Kwanzan Cherry Tree Insects
The “Kwanzan” flowering cherry (Prunus serrulata “Kwanzan”) will burst alive in early spring with clusters of double, dark pink blooms. This sun-loving deciduous shrub does not produce fruit, but does tolerate seacoast exposures and grows in U.S. Department of Agriculture plant hardiness zones 4 through 8. “Kwanzan” is no stranger to a vast array of insects that visit the tree throughout the year. Some of these insects are beneficial while others are more of a nuisance, which can cause varying degrees of damage.
Aphids, Scales and Spider Mites
Aphids, scales and spider mites are all-too-common pests that gardeners battle regularly. Their tiny size can make them difficult to spot; however, aphids can look like dots moving on the leaves while scales appear as moving bumps on the flowering cherry. Spider mites will cover leaves, stems and buds with a white webbing. An infestation of aphids, spider mites or scales rarely causes severe damage to trees, but will result in wilting, distorting and yellowing of the leaves. Chemical treatment is typically not warranted unless the life of the “Kwanzan” tree is threatened. Instead, use a hose to wash the aphids, spider mites and scales off the tree. To keep the pests under control, attract beneficial insects -- lacewings, predatory wasps and ladybugs -- to feed on these insects by adding plants such as tansy (Tanacetum vulgare) or dill (Anethum graveolens) in the area.
Several types of borers -- including Pacific flathead borer, peach tree borer and American plum borer -- will attack cherry trees. These insects bore through the trees, causing holes filled with sap or sawdust. The best defense against borers is to keep the cherry tree healthy and vigorous. Trees that are water stressed, not receiving proper care, injured or diseased have a higher chance of borer attacks then healthy, non-stressed trees. Prevention is the best defense since there isn’t much you can do to get rid of the pests once a tree is infested. Once a tree is infested, prune and dispose of infested branches. Insecticides, such as carbaryl, will only kill the adult borers and must be applied as the adults are laying their eggs before the tree is infested.
Caterpillars and Larvae
Several species of caterpillars and larvae will visit flowering cherry trees and create a five-course meal out of its leaves and flowers. Leafrollers attack young leaves, causing a torn and ragged appearance, while citrus cutworms eat holes in leaves, buds and fruit. Predatory insects, such as Trichogramma parasites, will help control leafrollers and citrus cutworms without chemicals. Trichogramma parasites can be purchased from garden centers and released into the area. Control leaf-eating and tent caterpillars by manually removing and disposing of the caterpillars or attract birds that will feed on them. If chemical control is desired, consider using fungicide that contains Bacillus thuringiensis, which is a bacteria that kills many damaging caterpillar species.
Not all types of insects that visit “Kwanzan” cherry tree are considered pests, and many of them actually are beneficial to you, the tree and your garden. Bees and butterflies are attracted to the fragrant, nectar-filled cherry blossoms and help pollinate the tree as well as other plants in your garden. Butterflies provide added aesthetic value to your garden and indicate the area has a healthy ecosystem consisting of other invertebrates. Birds also feed on butterflies, which means more butterflies in the area will lead to an increase of birds.
- Monrovia: Kwanzan Flowering Cherry
- Missouri Botanical Garden: Prunus Serrulata
- UC IPM Online: Tree Borers
- UC IPM Online: Aphids
- UC IPM Online: Spider Mites
- UC IPM Online: Scales
- UC IPM Online: Leafrollers
- Butterfly Conservation Europe: Why Butterflies and Moths are Important
- Fine Gardening: Attracting Beneficial Insects
- BananaStock/BananaStock/Getty Images