wriggling pupa

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kevinkk
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wriggling pupa

Post by kevinkk »

I've just finished a batch of Sphinx larva, and like a lot of pupa, they wriggle around, and could just about go for a walk.
Everyone has noticed this phenomenon with various species.
Have I missed something? How does that work exactly? My guess is that if I dissected a wriggly pupa, it'd be a mucky mess
of caterpillar guts. Has anyone ever X-rayed a pupa? What's in there that lets the pupa respond to moisture and being touched?
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Re: wriggling pupa

Post by eurytides »

X-rays won’t see the small muscles. Scientists have used microCT to scan butterfly pupae to look at how the adult butterflies form. However, I am not aware of any studies of sphingids. Not everything in the pupae turn to “goo.” Some muscles clearly remain intact. Perhaps intersegmental muscles move the abdominal segments.
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Re: wriggling pupa

Post by AZ-MOTH-er »

Besides the myth that everything in a caterpillar turns to an amorphous mass of goo when it pupates, here are some other absurd 'facts' that have been disproved and need to die:

Humans only use 10% of our brain capacity
We need to drink a gallon of water per day
Porcupines throw their quills
Coffee and tea are diuretics
We lose 75% of our body heat through our heads
Male mantids cannot mate unless their mate eats their head
Mistletoe berries (from New World species) are toxic
Caterpillars are sexless and indeterminate
(Individual) monarchs fly 3000+ miles while traveling to and from their overwintering places
Individual organisms can evolve
Size doesn't matter

I still hear these myths presented as fact to this very day.

This stuff dies hard.

If you've ever watched a prepupal lepidopteran molt and seen it carefully retracting palpi, proboscis, legs, wings from its larval skin and head capsule, you'll know that all these structures and appendages are already separate upon molting and can even move to some extent. And muscles must be present upon molting as I'm not sure just varying hydrostatic pressure alone would be adequate to cast off the larval skin.

And what a process! Imagine having to shed the inside of your mouth, your teeth, tongue, esophagus, the inside of your trachaea and maybe your lung linings, plus your rectum and colon lining to start a new job!
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Re: wriggling pupa

Post by kevinkk »

I was conjecturing, I don't recall ever reading in 50 some years anything about what is inside a freshly pupated caterpillar. We probably have
all seen the gradual development of the adult through the shell, as well as witnessing the process of emergence.
I won't comment on your list of myths it's tempting- in any event, the transformation process is an amazing one.
As to the last scenario- I'd probably choose crime as an occupation. It's bad enough getting a colonoscopy.
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Re: wriggling pupa

Post by Chuck »

Yes, old wive's tales die hard. There are those that have been disproven, and those that were known at the time, but forgotten; a repeated tale somehow stays alive. I think I could surprise even some of you with truths (non-insect) concerning "well accepted" facts.

Certainly caterpillar-to-goo-to-butterfly was disproven at least 50 years ago. I have an old Time Life book on insects that depicts an experiment to disprove the pupa-is-goo tale; so at least by the early 1970s it was suspect. Within the last year I read about a caterpillar where they'd identified the larval location of the wings; sorry I can't recall more.

I'm sure Adam can point us to the first "Pupae aren't Goo" publication.
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Re: wriggling pupa

Post by nomihoudai »

Here is a link to an article with pictures on phys.org, a science news platform: https://phys.org/news/2013-05-ct-scanne ... ysalis.amp

At the bottom you can find the reference to the actual scientific publication.
Lepidoptera distribution maps: lepimap.click
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Re: wriggling pupa

Post by adamcotton »

Chuck wrote: Wed Jan 11, 2023 12:58 pm I'm sure Adam can point us to the first "Pupae aren't Goo" publication.
Sorry, this is a bit outside my field, I don't remember any, although I do remember seeing an experiment pictured in National Geographic way back in the early 1970s (probably the one mentioned above) where they cut a pupa in half and connected the two halves with a clear tube and tissue grew through the tube to connect the halves together. I seem to remember it was a Saturniid pupa.

Adam.
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Re: wriggling pupa

Post by kevinkk »

That sounds weird. Do you recall if the halves were simply placed back together in proximity, or if there was a space in between? I wonder if the pupa matured into an adult.
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Re: wriggling pupa

Post by adamcotton »

There was a glass/plastic tube between the two halves of the pupa, so they could see the tissue growing inside. I do remember that the moth developed and hatched, but when it tried to fly the connection between the two halves broke and it died.

There were many pictures, and I seem to remember it must have been a species of American Attacini.

Adam.
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Re: wriggling pupa

Post by livingplanet3 »

adamcotton wrote: Fri Jan 13, 2023 8:33 am There was a glass/plastic tube between the two halves of the pupa, so they could see the tissue growing inside. I do remember that the moth developed and hatched, but when it tried to fly the connection between the two halves broke and it died.

There were many pictures, and I seem to remember it must have been a species of American Attacini.

Adam.
Indeed, that experiment was done with Hyalophora cecropia, in 1942. I have a book that features the photos, and briefly describes the experiment; "The Insects", part of the LIFE Nature Library series, published in 1962. I'll make some scans and post them here, later today.
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Re: wriggling pupa

Post by adamcotton »

livingplanet3 wrote: Fri Jan 13, 2023 4:57 pm Indeed, that experiment was done with Hyalophora cecropia, in 1942. I have a book that features the photos, and briefly describes the experiment; "The Insects", part of the LIFE Nature Library series, published in 1962. I'll make some scans and post them here, later today.
Thank you very much, my mistake - it wasn't in National Geographic. When I was very young my mother must have bought that book for me in the UK, and I still have it hiding on my 'general insect books' shelf here. I just checked, and indeed I have a copy of it up there, hiding behind Hölldobler & Wilson 'The Ants'. My mother used to subscribe to NG, and I thought that must have been where I saw the photos.

Adam.
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Re: wriggling pupa

Post by livingplanet3 »

adamcotton wrote: Fri Jan 13, 2023 5:34 pm
livingplanet3 wrote: Fri Jan 13, 2023 4:57 pm Indeed, that experiment was done with Hyalophora cecropia, in 1942. I have a book that features the photos, and briefly describes the experiment; "The Insects", part of the LIFE Nature Library series, published in 1962. I'll make some scans and post them here, later today.
Thank you very much, my mistake - it wasn't in National Geographic. When I was very young my mother must have bought that book for me in the UK, and I still have it hiding on my 'general insect books' shelf here. I just checked, and indeed I have a copy of it up there, hiding behind Hölldobler & Wilson 'The Ants'. My mother used to subscribe to NG, and I thought that must have been where I saw the photos.
Adam.
Scans attached -
Attachments
Cecropia_1.jpg
Cecropia_1.jpg (203.8 KiB) Viewed 111 times
Cecropia_2.jpg
Cecropia_2.jpg (228.42 KiB) Viewed 111 times
Cecropia_3.jpg
Cecropia_3.jpg (229.25 KiB) Viewed 111 times
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Re: wriggling pupa

Post by livingplanet3 »

Scan 4 -
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Cecropia_4.jpg
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Re: wriggling pupa

Post by kevinkk »

Thanks for doing this Livingplanet3.
it's interesting, I'm not going to go into my insect experiments when I was younger.
The mention of the fertilized ova is a surprise, although I know some breeders who decapitate male moths to induce copulation with difficult
species, but this experiment goes a little further than simple decapitation.
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