(UPDATED COVERAGE, 9:44 a.m., April 11) A different strain of the citrus greening bacterium has been found in the U.S. for the first time.
Candidatus liberibacter americanus, also known as Lam/Brazilian citrus greening, was found in a citrus psyllid near Mission, Texas, said Ray Prewett, president of Mission-based Texas Citrus Mutual.
The more common strain of huanglongbing (HLB), also known as citrus greening, is Candidatus liberibacter asiaticus.
Asian citrus greening has destroyed hundreds of thousands of acres of citrus in Florida and been confirmed in major citrus producers California, Arizona and Texas.
In September, The U.S. Department of Agriculture’s Animal and Plant Health Inspection Service established a 5-mile quarantine around a San Juan, Texas, citrus grove that tested positive for the Asian citrus greening.
Before the Texas finding, Lam had only been confirmed in Brazil, Prewett said. A single finding in China was not confirmed.
Lam was discovered in Brazil before the Asian strain, and was less destructive. In recent years, Asian HLB has become the dominant form in Brazil, and few cases of Lam in citrus are now reported.
Because of Lam’s lower heat tolerance, it’s possible that it won’t thrive in the summer heat of south Texas, Prewett said.
“We’re not happy about finding it, but we’re not sure we’re at the point that it changes things very much.”
The finding in Texas was made by the Texas A&M Kingsville Citrus Center in Weslaco and confirmed by the U.S. Department of Agriculture’s Animal and Plant Health Inspection Service, Prewett said.
Because the disease was found in an insect but not on a citrus tree, APHIS and the Texas Department of Agriculture have not taken regulatory action, Prewett said. But that could change. The infected psyllid was caught by an inspector, not found in a trap, Prewett said.
“Chances are there’s an infected tree,” he said.