Eugenia Psyllid is a pest on Syzygium paniculatum (Eugenia) also known as Australian Brush Cherry. It is a small winged insect about the size of an aphid. The psyllids suck juices from the plants. Females lay eggs on the edges of new leaves. The hatched nymphs crawl under the leaves and feed in protected pits.
New growth reddens, becomes distorted and appears “puckered up” with little bumps. Black sooty mold forms on the honeydew the psyllids secrete. All this results in a very unsightly hedge.
Eugenia psyllid is partially controlled by the parasitic wasp Taxamarixia. For this reason government agencies do not advise using broad-spectrum insecticides such as Isotox (Ortho Systemic Insect Killer) that leave a toxic residue that kills the good bugs along with the bad. They also need to be applied every four weeks. Merit (Imidacloprid) the active ingredient in such products as Bayer Advanced Tree and Shrub does not impact the beneficial wasp.
Regular pruning of new growth provides some control, removing eggs and nymphs. Some experts advise leaving pruning clippings on the ground for at least three weeks to allow the beneficial wasps to complete their work.
Safe sprays such as horticultural oil and Neem oil only work on exposed psyllids and do not harm the feeding nymphs in the leaves.
It is recommended to avoid excessive water and fertilization, which promotes rapid new growth psyllids love.
Psyllid populations may be monitored with the use of yellow sticky traps.
If you choose chemical control our best advice is to use Bayer Advanced Tree and Shrub. It is not sprayed, but poured into the soil, provides 12 month protection, and does not harm beneficial insects.