Since the early 20th century, Major League Baseball has played the game with bats constructed from ash wood. Known for its lightness and strength, ash has been proved to be an optimal resource for this application. This material is now being threatened by an invasive insect.
Northern white ash trees (fraxicus Americana) are currently being killed by emerald ash borer infestation. The borer is thought to have come to Michigan from Asia in wood packaging and crating. Since its discovery near Detroit, Michigan in 2002 the borer has killed tens of millions of trees in Michigan, and is expected to kill millions more in its spread in the north and northeast.
The spread but of the emerald ash borer is relatively slow (a half-mile per year) on its own, but the most common method for transport is by people carrying either ash firewood or ash botanicals to uninfected locations. The most effective deterrents to the spread have been enforcing up to $4,000 fines and quarantine, where all ash trees within a half-mile of the infected tree are cut down and destroyed. Some insecticides have proved to be effective against the pest, but spraying techniques over large forest areas have not been proved.
The Louisville Slugger company, one of the world's most recognized bat manufacturers, harvests ash from the border area of New York State/Pennsylvania. Mizuno in Japan does as well. This area is in the path of the spread of the emerald ash borer with isolated forests found to be infected in western Pennsylvania. Needless to say, Louisville Slugger is monitoring the situation closely, as it has been estimated that the borer's infestation could expand and overtake the harvest area within a few years.
In the event of a catastrophic destruction of ash trees, Louisville Slugger and other manufacturers are investigating the use of other woods. Oak and hickory are not considered good woods for bats, even though they were used in the period of around 1920 to 1930. Maple was at one time considered to be too heavy for bat construction, but advanced drying techniques yield lower moisture content for lighter bats. Rock and sugar maple seem to be the choice of the industry. Bats may also be turned from beech wood.
Worst case, the ash destruction could prove to have a truly detrimental effect on baseball bat production, from the standing of having either rare or non-existent raw materials. On the field, the result of using alternate woods could significantly change ball flight characteristics; also, many baseball players and fans are traditionalists, which might lead to rejection of newer wood bats. In the best case, emerald ash borers can be contained to only the areas currently infected, and baseball bat construction will continue its current course with ash bats.