Enhancing the nutritional composition of feeder insects with dusting and gut-loading

Everyone knows you are what you eat! But did you know, or realized, that the nutritional value of feeder insects depends a lot on what you feed them? Dusting and gut-loading of feeder insects is a very popular topic in reptile husbandry. But it is not much talked about when feeding bugs.

Of course, you want to provide the best food for your bugs. However, it is essential to know what good quality food is, which food you should choose and how you may enhance the food. And that is particularly the case with feeder insects. If you do not keep good care for your feeder insects, they make low-quality food. But even then, you could still make crickets, cockroaches and locusts better in quality. Let’s discuss what dusting and gut-loading are and why you may (or may not) do it to enhance your nutrition of feeder insects.

A group of super worms are eating a potato while in their habitat of oats.

What are dusting and gut-loading?

First of all, do you know what dusting and gut-loading are? Both are methods to enhance the nutritional composition and improve the total quality of live feeder insects as a food source.

Dusting is the use of rich nutrient powder product and dusts it over your feeder insects. It is a complete nutrient resource that is available at many pet stores. There is a variety of different products and even more brands that can be used, but most are focused on adding calcium. Dusting is typically done just before you are going to feed live insects.

Gut-loading, on the other hand, is the process where feeder insects are raised and fed high nutritious food to boost the nutritional composition. When you feed insects certain nutrients, they pass those nutrients to the animal for which the prey is intended. Gut-loading can be done through the whole life of feeder insects at least as long the food does not kill the insects but is often done just before feeding them. Gut-loading is accomplished by providing particular fruits, vegetables, cereals or complete manufactured insect diets. Of the last category, there are many commercial products available specifically for gut-loading.

There are high quality commercial gut-loading products available to boost the nutritional composition of feeder insects, like InsectFuel from Arcadia Earth Pro (Photo by Arcadia Reptile)

Why dusting and gut-loading may be necessary?

But why should you need to enhance the feeder insects? Are they not nutritious by themselves? Well, the answer is yes and no. Feeder insects contain nutrients by themselves by the food it had before. However, when you don’t feed your live insects and doesn’t feed them proper quality food, they also lack the good nutrients for the animal you are going to feed.

With that said, some feeder insects have some nutritional characteristics that make them less or more suitable but can be enhanced by dusting them with nutrients or providing them food with nutrients that are valuable for the animal that feeds on the insects. Have a look at the table below for a nutritional comparison of different feeder insects.

Species Moisture (%)Protein (%)Fat (%)Ash (%)Fibre (%)Calcium (mg/kg)Phosphorus (mg/kg)Ca:P Ratio
Locusts62.122.67.72.1N.D.957311:8
Dubia roaches65.623.47.21.22.980026001:3
Crickets77.115.43.31.12.227525201:9
Super worms57.919.717.71.02.717723701:13
Mealworms61.918.713.40.92.516929501:17
Waxworms58.514.124.90.63.424319501:8
Earthworms83.610.51.60.60.144415901:3.5
Fruitflies69.121.05.93.12.252640801:8
Source: Finke, M.D., 2002, Complete Nutrient Composition of Commercially Raised Invertebrates Used as Food for Insectivores, Zoo Biology 21:269-285 and dubiaroaches.com

So as you can see, the nutrients of feeder insects, if not enhanced or boosted, can be quite different from each other. Also, the calcium-phosphorus ratio is one that particularly is interesting because many animals need a ratio of 1:1 up to 2:1 (which mean live insects often lack calcium).

Secondly, the nutritional composition of captive-bred insects is dependent on its diet. Most (commercial) feeder insects breeders feed their insects with products to increase reproduction productivity and growth, to get the most outcome to sell, but don’t have much focus on the nutritional composition of the food they breed. That is why boosting the nutritional composition is, in many cases, necessary to do.

What are the pitfalls of enhancing the nutritional composition?

On the other hand, there are some pitfalls if you enhance feeder insects with a lack of knowledge about nutrition or about products available to do so. Therefore, let’s have a closer look at those pitfalls.

Pitfalls of enhancing nutritional composition of feeder insects include:

  • A lack of knowledge of animal (and human) nutrition: Some keepers have a good understanding of nutrition and adequately enhance the insect food source, but unfortunately, some do not have enough knowledge. Some retailers or even (private) breeders have little knowledge about nutrition for live insects.
  • Commercially available products ineffectiveness: Several studies are showing that commercially available products to gut-load insects are very inconsistent. Some are of high quality and work very well, but many — unfortunately — do not contain the nutrients as promised. And for some products, the nutrients are in such a form that they are not able to eat or absorb the nutrients.
  • Gut-load absorption and retaining time is relatively short: When you feed insects, the food remains in the body for a relatively short time. So, the food that you wish to contribute to the nutritional quality of the feeder insects only stays in the body for a short period. That means that you’ll need to feed these products continuously and prior to feeding. When you do not feed the insect for a day, the insect is already much less nutritious. Some nutrients are also poorly absorbed or not absorbed at all. Think of calcium. Many insects can’t use calcium and are therefore unable to absorb calcium from their food. It is the same with some minerals and vitamins. If you need high calcium insects, you should dust your insects prior to feeding, or you should choose insects that are high in calcium (such as black soldier fly larvae — also called calcium worms or calci-worms).
  • Dusting inconsistency: Besides the substantial difference in quality between different dusting powders, to apply dusting powder consistent is rather tricky, maybe almost impossible. It is difficult to measure the amount of dust necessary for all the different sizes of insects, and it depends how well it sticks, how fast the insects (or the animal that is fed) gets the dust off and how large the total surface is of the insect. With dusting, it isn’t easy to know if you are delivering nutrients too much or not enough. At least it is important to dust your insects just before you feed them.

What is the best solution for enhancing feeder insects?

If you ask a group of insect-eating animal owners, breeders and retailers of insect food about how to boost the nutrition to their animals, you will find many different answers and methods. And it is difficult to point out one ultimate practice to give the best live feeder insects, also because it is highly dependent on the needs of the species.

For example, if you feed tarantulas, you can skip the dusting. Tarantulas do not have bones as reptiles do, and too much calcium is detrimental or even deadly to them.

With dubia roaches, when feeding to much protein, they will store it as uric acid in their bodies. When feeding dubia roaches with high levels of uric acids is unhealthy and harmful for the animal you feed it to. With reptiles, for example, it is known to cause gout, which ultimately can lead to premature death.

In my experience, in the case of feeding bugs, it is the combination of methods that is best you can go for. At its base, you need to feed your live insects proper and high-quality food to keep them alive and healthy. Add to that the best quality gut-loading, so you have nutritious live insects. For animals that need higher levels of calcium, dust your insects prior to feeding.

Insects which should be gut-loaded are:

  • Dubia roaches
  • Crickets
  • Locusts
  • Mealworms
  • Morioworms

A combination of feeding different insects, all well-nourished, is also a good feeding strategy. Dubia roaches have good calcium to phosphorous ratio. Locusts are quality good and large prey. Wax moths and super worms are higher in fat. Take advantage of those qualities of different insects after researching the nutritional needs of your animal, and always adjust the diet and enhancements of feeder insects to the animal you wish to feed.

If you want to know more about the care of this important food source, you should read the page about the general care of feeder insects.

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