Integrating morphomolecular diagnostics and phenology studies for managing mealybugs as an emerging pest in potted boxwoods

Mealybugs (Hemiptera: Pseudococcidae) are an economically important piercing-sucking pest for ornamental plants worldwide. Their susceptibility to chemical control varies across developmental stages: early instars evade exposure through concealment, wax secretion inhibits insecticide contact, and intermittent feeding behavior prevents lethal toxin accumulation. Moreover, the timing of life stage progression differs among species, further complicating effective intervention. Consequently, precise species identification via integrated morphological and molecular methodologies is essential to ensuring that chemical applications are optimally timed to target the most vulnerable life stages. While there is ample research on mealybugs in the greenhouse setting, there is less known of infestations taking place in an uncovered or partially covered house growing areas. This study utilized mealybug infested boxwoods (Buxus spp.) within partially open structures (retractable walls and roof) in a commercial nursery as a case study to identify species present and document their phenology. Weekly visual scouting for nymphs and females, and yellow sticky cards for winged males and crawlers were utilized to record densities at the plant level. Ultimately, the information collected from this project allows for better informed identification and scouting techniques for mealybugs on boxwoods and other woody ornamentals, more efficient use of insecticide resources, and a reduction of non-target effects in mealybug management at nurseries. Additionally, results from this study can be compared to known behaviors of the mealybug in greenhouse settings to expand understanding of the mealybugs diagnostics, biology and ecology in partially covered houses.