How to raise mealworms:

A single container 

Transparency: This guide was produced by Justin Meyer at Midwest Mealworms and contains various affiliate links and Youtube links which could contain ads.

Intended Audience

The intended audience for the starter setup are those who want to raise mealworms for up to 3 or 4 geckos.  You could utilize this option for multiple reptiles/mammals depending on the size (or number) of containers you choose to use.

Please read this all the way through before ordering your mealworms - there is some initial preparation you need to do.

Benefits

The primary benefit of a single container setup is the ease of maintenance and reduced time needed to care for the mealworms.  You won’t have to spend time separating beetles out of your trays or keeping track of the age of the mealworms.

Downsides

By having all stages of life in the same container (larva, pupa, and beetle), you will see cannibalism and likely will not achieve maximum colony production potential. However, by adhering to the following guidelines, you will still be able to achieve the desired result of raising and maintaining your own mealworm colony.

Understand the basic life stages of a mealworm

Adult:  The beetle stage. In this stage, the male and female beetles will party hard and lay eggs to produce the next generation of mealworms.

Eggs:  Too small to see with the naked eye; eggs are deposited on the bottom of trays, on substrate, or on anything that may be in the enclosure (egg cartons/cardboard are common additions).

Larvae:  The worm form of mealworms.  This is the desired stage for feeding your reptile.

Pupae:  A Larvae will transition to the Pupae stage in preparation for becoming an Adult.  Many people have described the pupae as “alien-like” because of their appearance.  Think of the Pupae stage like the chrysalis stage of a caterpillar.  

Fun fact:  Pupae actually have more protein than Larvae.  If you find yourself with an

abundance of Pupae, try feeding them to your reptile!

Mealworm Terms

Frass:  Insect poop.  For mealworms and beetles, it is a dry substance that feels similar to fine-grained sand.  It is a very beneficial soil amendment that can be used on indoor and outdoor plants.  For more detailed information and recommended application rates/amounts, visit https://midwestmealworms.com/frass

Here is a picture of frass:

Note of caution:  Frass gets into the air very easily and is known to create/trigger allergies. Take the appropriate precaution when completing maintenance on your frass by wearing a mask and eye protection.  More details below in “Sifting your Frass.”

Substrate: The material that your mealworms and beetles will live on/in.  The best option is wheat bran, additional options are discussed below.

Acquire the necessary tools

Container

A clear storage container that is at least 6 inches tall, lid is optional.  This 16 quart option (affiliate link) will comfortably fit 1000 mealworms and 250 beetles at the same time.

Substrate

Popular options include wheat bran, rolled oats, or oatmeal.  These can often be found at grocery stores or locations with specialty/organic options.  You’ll need one of these substrate options, and enough substrate to fill your container to 1 inch in height.  Remember to prepare your substrate before using it, see “Preparing for mealworms” below.  Regardless of where you obtain your substrate, ALWAYS prepare it before use to avoid mites.

Moisture sources

Mealworms and beetles need a moisture source to hydrate.  Readily available options include potatoes or carrots.  Have a potato, or a few carrots, half an apple, something that you can add to your container as soon as you place your mealworms and/or beetles in place. NOTE: You will need to slice fruits and vegetables which have a firm exterior, like apples and zucchini. This is due to mealworms not possessing enough strength in their mouths to penetrate the skin of the fruit or vegetable.

1. If this is your first mealworm colony, try to avoid really ‘wet’ food sources like cucumbers, tomatoes, etc.  They work perfectly fine, but are much more prone to mold since they have a LOT of moisture.  If you use these, add less than you normally would if using potatoes/carrots. 

Mesh strainer

Needed for sifting frass.  Here are examples (affiliate link) if you would like to order online.  However, a simple 6 inch aluminum mesh strainer can usually be found at any general store as well.

Mask 

You will need a mask that covers your nose and mouth, to be used when sifting frass out of your container.  N95 masks are commonly used.  Mealworm frass gets into the air very easily - you need to protect yourself and those around you.  More info below on this topic.

Preparing for mealworms

1. Procure the necessary tools above.
2. If you are using a lid, use a drill or soldering iron to make holes in the lid.  20 holes will be sufficient.
3. Substrate:  Place the substrate in a deep freeze (0° F) for 48 hours OR cook it in the oven until the internal temp reaches 150° F (generally speaking, 200° F for 1.5 hours).  Complete this step when you are close to getting your live mealworms and/or beetles. Either way, let the processed substrate reach room temperature before adding it to the container.
4. Place the substrate into the container to a depth of 1 inch.
5. Place your container in a location which can maintain a temperature within a 70-80° range.  Higher temperatures and your colony will suffer heat die off.  Lower temperatures are fine, down to 50°, but you will see much lower production and much longer timelines for your mealworms to grow.
6. If you are ordering your mealworms online, spend a bit of time learning how your mealworms will be shipped, unboxed, etc.  Here’s a quick video for unboxing a shipment from Midwest Mealworms:  What to expect when ordering live insects

Acquire live mealworms (and maybe beetles too)

A few notes about getting your initial mealworm stock for your colony:

1. Sometimes, but not always, mealworms at big box stores are treated with a hormone that impairs/delays pupation.  It is likely that you’ll still be able to pupate them, but it could take longer and may result in more deformities.
2. Try to find a local producer on places like Facebook Marketplace, Craigslist, etc.  Suggestion - Support locally before buying online.
3. Order online: There are many places to order online; you want to find someone who has good ratings/reviews.  Amazon, Ebay, direct websites all work.  Here are a couple recommendations:
• PNW Mealworms - https://pnwmealworms.com/
• Midwest Mealworms - https://midwestmealworms.com/ full disclosure, Midwest Mealworms produced this document.
• Mealworms
• Starter kit including beetles

A few notes about whether you should include beetles in your initial setup:

1. Starting with JUST mealworms will still get you the desired result of an operating mealworm colony.  Buying beetles is not a requirement.
2. Including beetles will get you a jump start to getting baby mealworms of your own.  If you don’t include beetles, you will need to wait for your mealworms to pupate, then transform into beetles, then start laying eggs.
3. If you decide to include beetles in your initial setup, you want to make sure you are getting freshly hatched beetles from your supplier!  Beetles lay 95%+ of their eggs in the first two months.  When you receive your beetles, there should be a slight color variation of reds/browns/blacks as they should have just hatched.
4. Both of the companies mentioned above for mealworms also sell beetles.

Introducing insects into your setup

Once you have acquired your mealworms (and maybe beetles too), introduce them to your container as soon as you get them home. Simply place them into the container and add a few ounces of your moisture source to the bin (4 thin slices of potato, 3 baby carrots cut up, etc).

Begin monitoring your container using the Checklist below.

If you are supplementing your existing mealworm colony, do NOT add the mealworms and beetles immediately.  Store them in a separate container for at least 1-2 weeks to identify any issues or ‘stowaway’ insects.  It is very common for large mealworm producers to integrate ‘cleaner crew’ insects to eat dead material, but these reproduce very fast and can take over a mealworm colony.  If you spot something that isn’t a mealworm, a pupae, or a beetle, immediately euthanize it.  Once the 1-2 weeks have passed, if you don’t see anything wrong with the new insects, add them to your existing colony.

Maintenance and Care

In the first month of establishing your mealworm colony, you should monitor and check on your container every two days.  Once you have an established colony and routine, your experience will help you determine the optimal schedule that works for you.

1. Frass check -  Frequency:  twice a week

You want to ensure that your frass isn’t deeper than a half-inch.  If it is, follow the “Sifting Frass” instructions below.  

1. Substrate check -  Frequency:  weekly

You want to maintain a half-inch to one inch depth of substrate.  If your substrate is less than a half-inch and your frass is not yet a half-inch, add in more substrate.  Remember to either deep freeze or cook your substrate first!

1. Hydrate -  Frequency:  three times per week.

The goal for proper hydration is to feed your colony so that the moisture source is gone within 24-48 hours.  This will keep mold from occurring, and ensure your mealworms are hydrating properly.

Each time you hydrate:

1. Inspect your bin visually for any dried moisture sources or mold.    Remove if present.
2. Run your hand through the substrate/frass to find any moisture sources below the surface.  Remove if they are dried out.
3. If you have remaining moisture sources that were dried out, add less this time.  If you didn’t find any, add the same amount as previously used.

1. Cleaning - Frequency:  once a month

Ensure that once a month you wipe down the sides of your container with a damp cloth to ensure they stay smooth and clean.  Mealworms and beetles can climb the sides of containers if they get dirty or scratched, even plastic.

Maintenance and Care Checklist

Mealworm Farm Checklist - single container

Harvesting mealworms to use as feed

A simple rule of thumb to ensure your colony continues to produce is to only harvest 50% of the mealworms over the course of a month for use as feeders to establish new trays.

For example, if you ordered 2000 mealworms you should only collect a maximum of 1000 in a month.  This will also help ensure that when gaps in your baby mealworms occur (see “Sifting your Frass” below) you won’t be creating a situation where you completely run out of mealworms.  Over time you will likely end up producing more than you need, so this quantity could increase.

Harvesting is quite simple, use your hands or tongs to gently move the substrate and pick out the size of mealworms you need.  Another alternative is to harvest on the days that you feed moisture, because the mealworms will be drawn to it!  Place your moisture source in the bin, wait 2-3 minutes and the mealworms will begin eating and will give you easy access to grabbing them.

Sifting your Frass

Mask up every time you sift frass.  If you intend to responsibly raise your own mealworms for a long time it is vital that you wear a mask.  Otherwise you run the very high risk of developing allergies like asthma, runny/stuffed nose, hives, eye disorders, etc.  This is not a myth - I have had allergies my entire life and the first time I sifted frass it triggered my asthma.  I always wear my mask when working with frass.

Performing this task outside is highly advised!

NOTE:  Mealworm eggs are extremely tiny, and will most likely be sifted out with the frass. This shouldn’t be an issue as long as you aren’t pulling more than 50% of your mealworms to feed off.

1. Gather the required tools:  two empty containers, mesh strainer, mask.
2. Put your mask on.
3. Gently pour the contents of your container into your mesh strainer until it is ¾ full. 
4. Shake the mesh strainer to help the frass sift through into one container.
5. Empty the contents of the strainer into your second empty container.
6. Repeat steps 3-5 until you have sifted the entire container.
7. Place your colony back into the original container.  There may be eggs on the bottom of the container, do NOT wipe/remove these.
8. Add substrate to a level of 1 inch.

Now that you’ve collected your frass, use it on your plants/garden/lawn!  Head to https://midwestmealworms.com/frass to see recommended application methods and amounts.

Looking into the future

As you get your mealworm farm established, you’re going to run into questions and problems.  It happens to all of us - even me!  Not to worry, I have some recommendations:

1. Add a hygrometer to your setup.  There are many to choose from - grab something that works for you and utilize it to check your temperature and humidity.
1. I personally use SensorPush - their free app includes alerts and full tracking to see historical information.
2. Join the Mealworm Farming CO-OP Facebook Group.  This group is for all sizes of mealworm farms and all levels of experience.  Come and ask questions, search for answers, and share your experience to help us all learn.
3. Follow Midwest Mealworms to see reference material, the latest info on raising mealworms, and direct messaging with Justin!