SALEM — Oregon wildlife officials have identified two non-native and potentially invasive Cuban tree frogs that apparently hitchhiked into the state on nursery plants.

Both reports came on the same day, May 18, under strangely different circumstances, said Rick Boatner, invasive species supervisor at the Oregon Department of Fish and Wildlife.

One of the frogs was spotted on a tropical plant shipped from Florida to a Home Depot store in the Eugene area, and the other was found on a garden croton plant that had been purchased online through the e-commerce site Etsy by a customer near Corvallis.

“It’s rare, but not unusual, for creatures to come in on plants or in shipping containers,” Boatner said. “It’s critical to prevent non-native species from entering Oregon rather than try to deal with them once they’ve become established.”

Cuban tree frogs are native to Cuba, the Bahamas and the Cayman Islands, but have established a few highly invasive populations in places like Florida, Hawaii and the Caribbean Islands, where they outcompete native frogs and amphibians for space and food.

Boatner said the frogs are small, just 2-3 inches in length, which makes them hard to detect in plants. They are similar in appearance to Oregon’s native tree frogs, or peepers.

While it is not certain whether Cuban tree frogs can survive and become established in Oregon’s climate, Boatner said the department doesn’t want to take chances.

“We’re being cautious,” he said. “If you do find one, call us and let us know. We don’t want them out in the wild.”

Boatner urged nursery retailers and consumers to thoroughly inspect plants for invasive hitchhikers, and call ODFW if they find anything suspicious.

Tracking zebra mussels

Earlier this year, ODFW also discovered invasive zebra mussels in imported “Betta Buddy Marimo Ball” moss plants sold at pet stores in the Salem and Ashland areas.

Though Oregon and the Pacific Northwest are currently free of zebra mussels in the wild, the species poses a massive threat to agriculture because they attach themselves on hard services in waterways, which can cause blockages of irrigation pumps and headgates.

Zebra mussels cause an estimated $1 billion per year in damage and control costs where they have become established in the U.S.

Since reports of zebra mussels in the moss balls surfaced in April, the Oregon Department of Agriculture issued a 180-day quarantine on the product.

Moss balls may only be imported into Oregon if accompanied by a compliance certificate stating the product was inspected and free of zebra mussels within seven days of shipping. Moss balls without the required proof of inspection will be destroyed, and violations may result in a fine up to $10,000.

Boatner said ODFW will be conducting environmental DNA testing later this summer to track whether any zebra mussels have made it into the wild.

The agency is compiling a list of between 70 and 100 aquarium dump sites around the state — such as small city ponds — and will begin testing in July when the mussels’ spawning season begins.

”We’ve been identifying those places so we can start testing with the environmental DNA,” Boatner said. “It’s kind of like an early warning system.”

Boatner said officials must ultimately decide how they will handle the moss balls beyond the temporary quarantine, or whether they will ban the product.

The quarantine was announced April 19, meaning it will expire Oct. 16.

To report invasive species, call the Oregon Invasive Species hotline at (866) 468-2337, or visit https://oregoninvasiveshotline.org.