Two biological control agents for Bridal Creeper, the Bridal Creeper Leafhopper (Zygina sp.) and Rust Fungus (Puccinia myrsiphylli) have been established in Tasmania but current status is unknown.
Rust Fungus (Puccinia myrsiphylli)
The rust fungus attacks leaves and stems, reducing the amount of green plant material. It can produce many generations a year, resulting in large amounts of wind dispersed spores. It produces an over summering spore to survive the summer absence of Bridal Creeper. It should spread within and between Bridal Creeper infestations efficiently but spread will be faster with more regional releases of the rust.
The release technique for the rust is a simple process that entails shaking some of the spores onto the leaves, spraying them with water, covering them overnight with a plastic bag, then removing the plastic bag the next day.
The rust fungus has had a major impact in reducing bridal creeper populations, particularly in moist coastal areas where climatic conditions are conducive to rust epidemics.
Bridal Creeper Leafhopper (Zygina sp.)
The adult insect is white, 2–3 mm long and lives on the underside of bridal creeper leaves. Both the adult and juvenile stages feed on the leaves of the weed, causing them to turn white and, in severe cases, fall off. The plant will continue to grow but with much less vigour. Continual damage over several years will reduce new tuber production, making it less competitive.
Rearing the leafhopper is easy and many schools and community groups on mainland Australia have become involved in breeding up populations for local release. It can produce several generations a year and females are highly reproductive, so populations can quickly increase. The leaf hopper can also adversely affect bridal creeper, but its populations have a tendency to fluctuate from year to year, hence limiting its impact.
It will take many years for the biocontrol agents to reduce the density of bridal creeper due to the huge reserves stored underground in tubers.