After the species' proven success at weakening A. riparia populations, it was implemented in wide reaching projects in Hawaii and New Zealand.

Though the two species are closely related, the disease's effects on A. adenophora are comparatively benign; it does not form spores and produces only small lesions.

The fungus initially forms small, circular chloratic lesions on the upper surface of living A. riparia leaves.

Mid-19th century methods to control the plant on the island included spraying affected areas with a solution of arsenic or calcium chlorate.

[8] These early methods were not only toxic to the native ecosystem, but proved ineffective at limiting the spread of the plant.

[7] A $10,000 grant provided by Barbara Cox Anthony funded a total of three trips in search of naturally occurring biological control agents for the A. riparia.

[4] A rust fungus was identified in El Mirador, but limited biological information meant that it could not be transported back to Hawaii because of pathogenic quarantine regulations.

Because the fungus appeared highly specific to the A. riparia, it was permitted for live transportation to Hawaii by the Department of Agriculture and the Federal Animal and Plant Health Inspection Service.

[7] A host-range study was conducted in 1974 which concluded that E. ageratinae was specific to A. riparia and did not pose a significant threat to native flora.

A 1975 field test conducted on the Tantalus Ridge on Oahu proved the species' success as a biological agent.

In areas where the plant was dominant, sediment built up more quickly and slopes were less stable than with native ground cover.

[5] The fungus spread quickly across the North Island, both through wind dispersal of spores and by inadvertent trafficking by humans and other animals.

[10] On average, the population of A. riparia declined by 85% as a result of the introduction of A. ageratinae in New Zealand, and native cover has returned to the areas affected.

The plant thrives in warm, moist climates, and the majority of the country does not receive enough precipitation to foster such growth.

[3] A. riparia is a most significant threat to native ecosystems in the mountainous regions of southern Queensland and northern New South Wales which receive high precipitation.

[14] Following successful uses of E. ageratinae as a biological control agent in Hawaii and New Zealand, the species was a candidate for similar projects in Australia, but these were never implemented.

The fungus was present along much of Australia's eastern coast, though largely confined to Queensland and New South Wales.

[15] In May 2011, further A. riparia plants in New South Wales were intentionally inoculated after host-specificity tests found the fungus was highly specific and did not pose a threat to native flora.

By July 2012, the plant cover of A. riparia had decreased at tests sites in New South Wales and Queensland by an average of over 60%.