Wasp Cap Trap — Save the Bees, Ditch the Wasps!
Tired of wasps ruining your fruit trees and your summer afternoons? Meet the Wasp Cap Trap, the easy, bee-friendly way to keep wasps and honerts in check!
🐝 Save the Bees:
Unlike some traps that accidentally harm bees, this design is selective — it targets wasps while keeping our precious pollinators safe. Wasps are drawn in by the sweet scent of rotting fruit (we’ll mimic that with beer and sugar), while bees are smart enough to steer clear.
♻️ Recycles Plastic Bottles:
The Wasp Cap Trap uses a regular plastic bottle you’d normally throw away. Just screw the 3D printed cap onto the top, fill the bottle with your bait (beer + sugar = irresistible to wasps), and hang it up.
When it’s full (it will get gross), simply unscrew the trap, cap the bottle with its original cap (keep it handy!), and toss the whole thing out. No nasty cleanup needed.
🌳 How to Use It:
- Fill a plastic bottle with a beer (33 cl - 12 oz) and 3 teaspoons of sugar (the wasps ain't exactly chemists, you can just eyeball the proportions or use the convinient measuring scoop shown in the gif, brought to you by yours truly. Also better not to waste good beer on this the cheapest one you can find will be ok).
- Screw the Wasp Cap Trap onto the bottle.
- Pass a cord through the built-in slot to hang it wherever needed (fruit trees, gardens, patios), preferably at 150 cm (5 feet) or higher (doesn't matter that much, don't overthing this step)
- Best to set it up in the evening — wasps are less active, making it safer for you.
- Repeat as many times as you like, I hang a couple per fruit tree and a couple where you have people chilling.
- The best time to hang them is in march-april, at that time wasps and honets are out there making nests, if you mitigate the population at this time during the summer there will be less newborns. The trap is still effective during the summer months but you are just mananing the population and not exterminating the colonies like you would in spring.
- Done! Let it start protecting your fruit and your backyard vibes.
🧩 Two Versions Included:
- One for the modern and more common PCO 1881 bottle thread (standard for most soda and water bottles today).
One for the older PCO 1810 thread (less common now, but still used in some parts of the world, I designed this quite a while ago and this was the standard at the time).
Not sure which one you have? No worries — I included a quick test print to check before committing to a full print.
🖨️ Easy Printing:
- Prints in about 1 hour (at 0.16 layer height).
- No supports needed.
- Filament? ABS preferred for outdoor toughness, PETG works great too — but even PLA has held up fine for me.
- Brim included, kind of pointless for pla and petg, but I think most will be printing batches of theese, the brim offers some peace of mind.
- Pro tip: Print it in a bright color. Yellow is best wasps seem to love it, orange works fine and red works and also seems to attact fruit flies.
⚙️ Design notes:
This trap design it's nothing new, my grampa has been doing this since he was a kid and despites what he says I doubt he invented the concept, many commercial products achieve the same thing with the same idea. I saw the contest and I decided to optimize for printing the model I designed and have been using for years.
Some designs over-complicate things with small openings, non return cones and so on, in my experience they do more harm than good, make the openings to small and big hornets won't be tricked and can't go inside, this size opening it's what has been most effective for me.
I admit the heavy lifting is being done by the beer+sugar bait, the cap really it's just a way to prevent water from getting inside the bottle and a convinient way to hang it, if you really want to go the low-tech route, you can really just use iron wire and tinfoil, that's what grampa used to do! But if i say so myself this printed version looks pretty spiffy
Give it a try and let me know what you think!
Boost Me (for free)
If you like the Wasp Cap Trap, consider giving me a boost — it's free but helps me bring more projects like this to life!
🥄 Bonus: The Perfect Scoop for the Perfect Trap
Need an easy way to fill your trap with the right dose of beer and sugar mix without spilling? I designed a small tool called the Scoop 'n Slide that works great for this.
It’s a sliding measuring scoop that also functions as a funnel, super handy when pouring into narrow-neck bottles like the ones used for this trap.
Even better: one of the versions is exactly the right size for this use. No guessing, no mess.
