How to Raise & Breed Mealworms

Mealworms are not actually worms but the larvae of mealworm beetles, called Tenebrio Molitor. They are part of the diet of different animals and provide high levels of crude protein, fat and potassium. Raising and breeding mealworms at home is easy and requires simple equipment. To start a new colony, buy mealworms at a pet store or online. If adult beetles are available, you won't have to wait for the larvae to grow and have eggs and new larvae sooner. How soon you'll produce mealworms depends on the temperature, humidity and food supply; the better the conditions, the faster they'll grow.

Things You'll Need

  • Drill or awl
  • Two large plastic containers with cover
  • Substrate, such as fine wheat bran, corn meal or chick starter
  • Adult beetles or mealworms
  • Half of a raw potato, kale or cabbage leaves
  • Clean rags
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Instructions

    • 1

      Drill or poke small holes in the container cover to keep other insects out. Beetles and larvae need air, but not light. Spread a layer of substrate on the bottom of the container.

    • 2

      Put the beetles or mealworms and half a potato, some kale or cabbage leaves in the container. Place the container in a warm place; an ideal temperature would be 77 degrees to 81 degrees Fahrenheit, but as low as 72 degrees is also fine. The mealworms will develop more slowly in colder temperatures, however.

    • 3

      Feed the mealworms and beetles fresh potato, kale or cabbage every few days. Other fruit and vegetables also add nutritious value. Food that has high water content, such as kiwi, adds moisture but also becomes moldy faster and should be replaced more often.

    • 4

      Remove dead larvae, shed exoskeletons and dried or moldy food. Keep the moisture level high, ideally 70 percent, but not too high or the substrate could become moldy.

    • 5

      Place some rags in the container when the beetles turn black and are fully grown. The beetles will use the cloth to lay eggs. Remove the cloth weekly to separate the eggs and prevent the beetles from eating them.

    • 6

      Place the rags in a new container, also lined with substrate. The eggs are too small to see and take about 12 days to hatch. The larvae burrow into the substrate, molt and become "mini" mealworms. Those can be picked and used for feeding.

    • 7

      Sift through the substrate to find the white mealworms that transformed out of the larvae about ten weeks after the eggs hatch. The mealworms still stay below the surface at this stage and are soft because the exoskeleton hasn't hardened yet. About three months after hatching, the larvae reach maximum size and come up to the surface. They turn into pupae and come out as young white beetles about 15 days later.

    • 8

      Move the beetles into the adults' container. Their exoskeleton gradually becomes harder and they turn darker, becoming fully grown and very dark in about five days. The beetles start laying eggs about ten days after they emerge from the pupae.