The Asian Citrus Psyllid transmits the greening bacterium. The psyllid was first found in Florida in June 1998.
Psyllid eggs are 0.3 mm long, elongated and almond-shaped. The newly laid eggs are pale in color, then become yellow and turn to an orange color as the time approaches for hatching
Nymphs are 0.25 to 1.7 mm and yellowish orange. Larger nymphs can be seen with the naked eye usually found on the young flush. The nymphs are sessile and move slowly if disrupted. They secrete sticky waxy secretions similar to honeydew produced by aphids which causes sooty mold.
The adults are 3 to 4 mm long. They have a brown mottled body and feed at a 30 degree angle. They can usually be found on the underside of leaves and move quickly.
Psyllid feeding damage (Deformation)
Click to enlarge
The disease can also be spread by grafting, but not all buds from an infected tree carry the greening bacterium