That Reptile Blog – Reptile, Amphibian and Exotic Pet Care and Information

The mealworm has long been valued by pet keepers, but medical researchers are now giving it some respect as well.  A recent (December, 2008) article in the journal Science reveals that antimicrobial peptides manufactured by the mealworm beetle destroy any bacteria that happen to survive the original onslaught launched by the beetle’s immune system.

This is important because bacteria and other microbes that are not killed by drugs or immune system defenses often evolve into resistant strains, which are then very difficult to control.  This is currently a very serious human health concern, especially as regards hospital-based micro-organisms.

It seems that insects are particularly effective at preventing the development of hard-to-kill microbes, and that most of the credit for this is due a unique group of chemicals known as antimicrobial peptides.  It is hoped that human medications modeled after these peptides may serve to limit the emergence of dangerous drug-resistant bacteria, fungi and other microbes.

Mealworms have a long history as important laboratory animals.  You can learn more by checking the forum at the following location:

http://tenebrionidae.net/forum/.

Please also see my article on the proper use of mealworms as a pet food: Making the Most of the Mealworm: some tips on enhancing the nutritional value of this pet trade staple
Image referenced from Wikipedia and originally posted by http://www.entomart.be/

Today I’d like to take a look at a much-maligned food insect that can, if used properly, be an important addition to your pets’ diets.

Mealworms (larvae)
A steady diet of mealworms (I refer here to the small mealworm, Tenebrio molitor, not the giant mealworm, Zophobus mario) is not recommended for any reptile or amphibian. These beetle larvae lack essential nutrients, the calcium: phosphorus ratio is not ideal and the exoskeleton is high in chitin. Mealworms also have quite strong jaws, and may injure debilitated or small reptiles and amphibians.

However, newly molted mealworms, which are white in color, are soft, have weak mouthparts and lower chitin levels. I have found them to be an excellent supplementary food for amphibians, tarantulas, scorpions and reptiles and fish.

Mealworms will shed most frequently when fed heavily and kept at 76-80 F. I house my colony in a mix of wheat bran, corn meal and powdered multi-grain baby food, with a bit of Tetramin Flake Fish Food added in, and provide banana skins for moisture.

Mealworm Pupa
Mealworm pupae are a fine food for turtles, newts, aquatic frogs and those lizards that accept non-living food items. They are low in chitin and likely have a different nutrient profile than either the larvae or adults.

Mealworm (Darkling) Beetles
Beetles, comprising the world’s largest animal family, figure prominently in the diets of most insectivorous reptiles and amphibians (based upon stomach content studies). I have long used darkling beetles (adult stage of the mealworm) as a food item, and prefer them over the larvae in most situations.

Beetles newly emerged from the pupae are softer than later-stage animals, and brown in color. To ensure a steady supply, I remove pupae as they form and place them into a bare container. In this way the beetles cannot burrow into the substrate, and are thus easier to harvest. Warm temperatures and a good diet (see above) will ensure a steady supply. Be sure to leave some beetles in the colony for breeding purposes.

You can learn more about the specifics of the mealworm’s life cycle at:
http://lawrencehallofscience.org/foss/fossweb/teachers/materials/plantanimal/tenebriobeetles.html

Image referenced from Wikipedia: http://en.wikipedia.org/wiki/Image:Mealworms_in_plastic_container_of_bran.jpg