What to Know About Olive Psyllid Activity
Olive Psyllid (Euphyllura olivina) is a tiny pest, 1/10 inch long often not visible due to its white wax covered body, that feeds on Olive trees and is widely found in San Diego County and surrounding coastal counties. During ideal temperatures of 68° to 77°F psyllids can go grow from egg to adult in just 3 months. In March when new shoots and buds are present females will lay eggs, around May – June the second generation will develop on these buds and flowers, this is when most of their waxy excrement and plant damage occur. During September – October the third generation of psyllids developing often goes unnoticed, resulting in three generations populating per year. Adults will overwinter in sheltered areas of the hosts trunk. During warm temperatures psyllids are less active and will often die off during temperatures of 90°F or more.
Understanding the Damage
Olive Psyllids cause damage to trees by directly feeding on buds, flowers, tender shoots, and small fruit. In addition, their production of honeydew promotes the growth of sooty mold. This production can lead to premature defoliation and result in increased tree stress.
Extensive Psyllid feeding will distort and reduce vigor and overall health of Olives, especially when infestations are left untreated. In addition to the physical damage caused by feeding, Psyllids will also secrete sticky wax honeydew on leaves and any nearby plants or objects, creating a mess and encouraging the growth of sooty mold. This combination of damage can place significant stress on the tree over time.
Best Practices for Monitoring and Managing Olive Psyllids
While it appears Olive trees can tolerate low numbers of psyllids without significant damage it is most useful to monitor trees during active months of March-May. Although the second generation causes the most significant damage, it is best practice to implement measures before psyllids secrete their heavy wax coating during this phase. Reducing the population size of the first generation and during hot temperatures, pruning center limbs of the trees to enhance air circulation can help in management of this pest.
