Growing Mealworms

Mealworm Pupae and young Beetles

Growing mealworms is NOT something that everyone will be interested in doing for themselves, for sure.  Lately, I have had more than a few inquiries as to how I grow them that I thought I would share what I know about the process of growing some creepy crawly critters to feed your flock and, if you dare, feed yourself!!

That's right!  Mealworms are safe for human consumption!!  

But this post isn't about how to cook mealworms, although I do think they would be delicious pan fried with garlic butter and green onions...sprinkled with parsley.  I'm writing this to show you how to grow mealworms for your birds and reptiles.  You can even feed mealworms to wild birds.  In the dark days of winter temperatures and cold, I am sure wild birds would very much enjoy some fresh mealworms.

What you need

There are a few essentials that you will need for growing mealworms.

- containers to "contain" the critters

- bedding, which is also their food

- a water source which will just be a piece of veg

- mealworms or darkling beetles, the name of the adult stage of mealworms, breeding stock

- a cardboard egg carton, optional

That is all you need to get started.  Easy peasy.

Mealworm beetles eating a slice of green apple.

Container

For containers, I really like the wide three drawer set made by Sterilite.  You can fine them at Walmart for under $20 in Canada.  They are also on Amazon, if you are so inclined.  

Some people cut out the bottom of the top drawer and glue in a piece of plastic window screening.  This would be the beetle drawer.  The idea is that the beetles lay the eggs at the bottom of the drawer and the eggs will fall through to the next drawer.  The drawer they fall into would have bran in it and a piece of veg for moisture for when the eggs hatch.  I have not tried this, yet, but I intend to experiment.  

You can use any plastic container, really.  Or glass, like an old aquarium (you would just keep it like a colony, and not separate beetles, pupae and mealworms but you would loose many to them eating each other.)  You can buy plastic shoe boxes at dollar stores for very inexpensive.  Please remember to leave off the lids or cut MANY air holes.  

We use the drawer system because it is tidy and much less likely that it is going to get knocked over in my house.  I keep my beetles in one drawer and every week or two I sift them out and put them in a new drawer.  The bran left behind is full of eggs that will soon hatch and start to grow.  All the worms in that drawer should end up being about the same size and age.  

Once I figure they are big enough, I feed out a portion of the worms to my chickens.  The next drawer of growing mealworms should only be a week or two behind this drawer...and another drawer after this one...and so on.  I just figure out how many days I need to feed out of each drawer and roughly feed out that portion of  mealworms to my chickens and ducks each day.

Bedding

The mealworm bedding is also their food source so you want your choice to also have some nutrition.  Chicken feed is a good choice because there is all the nutrition needed for your laying hens.  I have not use it but I think I might try the power at the bottom of the chicken feed bags as an additive to the bedding.  

Oat meal is used often but I find it molds easily.  Mold can kill your mealworms.  If you find any mold, remove it immediately!!  

I like wheat bran the most.  It is easy to use and easy to sift when it's needed.  It has yet to mold in my system.  You can purchase at some farm stores and at bulk food stores.  Whatever bedding you use, make sure that it doesn't contain chemicals that may harm your mealworms.  Some feeds may contain products like diatomaceous earth which will kill your mealworms and beetles. 

You may choose to bake your bedding material to kill any possible OTHER insect larva or eggs hiding in it.  Spread the bran on a cooking sheet and bake in the oven at 200* for 20 minutes or so.  I don't know if you want to bake chicken feed or not.  Your call.  

Just recently I found out that mealworms love rabbit manure for bedding and food!  I'm going to try it!

Water

Your beetles and mealworms are going to need a source of water.  They will not do well with a bowl of water.  Easiest, is to just add a piece of vegetable.  My favourite water source is a chunk of carrot.  Carrot won't mold easily like other vegetables nor does it sweat moisture leaving you with soggy bedding that can mold.  Pieces of potato is a widely used option but I don't like it.  It turns grey and I want to throw it out but there are always mealworms in it.  Carrots look better and that's important to me, I guess.  

Some vegetables harbour insects like fruit fly eggs!!  You do not want to encourage fruit flies to your farm.  They are harmless but annoying.  Mealworms love bananas but only feed as much as they are going to eat in a few hours.

If your bedding molds, you need to pull out the molding bits.  Vegetable and bedding.  It can kill your mealworms.

Also, I killed a whole drawer of mealworms once by feeding them lettuce from the store.  It was not organic.  Something was on that lettuce that was simply a poison for the mealworms.  Even BT which is used in organic veg production and used to kill worms will probably not be very good for your mealworm populations.

Mealworm or Darkling Beetles

You will need breeding stock!!  You can usually purchase mealworms at any store specializing in pet food.  They come in containers of 100.  You can start with one container and have oodles of mealworms in 4-6 months.  Or, buy 3-5 containers and jump into the deep end with me.  

If you really want a jumpstart on your mealworm farm, you can maybe find beetles for sale on a local buy and sell. 

Cardboard Egg Carton

This one stumped you, right?  The egg carton is to make a bit of cover and hiding place for the beetles.  They like the dark so taking the bottom of the carton and placing it upside down in your beetle drawer gives them some dark places to hide.  It's not 100% necessary, but it makes for a more natural environment.  

Before you add the egg carton, put it in a bag and into the microwave.  Add a mug of water to the microwave and then nuke the egg carton and water for 1-2 minutes.  The plan is to kill any possible insect eggs that may be on the carton.  Once done, put the cardboard egg carton in with the beetles.  

How to put it together

Once you have your drawer system or container, put about an inch (2.5 cm) of bran at the bottom of one drawer.  Add your mealworms, or beetles, and an inch piece of carrot.  Close the drawer and keep in a warm spot in your home.  Mine are in the coldest spot in my home and are doing well but warm is better for growth.  

Check them every two days.  

Add more carrots when they've eaten all that is there or when it looks dry and hard.  

Soon, your mealworms will begin to pupae.  The mealworms will eat the pupae if they don't have access to a good water source.  Feel free to remove the pupae into another drawer.  The pupae need humidity so feel free to put a piece of carrot into the pupae drawer but no bedding.  Pupae neither eat nor do they drink.  The carrot is only for humidity. 

Check the pupae drawer when checking on your mealworms.  Once they begin to shed the pupae stage and become adults/beetles, you will need to move the beetles to their own drawer.  Add 1/2 an inch of bedding, the beetles, the bottom of a cardboard egg carton (upside down), and a piece of carrot to the beetle drawer.  Take care of the beetle drawer like you do the mealworm drawers.

Once every week or two, you need to sift the beetles out of the bran in their drawer.  The bran will be full of eggs and even a few little mealworms.  Put the beetles into a new drawer that is prepared like mentioned earlier with 1/2 an inch of bran, bottom of a cardboard egg carton (do not use the same egg carton) and a piece of carrot.  

The drawer you just took the beetles out of, flatten the bran out and add two or three 1/4 inch pieces of carrot to this drawer.  Add the egg carton that was in with the beetles...it probably has eggs on it and you want those eggs to hatch with the bran eggs.  The worms that hatch out will enjoy the egg carton, too.  Check it every other day.  Add more carrot when the old pieces are eaten or hard and dry.

A beetle only lives for 2-3 months so you need to plan for new adults almost as soon as you get your first adult beetles.  Mealworms take 3 months to mature and pupae and another couple of weeks before they become adults and will start breeding.  

So...the first and maybe second egg filled drawers you sift your adult beetles from, you will not harvest any mealworms.  Those mealworms will become your new breeding stock.  You will grow them to pupae and then to adult beetles to start the process again.  

When the mealworm drawers begin to look less like bran and more like powder, you may need to remove some of the powder and add more bran.  Sift the powder through a very fine sieve and toss any mealworms back into the drawer.  Add fresh bran to the drawer.

Mealworms!!

More info...

Mealworms poop.  Insect poop is called frass.  The bedding will begin to look like very tiny pellets or powder, like I had just mentioned.  This is mealworm manure.  It is a great fertilizer for your house plants or garden.  Fras can also be an allergen so wear a mask when messing around with the drawers or pouring into containers. 

I have never written the word drawer as much as I did when writing this post!  Wow!

This is not a fast food production for you chickens.  It takes time.  Lots of time to get to where you have a bunch of mealworms at all times to feed your chickens.  But it's only a few minutes every other day or so. Then you will have a nutritious protein source for your chickens, right in your own home.

If you are local to me, I have mealworms for sale or trade.  You can either start your own farm and grow your own mealworms or to feed your chickens. Feel free to contact me.

Mealworms Facts

• darkling beetles reach maturity within a few days of emerging from their pupae
• They live for only 2-3 months 
• A female can lay hundreds of eggs in her life
• Eggs take 4-19 days to hatch
• New hatched mealworms are white and very small
• The mealworms will shed it’s exoskeleton up to 20 times while its growing
• It continues to grow for about 3 months and will grow to about 1 to 1 1/4 inches long
• Pupae don’t move much nor do they eat
• After 6-18 days pupae will shed their form and become adults…Darkling Beetles
• You can refrigerate your mealworms.  They slow down and basically hibernate but they need to be warmed up to room temperature and fed about once a week.