Avocado lovers, beware. A study recently published in Fungal Genetics and Biology suggests a threat facing avocado crops in California and Florida could take a new turn.

Ambrosia beetles of the Euwallacea genus bore into avocado trees to farm Fusarium fungi, which they use to feed their young. It’s well-known that these fungi can damage and kill the infested tree, but the new study draws attention to an even more concerning possibility. If an ambrosia beetle cultivates its kind of Fusarium fungus in a tree that another beetle is using to cultivate a different Fusarium variety, those fungi could cross and create new, more dangerous strands.

It’s certainly a concern, considering that the invasive ambrosia beetle is currently undergoing a population boom. “Over the past four or five years, ambrosia beetles seem to be really out of control,” says David Geiser, plant pathologist at Pennsylvania State University and co-author of the study in a Pennsylvania State University press release. That’s because the beetles are hitching rides on wood cargo pallets shipped around the world.

Wait a minute! This sounds familiar: It’s the same way the invasive Asian longhorned beetle (ALB), which is threatening northeastern forests and the maple industry, arrived from China. It’s also likely how the emerald ash borer (EAB) — which is decimating the Midwest’s ash trees as we speak — arrived here.

So what can we do? Last Thursday kicked off Tree Check Month. Take a moment to learn the signs of ALB and who to call in your local area if you spot some.

And don’t forget how pests like these got here in the first place. Transportation of invasive beetles on wood doesn’t only occur over oceans. It can also occur from campsite to campsite. Remember not to move firewood. Our avocados, ash trees and maple sweets could depend on it.