Crofton weed biocontrol

Ageratina adenophora
Crofton weed

Crofton weed is a rapid-spreading weed that is invasive in many areas along the eastern coast of Australia, particularly cleared land that is not grazed (such as public reserves). Crofton weed reduces the carrying capacity of grazing land and restricts movement of stock and machinery. It is unpalatable to cattle, and poisonous to horses. Biological control is believed to be the only viable option to reduce dense infestations of Crofton weed, particularly in areas of mainland Australia and Lord Howe Island that are difficult to access. Three biocontrol agents have been released to control Crofton weed:

1. Crofton weed rust fungus *Baeodromus eupatorii*
2. Crofton weed leaf-spot fungus *Passalora ageratinae*
3. Crofton weed gall fly *Procecidochares utilis*

The combined effects of these three biocontrol agents are expected to reduce the growth and spread of the weed in Australia. The most recent agent, the rust fungus, was released in 2015 and 2016 at close to 250 sites in NSW and south-east Queensland. The rust fungus was confirmed as established at 59% of these sites within 6-12 months after releases. To enhance natural spread, community members may consider redistributing the rust fungus to sites where it is absent. Step-by-step guides (see the Resources tab) are available to facilitate releases of the rust fungus and to monitor release sites for establishment and impact of the rust. Once established in an area, rust spores are easily redistributed by wind to nearby Crofton weed infestations, facilitating the spread of this agent.

The CSIRO's [Crofton weed research](https://research.csiro.au/crofton-weed/) page provides further information on past research, or check the Blog page for updates on news and events.

紫茎泽兰（*Ageratina adenophora*，英文名Crofton weed）是一种扩散速度极快的入侵性杂草，在澳大利亚东海岸诸多区域大肆扩散为害，尤其喜生于未被放牧的清理地块（如公共保护区）。该杂草会降低牧场载畜能力，限制牲畜与农机通行；对牛适口性极差，且对马具有毒性。生物防治被认为是抑制紫茎泽兰高密度侵染的唯一可行方案，针对澳大利亚本土及难以抵达的豪勋爵岛区域尤为适用。目前已有三种生防因子被用于防控该杂草：
1. 紫茎泽兰锈菌（*Baeodromus eupatorii*）
2. 紫茎泽兰叶斑菌（*Passalora ageratinae*）
3. 紫茎泽兰瘿蚊（*Procecidochares utilis*）

这三种生防因子的联合作用有望抑制该杂草在澳大利亚的生长与扩散。其中最新释放的生防因子——锈菌，于2015年和2016年在新南威尔士州（NSW）与昆士兰州东南部的近250个站点完成释放。释放后的6至12个月内，该锈菌在59%的释放站点成功定殖。为促进其自然扩散，社区成员可考虑将该锈菌重新分布至尚未定殖的区域。现有分步操作指南（详见"资源"标签页）可协助开展锈菌释放工作，并监测其定殖情况与防控效果。一旦在某一区域定殖，锈菌孢子可通过风力轻松传播至附近的紫茎泽兰侵染区域，助力该生防因子的扩散。

澳大利亚联邦科学与工业研究组织（CSIRO）的[紫茎泽兰研究页面](https://research.csiro.au/crofton-weed/)可获取更多过往研究相关信息，也可查看博客页面获取最新动态与活动资讯。