Breeding mealworms

Mealworms are perhaps the easiest of the live foods to culture yourself. The only real difficulty is avoiding mites, which is relatively easy if you take the correct precautions. Mealworms can be used as a staple food for many species, and are popular with leopard gecko keepers.

What you need

You will need the following:

  1. A suitable container (I recomend an ice cream tub for smaller cultures, and a contico type container for larger cultures).
  2. A few egg crates or even toilet roll tubes (go ask your butcher for an old egg crate, they just chuck them away).
  3. A piece of stale bread.
  4. The culture medium (food) which will be discussed in due course.
  5. A tub of shop bought mealworms (only one is required, but you can buy more if you can cope with all the youngsters).
  6. Patience.

the culture medium

This is what the mealworms will live in and eat. Luckily for us mealworms will eat literally anything! Of course as you will be feeding these to your exotic pets you want to make sure they are healthy and nutritious. Don’t waste your money on expensive products designed to gutload your insects, you can make your own very easily.

What you use as a medium is really up to you, you just have to make sure it’s dry and they can live in it too. Because of this I suggest using a base of porridge oats (these absorb moisture well and provide a good medium for the mealworms to live on. To this I would add some very cheap dog biscuits (the cheaper the better because the cheaper ones have a higher grain content), plus anything you find around the house that you think could be nutritious. In the past I’ve added weetabix, ryvita, corn flakes, dried fruit. etc. To this mix add a sprinking of a vitamin powder such as nutrobal (if you don’t have any, just break open a multi vitamin tablet and sprinkle the powder over), and a sprinking of calcium powder (the powdery side of a cuttlefish bone is 99% calcium carbonate, so you can grate some of this off if you don’t have any powder).

Now you have the mix sorted you can add a layer about an inch thick into the container. Don’t make it any deeper, the babies always go to the bottom and I have heard of youngsters suffocating because of deep medium.

setting the culture up

Once you have the medium added to the tub, you can then add the egg crates. You don’t need many of them, just maybe two 2×2 pieces (by 2×2 I mean 2 of the little bump things), sat one on top of the other. All the meal beetles will live on here, as it gives them a place to group together for breeding. The stale bread acts as an egg laying site, so it should sit on top of the medium. Put it wherever you like, the beetles will find it. You don’t need to remove it as it can stay in there forever, however you might need to add a new one after a while as it is slowly eaten. You have everything in there now, so you just want to chuck the mealworms in there and let them get on with it.

If you want to speed things up, heat the culture to about 30c; this really isn’t necessary though if you can be patient.


This is where many cultures fail (I myself lost a good few due to too much moisture before I managed to get a solution) because when you havea lot of moisture you get mites. These mites are harmless, but they smell, eat all the food and can spread to your reptiles tank, so if you get mites you will have to destroy the culture (see the mites section below for information on what to do).

I have had success with two options when offering moisture. The first is drastic, butI have managed to have successful cultures where I’ve provided no moisture whatsoever. Don’t ask me how it works because I really don’t know. Productivity is down but they still produce a fair amount of mealworms. You cannot get mites this way, there is just no way you can reach the moisture levels needed for them to thrive.

Another method, which is the one I favour because it offers good productivity levels whilst keeping the risk of mites to the minimum, is to offer moisture once or twice a week. I usually offer this in the form of celery or carrot, which I chop up into sticks and place directly onto the medium. These are left there for a day (well, half a day, I put them in when I get up and take them out when I go to bed), and they offer moisture. All of the mealworms and beetles flock to them (mealworms seem to prefer carrot, whereas the beetles seem to prefer celery, but they aren’t fussy). Most of it will be consumed, but you will need to remove the remnants of the food to avoid moisture build up.

maintaining the culture

Once you’ve set it up, you will need to be patient as it will take a good few months before you actually start to see babies. Once you do start to see a healthy population of the size mealworms you require you can start to use them as and when you need. Make sure you don’t bleed the culture dry though.

Don’t forget to make sure there is always enough food available. How often you top this up will vary on culture size, temperature, etc

When you see the culture is thriving (this will take a few months) you may want to think about splitting it. Simply make up another tub with the medium and everything in as detailed earlier, then take half of your original culture and dump it in this new tub. Don’t forget to top up the culture medium in the first culture.

help! I’VE got mites!

Sometimes there’s nothing you can do about mites, it just happens. If mites happen to you I would recomend picking off about 20 beetles, putting them in a seperate DRY container with no moisture for a week (this will kill off any mites living on them). Your mite infested culture will need to be thrown away. You can use these beetles to start a new culture as mentioned earlier.