Thursday, March 29, 2012

Carpenter Bee Traps - My Own Design

Two years ago I posted about some Carpenter Bee Traps that members of the Northcrest community purchased as part of a group buy. Here's the original post:

I don't condone killing the bees unless they're a nuisance (in my case they make cheese of my house - with so much wood in the ceilings and eaves). This is one alternative that doesn't involve pesticides.

What the bee holes look like

Repaired hole, reopened by bees

There were a couple of things I didn't like about the design of those traps - the main one had to do with durability - the thin plywood began to delaminate with exposure to rain, etc - also the wood surfaces stained and were getting moldy. Plus I just thought they looked ugly hanging there with this long set of bottles underneath.

After one season of use

So after I took them down and examined the results (above) of a season of use, my initial thought was that I could paint them and put some roofing felt on thier tops (I have two) to keep them out of the weather a bit - all that seemed like a lot of effort for something that's basically made of scrap wood, stapled together. I decided to make up something of my own design. My goals: 1) keep it simple in construction; 2) something easy to make; 3) with a minimum profile, and 4) durability to weather. What I came up with is a length of scrap tubafore, with a couple of holes drilled in it. The cap of a bottle would be glued into a countersink on the bottom, eliminating the need for two bottles.

This was my prototype:

I had this "Goop" adhesive laying around -worked well!
Drill through the cap

Last year frankly there weren't enough bees to really mess with the traps. I think the previous year's traps basically "did the job" and eliminated most from the house along with their progeny. This year they were out once again and in numbers, so I revisited my earlier redesign and put a couple up - both the original design and my new design, for a comparison. I did paint my prototype before hanging.

Similar to prototype

The results after a couple of days:

As you can see, my new design on the right (this is looking out of a window under the South eave of my house) is just as effective as the original design. So I made a couple of variations of the design and put up some more:

Including this "under mount" version near the downspout - also very effective:

And the results thus far:

And the original:

I think I've gotten about 3 dozen bees so far - it's been 10 days or so. I think you can follow how I made these - very simple if you have a drill press and some Forstner bits but you can probably manage with a spade bit and 9/16" (for the bee hole) bit with some scrap wood. If you paint them (I used a coat of primer and one coat of the trim paint on my house) they'll last for many years - just remember to take them down when the bees are gone.

-- John


Anonymous said...

Does the "bee hole" in the 4" side of the 2 x 4 go all the way through the board or only part way? Why don't the bees just climb out of the bottle & get back out?

Your design is MUCH simpler than the basic design I found on YouTube.

John Eaton said...

The hole goes all the way through. What happens is that the bees fall into the bottle and they can't get a grip on the sides of the plastic to crawl out - nor can they get the lift then need as the approach the narrow opening at the top to fly out due to size of their bodies and what's required for them to fly up through the opening...

Anonymous said...

What is the diameter of the Hole going from the cap to the the bee hole intersect?

John Eaton said...

The hole is 9/16" in diameter...

JPL said...

Looks like a good design but I have a few questions:
*Why do the bees go into the hole and bottle? Do they think they are going into an old hole to reuse?
*Why drill the 4" side all the way through? Why not mate the two holes?
*It appears that you are using a plastic water bottle. What about a glass bottle?

John Eaton said...

Question 1: The hole is basically the same size as the hole they "drill" through wood, so it appears to be a burrow to them. The appearance is greater when a bee has been trapped - it's probably the buzzing sound.

Question 2: The hole that goes through allows you to position the trap over an existing hole. You're much more likely to trap bees.

Question 3: I guess you can use glass - my only thought is that something happens I'd rather a light-weight plastic bottle fell on my head than a glass bottle. Also, those plastic bottles are ubiquitous.

Old Sneelock said...

John I am ever so glad I went to your blog today.
Every time I move I run into a new type of insect pest. With this house it has been carpenter ants and carpenter bees.
I've had the exterminator out twice and for $300.00 he dusts the holes with powdered Sevin. The bag isn't marked but I checked and it's Sevin. After he leaves I caulk the holes shut. Within 2 days the bees have reopened the caulked holes and are back to living in the porch ceiling joists.
I'm going to build some of your bee traps so this spring I might just get ahead of them.
Dave Nighswander
aka Old Sneelock

Mark Ramos said...

Thanks! Keep it simple and things work. I will try them this year.

rich said...

Old Sneelock - You should wait until the next day or that night before caulking the holes, this alows for the bees to enter the hole and get in contact with the poison and also allows any bee that is in the hole to come out and carry the dust to other holes.

Also try buying some 1/2' hardwood dowels and insert them with a good glue and cut them flush with a razor knife. it works better than caulk.

Anonymous said...

The best I've done is to spray WD-40 into the hole(s) after the bees have come in for the evening. You don't even have to plug the holes. WD-40 kills the bee and the eggs within the nest.

Anonymous said...

I can hardly wait to make these clever traps...I like that it is simple and yet effective...I have sparyed hornet spray into the burrowed holes of the bee...I will let you know how these worked for me...Thanks...the hole on the front side of the 2x4 is drilled through and the cap topped hole intersected the front hole???

Michael Cole said...

These type of traps work well. If you use them in combination with stain additive NBS-30 you can eliminate most of your carpenter bee issues. NBS-30 is based on the Citronella plant and the bees won't even land on the wood. Lasts 2-3 years.

meklog37 said...

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CoachRob2016 said...

I was at the Atlanta Home Show and bought 4
Carpenter Bee Coffins as they had a great show discount. The traps attach discreetly underneath your deck railing , hidden out of sight underneath your Soffits and Fascia. I put one under my window sill as well. Great website with lots tips.

Brown kris said...

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