Poster: Impacts of ambrosia beetles on field nursery tree species with different tolerance levels to flood and drought stress

Flood stress predisposes nursery tree crops to ambrosia beetle attacks, but the impacts of drought stress have not been studied; furthermore, how nursery tree crop species with different tolerance levels to drought and flood are impacted by ambrosia beetle has not been understood. The objective of this study was to explore ambrosia beetle preference for tree species varying in their tolerance of water stress. Container-grown dogwood (flood and drought intolerant), red maple (flood and drought tolerant), and redbud (flood intolerant, drought tolerant) were assigned to flood, drought, and sufficient water with six single-plant replications. Two trials were conducted in May and June 2022. Flood and drought stress was imposed to trees for 28 days. Ambrosia beetle attacks were counted every other day for 28 days. Plant tissue core samples were collected at 7 and 14 days post flooding to determine ethanol content. Trees were dissected to count the number of attacks with gallery formation. Under flood stress, the highest number of attacks were recorded in dogwood and redbud trees but there was no attack in red maple. Of the total attacks under flooding, galleries were formed in 74% and 80% in dogwood, and 65% and 72% in redbud in trials 1 and 2, respectively. Dogwood assigned to drought had the fewest attacks, while redbud and red maple had no attacks. Tree species assigned to sufficient water had no attacks. This study suggested that nursery tree species intolerant of water stresses are more prone to attack by ambrosia beetles.