By Sam Wasson
Updated Dec 26, 2022
Every year, countless homeowners purchase real Christmas trees for their holiday celebrations. Unfortunately, these trees can bring more than a sense of holiday cheer and the scent of pine into homes. They can secretly carry thousands of unwelcome home invaders.
If you’ve ever purchased an infested, live tree, it’s an experience you won’t soon forget. Imagine getting out the decorations, and as you string the lights along the tree, you spot not one but hundreds of small critters crawling between the branches. This unsettling discovery would, of course, dampen the holiday cheer.
This article will aid you in avoiding this gross holiday season disaster by helping you identify the most common Christmas tree bugs and the best ways to prevent them.
Technically, thousands of different species of insects nest in conifer trees (pine trees). Therefore, listing out every kind of bug you could find in your Christmas tree would be nearly impossible. Instead, we’ll only cover the most common pests that specifically lay eggs within and infest Christmas trees. After all, finding a single stray grasshopper inside a Norway spruce, Scotch pine, or fir tree isn’t surprising, but the same can’t be said for swarms of aphids.
While most assume aphids are a summertime garden pest, some species love to chow down on and nest in conifers. As a result, aphids are some of the most common bugs in Christmas trees. Some Christmas tree-loving aphids include the spotted pine aphid (Eulachnus agilis), the pine bark aphid or adelgid (Pineus strobi), and the white pine aphid (Cinara strobi). Aphids are small insects that can come in colors ranging from black to brown, green, and white. They typically have long antennae and hind legs, occasionally possessing wings.
Most tree farms check for aphids throughout the year and take steps to prevent them, but the occasional nest can go unnoticed. Signs of an aphid-infested tree include discolored, warped, or loose needles and the growth of white, sooty mold along the trunk and tree limbs. Before bringing your tree home, always give it a thorough inspection for these signs of infestation.
Bark beetles are a small family of insects containing over 600 species spread throughout the United States. Bark beetles are small, pill-shaped insects about the size of a grain of rice with short legs and stubby antennae. Some bark beetle species may appear as though they have no head, as the pronotum hides it – this is the top portion of the beetle’s body, located behind the head. These pests come in many colors, from brown to bronze, black, red, or deep red.
Spotting bark beetle infestations can be trickier, as they mostly burrow and damage trees from underneath the bark. One of the only outwardly visible ways to spot a bark beetle infestation is the presence of frass. Frass is excrement produced by some wood-boring insects, like bark beetles or termites; it’s a fine, sawdust-like material that collects in the crevices of bark or at the base of a tree. Careful inspections can also reveal small holes along the surface bark.
These small pests are known as white scales, or by their scientific name, Chionaspis pinifoliae. These scale insects infest most pine, spruce, and fir species and are considered major ecological pests for these trees. Infant scales are called “crawlers” and have a bright red to pinkish hue, eventually turning yellow, then white as they age. Even as adults, these insects are extremely small, only measuring up to one-eighth of an inch in length.
Spotting these pests can be difficult, as their bodies resemble small, yellow-white bumps on pine needles when observed with the naked eye. However, they can be identified more easily by the excretions they create. As they feed, they produce a white, waxy substance that coats portions of the tree’s needles. These white patches can almost completely coat needles in large numbers, giving them a molded or mottled appearance.
Unlike the rest of the entries, praying mantises don’t intend to feed on or damage pine trees. Instead, mantises choose to nest and lay eggs in these trees because they hunt the more problematic pests scurrying around. Furthermore, it isn’t adult mantises you need to look out for, but their eggs. Mantises lay large, pod-like egg masses filled with over 400 individual eggs. These egg cases are about the size of a walnut and are light tan to dark brown. While uncommon, a single pine tree can host multiple praying mantis eggs.
Mantis egg sacs will hatch after a few weeks of being brought indoors, and if it does, you could have hundreds of baby mantises (called nymphs) running around. While harmless (and great for catching other bugs), these mini-mantises can be unnerving and unsightly, especially in large numbers. However, it’s not recommended that you destroy a mantis egg if you find one, as mantises are beneficial insects that voraciously hunt more dangerous pest species. If you come across a mantis egg in your Christmas tree, simply snip off the part of the limb the egg is on and carefully place it outside.
Many species of spider mites can infest Christmas trees. Some have spots, some are red, and some spin webs, but their distinguishing features are unimportant, as you won’t be able to determine much with the naked eye. Spider mites are extraordinarily small, less than one-twentieth of an inch in size, and appear as little, barely moving specks.
Spider mites can be a pain to spot on pine trees since their natural coloring can (depending on the species) allow them to blend in the branches and needles. Even worse, the damage mites inflict on a tree is subtle, often resulting in small, off-white marks on needles. However, large infestations can result in yellow needles. The best way to spot these mites is to shake the branch, or the entire tree, over paper or a large drop cloth. If the mites are present, they’ll fall onto the cloth or paper and appear as pepper-like, small red dots.
While uncommon, finding pests inside your Christmas tree can be unsettling. Thankfully, most are not dangerous, nor do they threaten your home or possessions (except maybe your houseplants.) If you come across unwanted hitchhikers during the holiday season, vacuum them up, take your tree outside, and give it a good shake. If your pests are too persistent, diatomaceous earth or neem oil are safe, inexpensive, and reliable natural insecticides. Finally, you should contact a professional pest control company if you fear you obtained an infestation from your Christmas tree.
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