Landscape and Nursery - Japanese Maple Scale

Japanese Maple Scale can proliferate and stunt these maples and other woody plants. The following is information on the this pest and its control.

Japanese maple scale is being found currently in nurseries and landscapes. Check in your area for crawlers. We have found this scale on maples, zelkova, holly, styrax, yellowwoods, and many other woody plants. This scale is tiny (< 0.5 mm) and has an elongate white cover and is found on the bark and branches of its hosts. This scale has two generations that overlap because eggs hatch over an extended period of time. Controlling this scale is challenging because new crawlers are emerging and present over an extended period of time.

Control: Distance or Talus can be applied now. A 2% horticultural oil can also be used but repeated applications may be necessary. Since this scale is difficult to control and has 2 generations of potentially overlapping adults, consider waiting another week to 10 days for more eggs to hatch to provide better control.

Information taken from the June 27, 2008 edition of the TPM/IPM Weekly Report for Arborists, Landscape Managers & Nursery Managers from University of Maryland Cooperative Extension.