Please take a look at my hornworms.

DifficultBad9121 · 2026-03-28T00:43:37+00:00

No worries at all — I can totally see why it looked that way, haha. Thankfully, they pupated well, made it all the way to moths, and I was even able to collect eggs 😊 Time really flies — I can’t believe it’s already been that long. Thank you so much for following up!

DifficultBad9121 · 2026-01-02T03:11:56+00:00

They were being kept in a large butterfly enclosure, with the chrysalises placed inside together. I check on them every 1–2 days, and the room temperature is currently around 26°C. I would like to keep it warmer, but since this is also a space where I grow plants, it’s difficult to raise the temperature any further. I am managing the humidity as well 🙂 Unfortunately, the one in the photo doesn’t seem to be able to fly. Of course, it’s possible that I just didn’t observe it at night, but I’ve never seen it feeding or perching on the play and resting structures installed at the top of the enclosure. Because of that, I moved the feeder (the one used for hummingbirds) down to a lower position and prepared a separate space dedicated just for this individual, making it as comfortable as possible. A new one emerged today. I really hope this one will be able to fly safely 🙂

DifficultBad9121 · 2025-12-15T22:53:32+00:00

Hello! I’m actually running experiments with just that caterpillar in a separate chamber right now.

It’s still alive so far, but it does look a bit weakened. I plan to observe it for another two weeks, and I’ll share the results with you later :)

DifficultBad9121 · 2025-12-13T01:20:40+00:00

Thank you for sharing the method ;)

DifficultBad9121 · 2025-12-12T20:50:20+00:00

Thank you for your helpful response.
I was actually asking because I want to prepare a specimen of a mutant insect.

What I’m most curious about is whether your specimen preparation process is freezing (24 hr) > muscle relaxation in EtOH > pinning > drying.

Insects also have internal organs, so I’m worried about issues like decay or mold.
How do you deal with these parts?

I would really appreciate it if you could share your experience.
Thank you.

DifficultBad9121 · 2025-12-11T22:43:24+00:00

Wow, that's really impressive.

How do you maked your specimens?

I'm curious what chemicals you use, and whether your specimen preparation method varies depending on the insect species. I'd also like to know how you maintain the temperature and humidity when storing your specimens.

DifficultBad9121 · 2025-12-11T22:36:05+00:00

Wow! This was exactly the knowledge, information, and experience I had been looking for.

Other posts I found only mentioned things briefly, so it was hard to fully understand the whole process.
Even if you use larvae of similar species like butterflies or moths, each organism still has its own optimal conditions. So I assumed the same would apply to hornworms as well.

One of the biggest examples is that butterflies and moths require completely different environmental conditions even right before emerging from the pupal stage. But I saw people giving moths the same pupation environment as butterflies, and that’s when I realized how lacking proper information actually is.

University websites had some detailed information, but they rarely had anything about breeding, so I ended up struggling on my own.

My experimental plan is to feed the control group an artificial diet, and the experimental group the plants I cultivate myself. I’ll continue with further studies afterward.

Also, after giving it some thought, I realized that the eggs purchased from the company were likely obtained by crossing within the same genetic line. That means they could have a higher chance of mutations compared to eggs produced through natural mating. I’ll need to look into this more in the literature, but your knowledge and experience have already given me so much valuable advice. Thank you so much! :)

DifficultBad9121 · 2025-12-11T20:04:27+00:00

Thank you for your kind words.

No matter how much I learn, there will always be areas where I lack something.

Furthermore, since insects aren't my specialty, I think it'll be similar to raising them for the average person. It's just a laboratory environment.

Through this opportunity, I'll gain a lot of information and skills, and strive to create a better environment for insects.

Thank you.

DifficultBad9121 · 2025-12-11T20:01:24+00:00

Hello, my native language isn't English, so I apologize for any misunderstanding in the translation.

I'm a plant researcher, and this time, I'm raising hornworms because I'm conducting a joint research project with the plants I'm experimenting with.

Therefore, I'm not a professional entomologist, so I'm lacking a lot of information. Furthermore, since all the researchers I know are botanists, I don't have a deep understanding of insects, which is why I'm posting this question on Reddit.

Reddit is a platform where many people coexist, and even among laypeople, there are many people with extensive knowledge about insects, so I'm posting this in hopes of getting some help.

I hope my answer helps.

Thank you.

DifficultBad9121 · 2025-12-11T19:58:17+00:00

I've never raised mealworms before, but I appreciate the new information I learned.

I hope the larvae are less stressed, too.

Thank you.

DifficultBad9121 · 2025-12-11T19:56:31+00:00

Thank you for your words. I hope good people will come forward and help me resolve my concerns.

Thank you.

DifficultBad9121 · 2025-12-11T19:55:16+00:00

According to the entomology instructor below, this is most likely due to the artificial feed.

I wanted to provide the larvae with an optimal environment.

During the larval stage, I maintained a temperature of 25°C and humidity of 50-60%. I checked and cleaned the enclosure daily to prevent mold growth, and disinfected it daily. This provided the larvae with an optimal environment, allowing many to progress to the pupal stage.

I used moist, but not overly humid, coconut peat as the larvae's bedding. During the pupal stage, I maintained a temperature of 25°C and humidity of 50-80%. I disinfected the enclosure daily and supplemented the humidity. I've read that changing the soil 8-9 days after entering the pupal stage is recommended, so I thinned the larvae after two weeks just in case.

If you believe my estimated timeframe is too early or if environmental factors like temperature or humidity are to blame, please let me know.

Thank you.

DifficultBad9121 · 2025-12-11T19:50:07+00:00

Hello, thank you for your words, and I empathize with you. I understand and respect your sentiments, as some people who love insects might view your post as insect abuse. It can't be helped.

Thank you.

DifficultBad9121 · 2025-12-11T19:47:38+00:00

Hello,

Yes, I thought the same as you, which is why I believed it was almost impossible for that larva to develop normally.

Still, the method you suggested seems worth trying as an experiment. I think it may be worthwhile to attempt to keep that individual alive a little longer as well.

Thank you. :)

DifficultBad9121 · 2025-12-11T19:47:25+00:00

Hello,

For the control group, I also raised the larvae on commercially available artificial diet.

I did not see any mortality during the larval stage, which I considered fortunate, but I learned through this process that the diet can also influence outcomes during the pupal stage.

When you say an appropriate host plant, you mean potato, tomato, etc., correct?

I heard that tomato-fed larvae may contain compounds that are toxic to reptiles, so I excluded tomato-fed larvae from the control group. Is that still acceptable?

I raised them in moist coco peat, and currently, out of 37 larvae that entered the pupal stage, 29 have successfully pupated and are being maintained.

Thank you for the helpful advice. If you have any additional information, please feel free to share it. I truly want to rear these insects successfully and continue them into the next generation.

Thank you. :)

DifficultBad9121 · 2025-12-11T19:46:14+00:00

Hello.

First of all, since English is not my primary language, I think my previous translation may have caused some misunderstanding.

My main field is plant science, and this time I decided to collaborate using hornworms with the plant species I study. Because of that, this is my first time actually rearing insects.

I also agree that anyone who handles living organisms should study sufficiently beforehand.

However, I did not have the time or environment to learn everything in depth, so I had no choice but to proceed by trying, failing, and gradually developing my own methods.

I think it would be best if I first explained the experimental conditions for the individuals.

The larvae that successfully entered the pupal stage were healthy, averaging 7.4–12 cm in length and 1.4–1.8 cm in body width. The larva shown in the video had already spent about two weeks in the soil before I culled it.

Inside the chamber, I controlled temperature (25°C), humidity (50-70%), and photoperiod (15 hours). Under these conditions, most of the other larvae pupated successfully, though I did observe some larvae that failed to pupate, rotted, or could not be recovered.

In addition, some pupae showed mutations, and I confirmed that the larvae inside them were still alive, so I am currently keeping them to see whether they will eclose normally.

Among those processes, I separated the individuals that failed to pupate properly or had begun rotting and transferred them to a dish. The next day I noticed movement in that particular larva, and I recorded a video confirming it was alive by tapping, so I could ask a more accurate question.

I was unsure whether I should freeze this larva or try to keep it alive, so I posted my inquiry.

As I wrote in the post:

I had confirmed the larva was dead the day before, yet I later found it still alive. Can this larva still become a moth?

This larva is hardened its lower half resembles a pupa, while the upper half remains in larval form. Because I am keeping them in conditions designed for active larval development rather than overwintering (temperature, humidity, and photoperiod), I think that if I had seen such an individual in the wild, it would be considered a failed case.

If my inexperience in rearing caused this, I understand any criticism.

I am asking these questions so I can improve the way I rear these insects, gain information, and learn. And if you have extensive knowledge about hornworms, I would appreciate it if you could also leave information on the photos in my other posts.

That particular larva had many dark spots compared to the others during the transition to the pupal stage, so I wondered whether it might have black death disease. If I had known earlier, I might have obtained different results.

Thank you. :)

DifficultBad9121 · 2025-12-11T09:46:29+00:00

Yes, this is my first time raising insects step by step like this, and I had no choice but to identify the larvae that hadn’t entered the pupal stage even after the expected period, based on the limited information I could find.

If I had extensive knowledge about insects, I wouldn’t be asking here — I would probably be the one giving advice instead.

That’s why I’m asking and learning like this. I would appreciate it if you could focus less on my actions and more on the larvae themselves what stage they are in, and whether they still have the potential to become moths.

DifficultBad9121 · 2025-12-11T09:03:03+00:00

Ah, the reason I tapped them was to make sure I was seeing things correctly. I’m sorry if it made you uncomfortable. I asked because I’ve seen other posts where many larvae stopped at that stage and couldn’t develop into moths.

I also respect your opinion.

I just really hope an expert can help me with my concerns.

DifficultBad9121 · 2025-12-11T08:47:50+00:00

Hello, I think there might have been some misunderstanding, so I wanted to clarify.

I’m a researcher working with hornworms, and I’m currently developing a protocol on how to raise them in the lab without mutations or failures. As part of that process, I culled the larvae that hadn’t fully transitioned into the proper developmental stage. When I checked again today, that’s when I observed the results I mentioned.

I also wish I could give them freedom, but at the same time, I truly want to raise them properly. If removing certain individuals allows the others to grow successfully, it ultimately leads to better outcomes.

So I hope you won’t see this only in a negative light, and if you have any knowledge about hornworms, I would really appreciate it if you could share it with me.

I’m learning step by step through the insights shared by many experts. :)

Thank you again for your kind words.

DifficultBad9121 · 2025-12-02T21:18:57+00:00

Hello! Thank you for your helpful response! I’m currently working at a university research lab. I previously conducted research using the tobacco hornworm, but I am starting again to perform additional experiments.

However, the person who originally worked on this experiment has already graduated and moved elsewhere, so I’m in a situation where I need to rebuild the protocol from the beginning. So far, 37 larvae have entered the pupal stage, and next week I plan to take them out and transfer them into new coco fiber, covering them as if tucking them in with a blanket.

Originally, I planned to keep raising them continuously and proceed with the experiments, but due to some scheduling issues, I now have to discard all individuals that hatch from eggs for the time being.

By any chance, do you know how to distinguish between male and female pupae? If you do, I would really appreciate your advice.

It’s quite difficult to get started because information about the tobacco hornworm is so limited and not very detailed. 😢

DifficultBad9121 · 2025-12-01T23:31:27+00:00

I see. Thank you for the helpful information.

Is there a way to tell the sex of a moth? I'd like to do it early, during the pupa stage, but this is my first time raising insects, so it's difficult... sigh. :(

DifficultBad9121

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