Figuring Out Figure: Ambrosia
"Ambrosia" is a term that's commonly applied to lumber from eastern red and silver maples that has streaks of color caused by an infestation of the ambrosia beetle. But "ambrosia beetle" really is a generic term for many different types of beetles whose larvae bore into trees and deposit a fungal symbiont into the wood. This fungus breaks down the wood into a compound that the larvae can eat. Beetles usually infest dead or dying trees and often will enter the trunk through a broken branch or other injury. Infested trees are more prevalent in warmer areas of the country, their incidence declining in northern Pennsylvania and New York.
The ambrosia figure has a tapered, oblong shape running with the grain, and usually a grayish color. (See image 1) The figure pattern can be mild or dense, depending on the degree of infestation. Ambrosia maple also is called "ghost" maple, because the stains look like ghosts suspended in the board and the larvae tunnels appear to be eyes. I have seen both curly and burl maple with ambrosia stains. (See image 2)
About the author:
Rick Hearne, owner of Hearne Hardwoods Inc. in Oxford, Pennsylvania, has been in the specialty lumber business for over 25 years. Hearne Hardwoods carries an inventory of 1 million board feet of lumber in over 120 different species, including at least 100,000 board feet of variously figured maple.