General Guide to Raising Beetle Larvae
Introduction
Introduction
Coleoptera is an exciting insect order to raise. I am intrigued by their metamorphosis. I have been keeping beetles for several months now, and I thoroughly enjoy the experience.
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All Beetles start from eggs, then go to larvae, pupae, and eventually adults. The odd thing is, the larvae stage has three steps: the L1 instar Larvae, the L2 instar, and the third and final stage, L3 Instar.
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If you haven't heard these terms before, they mean how many times the insect has shed their skin. In this instance, the three stages mean the larvae has shed three times to reach its final stage. Then it will become a pupae. The time in which the larvae becomes a pupae varies with different beetle species. Some beetles take longer to become a pupae, some don't take much time at all. We will go through it later on this page, but it is mainly general grub raising we will be covering.
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What do you need to raise Beetle Larvae?
In terms if Beetle grubs, we are talking about your exotic beetles. Forget about ladybirds. They have similar stages to the bigger variety of beetles, but they do not require everything that the exotic varieties do. This is a vital list of what is needed to raise beetle grubs.
1. A large tub or medium-sized tub-
It may be obvious that you need a tub to place your beetle larvae in. However, it is not always obvious what size to place them in. This is species and size-dependent. Usually, the rule is, small species of beetle grubs, such as the Sun Beetles, can be kept in small to medium-sized plastic tubs. They are smaller grubs even when they grow to instar L3. They develop at a quicker rate than bigger breeds of beetles and can become an adult within a few months. However, when it comes to my bigger Elephant Beetles( Megsoma Elephas), I keep them in a giant plastic storage container. These grubs are massive and are known to reach an incredible weight before going into the pupae stage. I also have six of them in there, so the extra space was needed.
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No matter what size container you have, you must ensure that you drill small to medium-sized holes in the side( they burrow underground, so this is the most crucial spot) and at the top. Too little ventilation will suffocate them, but too much will make them cold. They need an average temperature of 20 degrees Celsius to 24 degrees Celsius. We will talk more about temperature and such later on. ​
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2. Rotted Wood( Oak preferably) and leaves-
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Beetle Grubs feed on rotting wood or leaves. Some prefer just leaves, some like both added to the mix. Anything rotten is a good source of food, except conifer and Pine. Conifer and Pine are toxic to beetle Larvae and will cause death if used as a source of food. The best way to acquire rotten wood is to go around to your local park and search for some. Or, if you can't identify different types of rotten wood, you can purchase some. Sterilize all rotten wood and leaves found from outside with boiling water to ensure any harmful bacteria or fungi does not make their way into the soil, therefore causing great harm, and even death to your larvae. Grind wood and leaves together to create a fine powder. Then mix into the Flake Soil.
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3. Flake Soil-
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It is incredibly crucial that you use the correct substrate for your beetle Larvae. If you give them incorrect soil then they will become diseased and die. I made this mistake with some of my Japanese Rhino Beetle Larvae. Being new to the Coleoptera game, I had done some research, and many sources had said normal coco soil was fine to use. However, I found that my Japense Rhino Beetle Larvae had turned a grotesque greyish colour and were slowly, painfully rotting. Horrified, I moved them from the pot. I did more digging in a Breeding beetles book I had purchased. It turned out, that Rhino Beetles and Stag Beetles require Flake Soil. So many beetle breeders say that Sun Beetles do not, but it is generally better than normal compost. It has a lot more minerals for the larvae arising from the soil. Plus, compost can contain harmful chemicals and pesticides and will kill your larvae. The only downfall is cost.
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The flake soil should be mixed with the rotten leaves and wood. It is important that you don't just leave the food at the top. Remember, larvae burrow, and will move around the tub. I suggest that you layer your pot. One layer is food, the next layer soil, then food, and so on.
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Ensure the flake soil is pest free as in the past I have purchased some and it consisted of lots of gnats which will compete for food alongside your beetles. You can get pest tape or can even use breathable medical tape to cover the enclosure. This will prevent any pests such as white mites, red mites and even nasty gnats from accessing your enclosure, and causing damage to your beetle or larvae. Just remember to use breathable tape with some minute airholes in, otherwise you will limit beetles and beetle larvae air supply.
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4. Water sprayer- A water sprayer is needed to spray the enclosure every few days. The soil must be kept soft and slightly damp to prevent dehydration. On the flip side, over spraying can cause an overgrowth of mold, therefore death. The general rule to make good soil consistency, is that you should be able to form it into a small ball with your hands.
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5. Beetle protein supplement( Optional)- Many breeders use Beetle protein supplements to help their larvae grow. It is highly recommended that you use this within the later stages of larval development. You can purchase the product Beetle Boost from eBay, or the Spider Shop. It is basically shrimp ground up but the stuff is great quality and will lend a great hand in helping your grubs grow into a healthy beetle. This could be the difference between your beetle becoming a smaller (minor beetle) or a large (major beetle). Of course, do not add too much as this will attract mold. It is suggested that you add this monthly over the course of your beetle larvae's development.
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6. Scales- For weighing your larvae weekly.
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How do I raise my Beetle Larvae?
It is a reasonably straightforward process to raise beetle larvae. However, some elements can be tricky. For example, when I first started growing mine, I was unsure how much wood to put in, but once you get past that, it's pretty simple.
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It does also depend on the species of beetle you are raising. Small to medium beetle larvae such as the Sun Beetles, Flower and Jewel Beetles are easy to rear, breed and grow.
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The Sun Beetles take an average of 3 to 5 months to become a complete beetle, whereas stag beetles can take from anywhere between 3 to 7 years. However, this does all depend on temperature. Temperature can play a massive part in speeding up or slowing down metamorphosis. The warmer it is, the less time it will take for the larvae to develop; the colder it is, the longer it will take.
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The most important factors when caring for your larvae are...
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1. Temperature- We have already discussed this a little bit, but it's such an important factor when taking care of larvae. No heat mat should be used. A heat mat will cause the soil to dry up and the larvae to shrivel. Keep the larvae in a room that is warm but not boiling. Avoid keeping the enclosure near the window as drafts will cause larvae to be too cold. Sunlight will disturb the larvae. Keep the container with larvae in somewhere dark to avoid stress.
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2. Humidity- Humidity is fairly crucial with larvae. You must make sure the soil is not too damp, but soft. If you do not spray the soil often it will dry up and cause your larvae to dehydrate. Even as adults the enclosure should be sprayed for dehydration and to prevent beetles spiracles(Respiratory opening) to dry up.
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3. Substrate and Food- Why have I put these two together? Well, you mix the food in with the substrate. Preferably, the oak leaves and shredded wood should make up most of the substrate. This way the larvae will be able to reach their food. If you were to place the wood and leaves just on the surface, they won't eat it, as they spend most of their time tunnelling under the soil.
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4. Weigh- Many people do not think weighing larvae is important. However, like with all animals, it is crucial to keep an eye on their weight to ensure that they are eating and are healthy. If they are gaining weight and producing faeces, you can tell an animal is eating. Also, weight can help you indicate when Larvae are preparing for pupae stage. Some types of beetle larvae can go up to 100grams plus before going into a pupal stage! You can also tell when pupal stage is approaching by the yellow shading they turn beforehand.
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5. Check occasionally, but not daily- This one is important. To ensure proper larval growth, you must avoid picking the larvae up too much as this can cause a lot of stress. But, you also must check your larvae for illnesses and injuries. We will go through this on another page.
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6. Half Clean- Beetle tubs must be cleaned every so often. The amount of time you clean this varies on the size of larvae or the quantity of you have in each tub. For example, I have six giant L3 Larvae in one huge tub. I take clumps of soil out every few weeks and replace them with new flake soil. Why? Well, larvae, especially large ones excrete a lot, and if left unclean they will start to go off their food. Then, they will lose weight and can shrivel up. Once they reach that state it is hard to get them to feed again. It is also a good way to keep their enclosure fungi free.
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I say 'Half Clean' in the title because a total clean is never recommended. Yes, it seems odd, why not clean the entire thing? Well, here is why; if you were to replace old soil with completely new stuff, the larvae will not be used to the new bacteria in the soil. This can upset their gut and halt their growth.
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Megsoma Elephas( Elephant Beetle). Currently weights 84 grams( The size of Luna my White Tree Frog!)
Sources for both photos below.