Mealworms are an excellent source of protein for fish, birds, turtles, small mammals, scorpions, large insectivorous spiders, centipedes, praying mantises and even humans. They also are used as fishing bait and in science experiments by schoolchildren. With all these potential markets, learning how to raise mealworms for profit may be the business for which you are looking. It does, however, take about three months to get started, and requires preparation and maintenance to prosper and avoid excess odour.
Purchase mealworms from a mail-order company or a pet store. Get at least 100 large mealworms to begin with, or up to 1,000 if space permits and you have additional containers.
Set up a clear plastic storage container that is at least six inches deep, and between 17 and 24 inches long. A clear container allows you to keep track of how much waste or frass has accumulated so you can clean your mealworms before they start to smell. Drill holes in the plastic lid to prevent condensation from developing, and to keep out any spiders, birds, mice or rats looking for a meal.
Fill the plastic container about two inches deep with a mixture of 10 parts oat or wheat kernels to 10 parts rolled oats flour; add one part powdered milk and one part brewer's yeast. Do not substitute instant oatmeal as it makes it difficult to sift out the worms later.
Place a few scraps of cloth in the grain to prevent it from becoming packed too tightly for the worms to breathe and move. This is both bedding and food for the mealworms and beetles.
Place your mealworms or beetles in the container and cover it. Place the container in an area that is relatively dark (no direct sunlight), and that has a temperature between 22.2 and 27.2 degrees Celsius. Temperatures below 16.7 degrees Celsius hamper reproduction, which will slow your business and lower profits. Use a reptile heater if necessary to maintain the proper temperature.
Add small pieces of cabbage, slices of potatoes or apples, or kale leaves every two or three days. Placing them on a plastic lid makes them easy to remove when you are changing the food or bedding. Lightly spray a small piece of burlap with water and place it in the container to help keep the environment moist. Too much moisture creates mould.
Regularly clean out the dead mealworms and beetles , along with old food. Sift the grain mixture through a wire mesh basket to remove the frass, and separate the worms from the beetles. Do not throw out any eggs. Another way to separate the mealworms from the beetles is to place several sheets of paper towel or newspaper in the container. The mealworms crawl between the layers to pupate, and you can easily collect them. Wash the container and add fresh grain mixture two or three times a year.
Separate the beetles and mealworms as necessary to avoid overcrowding. Place the beetles in the second clear plastic storage container after you have prepared it in the same manner as the first container. Follow the steps for adding feed and moisture.
Store the collected mealworms in a covered container in the refrigerator until you sell them. Make sure the container has air holes. The refrigeration slows down the morphing process. Mealworms left in the container eventually turn into beetles, which lay eggs that hatch and become mealworms, thus replenishing your supply.
Adult beetles make your colony grow faster since you do not have to wait for the mealworms to morph and reproduce, but they are more expensive. For every 20 beetles, you should get 350 adult mealworms in about 200 days. Beetles die after laying eggs. The frass, or waste, from the mealworms and beetles makes an excellent fertiliser for plants and flowers.
Avoid purchasing "giant" mealworms as they may have been treated with an insect growth hormone that slows the morphing process, and makes them sterile if they do morph into beetles. Avoid using a wooden container to raise mealworms as they may climb up and out if the sides are rough enough.