Spread and distribution of crapemyrtle bark scale, Acanthococcus (=Eriococcus) lagerstroemiae (Kuwana), in Tennessee

Crapemyrtle bark scale (CMBS), Acanthococcus (= Eriococcus) lagerstroemiae (Kuwana), is an invasive insect pest native to Asia. First found in the U.S. in 2004, it has become a threat to production and health of crape myrtles in the ornamental nursery industry and in landscapes in the U.S. Although feeding is not fatal to many crape myrtles, its effects on aesthetics affects the sale ( >$46 million annually) and use of crape myrtle in landscapes. This pest species has been found in numerous southeastern states, including Tennessee, where it was found in 2013 in west Tennessee. Little is known about its state-wide and localized distribution on crape myrtles in Tennessee. Our goal is to gain additional knowledge to mitigate CMBS before it becomes an economic barrier for crape myrtle production and growth. Although its spread across the state has been limited and slow, it has been found in the major metropolitan areas in east, middle and west Tennessee. In Knox County (east Tennessee), this invasive pest has been found in a few locations, mostly in the western part of the county. During a two-year study, its spread from the initial locations in east Tennessee was limited. Thus, a field study was designed to assess the spread of CBMS crawlers by wind and natural dispersal. A second study investigated CMBS establishment on different varieties of crape myrtle. This paper describes the results of these studies highlighting distribution, spread, and varietal influences on CMBS populations. Results of this study will inform management decisions.