Eugenia are woody, evergreen flowering plants in the Myrtle family. Often found in landscapes as ornamentals, Eugenia’s glossy green leaves can become infected with the Eugenia psyllid (Trioza eugeniae). The Eugenia psyllid sucks plant juices from leaves and excretes honeydew that provides habitat for sooty mold. Introduced to California from Australia in 1988, Eugenia psyllid has become a serious threat to local landscapes.
Infected leaves look similar to peach leaf curl. This psyllid attacks new growth at terminal (end) points, leaving bumps and pitted areas. Leaves may also become discolored and appear red. Heavy infestations can cause the leaves to fall off (defoliation) and can kill a mature plant. Adult Eugenia psyllids are dark brown with a white abdominal band. Nymphs are yellow with orangish-red eyes.
Tiny, golden eggs are laid on leaf edges. Eggs hatch into first-instar nymphs, called crawlers, that feed on new growth. Nymphs pass through five instars before becoming winged adults. Mature Eugenia psyllids are only 1/10” to 1/5” long. They are related to aphids, but they have more powerful jumping legs and shorter antenna.
When Eugenia psyllid first arrived in California, the damage was so extensive that many home owners were forced to remove Eugenia plants from the landscape. In 1993, a parasitic wasp (Tamarixia dahlsteni) was released in Santa Clara County. This beneficial insect has helped bring Eugenia psyllid populations to manageable levels.
Since Eugenia psyllid nymphs prefer feeding on new growth, regular, frequent shearing can reduce infestations. Shearing is recommended at 3-week intervals during periods of new growth. It is important to leave the clippings on the ground, around the shrub or tree. This causes the eggs and nymphs to be on the ground, where they will die, while still providing food for parasitic wasps.
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