Miami ? A plant illness that could endanger Florida’s $9 billion citrus industry has been found for the first time in the United States, agriculture officials said Friday.

The bacterial disease known as citrus greening was found in samples collected from two trees in South Florida, officials said.

Citrus greening is not a threat to humans, but it has harmed trees in Asia, the Arabian Peninsula and Africa. Its first U.S. detection was confirmed by the U.S. Agriculture Department after state scientists sent the samples there.

The disease, primarily transmitted by insects, affects the vascular system of plants and causes infected trees to die in a few years.