Miconia infestations can be headaches for homeowners


Your article about miconia was informative, but even checking with the Invasive Species website, there is an obvious shortcoming. Specifically, while the problem of miconia is not new and is fairly well known, there is nothing that addresses what can and is being done to control the species. … Yes, I do control invasive species on my property, but my neighbors do not.

Consequently, miconia seeds continue to be spread into my property, and it is a never ending battle. I physically remove the plants. Yes, I have reported the appearance of the plants from when I first saw them. No, nothing was done (no money). When I asked about getting some of the control agents (fungus) I was told it was not available (or cleared for introduction/use) in Hawaii.

I do not write as a criticism of your article, but to ask that more productive information be provided to deal with the problem, rather than just to describe the problem. — A.A.N.

Basically your comments are correct: homeowners are left with few to zero options. As with many of our agricultural concerns, they are fraught with money, labor, and political disputes making a focused and productive effort difficult. For the main infestation area, which is primarily from Mountain View to Laupahoehoe, there is not much that can be done as far as eradication.

Researchers and organizations like the Big Island Invasive Species Group are doing the best they can with what resources they have.

Some thought has been given to organizing volunteer workdays to physically remove young trees from specific sites. There are challenges to these events, but with persistence, they will occur in the future. Recently in Tahiti, where they are contending with an enormous invasion, a “miconia raid” was organized by local officials. The goal was to destroy as many miconia trees as possible in one day. Prizes were given to the best team. For those reading French, see full details at: http://www.tahiti-infos.com/Un-Raid-contre-le-myconia-a-Mataiea_a60471.html.

As you mentioned, reporting new sightings of miconia is important. Areas along the scenic routes have been well inspected. But the more obscure regions need reporting, especially around Honokaa and the Waipio Valley, which are the new zones of concentration. Current efforts seek to contain the miconia south of that area and out of Kohala.

The only true hope is biological control which is a long term measure. A fungus which attacks the leaves and causes premature leaf drop was released some time ago; the results were disappointing. This fungus is no longer being produced; however, it is widespread on the Big Island. In Tahiti, the same fungal, biocontrol agent worked well with the best results at higher elevations where there is more rainfall and temperatures are cooler.

There are other biocontrol agents currently being investigated. They include a weevil which bore out the stems, another weevil which feeds on fruit, a caterpillar which feeds on the leaves, and a gall wasp which galls the fruit and other plant parts. These are all potential agents to bring about the demise of the miconia population. If all goes well with any of these biocontrol agents, it will be, at least, a couple years before they are even released.

For chemical control, Garlon is recommended. But once the trees are killed with herbicide, inspection of the site must continue for up to 15 years due to the seeds’ long-term viability in the soil.

Hilo resident Nick Sakovich is a professor emeritus of the University of California. He has worked in the field of agriculture for 30 years. Email your questions to Sakovich at askthegardenguy@earthlink.net.

 

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