Cool Critters: Snug as a bug in a Christmas tree? How to keep your holiday as free of creepy-crawlies as possible

December 2023 was not a good time to be an insect in a Christmas tree.

It began with a TikTok post: “Beware of the real trees.”

Written by Andrea Coward of Ohio, the post included a series of pictures of tiny, spindly bent-legged insects perched on branches of a lighted Christmas tree in the family living room. Coward had purchased the fresh-cut tree two weeks earlier from a nearby tree farm, she explained, and was shocked when she saw movement among the ornaments. It turned out the tree was infested with a “million” praying mantises that had hatched from eggs hidden among its branches, she wrote.

Coward’s post racked up more than 4 million views and loads of comments. “The fresh pine smell isn’t worth it,” wrote one viewer. “I would literally die!” another exclaimed.

Then media outlets picked up the story, ranging from Good Morning America and ABC News to Yahoo News and The Mirror.

“My Christmas tree hatched millions of creepy crawlies,” one headline blared. “Thousands of bugs could be lurking in your Christmas tree,” another proclaimed. And this: “Beware of bug-filled Christmas trees.”

By mid-December, bug-infested Christmas trees were the big bugaboo (so to speak) of the holiday season. And praying mantises were supposedly only the tip of the iceberg. Spiders, aphids, booklice, weevils and beetles lurked in holiday trees as well, according to news reports.

“There could be more than 20,000 bugs in one tree,” one article stated.

Gasp!

Now that it’s December 2024, here we are again, driving home with Christmas trees strapped to our car roofs and in pickup truck beds. It’s hard not to wonder: Is this cherished Christmastime symbol a launching pad for insect invasions inside our homes?

First, some perspective. Bugs live in trees, especially during winter. It’s how they survive the cold weather. And since many Christmas trees come from forested areas and tree farms, there’s a chance that at least some critters or their eggs will remain on the bark, limbs and needles, entomologist Richard Zack of Washington State University said.

“The Christmas tree is a great place for insects to spend a winter as they are very compact with a lot of branches that help keep them safe,” he said.

Here in the Pacific Northwest, that could mean aphids, beetles, mites, spiders (don’t worry, only the harmless variety) and the European praying mantis, Zack said. While some remain dormant when brought indoors, it’s not unusual for species such as the praying mantis to become active when exposed to the home’s warmth, he explained.

“The temperature tells them, it’s spring – let’s go!” he said, emphasizing that they don’t survive long due to lack of food. This means they won’t grow big or reproduce inside your home.

In our region, the praying mantis is a likely critter to emerge. Introduced to the U.S. about 40 years ago, their populations in the PNW have grown significantly in recent years, Zack said. This is good, because they eat pests in gardens and crop fields. But crawling among your Christmas tree ornaments? That’s another story.

Chances are, however, it wouldn’t be anything like the Coward experience in Ohio, where multiple eggs encased in a sac apparently hatched indoors. Did a “million” baby mantises really emerge? Probably not – or even a thousand, for that matter. Here’s why. Each egg sac, called an oothecum, holds about 100 eggs, according to Zack. This means Coward’s tree would have been covered with roughly 10,000 sacs. And mantis egg sacs aren’t small. Measuring 1-2 inches long, they resemble oblong light-brown blobs of foam insulation.

Also, keep in mind that praying mantis babies aren’t large and lime-green like the adults. They are drab-colored, less than a half-inch long, have no bulging eyes and no wings.

So yes, a Christmas tree inside your home might harbor an oothecum or two, but not typically. That’s because commercial growers and many tree lot operators put their trees through mechanical shakers to dislodge them and other bug species, according to the Pacific Northwest Christmas Tree Association.

This means the odds increase when you harvest your own tree. The solution, though, is simple.

“Give the tree trunk some good thumps on the ground before you transport it indoors,” Zack advises. This is probably a good idea regardless of whether you cut down the tree yourself or get it from a retailer, he added.

After all, we share this world with zillions of bugs. It’s no surprise, then, that a few might be overwintering in the comfort of an evergreen tree headed toward your home.