Magnolia Soft Scale

Homoptera: Coccidae, Neolecanium carnuparuum

Author: Eric R. Day, Director, Insect Identification Laboratory; Virginia Tech

Publication Number 444-623, Revised 2003

Plants Attacked

Magnolia

Description of Damage

Heavy magnolia soft scale infestations cause stunting of twigs and undersize leaves, visibly weakening the trees. Small trees may be killed. Large trees lose branches and tree shape may become irregular.

Identification

The color of females ranges from a dull grayish brown to a dark brown or a smoky hue. Scale has a varnishlike appearance. Some specimens appear covered with a powdery wax material. Females are hemispherical and about 1/2 inch in diameter. Magnolia soft scale, Neolecanium carnuparuum, is in the order Homoptera and family Coccidae.

Life History

The overwintering scale begins feeding in late spring or early summer and matures by early August. The females, which are parthenogenetic, give birth to living young in late August. The old adults then fall from the plant. The crawlers soon settle and feed on plant juices. They develop to second instar before cold weather and overwinter in this stage.

Control

Dormant oils may be sprayed in March or April prior to bud opening. Sprays for crawlers may also be applied in late August and repeated 10 to 14 days later.

Remarks

Controlling crawlers is usually easier and, in most cases, gives more effective results.

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