Weird white bug deposit on clethra

Asked May 31, 2020, 4:10 PM EDT

Wondering what this is on the leaf bottoms of our sweetspire/clethra? Not sure whether it’s a pest or friend. The white part is sort of cottony and gooey and the brown is sort of a shell/hard.

Montgomery County Maryland

3 Responses

Hi - This is a type of pest called a soft scale. They are insects that feed on the plant sap, which can lead to yellowing and gradual decline of the shrub if there is a severe infestation left unmanaged. If you see just a few leaves with these, the easiest thing to do it to wear garden gloves and pick them off by hand -- and pick off any you see along the stems. There are some beneficial insects that can help to control these pests naturally. Once you remove these scales, continue to monitor your plant regularly during the growing season. If further treatment is necessary, you can spray the shrub with a dormant rate of horticultural oil during the dormant season (when leaves have fallen off deciduous plants) to control overwintering scales. Here is more information about soft scales and how to manage them, https://extension.umd.edu/hgic/topics/soft-scales-trees-and-shrubs#insects

Christa

Thank you so much! I’ll pluck them off and keep an eye on the plant.