South Texas citrus threatened by HLB disease.
The war against Citrus Greening disease goes back to 2005 when Florida’s lucrative citrus industry was assaulted by Asian Citrus psyllids, which led to the devastation of much of the state’s citrus crop and created concern among U.S. citrus growers nationwide at the prospect of facing the threat.
That war against the psylid and the plant-killing bacteria it carries (huanglongbing, better known as HLB) has spread over the last 10-plus years as the pests migrated from the Southeast coast westward to Texas, finally reaching California’s and the rich citrus growing areas.
While advances in research on both the citrus disease and the psyllids that vector it from state to state and country to country have intensified through the years, new technology and defense systems have been and are continuing to be developed in agriculture’s ongoing battle against citrus greening.
A new tool being tested may add to the arsenal of weapons to manage and control the spread of huanglongbing by targeting the reproductive activity of the insect that spreads the disease.
HLB is one of the most destructive diseases of citrus worldwide. Originally thought to be caused by a virus, it is now known to be caused by unculturable phloem-limited bacteria. Three forms of greening have been described so far. The African form produces symptoms only under cool conditions and is transmitted by the African citrus psyllid Trioza erytreae; the Asian form prefers warmer conditions and is transmitted by the Asian citrus psyllid Diaphorina citri. Recently, a third American form transmitted by the Asian citrus psyllid was discovered in Brazil. This American form of the disease apparently originated in China.