Project overview
Four biological control agents have been released against old man’s beard: old man’s beard leaf fungus (Phoma clematidina), old man’s beard leaf miner (Phytomyza vitalbae), old man’s beard saw fly (Monophadnus spinolae), old man’s beard gall mite (Aceria vitalbae). A second importation and release has been made of the old man’s beard sawfly. All four agents attack the foliage, and the fungus also damages the stems.
The leaf miner has established and is common and widespread but is attacked by parasitoids and so has had little impact. The fungus had some impact early on but has since died out. The sawfly was recovered at one site only but another importation and field release was made in 2020. The sawfly has now been confirmed as established at one site in Canterbury. A fifth agent, a bark beetle (Xylocleptes bispinus), was found to not be host specific and was rejected as a potential biocontrol agent. The old man’s beard gall mite was first released in 2021.
