Do real Christmas trees have bugs or spiders?
3 min read · Published
Most real Christmas trees are bug-free. Here's what occasionally comes in on one, why it's harmless, and what to do if you spot something.
Most don’t. Penn State Extension, which advises Christmas tree growers in the US, says “most real Christmas trees are free of insects and other arthropods” (Penn State Extension). Now and then a few small creatures come indoors with a tree. Penn State says none of the species that might arrive this way “are dangerous to the home, its contents, or occupants”.
Why a tree might bring bugs in
A 6 to 7ft Christmas tree spends seven to nine years growing in a field (BCTGA). Like any outdoor tree, it can shelter insects and spiders spending the winter as eggs or dormant adults. When the tree comes into a warm house, some of them wake up. They may stay on the tree, or head for light: windows in the day and lamps at night (Penn State Extension).
They don’t last long. Penn State explains that dry, heated indoor air and the lack of anything to eat mean they “usually die indoors within a short time”. Penn State says they aren’t indoor species, so they can’t settle in your home.
What you might see
Penn State’s guide was written for North American trees, so the exact species differ from those on UK trees. It describes these groups of creatures (Penn State Extension):
- Aphids. Conifer aphids are usually black, grey or brown with long legs. They stay on the tree but may move off as the needles dry out.
- Spiders. Penn State says these are insect predators that “are not dangerous to people or pets”. They may spin small webs on walls or furniture, which you can hoover up. People post photos of them every December (Reddit r/christmas).
- Mites. Mostly tiny, pale and unnoticed. Penn State says none of the mites found on Christmas trees bite or pose a threat to people or pets.
- Egg masses. Clusters laid on the trunk or branches, which can be scraped off.
- White fluff. White woolly patches on needles or bark are usually adelgids, aphid-like insects that cover themselves in wax.
If you can’t identify something, photograph it and post it on a bug identification forum. The r/whatsthisbug forum gets these photos every winter (Reddit r/whatsthisbug).
What to do
- Shake the tree hard outside before it comes in. Penn State says this dislodges many of the adults. A good shake also gets rid of loose needles and helps with mould and allergies. See Can you be allergic to a Christmas tree?
- Check the trunk and inner branches for egg masses, and scrape off any you find.
- Remove any bird’s nest. Some people keep them for luck, but Penn State warns they can contain bird mites.
- Hoover up anything that collects on windows, walls or ceilings.
- Otherwise, leave it. Penn State’s advice is to leave insects on the tree until the tree goes out.
Never spray a tree with insecticide
Penn State says “Aerosol insect sprays are often flammable, usually not labeled for indoor use, and should not be sprayed on a Christmas tree” (Penn State Extension). A cut tree covered in flammable spray, with fairy lights wrapped round it, is a fire risk. See Christmas tree fire safety.