Can Invasive Species Ruin Baseball?

By Mike Szydlowski CPS Science Coordinator

Well no, not really. However, quite a few people, including Major League Baseball are concerned that they could ruin a part of baseball tradition. The enemy this time is the emerald ash borer. The metallic green beetle should not be anywhere in the United States but it hitched rides over to our country using our modern methods of transportation. More specifically, this beetle came by way of cargo ships across the ocean.

Home Sweet Home?

The emerald green ash borer has been on Earth for a lot longer than humans have. So why is it just now that these bright green bugs are becoming such a problem? As with just about any invasive species, the problem is due to the unnatural transportation of an organism outside of its natural territory.

The ash borer is native to a large part of Asia. The females lay their eggs beneath the bark of ash trees and the larvae spend the first part of their life feeding on the soft tissues of the large tree. As they feed, the beetles create tunnels in the tree’s tissues that are used for the circulation of the tree. Once enough of the circulation is cut off by these tunnels, the tree will starve and die.

The difference is, in Asia the emerald green ash borers only seem to go after sick and dying ash trees. Scientists have found that the ash trees in Asia have a slightly different chemical composition than the ash trees in North America. It appears that the Asian ash trees have a chemical defense against these beetles. It is different in North America. The beetles are successful inside any ash tree. There are no chemical defenses here. That is the harm in bringing a new species into a new ecosystem.

Beetles and Baseball

Even if you hate trees (that is not normal by the way), the emerald green ash borer may affect you in other ways. The two major baseball bat makers, Rawlings and Louisville Slugger, have huge dedicated forests of ash trees for the sole purpose of making baseball bats. These invasive beetles are within just 100 miles of reaching those forests.

Almost all wooden baseball bats used to be made out of ash. Even today, over 50% of baseball bats come from this important tree. Have you noticed that more players are breaking their bats during games? This has MLB officials worried and it turns out it is because more players are switching to maple bats. The grain of a maple tree is different than an ash tree. For this reason, maple bats break and send splintered and jagged pieces of wood flying into the stands much more than ash bats.

Baseball officials are taking the issue of emerald green ash borers serious enough that they have contracted scientists and companies to try to find new sources of wood for their bats in the future. These invasive beetles have killed over 500 million ash trees in the United States already and officials worry that they may all be wiped out. Already MLB has approved new birch wood bats to add to the already approved ash and maple bats.

What can be done?

A chemical has been found that will kill the larvae but it costs about $200 per tree and must be injected into the tree. Therefore, that is not a practical idea for saving whole forests. The United States approved the release of wasps from china that will kill the larvae but it is unclear how that is working and this new wasp could pose other unintended consequences in its new ecosystem. And finally, scientists have found that if they purposefully injure one ash tree, a large number of the beetles will go to that tree and then they can shred the tree and beetles to try to save the rest of the trees. This may help a little but it is not enough.

The beetles do not naturally spread very far on their own. However, when an infected ash tree dies it is often cut up and the firewood is transported all over the place — with live emerald green ash borers still in it. And it seems like a broken record, but even climate change deserves some blame. The warmer temperatures are allowing the insects to survive in new locations that used to be too cold for them.

Some humans are probably sick of hearing it, but this is yet another of countless examples that show how delicate and unique are ecosystems are. Organisms evolved together for millions of years with success. However, these faster changes have leave ecosystems unprepared and unprotected.