Crape myrtle bark scale (Acanthococcus lagerstroemiae) (CMBS) is an invasive felt scale in the family Eriococcidae. CMBS was first detected in the United States in Texas in 2004 and has since spread throughout many southern states. CMBS feeds within the phloem of trees, creating copious amounts of honeydew, and reducing flower blooms.
Treatment Strategy
Because all life stages are present throughout the growing season multiple foliar applications throughout the growing season may be prudent. Recent data shows there are peak crawlers present in spring and summer, recommendations for foliar applications are to treat just before these times. Systemic treatments of Transtect are very effective method of treatment. Proxite is considered reduce risk for beneficial insects.
Signs of Damage
- Feeding creates copious amounts of honeydew and sooty mold
- Reduced blooms on crape myrtles
- Populations build up quickly, adults and nymphs covered in waxy white threads will be evident
- Nymphs develop through 3 stages
- They begin pink but turn darker pink or brown as they mature
- Adult males continue a complete metamorphosis and emerge as small, winged insects
Twice-stabbed beetle feeding on CMBS
High population of CMBS
Nymphs (crawlers)
Jim Robbins, Univ. of Ark. CES
Trees At Risk
Several Species Including:
- Crape Myrtle (Lagerstromeia spp.)
- American Beautyberry (Callicarpa americana)
Biology
- No development under 68F
- 1st instar crawlers are mobile and travel to new feeding sites
- After 1st molt the nymphs settle, lose their legs, and continue feeding and growing
- Adult males continue a complete metamorphosis and emerge as small, winged insects
- 1 generation every 3 ½ - 4 months 77-86F (2-3 generations per year)
- Females lay 100-300 eggs beneath waxy thread-like covering
Always refer to product label for rates and approved uses. Some images courtesy of forestryimages.org or Wikimedia Commons. Use of the images does not imply endorsement of treatments.
