African citrus psyllid

The African citrus psyllid (scientific name: Trioza erytreae) is a destructive pest belonging to the family Triozidae. It is recognized globally as a primary vector for Candidatus Liberibacter species, the causal agents of the devastating citrus greening disease (Huanglongbing). Due to its capacity to destroy entire citrus industries, it is strictly regulated in many parts of the world.

The host range of Trioza erytreae is largely limited to the family Rutaceae, with a strong preference for commercial citrus species such as lemons, limes, and oranges. The insect specifically targets the flush (young, tender growth), as these tissues provide the necessary nutrients for the development of both the nymphs and the adults.

The life cycle begins when adult psyllids lay eggs on the edges of young, unfolding leaves. After hatching, the nymphs anchor themselves to the leaf surface, feeding on plant sap. During this feeding process, they inject toxins into the plant tissues, causing the leaf cells to proliferate rapidly, resulting in the formation of distinct, pit-like galls.

The primary economic damage is twofold: physical damage from sap-sucking, which leads to distorted leaf growth and tree stress, and the transmission of deadly bacterial pathogens. Once a tree is infected with citrus greening, the fruit yield drops drastically, the tree produces bitter, lopsided fruit, and the tree eventually dies, requiring complete removal and destruction.

• Implementing strict quarantine and exclusion measures to prevent introduction.
• Regular inspection and monitoring using yellow sticky traps in orchards.
• Chemical control targeting adult populations during the flushing periods.
• Biological control through the release of specialized parasitoid wasps.
• Pruning and destroying infected branches to lower the inoculum pressure.