Project Overview

Reports

Commodities

• Additional Plants: ornamentals, trees

Target Pests

• Target Pests: scale

Practices

• Pest Management: behavioral control, biological control, biorational pesticides, pesticides

Crapemyrtle bark scale (CMBS), is an invasive scale insect first discovered in 2004 in an urban landscape near McKinney Texas. Since then, CMBS has expanded into 12 more states.  In Alabama, CMBS is well established in southern and northern counties and is now detected in multiple locations in the metro Birmingham and Huntsville areas. Feeding by CMBS reduces the aesthetic value of crapemyrtle, decreasing its bloom size and vigor, causing branch dieback, and producing honeydew which leads to trunks and branches darkened with sooty mold. As with most new pests, there is often a lag between pest arrival and the availability of Extension resources. With urban tree problems, often the persons making treatment or site decisions are not being reached by Extension or IPM programs. Soil or trunk applied neonicotinoid insecticides are widely used for control of CMBS.  Soil and trunk application techniques can decrease the potential pesticide exposure to humans relative to insecticides applied as foliar sprays. These application techniques also do not place fresh residues on the foliage which can reduce exposures to natural enemies. The current Extension recommendation for CMBS is to treat infested trees annually, and all other crapemyrtle trees in a landscape even if only one tree in the landscape is infested. Dinotefuran and imidacloprid are the two systemic neonicotinoids being widely used for CMBS management. Crapemyrtle produces an abundance of flowers that are nectarless but produce large amounts of reward pollen. The Held lab recently reported that dinotefuran and imidacloprid, when applied as soil drenches at the rates labeled for CMBS control, will translocate into crapemyrtle pollen and are present at levels that would provide contact and oral toxicity to bees and other pollen-feeding insects. The risks to non-target insects are greatest for the first flowering and year after application. Fortunately, foliar applications of limonene can reduce CMBS populations by 69.5% in 4 wk relative to non-treated control when applied at crawler hatch.  Recruitment of lady beetles to trees can be enhanced by hanging yellow panels in infested trees. Also, yellow panels hung in the canopy of infested trees can reduce CMBS populations by 44% in 2 months relative to trees with no panels. The proposed Capstone project will combine the outcomes of our recent research with visual attractants and low risk alternative controls for management of CMBS in urban landscapes. Our goal is to produce an innovative and actionable alternative to systemic insecticides for CMBS management. The objectives have research demonstration and Extension components. The Extension objective will address the accurate diagnosis of CMBS and associated natural enemies through in-person meetings and products (bookmarks and training modules), and gauge adoption of these alternative practices. The research demonstration will deploy panels, limonene treatments, or both on trees in the urban landscape. The demonstration and comparison to the current standards are critical to pieces of data to foster adoption especially for arborists and landscape managers whose professional reputations are at stake when promoting alternative controls. This will have the short- and long-term effects of reducing preventive and indiscriminate use of neonicotinoid insecticides in urban landscapes for CMBS management.