Magnolia Scale

Characteristics

Magnolia scale is one of the largest species of scale insect in Ontario. They appear as round bumps on the stems and branches of various species of Magnolias. Depending on the time of year these bumps are either glossy and yellow or covered in a white powder. Magnolia scale creates a shell-like barrier made of their own skin which feels waxy if touched. These insects feed on the sugars underneath the bark of Magnolia trees.

Signs & Symptoms

Trees affected by magnolia scale will have a variety of signs and symptoms. Scales tend to congregate near the tips of tree branches near where the leaves flush. These branch tips will be covered in the many bumpy scales, and a black looking sooty mould that grows on secreted honeydew from the insect.

Infested trees will show decline in their canopy, and produce smaller yellow foliage. Trees will usually be swarmed by wasps as they are attracted to the honeydew produced by the scale.

Treatment & Recommendations

Dormant oil is a recommended treatment for trees with Magnolia Scale. Dormant oil suffocates overwintering insects, reducing their population during the summer. Scales can also be scraped off stems manually.

Heathy well cared for trees with adequate water and soil conditions tend to be less prone to scale infestations.

If your tree is suffering from magnolia scale give us a call. One of our qualified arborists will assess your tree and provided recommendations for treatment and long term care.