Moth being released to control plant invading ranches

State entomologists are releasing about 1,000 moths at a Hawaii cattle ranch in an attempt to control a fast-growing weed that's toxic to cattle.

The moth is called the Madagascan fireweed moth.  Its larvae eat the leaves of the fireweed plant that's making it difficult for ranchers to raise cattle.

The moths are being released on Wednesday at Kahua Ranch in Waimea.  The state Department of Agriculture hopes to release more than a million moths this year.

The plant is native to Madagascar.  It's not known when it was introduced to Hawaii, but it showed up in Big Island pastures in the 1980s.  Officials believe fireweed came to Hawaii in mulch imported from Australia.

The weed is now infesting more than 850,000 acres on Maui and Hawaii islands.