Darkling Beetle Breeder Box For Mealworms

Building a breeder box with egg filter for Darkling Beetles.

Things needed:

Plywood, at least 1/2 inch thick.

Two cheap plastic containers with a level rim. I got these for $1 each, dollar store.

Pen or pencil.

Drill with drill bit to fit what size of screws you have & screwdriver.

Jigsaw.

Two clamps.

Sandpaper.

Box knife.

Aluminum window screen.

Silicone sealant.

Hope I didn't leave anything out but will discuss options as we go.  Some people raise mealworms all in one container for all cycles of life.  This is convenient for some and alright if that's what one wants to do.  We're in this for maximum production and so we're making a screen bottom container for the Darkling Beetles to breed.  If in the same container, they will eat their own eggs.

When we have a good number of breeding beetles, we will set them over a solid bottom container for a certain period of time and then replace the container below.  This will ensure our growing mealworms stay pretty much the same size.

This will work for any size of level top container one wants to use.  Using small containers will not require screen bracing whereas larger opening containers may to prevent screen sagging.  Since we're just starting out and dealing with what will be very small hatchling mealworms and beetles breed best in large numbers in close proximity, a small, 6 quart container will suffice for now.  Some experimenting will have to be done to figure the maximum amount of beetles we can allow for one container. 

Here we go.  Lay a container top down onto the plywood.  Trace a line around it, leaving enough space to have 1" of wood frame outside the container.





Drill screw holes around the perimeter about 2" - 3" apart.  Countersinking with a countersink bit or tool or a larger drillbit is nice and will give a better finish. 

The piece is cut out with a jigsaw and laid onto another piece of plywwod and clamped. You can of course double up the wood from the beginning if you like but I only drilled completely through the top layer to give screws a good bite into the lower layer when assembling later.  A pilot hole for the jigsaw blade is drilled through both layers of wood.  The inside is cut out while remaining clamped to assure exact cuts on both pieces.  The clamps need to be moved to make room for the saw.

Next we see the centers cut out.  After this the lower piece of wood is cut out, using the top piece for a blade guide.

Both pieces cut out and edges sanded.

Ok you have to imagine with me installing the screen and it's good to have a pair of leather gloves. Cut a piece of window screen that will stick out at least 3 inches on three sides to have something to pull with one hand, sandwich it between the wood layers. Start all screws into holes with fingers so they are ready.  We start along a side making sure our wood pieces are aligned flush, screen flush with the outside wood edge on the side we are beginning with, tighten the center screw tight.  Then along that same side, pull the screen away from the center screw toward the ends as you tighten each next screw.

Now go to the opposite side, again with the center screw and tighten it tight while pulling the screen with your free hand.  Best way to describe this is fingers next to the wood for bracing while pinching and pulling the screen.  Work toward each end, pulling the screen opposite the screw on the other side and away from the center screw on that side you're on. 

When two opposite sides are complete, do the ends the same way, always pulling and tightening.  When you get done, if you did a good job the screen will be very flat and tight.  Now you can trim off the excess screen along the seam with a box blade or Dremel rotary tool cut-off wheel. Leave no wire ends poking out that will stab you when handling.  If your screws are poking out the other side, grind them off flat & flush to the wood.  Best to start with the right length of screw. :)

I've tried with no success with simply attaching screen to plastic container bottoms by various methods.  It always ends up loose and sagging so I came up with this and it works well. I personally don't like sagging in my screen bottoms. If it doesn't bother you then do whatever works.  Regulation aluminum screen frame material and accessories are expensive, hard to install for beginners and will not give a custom full-fit to the container as will this method. 

If we made a good cut in the beginning, the top of a container will fit right into the wood frame and flat onto the screen.  The bottom is cut off one container which now becomes the top of the beetle box with screen bottom.  Some dabs of silicone around the outside is all that's needed to secure the container to the wood unless you plan on getting rough with it. In that case put alot of silicone haha!  All we really need is for it to stay secure enough the beetles can't get out under the edge.  I have observed them rooting around and several of them in unison might just lift the unfastened container and escape!

The finished product set on a solid bottom container we can change out ever so often when we have lots of breeding beetles.  As they breed and lay eggs, with all their running about through the bedding, their body action will keep the bedding moving and eggs falling through the screen, into oats, bran or whatever we want to use for the baby mealworms to eat when they hatch.  After the mealworms get big enough to not fall through the screen, they can be put into a Clean Bug System.