Entomologists and staff in Honolulu were busy not only trying to keep the quarantined pests alive, but it also meant that they also had to grow the fireweed to host the moths. The agriculture department is also testing four other potential natural enemies of fireweed, each which appear to attack different parts of the plant.
"Until now, we have been able to keep generations of this moth alive under quarantine conditions," said Darcy Oishi, section chief of the Biocontrol Section. "We have now switched gears and begun to ramp up production to increase the chances of successful control of fireweed. With the support of the ranchers and others, we hope to release more than one million moths this year."
"Biological control of pests can be the most efficient and cost-effective method to manage significant pests," added Dr. Neil Reimer, manager of the Department of Agriculture’s Plant Pest Control Branch. "Since 1975, HDOA has released 51 biocontrol agents and all have been successful and none have been found to attack anything but the target pest or weed."
"Fireweed has proven to be highly invasive and in certain areas has reduced the forage production by as much as 60 percent," said Dr. Mark Thorne, state range specialist with the University of Hawaii College of Tropical Agriculture and Human Resources. "With the pending release of Secusio, ranchers will have a valuable tool that will help them recover some of the economic value of their pastures."
Biological control, which utilizes natural plant enemies and/or diseases, is needed in natural and managed ecosystems as a tool for managing invasive plant species that are too widespread and expensive to control using herbicides and/or mechanical removal methods. Although challenging to implement, effective biocontrol can provide long-term, large-scale, highly selective control of otherwise prolific weeds. Current research methods thoroughly test potential biocontrol agents prior to release to ensure that they only attack the target weed and not other native or beneficial plants or animals.
Hawaii continues to be a leader in biocontrol of pests, according to state officials. The Kingdom of Hawaii was a world leader in biocontrol with successful introductions of a beetle to control cottony cushion scale in 1890. After Hawaii became a U.S. territory in 1900, biological control methods progressed with the introduction of several insect species to control lantana in 1902. Since then, researchers in Hawaii continue to be internationally recognized in biological control of weeds and plant pests and have collaborated with colleagues worldwide on the biological control of invasive weeds and pests such as miconia, fountain grass, banana poka, ivy gourd, gorse, wiliwili gall wasp and nettle caterpillar, among others.