A relatively new insect appearing on crapemyrtle in our area is the Crapemyrtle Bark Scale, or more commonly referred to as CMBS. The insect was first discovered in Dallas, Texas in 2004 and was thought to be identical to Azalea Scale. However, it has since been identified as a pest specific to crapemyrtle and pomegranate plants in Asia.
Since its initial sighting in 2004, CMBS has spread rapidly and was discovered in Little Rock in 2014. This pest has now made its way to the River Valley.
We suspect CMBS emerges between May and June in our area, but these little crawlers were found in Little Rock on a warm day in January. The exact number of generation per year is unknown, but we believe there are two in Arkansas. Crawlers and nymphs of the CMBS have been observed over-wintering under loose bark and in cracks and crevices of the crapemyrtle.
Based on current experience noted from the University of Arkansas, it does not appear CMBS will be easy to control. The university does have a couple helpful suggestions:
- A dormant oil applied in the late fall/winter to the bark and crotches where the crawlers and nymphs can shelter may be beneficial in controlling population.
- A systemic insecticide applied between May and June can also be effective.
If you notice symptoms of these scale insects on your crapemyrtles, give us a call and we will be happy to do an inspection. You can also call your local Cooperative Extension Service to have them inspect your crapemyrtle. Please note that CMBS can kill crapemyrtle of both old and new growth.
At this time, Tri-Hill turf and pest is suggesting a dormant oil treatment in the late fall/winter with a systemic insecticide in the spring.