Insecticide For Azalea Bark Scale

Azalea bark scale is a common pest of azaleas and other rhododendrons. Scale soft bodied insects are difficult to see with the naked eye. They are distinguished by their hard shell. Scales were previously categorized into several different families and the Azalea bark scale was included in the Pseudaulacaspididae family. This was based on aspects of their anatomy, tensile strength, flexibility, and method of reproduction.

Insecticide For Azalea Bark Scale

If azalea bark scale is found, Michigan State University Extension recommends spraying infested plants with a 2 percent concentration of a horticultural oil in mid-July. Spray after the azaleas are done blooming to avoid spraying over bees and other pollinators, and to avoid flower injury. Heavy infestations can be sprayed again two weeks later. Later in summer or next spring you can determine if any live scales are present by using a fingernail to scrape off some of the crusty buildup on the stems. If scales are juicy, they are alive. If the crusty residue is dry and flaky, the scales are dead. Dead scales may remain on stems for a year or more. An oil spray applied after the crawlers emerge is usually very effective in controlling azalea bark scale, but keep checking each year and spray again when necessary.

An alternative treatment for azalea bark scale is a basal soil drench with imidacloprid. One product with good directions on the label for applying imidacloprid as a drench is Bayer Tree and Shrub Insect Control. This product is mixed in a bucket of water and poured around the base of the shrub. Several other products are also available that contain imidacloprid. Because imidacloprid is a systemic insecticide that is absorbed through the roots and moves up into the foliage, some insecticide may move into the flowers. Protect bees and other pollinators by waiting until after the shrubs are done blooming before applying the basal soil drench. Research is underway at this time to determine if enough imidacloprid will be present in the following year (one year after a basal drench is made) to be detrimental to bees when the azaleas are blooming.

Insecticide For Azalea Bark Scale

Azalea Bark Scale is a common insect pest that can affect azaleas, rhododendrons, and other plants in the Ericaceae family. The adult female scale feeds on the underside of leaves, while the immature “crawler” stage lives on the bark of the plant. Depending on the severity of infestation and variety of plant affected, this pest can cause yellowing and leaf drop, dieback of twigs and branches, or death of the entire plant.

Insecticides containing acephate or imidacloprid are effective against Azalea Bark Scale. Insecticidal soap spray can be used in small areas where other chemicals are not appropriate.

List Of Insecticide For Azalea Bark Scale