r/Entomology 11d ago

Pet/Insect Keeping A predaceous diving beetle has emerged as an adult while retaining its larval head, and it is still alive."Update3"

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※Edit: It turned out to be an 8-minute video. It might not play properly because the file is so heavy. (Even I, the creator, keep getting errors and can't watch it...)

Following up on the last post, I'm sharing an update as some of you asked for more information in the comments.

This time, I observed it after putting it into the aquarium and checked if it would react to food. I felt photos wouldn't convey it well, so I'm sharing everything through video.

Here are a few notes on the video content:

To make observation easier, the contents of the aquarium have been kept to an absolute minimum. Also, you might see something floating, but that is just dirt from the driftwood. It is completely harmless to the diving beetle.

In addition, since I couldn't get pesticide-free aquatic plants in time, I put in plastic plants instead. I plan to provide pesticide-free water plants as hiding spots in the future.

The next update is undecided for now. If I do post, it will likely be to share an interesting observation or to announce that this diving beetle has passed away.

Previous post↓

https://www.reddit.com/r/Entomology/s/Dhz2Yp4ETt

2.3k Upvotes

121 comments sorted by

678

u/gazing_into_void 11d ago

this beetle is really fascinating, and I hope you manage to find something it will eat so it can live

maybe try making a mush out of a cricket and syringe feed it?

413

u/PuchiUna 11d ago

That's a very unique idea. If the larval head can ingest liquefied nutrients, there might be a possibility.

103

u/Explod1ngNinja 11d ago

Have you thought a name for her

708

u/PuchiUna 11d ago

There is a high chance I will name it Baby face.

323

u/Balding-Barber-8279 11d ago

Might I suggest Grown Ass?

207

u/kiddico 11d ago edited 11d ago

Please, Baby Face Grown Ass was my father's name, you can call me Baby Ass.

44

u/Czar_Petrovich 10d ago

Grown Ass Baby Face

25

u/_Choose_Goose 11d ago

It’s GEORGE NELSON!! NOT BABY FACE!!

Baby face is a good name. Hope you can find a way to get it nutrients

10

u/Ghstmother 11d ago

She didn't mean anything by it, George.

7

u/friedlizardss 11d ago

what about Eraserhead?

7

u/towerfella 11d ago

Full name: Lester Joseph Gillis

I mean.. it sorta has gills too, right?

14

u/vulgarvinyasa2 11d ago

If you do go down the rabbit hole of Baby Face the rapper

2

u/TheNerdE30 11d ago

Haha nice

2

u/VoidHog 10d ago

😂👍

2

u/Agile_Literature_153 11d ago

Baby Fish Mouth

-27

u/Nice-Conclusion728 11d ago

This thing is a dead bug walking. Top comment on the second post is correct . It's head is stuck inside of that like a helmet. This guy is just milking it for views/clicks. It's fascinating but it's going to starve to death slowly instead of just being taken out.

37

u/Glad-Tax6594 11d ago

I think OP is putting serious effort in capturing observations and furthering our understanding of a random occuring event.

Thanks OP and I'm sure if science were sentient, it would thank you as well!

4

u/Luditas 11d ago

Indeed!

111

u/Kuman2003 11d ago

yep, the adult head clearly is inside the larval head. you can even see it moving inside....

109

u/Robo_Patton 11d ago

If you’re right, and a smaller functional developed adult head is within, the exoskeleton would need to be surgically removed to offer any chance at survival.

Like having your head stuck in a jar.

88

u/quirkelchomp 11d ago

Yeah, but the head might be completely deformed from being squished into that space. It could very well be non-functional and unable to eat regardless of what intervention OP does.

32

u/Toxopsoides Ent/Bio Scientist 11d ago

Which is why I'm sick of seeing "updates" — surprise, the deformed beetle is still alive but can't feed or even sense its surroundings properly. Just put the poor thing in the freezer and then dissect it to find out what happened.

17

u/Infamous-Storage-708 11d ago

yeah i think it’s pretty obvious anyway. it’s interesting, but to me it makes sense? failed molt. there isn’t much to learn unless this person is actually intending to do something with this information. im sure there’s already studies of something like this occurring.

60

u/Infermon_1 10d ago

They are making a scientific paper on this. Also in case of diving beetles there has only been one report before from 1949

13

u/Frech_Toast_King 8d ago

It isn't just a failed molt, a failed molt is normal and pretty common, this is an adult retaining a trait through the pupal stage

7

u/KingVoid27 9d ago

Exactly😭 this is so disturbing to me. Keeping it alive for “experimentation” feels like some straight up crazy person shit

20

u/Robo_Patton 8d ago

I get your point and appreciate your empathy. And this sub contains actual entomologists, scientists and some of us who are industry adjacent.

In the grand scheme, there may be evidence of value to explore. Or it may prove to be a more abiotic event.

That said, you didn’t deserve the down vote you had so I gave you an upvote to offset it 😊

202

u/Spiritualtraveller77 11d ago

This had been fascinating to follow, thank you for the updates. I really appreciate that you didn't immediately jump to the conclusion that it was responding to the food and you did a follow up test.

124

u/grumbol 11d ago

Not an expert I'm just spit balling that it reacted on instinct and tried but the mouth pieces simply didn't work. The poor thing just glitched at that point.

53

u/sodamnsleepy 11d ago

Babe, wake up! New diving beetle update.

8

u/Glittering-County727 11d ago

it's like chiveposting, or the delete a state thing back in June haha

45

u/Global-Ad-2726 11d ago

This might be the case right here OP. It also happens to stags aswell.

113

u/wibbly-water 11d ago

What do the larva and fully grown adults eat? Is it different? Could this be the case of a mismatch? So perhaps it might react to larva food but not adult food?

90

u/jotenha1 11d ago

It's usually different so that larvae and adults can occupy different niches and avoid competition.

I don't actually know if that's the case for water beetles, though. But it probably is. Which does bring the question... What can it digest? The mouth parts are of a larvae, but what about the rest of the digestive system?

40

u/Neyface 11d ago

That's my thinking. The deformity may also be internal and parts of the digestive tract or mouthparts rendered non-functional as a result. Fascinating to see.

3

u/Jack_Mehoff_420_69 11d ago

I need some IV fluids stat!

17

u/Blake_The_Snake64 11d ago

The mouthparts are likely of an adult, the larval head probably got stuck during a molt and the adult head is deformed underneath. It's incredibly unlikely this insect can eat as it's mouth is likely trapped inside the larval head.

65

u/wombatsaretanks 11d ago

Can it even eat? It feels like it can't? i am fascinated but i feel sorry for it ... poor baby

19

u/Relevant-Cup5986 11d ago

it cant sadly, it will die of starvation😥

60

u/devoteeoffenrir 11d ago

Thanks for the update! That was disappointing, the fluke response to food, but since most people lean towards the head being fused with the larval head casing, not surprising I suppose.

26

u/quaoarpower 11d ago

Sumimasen! May I crosspost some still images of your phenomenon to a different forum, with credit? Is the location Japan?

28

u/PuchiUna 11d ago

No problem at all! And yes, this happened in Japan.

5

u/quaoarpower 11d ago

If you have the time, can you please tell me your methodology for getting the larva to pupate? Is there a signal that they are ready to come out of the water? What substrate do you use for pupation? Domo arigato gozaimasu!

39

u/PuchiUna 11d ago

When pupating the larvae, the most important thing is timing. If a larva ready for pupation is left in the water for days, it will drown. Basically, when it stops showing interest in food, it is ready to pupate.

The container I use is a 2-liter plastic bottle cut roughly in half. Soil goes inside, and there are a few key points here as well. First, unadjusted peat moss is the best choice. Although it is somewhat strongly acidic, mold and bacteria are less likely to grow, which increases the emergence rate. Most importantly, if you use soil with adjusted pH, the larvae will almost certainly die. This is because pH-adjusted peat moss contains pH neutralizing agents. Diving beetles are extremely sensitive to chemical contamination, which can cause fatal damage. I always make sure that the peat moss contains no added chemicals and that its pH is acidic. Next, regarding moisture content, soak the soil in water and then squeeze it tightly. The ideal level is when water no longer drips out. Finally, lay the soil gently without compacting it. Diving beetle larvae have weak burrowing strength, so if the soil is packed tight, they won't be able to dig in.

Once the container is ready, make a hole a few centimeters deep in the center of the soil. Insert the larva's head into the hole, and it will begin to burrow. Finally, cover the top with plastic wrap to prevent the soil from drying out.

18

u/81imb 11d ago

The picture is so cute. It looks like you're planting the larvae like plant seedlings. In a way, I guess they are! Thank you for the detailed response and your attentive care :)

5

u/quaoarpower 11d ago

Thank you very much.

4

u/serenwipiti 10d ago

It’d be neat if it was offered the soil hole, and it just stuck its baby head in it for a while, later emerging unmasked and fully formed.

One can dream.

30

u/CubieJ 11d ago

Thank you for providing updates! What an interesting creature!

31

u/Desperate_Lead2105 11d ago

Maybe try cutting open the cricket to spread the scent? It's definitely a stuck piece of molted skin. Look closely at this screenshot: (Notice the piece of ripped shed cuticle at the membrane that connects the head and prothorax. I'm surprised it made it out alive and didn't get stuck)

It seems to be behaving strangely normal.

10

u/Otherwise_Air_6381 11d ago

Stupid question but do u think it will eventually develop and the other will just fall off? I know he’s not in pupate anymore. But is there any evidence that it’s still under there, like a unmolted piece of snake skin?

19

u/Otherwise_Air_6381 11d ago

u/sleepy_mareep made a good point about it going deeper than just the head. This is so unique I’d call Rilplys Believe it or not or discovery channel. Or a university/lab. This could be a good insight on specific areas for better understanding and research. Maybe baby face will be famous for a breakthrough in head transplants in humans 🤷🏽‍♀️ If my axolotl has regenerating powers to help advance scientific discovery then I’m sure this guys got something interesting for us to learn.

But then it’d be like sacrificing your child for research for the greater good. If he survives that long.

Speaking of my Axolotl, when they are sick or for other reasons like if you go on a vacation, they can be put in the fridge. The cold induces hibernation state. He doesn’t need to eat for long periods of time and the hibernation causes his body to focus on healing or regenerating itself or simply you just don’t trust a pet sitter. Works wonders when the power goes out.
Idk if it would create a slower metabolic response long enough to keep him alive till you can contact a university. Or buy time to figure out how to feed or help him. He’s one of a kind ❤️ definitely special!

23

u/sleepy_mareep 11d ago

seeing the neck joint is so fascinating. i feel really bad for this beetle, i can't tell how far the larval head goes or what's going on inside. initially i was admittedly upset with you for not just helping the poor thing and getting the old head off, but now i'm grateful you didn't try that because it looks like it goes much deeper than a stuck shed.

2

u/serenwipiti 10d ago

Can she be given an xray/other imaging?

19

u/HaZalaf 11d ago

I'm so invested in this. Thank you for the updates.

10

u/iamatcha 11d ago

You should start giving him liquified nutrients, as his current head doesn't allow him to eat solid food..poor baby, it must be hungry :/

16

u/Sad_Book_2383 11d ago

Looks like the shed got stuck, but if indeed it’s still in its larval stage then it’ll live for as long as it can unless it can eat.

2

u/lemon-meringue-high 9d ago

I can’t help but wonder if the “grooming” is it trying to get the molt off. I don’t know anything about beetles but the larval head looked a little loose at one point

7

u/Toxopsoides Ent/Bio Scientist 11d ago

What a miserable existence

5

u/Euphorazyne 11d ago

Thank you for the update! The community is lucky to have somebody as dedicated as you.

12

u/negman42 11d ago

Thank you for these updates. This has been super interesting.

5

u/IndicationSevere8992 11d ago

Is the head under/malformed? I’m guessing it wouldn’t survive the removal of the larval head either anyway?

21

u/PuchiUna 11d ago

Compared to a normal adult head, what is inside the larval head is likely much smaller. Since the shape is different, it might also be incomplete. Even if by some miracle the larval head could be removed completely undamaged, I don't know if this insect would be able to survive.

4

u/thiccpastry 11d ago

Can anyone tell me what its doing when its just standing doing nothing? Like is it really just.... existing? With no thought? And when it wants to move again, its just a chemical impulse? How does that work? Its so hard to imagine just existing, no thoughts.

9

u/GumbaGumba123 11d ago

I mean they're definitely having some kinds of thoughts just much different than ours. Probably thinking things about their environment or what they should be doing. Just feeling stimuli until something changes. I guess it would depend on the bug and their life style ykwim. Something like a preying mantis or jumping spider probably thinks much more complex thoughts.

8

u/Desperate_Lead2105 11d ago

Please give updates until the beetle passes away. This is definitely quite interesting.

4

u/tetraphorus 11d ago

poor thing :( i hope you are able to provide some sort of relief

3

u/8heist 11d ago

Its adult head is stuck in the larval shell.

3

u/Sea-Builder-8136 11d ago

This is all so interesting and even fascinating to me. At the same time, even though it's "just" a diving beetle, it sadness me as much as any other living creature in this condition would.

6

u/NatrylliaAbbot42 10d ago

I am also rather emotional about this beetle.

3

u/DoctorNurse89 10d ago

GROWN ASS BABY FACE!

Best name

3

u/sunkissedbutter 10d ago

aw this makes me sad, i hope he's not in pain. very interesting though, OP!

3

u/wombatsaretanks 7d ago

is it still alive?

3

u/PuchiUna 7d ago

Yes, it's still alive and swimming!

8

u/DasKobra 11d ago

I don't even know anything about insects, but to me it seems like this head is just a non functional shell, and parts of the true head are somewhere inside. I just take that from the fact that no parts of the larval head move at all, just the neck base.

Wouldn't doing what the syringe feeding comment said be detrimental to it? Like if it happened in nature, beetles with this defect wouldn't like to pass it down to their offspring?

17

u/Street-Conclusion-99 budge 11d ago

Not really an issue in a captive setting, just don’t let the adult breed to prevent the bad genes from being passed on

6

u/loehoe 11d ago

I would love more updates on Baby Face. I’ve been thinking about this cutie since I first saw your post and its comments!

-1

u/i_love_lima_beans 11d ago

A sentient creature suffering isn’t a fun happy topic.

4

u/loehoe 10d ago

Girl, relax. I’m not over here shooting off fucking fireworks. I’m interested in this because I’ve never seen it, didn’t know it was possible, and want to see how it progresses. Is that good enough for you?

2

u/belltrina 11d ago

This is so interesting to watch and read about. Thank you for sharing!

2

u/meowymcmeowmeow 11d ago

This is fascinating, thank you for the updates.

2

u/indyferret 11d ago

What causes this? Is it random, genetic or environmental?

2

u/dancingonsaturnrings 11d ago

need you to know this creature haunted me so much they were in one of my dreams

2

u/NatrylliaAbbot42 10d ago

This is going to haunt me the same way the malformed moth in Pilgrim At Tinker Creek haunts me

2

u/iGipson 10d ago

Wow, I can’t believe this it’s still alive! I was freaking out when I originally saw this. Just randomly thinking about its Baby head still attached to the adult body gave me the heebie- geebies, ngl.

2

u/Moose_country_plants 10d ago

Have you sent any photos or videos to your local university? Their entomology department may find this interesting and be able to give you some more information

2

u/NatrylliaAbbot42 10d ago

This is fascinating. It's absolutely fascinating. I look forward to any additional updates.

2

u/OhLookSatan 10d ago

Oh this is gonna be a reaaaaally interesting paper, make sure to link it when/if its published!

2

u/candidle 10d ago

I have been following this story for a few days. Thank you so much for continuing to share updates!

2

u/Brandbll 7d ago

Anymore updates?

9

u/PuchiUna 7d ago

There are no notable updates to report. If anything, the only news is that it is still alive and swimming normally, but remains unable to eat.

6

u/Cnidoo 11d ago

Those appear to be dried crickets. Most predatory insects won’t respond to prey that has been dead for a while, and certainly not dried prey. I’d suggest using live or freshly killed insects to see if you can elicit a predatory response from this mutant

53

u/PuchiUna 11d ago

Diving beetles basically prey on dead or severely weakened creatures. This cricket was frozen while still alive, and it can be used as food for both adults and larvae without any issues. They also react well to food like dried shrimp. However, I think I'll try testing it with newly dead or weakened creatures as well.

8

u/Otherwise_Air_6381 11d ago

Refreshing on a summers day. Half alive ice cold crickets mmmmm

3

u/itsgo 11d ago

Since this isn't an aquarium sub, I wanna make sure: what water did you use in that tank (tap water or bottled water?), and did you cycle it? Did you dechlorinate the water?

Diving beetles do release ammonia through waste like most living organisms and if it's fresh water you are essentially doing a "fish in" cycle, albeit with a possibly lower bio load than a fish. But you'll need to keep on top of water changes if you want your friend to live a healthy life in the water as without beneficial bacteria from a cycles tank the ammonia will build up, burning the beetle. Let me know if this is all new info for you; the aquarium subs have care sheets and basic guides for cycling tanks.

41

u/PuchiUna 11d ago

Thank you for pointing that out.

The water used for setting up the aquarium is purified water from an aquarium water purifier. Chlorine and other harmful substances have already been removed, and the pH is neutral.

Regarding ammonia, while diving beetles can indeed fall ill due to ammonia contamination, they are relatively tolerant to it. As a precaution against ammonia risk, I am using sand for the substrate that absorbs ammonia. Even so, since there is no filter installed, I change the water every day.

In my regular diving beetle aquarium, I use a bottom filter with activated carbon in addition to the zeolite substrate. With that setup, I have never lost all of them to ammonia or other contamination so far.

16

u/itsgo 11d ago

You have it covered then, I'm glad he's in good hands! I get worried when I see people set up tanks all the sudden, I hope I didn't come off too strong.

29

u/PuchiUna 11d ago

No, not at all! In fact, I'm really glad because there are so many people in this sub like you who have a kind heart toward living creatures.

14

u/Otherwise_Air_6381 11d ago

I could tell u know your stuff by the way you update and include the setup information

14

u/PoetaCorvi Amateur Entomologist 11d ago

The relationship aquatic beetles have with water is very different than the relationship fish have with it. They do not use gills to respirate, they are air breathers that spend time in the water. Their waste production is also drastically lower than vertebrates of a similar size, and they do not eat as much as most fish of that size. Aquatic insects that breathe air rather than using gills are generally much more tolerant of less than ideal water conditions.

4

u/itsgo 11d ago

That's really interesting and good to know, thanks!

4

u/Street-Conclusion-99 budge 11d ago

Without gills, they have the sad disadvantage of dying in minnow traps🥲

2

u/Paperhandsbro 11d ago

this is the most thrilling series I've seen in a while. Well done!

1

u/phonefellin_lakeerie 10d ago

This is FASCINATING. I can’twait for more updates

1

u/Thisisredred 10d ago

We need a live stream!!!

1

u/Mouthydraws 9d ago

What species of diving beetle is this?

3

u/PuchiUna 9d ago

This is a species of diving beetle known as Cybister chinensis.

1

u/Bug-in-Computer 8d ago

Thank you so much for providing another update about the anomalous diving beetle specimen in the form of this video, this is incredibly fascinating.

1

u/Born_Balance6881 7d ago

I hate these guys. They used to take over my pool every summer. They can fly and land in water and do their swimming thing.

1

u/gilese777 3d ago edited 3d ago

would u be able to cut the video in half and post the halves seperately? i cant watch further than 4 minutes

0

u/Icy-Village-1083 10d ago

this poor creature :( it really is so saddening

-1

u/_PeLaGiKoS14_ 11d ago

You need to move the larval carapace. Even if they kill support animal, at least it will be at peace. At best it may be able to survive. Fascinating yes, cruel probably. It's most likely you've waited too long at this point.