During entry into trees, ambrosia beetles often inoculate trees with additional pathogenic fungi or bacteria. For example, under controlled conditions, Xylosandrus germanus Blandford was capable of Dutch elmdisease pathogen transmission.
Beetle larvae complete their development in the tree, and female progeny exit the tree to begin a new gallery.
Due to the cryptic nature of scolytids, ambrosia and bark beetles often are transported from one region to another in trees or wood products.
Many of the ambrosia beetle species that currently occur in the United States are foreign introductions.