T. molitor AKA "Golden Mealworms"
T. molitor, AKA “Golden Mealworms” are a very popular feeder for reptiles. They, along with crickets, are usually available at pet stores and sold as feeders. They are often also sold as bait for fishing. They are very inexpensive and can be used somewhat regularly as feeders. They are more of a treat than a “staple” feeder because they can be rather fatty and have a lot of chitin (basically a hard shell.) This chitin can be difficult for chameleons to digest. Because of this, feeding too many can sometimes cause impaction in the chameleon. This is a blockage of the intestines which can become fatal if it is not treated. Mealworms grow to about 1 inch long and come in all sizes. Sometimes the smallest size, about ¼ inch, are referred to as “minimealworms” but should not be confused with A. diaperinus or T. obscurus.
Appearance
These worms are a yellow or golden color. They can get to about 1 inch long. They have 4 life stages. They begin life as eggs which then hatch into larvae (singular larva) or the “worms.” Once they reach about 1 inch in length they are ready to pupate into pupae (singular pupa) which are sometimes described as looking like aliens. They then turn into the adult stage of their life in which they are beetles. The beetles are about 3/4 of an inch long, are very oval, and black or dark brown.
Housing
They require a tub approx 3-4 inches deep with a substrate at least 1-2 inches deep. A substrate of oats or bran will sustain them, but it is not best for the animals that will be eating them. A better substrate would be a finely ground mixture of oats, bran, bee pollen, spirulina, brewers or nutritional yeast, ground beans, etc. They should be given a water source at least once a week. Carrots, potatoes, apples, leafy greens, and other veggies work well for this. Do not allow the substrate to get moldy. These worms can be kept in the fridge to prevent them from growing however, they should be taken out of the fridge at least once a week for a couple of hours to allow them to eat and drink water. They should also be allowed to eat and drink water for several hours before being fed to pets.
Breeding
The larvae will turn into pupae without prompting, unlike superworms. They need to be kept warm (not in the fridge) for this to happen. The pupae will turn into beetles on their own after a week or two. The beetles will breed on their own and lay eggs in the substrate. Beetles appreciate a bit of space to climb on so egg crates or paper towel rolls should be used in the enclosure. Using a fine substrate allows for the larvae to be easily sifted with mesh to collect and transfer the larvae.
As Feeders
Mealworms can be used fairly regularly as feeders but shouldn’t be used too often. They are a fairly fatty feeder and have a lot of chitin (hard shell.) This chitin makes it difficult for chameleons to digest and it can cause impaction issues when feed too often. Impaction can become fatal if it is not treated. Mealworms shouldn’t make up more than about 10% of the chameleon’s diet.
