VOA常速英語：亞洲細菌威脅到佛羅里達橘子樹

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Florida's citrus fruit industry is facing a serious threat from a bacteria carried by an Asian insect. The widespread infestation again highlights the danger of transferring non-native species to American soil.

Citrus ranchers in Florida are burning orange trees damaged by a spotted brown bug called psyllid. It is a native of Asia and carries what the Chinese call "the yellow dragon disease.

" Florida ranchers call it “greening.”

While feeding on citrus leaves, the bug infests them with bacteria that clog the tree’s capillary system, slowly choking it to death. The fruit borne by the diseased plant is small, it falls off and the tree eventually dies.

No citrus-growing countries have developed a cure.

Farmer Ellis Hunt is extremely frustrated. “When you spend the money to raise it, and get it almost there, and it turns loose and hits the ground, that's ... a disaster. That's heartbreaking,” he said.

To make matters worse, Florida’s $9-billion citrus growing industry, second only to Brazil, is fighting growing foreign competition and declining sales due to U.S. consumers' growing aversion to sugar and carbohydrates.

The industry's 75,000 jobs depend on finding a cure to the disease.

At the University of Florida's Citrus Research and Education Center, some of the world’s best botanists and entomologists are trying to save the existing trees, grow new ones resistant to the bacterium, and make the insect incapable of transmitting the disease.

Entomologist Kirsten Pelz-Stelinski said the problem is keeping her awake at night.

“It's something I think about every day. I think about it at night when I'm supposed to be sleeping. It's a huge problem, and we need to come up with as many tools as we can,” she said.

Pelz-Stelinski said it may take as long as five years to come up with a way to make the psyllid bug free of the dangerous bacteria.

In the meantime, botanists are experimenting with grafting as a way to keep the existing trees alive, while citrus farmers try to control the disease by spraying the trees and feeding them with nutrients -- added expenses that further shrink their income.