The State Department of Agriculture's Plant Pest Control Branch has been studying the Madagascar Ragwort, also known as fireweed, for years. Its bright yellow flowers look almost like daisies. But scientists point out that the fireweed contains a chemical that can damage the internal organs of cattle and other livestock, thereby killing them."It's a very serious problem to ranchers and it's widespread, covering literally thousand of acres in Hawaii right now," says Neil Reimer, chief of the Plant Pest Control Branch for the Hawaii Department of Agriculture.
The Madagascar Fireweed has invaded more than 400,000 acres of ranchland on Maui and the Big Island. It's so bad that officials estimate the cost of using chemicals to battle it would be millions of dollars every year. So state scientists say they've figured out a better way. There's a certain type of caterpillar that just loves to feed on the deadly weed.
"Caterpillars in general have a voracious appetite so it'll go out there the moths will lay a lot of eggs and you'll get a lot of caterpillars on the field and they'll feed on the weed and keep the population down," said Reimer.
A field entomologist traveled to Madagascar and brought the caterpillars here for extensive research. As the caterpillars develop into moths, they are essentially natural enemies of the fireweed plant.
"It's very host specific to plants within that family that the fireweed is in and it does not attack any of the native plants or any other plants that are of concern," said Reimer.
Scientists will be asking the state Board of Agriculture for a permit on Tuesday to use the caterpillar. If approved, scientists will also need permission from federal regulators.
"The worst thing we can do is release something and then have it attack something else that we don't want it to," said Reimer.
Reimer says if all goes well, the biological control of the fireweed will start by the end of the year.
