MEALWORM CARE SHEET

This Care Sheet concerns itself with the larvae of the darkling Beetle (Tenebrio molitor). Whilst they can be a source of emergency food for your Bearded Dragon if your cricket supplier lets you down at the last moment, they are not suitable as a mainstay of a Beardie's diet because they have such a thick skin and so little digestible material inside. A Bearded Dragon that is fed a diet high in mealworms runs a significant risk of becoming impacted; only the white freshly moulted larvae should ever be given. For young dragons, small crickets are the very best choice there is, while adults do much better on superworms than they even could on mealworms. They make a great food for wild birds however and if they are looked after properly, they are odorless, clean and pretty easy to maintain, raise and breed.

INTRODUCTION

Once upon a time there were 'mealworms'; that's all, no zophobas, no king mealworms, just plain old mealworms, the larvae of the darkling beetle- a commercial pest. You could buy them at the local hardware store in England- I used to feed them to my slow-worms (Anguis fragilis).

LIFE CYCLE

In the wild, the typical life cycle of the Darkling Beetle (ova - larva - pupa - imago) takes 12 months, although it can vary from 4 months to 24 months depending on the climate. Each female beetle lays between 500 and 1000 eggs in the bran or flour they infest. Don't try looking for them- they are sticky when they're laid and immediately get covered in flour etc and look just like the rest of the debris at the bottom of the container.

After about a week, the eggs will hatch, but the larvae are so small that the first indication you will have is if the flakes of bran move 'by themselves' as the minute larvae burrow around in the container. The larva will molt its skin several times as it grows- these freshly molted 'white' larvae are nice and soft and ideal food- even for baby Dragons. In anything from 3 months to 7 months they will reach full size and pupate.

Normally, the pupal stage lasts 2 - 3 weeks and the beetle then emerges- changing from a beige to red; brown and eventually back after about 2 days. The freshly emerged beetles are also soft and again make good food for Dragons- I wouldn't recommend the black adults - they are too hard.

FOOD/ MEDIUM

You can use any kind of cereal bran (wheat, corn, oat etc). I buy mine either from the local farm feed store or get wheat bran straight off the shelves of the local supermarket- but it's cheaper from the feed store!
You can make this medium even healthier for your mealworms by adding some alfalfa flakes, baby cereal or even poultry mash (make sure it has no steroids or other hormones in it). For your larvae and especially for the beetles, you should also include raw apple, potato or carrot.
Mealworms are able to absorb water from the air, so unless you live in a very dry climate or keep your mealworms in a dry room, there is no need to mist them- if you do, be careful not to overdo it or the bran will turn moldy very quickly.

GETTING STARTED

Mealworms are available by mail order or from your local 'herp' pet store. Some regular pet stores also sell them as bird food. Check that they are healthy- nice and round and with no dark brown dead and smelly ones. A lot of pet stores just stick them in a 'fridge and don't bother to look after them- not a good source for your breeding colony.

Once you have bought yourself some healthy mealworms- I would suggest at least 100- you are ready to set up your 'colony'. I use the 1 gallon ice cream tubs, although you can use any flat broad container. The advantage of the ice cream tub is that you can make breathing holes in it that are the right size and easy to do.

Get a Diaper Pin or similar sharp instrument (not too fat or flour moths will get their bums through the holes and will spoil your culture) and riddle the lid with holes about ¼" apart. Then (and this is my secret for success) do the same thing to the top of the tub itself- not the bottom or the dust and poop will fall out and spoil your nice sideboard (what do you mean, you're not keeping them in the living room?). Mealworms hate to be too humid. They like moisture, but just like crickets and most captive bred insects, they don't like to live in a swamp.

Place 2 to 3 inches of bran in the bottom of the container (you can sterilize it in the oven beforehand at 200º Fahrenheit if you want- it will kill grain mites and flour moth eggs or larvae) and cover this with about 4 layers of newspaper or burlap (newspaper is cheaper). If you mist your mealworms, be sure to only mist the paper or burlap to help prevent could.

And there you have it! A mealworm colony. Change the fruit/veg if it dries up or shows signs of could and keep the bran topped up and you mealworms will live very happily thank-you. Some authorities say that you should keep the colony where it can receive normal daylight/nighttime exposure- I haven't found this to be particularly necessary. Mine live in the basement.

TEMPERATURE

No lower than 40ºF and no higher than 80ºF is the recommendation, but in a granary, temperatures (especially in the hot South) can reach 90ºF or 100ºF . Room temperature is fine unless you're in a hurry, in which case anything up to 80ºF is fine.

MAINTENANCE

The mealworms 'poop' is a powdery waste that collects in the bottom of the container. From time to time it is a good idea to sift this out and just keep the fresh bran and mealworms. HOWEVER, if you also have beetles in the container, this 'poop' will probably also have some eggs in it, so you will need to keep it for months just to be sure you're not throwing the babies out with the bathwater.

TO MAKE A NEW COLONY

You can remove larvae, pupae or beetles at any time and start a new container.

REFRIGERATION

You can refrigerate your mealworms (42º - 56ºF) but I personally don't recommend it. They're easy enough to breed, why bother keeping them on store. If you have too many, you may well be able to sell them to the local pet store!.

DISEASE

When you put your store bought mealworms into their new home for the first time, DON'T include any of the very dark brown dead ones, or any that look as if they might be going that way. Choose only the really healthy wriggly ones. There is a particular kind of disease (probably a virus) that affects mealworms, and it can decimate the entire colony and make it stink too. A healthy colony of mealworms smells like- well, bran! If you hate to pick them up, try tipping them out onto a metal tray (a big baking tray works well) and as they spread out, you can pick them up with tweezer. That way you only transfer healthy mealworms to the nice clean environment you have prepared for them, not dead ones, and not infected food.

NUTRITIONAL INFORMATION

This Care Sheet and in particular this information on nutrition is taken from an excellent article in REPTILES Magazine (July 1996) by Nancy Nehring.
Mealworms consist of the following:- Moisture 57%, Protein 24%, Carbohydrates 2.8%, Fibre 2.3%, Calcium .02% (you can increase that by supplementing the bran with a high calcium baby food) . So you can see that they are quite rich- I would only use then as treats, only when white and soft and at other times, only if I had run out of crickets. Don't forget that the evidence is beginning to show that adult Bearded Dragons eat a lot more vegetation and a lot less 'bugs' than youngsters- with the amount of Protein in mealworms, you run the risk of giving your BD's an unhealthy lifestyle if you rely on mealworms too heavily.

And as usual, if you find out anything useful- LET ME KNOW!

Good luck! Bill Mears