So, you’re harvesting some pine cones and you’re afraid that they may be infested with bugs.
The truth is that these pine cones are home to dozens of tiny pests- including worms, weevils, beetles, and even some flying pests.
You’ll want to make sure that you clean it out before you bring it into your home for decoration or use it for an art project.
In this guide, you’ll learn about:
- Identifying the types of bugs that live in pine cones
- How to check your cones for bugs
- How to clean your pine cones from bugs
- Baking, bleaching, boiling, microwaving pine cones
- Using pine cones as a bug killer
Whether you’re using the cones for your next craft project or just collecting them for sport, you should have everything you need to know to clean them properly and identify the type of pest inside the pine cone.
If you have any questions, you can leave a comment and ask (as usual).
Sound good? Let’s clean up those cones!
Do bugs live in pine cones?
Bugs definitely live in pine cones. See for yourself:
Being that it’s an object full of nooks and crannies for bugs to wedge themselves into, the cone provides a safe hiding place for bugs to live, feed, breed, and thrive.
Pine cones house dozens of different pests, everything from beetles to weevils to mites to flies. They’re also used by beetles to deposit eggs, serve as an incubator for larvae, and provide a food source for larger animals who may eat the grub found inside it.
So they’re extremely beneficial.
But for someone who wants to use the pine for their indoor decorations or as a craft item, those pesky bugs are a nuisance. They can bite, infest your home, or even ruin the glue you use in your art project.
So let’s learn about the various bugs that live in these cones, and whether or not you should get rid of them.
They’re not all bad!
Should you be worried about the bugs in the cones?
Well, yes, if you plan to handle or store the pine cones inside your home.
You may be bringing in an infestation of beetles, flies, worms, or other pests if you don’t properly clean it first.
Some bugs are known to bite which can be an issue. Imagine trying to glue something onto it only to get bitten during the process.
Or putting the cones next to your sofa and then finding bugs crawling out of it to nip you in the feet during your favorite show.
This is why it’s important to identify possible bugs and get rid of them first.
After all, pine cones are like a sponge full of nature- including the bugs!
If you’re getting your pine from the store, chances are that they’ve been already cleaned. Those cinnamon or peppermint scented cones that many stores sell during the holidays should be bug-free.
But if you’re harvesting them from the outdoors, this is when you need to be extra careful about potential pests living inside the cone.
Pine cone damage from pests
Bugs can and will damage the cone.
Cone damage is one of the signs that pine is infested in the first place.
Beetles will chew through the holes at the base of the cone. Eggs will be deposited all over the internal structure.
Tiny black cone beetles can be found feeding on the inside and chewing through the stalk.
If your pine cones have pests, you’re likely to see damage internally and externally.
This is why you need to clear the bugs first before you use them for decor or crafts. The last thing you want is to spend hours making cinnamon scented pine cones only to have bugs destroying your masterpiece.
You may also see bug poop (frass) all over the cone.
Sometimes they poop so much that it coats the cone in sparkling “glitter!” The grass buildup may come out of the cone’s gallery (bottom portion).
Types of bugs that live in pine cones
Pine cones are home to all sorts of critters.
Here’s a list of the most common bugs in pine cones that you’ll find in the wild:
Cone weevils (AKA “snout beetles”) are found during the springtime and will eat male flowers.
Their only job is to find a female weevil to mate with and then the female will bore a hole inside the cone to lay eggs. Eggs are laid in small batches and the larvae destroy the cone.
Cone weevils are commonly found in the United States, especially on the western side. The larvae feed on the outside and will both consume and poop inside it.
If you’ve ever shaken a pine cone and saw a bunch of powdery tar comes out, this may be weevil poop (frass). The larvae are extremely destructive and will bore out the inside of the cone.
These are the worst of the bunch.
They’re destructive and known for the ability to completely eat up the inside of a seed cone. They attack cones through the base stalk and then will eat the internals up, which kills the pine cone entirely.
They can also deposit eggs to raise larvae, which will further destroy the cone.
There are different species part of the Conopthorus genus. They look like miniature black beetles and you may see them crawling out of the pine.
There are many different types of cone beetles- some of the most popular are blister beetles, snout beetles, and blister beetles.
Coneworms come from an adult moth that lays larvae into pine flowers and cones.
The larvae will infest the internal structure and develop frass and residue all over it. If you’ve ever picked up a cone that’s littered with powdery substance, it could be the work of coneworms.
Some cone worms include the Southern Pine Coneworm, Webbine Coneworm, Slash Pine Seedworm, and Spruce Worms. Seed Worms will feed on seeds and then escape by boring a tunnel.
They can be seen leaving behind silky white webbing on the pine cone.
They feed on the cone and damage the outside. The female adults will lay eggs that look like white ovals between each scale. The larvae bore tunnels to the cone tip and then leave the cone entirely.
Over half the pine can be destroyed by a single maggot.
Gall midges are tiny flies that are orangish in coloration.
They don’t do much damage to pine cones but will affect the nutrients available to pine seeds.
You may find some galls stuck on the scales of your cone.
Thrips are commonly found eating flowers, leaves, and fruit.
Slash pine flower thrips will affect conifer production and damage the flower bracts of the pine cone.
You’ll see clear residue on the surface of the cone. Florida cones are commonly infested with thrip activity.
Shield bugs will pierce the plant in the late summer.
They feed on seeds using their mouthparts and are commonly found in seed orchards. These bugs are part of the same group that houses stink bugs.
Southern leaf-footed pine seed bug
These bugs also have piercing mouthparts just like shield bugs.
They feed on the ovules in cones, which halt any reproductions.
You may find some pines that are collapsed or empty inside. Distorted or convoluted pine cones may be because of leaf-footed bugs.
Do spiders live in pine cones?
Yes, some spiders inhabit pine cones.
Namely, Euryopis Formosa, which is a spider that’ll make its way into the cone and use it as shelter.
You can also check out this resource for more information on E. formosa.
Spider mites may also find their way into them and are very hard to see because of their small size.
But if you see webbing on it, it could be spiders OR the work of cone maggots/worms leaving behind their shiny silk.
Bugs that look like pine cones
Some bugs LOOK like pine cones.
When you think you’re harvesting a ripe cone, you could be grabbing a bug-shaped one as an evolutionary trait.
Check out this bug and tell me what you think:
It’s called a bagworm. And it’s pretty unique.
Do pine cones need to be cleaned?
That depends on what you plan to do with them.
If you’re using a craft project and plan to bring them inside your home, you should clean each pine cone thoroughly to prevent a pest infection.
But if you plant it, leaving it outside somewhere may be unnecessary since new bugs can just go into the cone even after cleaning it.
How do you get bugs out of pine cones?
Here are some DIY home remedies to kill bugs in pine cones naturally (and not).
Use the method you like best that’s most accessible to you.
Do whatever suits your project for the pines.
Pine cones can be sterilized by boiling water.
- Bring a pot of water to boil and gently drop the cones in the hot water.
- Let them boil for a few minutes, then drain the water.
- Allow them to cool to room temperature.
- Then rinse them under hot water.
This should kill the majority of pests hiding inside the pines. As with any cooking situation, be careful and use common sense.
Boiling is fast if you want to prepare the pine cones for crafts. There’s barely any waiting because after boiling, you just need to dry them off. You can leave them in bright sunlight for an hour or so to dry off.
Then they’re ready for your project. This leaves no smell and no residues, unless you have hard water. But it’s the easiest way.
Use a vinegar bath
Vinegar can be a powerful, natural pest killer that you can bath your pine cones in to kill pests that are hiding between the bracts. All you need is some vinegar, a container, and pines.
Note that the soak will leave the cones smelling vinegary for quite some time.
So if that matters, you may want to dilute it with water to lessen the smell.
This also works on both cones that have already opened or are still closed. Either way is good.
- Take a container that fits all your cones and fill it up with vinegar.
- You can dilute it to 1:1 with half vinegar and water if you want.
- Put the cones in and make sure they’re completely submerged. Let them soak for at least 24 hours.
- This process will kill bugs hiding inside the bracts, larvae, eggs, spiders, flies, gnats, beetles, weevils, and the whole shebang.
You may even see some floating to the top after they die from the vinegar!
When enough time has passed, take the cones out and wash them under warm water to clean them off and remove some of the vinegar smell. Pour the vinegar out and wash the container. Congrats.
You should now have sterilized pine cones!
If you don’t have vinegar, some other alternatives you can use are lemon water or lime water.
Diluted bleach can also be used to bath pine cones, but note that this isn’t as safe as using vinegar or boiling.
Bleach has a lot of hazards, but it’ll also sterilize the pine.
You can put the cones in a diluted bleach tub for a few minutes to kill all the bugs.
Read the labels on the bleach container and use as directed. Bleach comes with its host of problems, so you should avoid this method if possible- especially if you plan to use the pines inside the house.
It also leaves them smelling like bleach for a long time.
Bake pine cones to kill bugs
Baking pine cones is the tried and true method for exterminating the pests that could be hiding inside. Be careful if you plan to microwave or bake them.
NOTE: Pine cones can catch on fire before you know it. They also produce a ton of soot. So be on your toes. If you don’t know what you’re doing, stick with the easier methods like a vinegar bath. People use pine cones to start fires in the wild for camping because of their volatility.
There are some things you should know before baking them:
- Once you put a cone and heat it, it’ll force them to open up (if not already)
- There will be a powerful scent from the fresh pine being heated up
- Heating opened pine cones will slightly distort the shape of it
There are many different ways to do this, but the typical process is as follows:
- Preheat your oven to 200 degrees F.
- Line your oven pan with oven-safe aluminum foil.
- Place the pine cones in a grid formation on the pan. They shouldn’t be touching each other and should be relatively free of debris. You’ll want to clean them with a damp cotton bud or rinse them under the sink if you notice a lot of dirt, leaves, or other debris stuck on them.
- Slide the pan into the oven.
- Bake for 30-45 minutes.
- Inspect the cones frequently. They should start to open up. When they’re fully opened, turn off the oven and let it cool to room temperature.
- Put on your favorite oven gloves. Remove the pan and inspect the cones. They should be completely baked and opened.
- Wash off any new debris, eggs, worms, webs, or dead pets you see.
- Do NOT leave the oven to bake the pine cones unsupervised.
Exercise caution as there may be materials lodged into the pine cone that you missed. If the cones already opened, it’s possible that it picked up some flammable materials stuck inside.
Use common sense and be safe when baking, as with any other recipe or craft project.
Can you microwave pine cones to kill bugs?
Pine cones can be put in the microwave when proper precautions are taken. The heat from the appliance will kill any bugs and the majority of eggs inside or on the cone.
If this is OK, then you can microwave them by preparing a paper towel on a plate that’s safe for the microwave.
Only put 1-3 cones at a time. Don’t overload it. Microwave on low power for 1 minute to eliminate any pests. Watch it while it microwaves. Do NOT let it burn. If you smell smoke, you microwaved it too long. Use lower power.
You should use common sense and take all necessary precautions before microwaving anything. The pines should also be cleaned thoroughly to make sure there’s nothing flammable on it that could spark your microwave.
If you have the slightest doubt, don’t do it. You could start a fire or burn yourself.
They should start to expand and open up over time.
Once they’re fully open, you can carefully let it cool to room temperature and then take it out to inspect. If you see white webs, residue, or frass, this means that it was previously infested with pests.
Check for eggs or live bugs inside. If everything looks good, clean it with a cotton swab to remove debris from the inside and between the bracts.
Can pine cones be used to kill bugs?
Pine cones have been speculated to repel some bugs naturally because of their scent they release.
They contain the aromatic scent of pine, which is known to have natural repelling properties against spiders.
You can leave a few cones around your home in areas that have past activity. This could be a natural, DIY solution to keep those pesky bugs again.
Pine cones can be a natural and free remedy that you have “lying around” to keep the bugs out of your property.
Here are some references you may find useful:
Enjoy your bug-free pine cones
Now that you’ve learned a little (or a lot) about the various types of bugs that inhabit pine cones, you can go forth and make an educated decision of whether or not to get rid of them!
Some bugs are completely harmless.
They’ll leave on their own over time as the cone is in a new environment that’s not favorable to them.
Other bugs should be eliminated because they can bite or infest your property.
After all, you don’t want to spend time making a craft with your cone only to transport bugs to someone’s house!
If you have any questions, post a comment below and I’ll get back to you ASAP! Or if you found this page useful, please let me know as well =].
Tell your friends who may get some value out of it.
Thanks for reading.
Currently an active researcher in the pest control industry for the past 8 years- with a focus on using natural and organic methods to eliminate pest problems.
I share handy DIY pest techniques I come across here to help out others (and possibly save them from a mental breakdown).
Fight nature with nature.