https://lh3.googleusercontent.com/1pkG-REcvVSR1uqno1vp2bnXKCk9egNZr-rO16wwkC4Sggt4an-8Q4hP5FnOwHFBjmhcGG8lfjzv=s0 "medium.jpg")
Cinnabar moth larva, [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/) © Brett Sandford