Bugs on a Magnolia Tree

The magnolia tree is prized for its fragrant blooms.

The landscape of the southeastern United States just wouldn't be the same without the stately magnolia tree. A common and inviting sight, the magnolia is prized for its large fragrant blooms. Unfortunately, the magnolia can sometimes be plagued by insects.

Magnolia Scale

Of all of the insects that may be drawn to the magnolia, the most common is the magnolia scale. Magnolia scale is an insect that is approximately 1/2 inch across and feeds on the sap of the magnolia tree. After the magnolia scale feeds off of the sap, it excretes a substance, known as honeydew. Honeydew provides a fertile environment for sooty black fungus to develop, which is also harmful to the magnolia. Horticultural spray oils can be used to treat magnolia scale.

Beetles

Magnolias often are plagued by beetles, though not all beetles are bad for a magnolia. Magnolia flowers produce a pollen which is rich in protein that many beetles feed off of. Those beetles in turn fertilize the magnolia flowers. Japanese beetles may sometimes become a nuisance on a magnolia and can be either removed by hand or sprayed with an insecticide. If you live in a climate that gets cold in the winter, the drop in temperature will also kill off the beetles.

Other Pests

For very young trees, slugs may be a problem. Luckily, slugs are easily eradicated through use of baiting systems. Older plants may also be affected by leaf miners, which will eat small trails in both the leaves and flowers of your tree. Although you can treat them with insecticide, the leaf miners don't usually harm the tree.

References

• University of Kentucky: Magnolia Scale
• Herbs 2000: Magnolia's Pests and Diseases