Baseball. It’s America’s favorite pastime. So how is something as small as insect larvae threatening this American tradition? Emerald Ash Borers are quickly infesting forests across many states, which may threaten the supply of ash available for manufacturing baseball bats such as the Louisville Slugger.
The Emerald Ash Borer (EAB) is an invasive insect that is responsible for the destruction of tens of millions of ash trees across several states. The EAB is bright green and metallic in color and is small enough to fit on the face of a penny. As you can imagine, this makes spotting it in the wild even more difficult.
The larvae of EABs cause the majority of the destruction seen in ash populations. The larvae tunnel under the bark of the tree, causing damage to the systems, which transport food and water. Eventually, this process kills the tree via starvation.
Due to the devastation caused by EABs, researchers are continuously looking for methods to combat the depletion of America’s ash population. Recently, engineers at Penn State and Western Michigan University developed decoys to help battle the beetles.
An essential step in preventing the spread of EABs is to trap the males before they are able to find females for reproduction. Trapping may sound like an easy feat, but it unfortunately is not. In the past, green plastic bugs have been unsuccessful at luring male EABs in to the traps because they are smart enough to differentiate between real bugs and decoys.
The engineers at Penn State and Western Michigan University originally tried producing the decoys with 3D printing, but that method proved unsuccessful, as “this approach does not replicate the fine structure of the elytra, the hardened forewing of the insect, which is apparently necessary to attract males.” A more than 40% increased success rate was achieved by a second method of decoy manufacturing. This method required “the biomimetic fabrication of a negative die and a positive die, which were used to stamp the decoys on a plastic sheet. The stamped decoys were cut out and first painted black and then metallic green.”
Although the original production rate of the decoys was low, Akhlesh Lakhtakia, Stephen E. Swiontek, graduate student in engineering science and mechanics, Penn State, and Tarun Gupta, professor of industrial and manufacturing engineering, Western Michigan University, enhanced the biomimetic approach. Rather than using one euthanized female to make the biometric molds, they used ten. After the plastic was heated and allowed to cure, the lures were cut out and pained to look just like the stamped lures. According to Lakhtakia, the heat curing method is better because it requires only one mold, thus making it a single step process. This also makes it faster and less expensive to manufacture.
Although they realize that the EAB is impossible to stop because it is spread across half of the country and simply moves on once it destroys an entire ash population, the engineers hope that their decoys can be used trap any EABs entering unaffected populations of ash trees and new ask trees planted in the previously devastated areas.