Beetles not native to Southern California are causing much damage to trees, including those that bear avocados, a lucrative California crop. Scientists at the University of California-Riverside are fighting this problem with the help of 3-D printers.
The invasive beetles are from Southeast Asia, and scientists aren't sure how they got to California. One guess is that they were in packing materials used in shipping products to California from Asia.
Once here, they've been doing plenty of damage. Akif Eskalen, a plant pathologist, said that "most of the landscaped trees in Southern California are infested right now, and it’s spreading.” The beetles can kill a tree in one or two years, three at the most, he said.
Close to 40 species of trees are susceptible to damage by these beetles, including the avocado tree, which represent "a very important industry in California," Eskalen said. "A lot of people are making money. Their job is dependent on that.”
The beetle, technically known as the polyphagous shot hole borer, drills holes into a critical part of the tree, disrupting the flow of water from the roots to the leaves. It also carries a fungus in its mouth that harms the trees. The fungus grows and further clogs the vessels that carry nutrients and water to the tree, eventually starving it to death.
Entomologists have been trying different treatments to kill the beetles and the fungus. But it was time-consuming and difficult to learn whether the treatments worked until a 3-D-printed bug trap was developed to place over the holes in the trees.
“We catch the sawdust and the frass — the beetle poop, as it were — and so then we would know if the beetle is active in there,” said Richard Stouthamer, a professor of entomology at California-Riverside.
If the beetle is still active, that means the pesticide is not working. Scientists say a 3-D-printed trap speeds up the data-collection process and makes the results reliable. The 3-D printer allows researchers to easily tailor their traps to the insects they are studying.
“What the 3-D printer allows us to do is to prototype new designs extremely rapidly and to create those designs not only for prototype testing but, as with this particular printer, we’ve been able to print off hundreds, probably approaching a thousand now, of the designs that we have,” said postdoctoral scholar Roger Duncan Selby.
The university's lab isn't the only one that benefits from 3-D printers.
“It’s going to be a very common thing to have in labs, because often you need something specialized, and then once you have the ability to program these things, you can make it," Stouthamer said.
It’s a relatively inexpensive tool that can create new possibilities for researchers to help them get results.