Spalted Ambrosia Maple
"Ambrosia" Maple is usually a soft maple that has been penetrated by the Ambrosia Beetle. The beetle is not large, and creates a series of holes or tunnels into the wood. One result is a series of streaks that mark the penetration and surrounding wood. At times the penetration streaks may be amplified by mineral stain and spalting, which will enhance the appearance of the wood but not be detrimental structurally.See more detail about the Ambrosia Beetle at http://www.fs.fed.us/r3/resources/health/field-guide/wb/ambrosia.shtml.
The Ambrosia Beetle creates extremely small holes (think pinholes) in dead or recently cut hardwood or softwood trees, green lumber and logs, usually boring directly into sapwood. In the process of boring, the beetle brings two fungi along into the boring tunnels. One of the fungi sustains the beetle, and the other grows on the wood walls of the tunnels and stains the wood. The activity of the Ambrosia Beetle in itself does not usually detract from the strength of the wood, though an infested log will likely start to spalt and then become weakened.
It should be noted that Ambrosia Maple is not a species of the maple tree. The term is strictly related to the "damage" done to the wood by the Ambrosia Beetle. Though found in many different types of wood, the this "pest" beetle seems to leave the most distinctive markings in maple.
Maple grain colors are varied and can be cream, streaked, light brown, and swirled. Thanks to the Ambrosia Beetle there can be some extremely interesting and artistic wood pattern in ambrosia maple. Mixing together the activity of the Ambrosia Beetle and the wood spalting process can result in an even more unusual looking piece. Such pieces lend themselves to production of many unique and fine spalted woodworking products. When working spalted Ambrosia Maple care must be taken to use sharp, well maintained tools. Beetle tracks and voids in the wood can result in splitting when contacted by a cutting edge. If the piece is spalted then also be aware of the issues when working with spalted wood.