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MLA Full: "You Need to Know About This Caterpillar." YouTube, uploaded by vlogbrothers, 13 September 2019,
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APA Full: vlogbrothers. (2019, September 13). You Need to Know About This Caterpillar [Video]. YouTube.
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Chicago Full: vlogbrothers, "You Need to Know About This Caterpillar.", September 13, 2019, YouTube, 03:59,
Citheronia regalis is a giant silk moth...though these don't actually produce silk, which is why it's better to go by their family name saturniidae. Citheronia regalis actually digs into the ground to pupate instead of building a cocoon, silk.

There are over 2400 species of saturniid moths and each of them have this same life cycle. They stuff themselves with food during their caterpillar stage and then use their adult, flying stage only as a way to find a mate for the next generation.

The Butterfly Farmer

Bart Coppens

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Good morning John it’s Friday,

You know how caterpillars become butterflies- well that is a lie. Any given caterpillar you spot honking its way down the sidewalk, there’s a 90% chance that that fresh little wiggler is incapable of becoming a butterfly and instead it will become a moth.

And John, moths: oh my God they’re so good. “What precisely is a moth?” you ask. Well here’s where it gets a little bit messed up because butterflies are like a thing- they have a single common ancestor. Moths are just anything that’s not a butterfly: any scale winged thing that isn’t a butterfly- moth. Is it more closely related to some butterflies than it is to some moths? Doesn’t matter, moth and talk about a branding problem right, butterfly is this beautiful word- it spoonerises to flutterby and then moth- it sounds like the noise you make when a moth flies into your mouth but moths, moths, moths, moths, moths. 

We’re stuck with the name. Let’s just look at these beautiful creatures and the one I want to talk to you about today is mostly the regal moth. Why: because of its caterpillar- The Hickory Horned Devil- which looks like this. You will never forget this caterpillar or probably its name cos it has got brand power- brand too strong. Now there are other Horned Devils out there. This is the largest of The Horned Devils, it’s from South America.

But The Hickory with its blue body and its red horns-why does it look this way? Well because it’s basically a hot dog with legs- it’s very good eating. It looks fierce but it’s not; it can’t sting, it can’t bite, it’s not venomous, it’s not poisonous but it’s too big to hide from raccoons and possums so its got to make those fuzzy folk worry about their noseies and toesies before grabbing on and taking a bite but lots of caterpillars don’t become gigantic food bags. In fact, the Hickory Horned Devil is the largest Caterpillar in the US.

So why is it so big?- because The Hickory Horned Devil has to consume massive amounts of food because Saturniid moths ,which this is one of is over 1000 species of these guys, do not have mouths once they become moths.

Once a Saturniid Caterpillar pupates, it will never eat again and so these caterpillars eat 2-3× their own body weight in leaves everyday, growing in size over 1000× in the course of a month. They don’t even digest the cellulose of these plants, instead they basically juice the leaves in their guts.

This time-lapse footage by the way is from John The Butterfly Farmer and his channel is amazing- there will be a link in the end screen and description.

When males emerge from their chrysalis, they fly sometimes for miles, trying to sniff out a female with their extremely sensitive, feathery antennae.

Their job is to locate the female because the female’s job is to use all of its energy creating 100s of very large eggs. The female Regal Moth does not fly until it mates and if it does not mate, it never flies- it just dies waiting. They have to mate and lay their eggs within the 7 days they have to live in their adult forms. 

The strategy of Regal Moths and other Saturniid is that the moth phase exists only for mating and breeding and to pull that off, the Caterpillar needs to be successfull in storing fats and proteins before it pupates and so it has to get big and full of nutrients which makes it a perfect snack so it has to look ridiculously fierce. Pretty much anything would see this juicy boy and think “that is not worth the risk” which is also how most people feel about them even though they are completely harmless. Still be nice because they are a marvel even if they are a little terrifying.

John, I’ll see you on Tuesday.

The bizarre beasts pin club was so successfull that this month and this is the only time we’ll do this, we’re actually gonna give you 2 pins: both the Caterpillar and the Moth.

Thank you to everybody who signed up and thanks both to The butterfly farmer and to Bart for letting me use their moth footage. Both channels are linked here.