Visible symptoms include wilted foliage and strings of boring dust that may protrude from the bark as tiny sticks or tooth picks. These strands may reach 1.5 inches if wind and rain do not break them off. The beetles are present most of the year, but Clinic records indicate Asian ambrosia beetles are most active in March. Eggs, larvae and pupae are found together. There are no individual egg niches, larval tunnels or pupal chambers.
High humidity is required for successful reproduction.
Adults and larvae feed on a mold-type of fungus known as ambrosia that the beetles introduce as they tunnel into the sapwood and sometimes heartwood of trees and logs. The fungus grows on the walls of the tunnel. With this species, the beetles bore galleries straight into the wood from 1 to 3 cm or more. The tunnels then branch one to six times in the same plane following an annual ring. In small trunks and branches, the galleries go straight in or spiral upward from the point of attack around the stem or limb, branching upward or downward from the spiral gallery.