Hornworm Care and Breeding

After reading many posts asking for help breeding hornwoms or lamenting over failed attempts at rearing or breeding I decided to write an instruction manual of sorts. Keep in mind this is just from my experience and not intended to be the end all be all of hornworm care and breeding.

Let us begin with the egg.

You might decide to buy eggs in order to be more economical and wonder, ok now what?

First you will want to be sure you have a deli cup with hornworm chow inside (I use chow from Great Lakes Hornworms or Mulberry farms usually). You can place the eggs on the lid of the cup and then put the cup on and allow them to hatch at room temperature or a bit higher. I keep all of my feeders in a room of the house that is kept at 75-80 degrees to maximize growth.


If you don't have a deli cup you can try to just put the eggs in a Tupperware with some screen or gutter guard (comes in a roll from lowes) Link to Lowes Gutter Guard and just be sure they can make it up to the food.

I make my own deli cups. I order cups with mesh lids and then use the gutter guard and twist ties. This also makes it easy for me to pull out the entire mesh and food when I am ready to transfer the worms to a bigger container.

The worms will hatch and climb up to the food in the cup.






I allow them to grow in the cup until they are large enough to move. I make sure to take the lid off to dump the frass everyday and also inspect the food for mold or bacteria. If you see any mold, white milky spots or a film on the food you will want to get them transferred out of the cup as soon as possible to avoid a total loss of worms. I have read that in the case of mold you can just remove the mold spot, but I don't take any chances.

If you need to slow down the growth of the worms in order to prolong the time you can feed them, you can put them in the refrigerator. I usually put them in a mini frig I have set at 50 degrees. I have read that they can go in for up to 2 days; however I have never put them in for more than a day at a time. I will put them in for a day and then leave them out for a day.

When the hornworms grow big enough to move, I then transfer them from  the deli cup to a modified tupperware container. I use the sterilite 6Qt (5.7 L) Tupperware containers that state they are for shoe storage.  Any Tupperware that is around that size should do.  I then cut out the lid and hot glue some screen to it as shown below.  I also cut some gutter guard (Link to Lowes Gutter Guard) to place in the bottom. I also put bottle caps in the bottom to raise the gutter guard up. This layer of gutter guard allows the frass to fall through and makes daily cleaning easier.



This is where I will grow the worms while they are fed off and until they are ready to pupate.

I store the hornworm chow in the refrigerator and only put enough for them to eat each day in the container. This helps to ensure the food is fresh and does not get contaminated. When I add fresh food I remove all of the old food and clean the container. Proper cleaning and maintenance will ensure healthy hornworms.

I also take out a few that I plan to feed off within the next couple days and gut load them with greens, squash, carrots and red bell peppers. They will readily eat many of your typical gut loading veggies.

If you plan to breed them you may also want to keep them on a light cycle. Longer days, around 14 hours, promote more rapid development. Shorter days, 12 hours or less, could result in them going in to diapause once pupated and this could last for months. I keep the last stage of the worms and the pupae in a screen cage with a light on top set to 14 hour days to ensure the pupae do not go in to diapause.

I usually separate my hornworms in to two groups, the ones that will be feeders and the ones I will use for breeding.

After you have grown your hornworms to full size you may wonder what to do when it is time to pupate. You might even wonder how to tell when they are ready to pupate.

The hornworms will grow to over three inches prior to pupating.


Once they reach this size there will come a time when they stop eating and start roaming around. They will then change to a lighter color and you can see the vein pulsing on their back. This is when they are ready to go in to the dirt.


There are many options for substrate, I prefer to use eco earth. Some people also use soil, moss or I have heard of just using paper towels to keep them. I have had the best experience using eco earth. When they are ready just put them in the container that has the moist substrate and they will burrow when ready.


Some may burrow immediately while others may take a day or two. I usually keep the dirt containers in a large bin as they tend to roam all over during this stage and will climb out of the container. They can roam around for a couple of days before finally staying put in the dirt.

After burrowing they will slowly begin to pupate. They will change from green to brown and eventually harden. It is very important to mist the dirt daily to ensure proper development of the moths. One major result of failing to keep them moist is stunted wing development in moths. If the moths have stunted wings they will not be able to fly and will not survive. You may also want to arrange a light as a longer day cycle (14 hrs) will result in faster moth development. If they are on a short day cycle (12 hrs) the pupae could go in to diapause that can last for months. As stated above, I keep the final stage of worm and the puapae in the screen cage that I use for the moths.



I usually dig my pupated worms up after about a week or so and transfer them to new containers of fresh dirt. I do this because I have lost entire batches due to a worm that burrowed only to die and rot or due to feces being in the soil and molding. Many times that I do this I do indeed find a dead worm in the soil.

About 3-4 weeks after the hornwoms pupate they will be ready to hatch in to hawk moths. You will want to be sure you have a cage or some other equivalent set up ready. I use a small repti breeze screen cage. I have a stick across the top to tie the humming bird feeder to and I line the walls and floor with plastic used when painting, as the moths can be pretty messy. The moths expel a liquid (meconium) when they emerge which can be messy. They can also kick up the dirt from the pupae tray while flying around. I do not put the humming bird feeder in the cage until I see a moth emerge.



The moths require the humming bird feeder in order to eat. It is best to use commercially available humming bird food from your local grocery store, hardware store or walmart. Attempting to mix your own solution could result in death of your moths.

When the moths first emerge, they will have small wings, once they climb up the screen they will sit there and puff out their wings to their full size. They do this pretty quickly, so if you see a moth the next day that has small or wrinkled wings, they likely are deformed and wont puff out to their full size. These moths will die pretty fast as they cannot eat.

Here is a moth drinking from the feeder.



Video of Moth Drinking

I also place a small potted tomato plant in the cage for them to lay their eggs on. The moths will breed by attaching their abdomens together and then the females will lay tons of eggs all over the plant and even on the cage walls and hummingbird feeder. It will be important to pick the eggs daily or they could get out of control. You can use other plants, however I have found that I get more egg with tomato plants.

The eggs will be small and green, but they are fairly sturdy and easy to collect.



Now for our hand at an artistic hornworm photo shoot.


And of course one of our boys with a hornworm
They even love to eat the Moths




27 comments:

  1. I've followed your guide on breeding horn worms and all of my moth came out deformed with no wings or shrivled wings what am i doing wrong??? thanks for any help

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    1. Hang a piece of paper towel or screen material for the newly hatched moths to climb. Their wings are wet when they hatch and they need to hang to get the blood flow going and pump through the wings. If they get caught in their container with no way out or nothing to climb their wings won't unfold correcrly.

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    2. Is it possible to feed them only fresh vegetables and still successfully get them to pupate? I don't have easy access to premade hornworm food.

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    3. Replying to my own question. Yes, my hornworm is currently a chrysalis and I only fed it carrots and lettuce :)

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  2. WHAT CAUSES DEFORMED OR STUNTED WINGS ON MY HORNWORM MOTHS, 1ST 2 NICE, NEXT 3 STUNTED... HOW CAN I PREVENT THIS,
    THANK YOU

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    Replies
    1. If you do not keep your Eco Earth damp by misting daily, it can result in the wing problems you describe. You can prevent the issue by remembering to mist and also by making sure the earth is not packed too tightly around the pupae.

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    2. LaylaJanuary 27, 2019 at 12:56 PM
      Hang a piece of paper towel or screen material for the newly hatched moths to climb. Their wings are wet when they hatch and they need to hang to get the blood flow going and pump through the wings. If they get caught in their container with no way out or nothing to climb their wings won't unfold correctly.

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  3. Replies
    1. The post says: "It is very important to mist the dirt daily to ensure proper development of the moths. One major result of failing to keep them moist is stunted wing development in moths." Maybe that could be your reason.

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    2. LaylaJanuary 27, 2019 at 12:56 PM
      Hang a piece of paper towel or screen material for the newly hatched moths to climb. Their wings are wet when they hatch and they need to hang to get the blood flow going and pump through the wings. If they get caught in their container with no way out or nothing to climb their wings won't unfold correctly.

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  4. Here's a suggestion about providing a vertical surface/newspaper in the Moths/Adult section. https://entomology.unl.edu/scilit/care/hornworms.pdf

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  5. I followed the instructions perfectly and 5 of my 8 worms died. How do I keep the mortalities lower?

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  6. What's the perimeter of the plastic around the cage? Do you have fans running and is there an smell/odor ruining the room?

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  7. Do you need tomato plant or can you use somthing else

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  8. When researching Hummingbird Feeders, I learned that most of them do not fill the flowers with very much nectar to prevent bees and other insects from gaining access to the nectar. The hummingbirds can still reach it because of their long beaks that reach way inside the flowers. What kind of hummingbird feeder do you use and how do the adult moths access the nectar in it?

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  9. Update: After posting this, I researched hummingbird feeders on Amazon and noticed two possible hummingbird feeders that would likely work for moths. An optional bee guard is available for PerkyPet brand feeders so I believe this is one possibility when you don't use the bee guards. I ended up going with the First Nature 2 pack of 16 oz feeders because they were inexpensive and there were several reviews from customers complaining about the feeders attracting more bees than hummingbirds. I did read one review that had been recently posted asking them why they were still shipping the old model that attracts bees when they have a new model that doesn't so this may be changing. I do know that the one I received last month was the old style because the hummingbird food comes right up to the top of the flowers where the moths will be able to access it.

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  10. Hopefully this gets a response. Where do you keep your moths? It looks like inside. These moths are day eaters I'm pretty sure. They need the sun as well to warm them. Do you have some kind of artificial light for them? Thank you.

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  11. This was awesome thanks for sharing!! I’ll have to try for my babies I have two bearded dragons 🦎💖💖

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  12. Thanks for this! Amazing. Can't wait to try.
    I have some worms that look like they want to hand to pubate. Is that normal/ OK???
    How long do the moths live? Do they lay eggs more than once?

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  13. Hi, what is the best thing to put at the bottom of the moths screen cage? Is that paper towels?

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  14. What kind of light source do you use?

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    Replies
    1. I used Arcadia shade dweller 7% UVB and had success

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  15. Tomatoes are nightshade witch are poisonous that's why I'm not plucking them off My tomatoes outside why do you use them?

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    1. My thought is the author removes the eggs from the tomato plants before the larvae have a chance to consume the plant. I can see the convenience of having the eggs mostly in one place.
      I have raised a few generations of hornworms and love the amount I have to feed my pets after they grow. My least favorite part is collecting the eggs because they glue onto the screen and the feeder, basically everywhere.

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    2. These moths actually prefer nightshades to lay their eggs on in the wild.

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  16. This comment has been removed by the author.

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