http://www.bloomberg.com/apps/news?pid=20601116&sid=a7tGwUO8IGWo&refer=africa

South African $1.2 Billion Fruit Industry Braced for Fly Strain

By Jonathan Tirone

March 10 (Bloomberg) -- South Africa’s 12.8 billion-rand ($1.2 billion) fruit industry is braced for a possible invasion of a new strain of fruit fly that has spread across the continent in the past five years.

“We’re very aware of it and we’re doing a lot of surveillance,” Justin Chadwick, chief executive officer of the region’s Citrus Growers Association, said by phone today from Hillcrest, South Africa. “It’s concerning because it’s a more vigorous fruit fly that can damage a wider range of host species.”

Bactrocera invadens, originally from Sri Lanka, was discovered in Kenya in 2003 and has spread southward. South Africa, which closed its borders to Namibian fruit exporters after the pest turned up there in November, is yet to be affected, Chadwick said. Citrus sales in South Africa rose 53 percent to 5 billion rand in 2008, according to the Department of Agriculture.

Infestations of bactrocera invadens could cause countries to stop buying South African apples, mangoes and citrus fruits, said Marc Vreysen, who heads a United Nations biotechnology lab in Seibersdorf, Austria. The lab is trying to breed sterile male flies to stem the plague.

“The scary part about these fruit flies is that they’re so virulent,” Andrew Jessup, an entomologist at the lab, said in an interview yesterday. “The U.S. is particularly scared of this one. These flies are good at adapting to new climates.”

Sterility Program

The insects, which can travel as much as 100 kilometers (62 miles) over their 3-month lives, eat the fruit and lay eggs inside the flesh.

“The key will be to make enough sterile males that can go out and breed with the females,” Jessup said, standing in front of a mesh-covered box containing 200,000 fruit flies. They’d all been subjected to radiation to make their offspring sterile.

The UN helps Guatemala, Spain, the U.S. and other fruit- growing countries build insect factories that produce as many as 2.5 million sterile male fruit flies a day. The females they impregnate won’t yield subsequent generations of larvae, Vreyson said.

To contact the reporter on this story: Jonathan Tirone in Vienna at jtirone@bloomberg.net.
Last Updated: March 10, 2009 06:56 EDT