Huanglongbing (HLB), also known as citrus greening disease, is a devastating bacterial disease that affects citrus plants. It is spread by the Asian citrus psyllid insect and has caused significant economic losses in the citrus industry worldwide. HLB causes symptoms such as yellowing and mottling of leaves, stunted growth, and ultimately leads to the death of the tree. Researchers are actively studying HLB in order to find ways to control and manage the disease, including breeding resistant citrus varieties, developing treatments to control the psyllid vector, and improving disease detection and management strategies.