The Hickory Horned Devil! (Citheronia regalis)

This week we are learning about a special giant silkmoth belonging to the subfamily of royal moths! These ones don't produce silken cocoons which are very uncharacteristic for a silkmoth. 

Support the show :) -> https://www.patreon.com/user?u=46499107

IG: https://www.instagram.com/insects4fun/

FB: https://www.facebook.com/profile.php?id=100085443614825

Email: Insectsfordummies@gmail.com

 

This week's music artists: HM Surf, PurrpleCat, mell-ø, S N U G, and Sleepermane.

 

Transcript: 

 

Welcome to Episode 31 of Insects for Fun! I’m your host Mitchel Logan and today we’ll be talking about a very cool Giant Silkmoth

 

The regal moth also known as the royal walnut moth or the hickory horned devil is a very large and beautiful moth in my favorite family of moths known as Saturniidae or the Giant Silkmoths. I’ve personally been raising Saturniids for the better half of a decade starting in my Senior Year of High School. If people are interested I might even sell eggs and cocoons for whatever I have at some point in the future, for subscribers of this podcast. 

 

Anyway! Today we are looking at only one of these beautiful creatures and one that I personally have never actually seen in real life. This moth is considered common in the southeastern states of the US and has become incredibly rare in states above New Jersey. I think its current range is actually south of Jersey west to Ohio and the edge of the great plains down into Eastern Texas but historically this moth could be found in New England as well. 

Unlike the other members of the Giant Silkmoth family this moth does not produce any silk! Usually, Saturniidae moths will weave silken cocoons which protect their pupae from outside forces, but this moth along with others in the subfamily Ceratocampinae actually bury into the ground before pupation. This feature makes them and all the other royal moths very difficult to find and tricky to raise. 

 

Before I continue I want to share with you a visual description because the regal moth or royal walnut moth, true to the name, is a very stunning creature. The body is red with yellow bands and the wings are grey with red lines going down them. There are also a few yellow ovals in between these red lines as if someone with a paintbrush decided to just dab some contrasting colors. This moth has the largest mass of any other moth above Mexico and has a wingspan of 9.5 to 15.5cm. The females are actually larger in this species which isn’t always the case with moths in this family. 

Earlier I mentioned how Hickory Horned Devils make pupae in the soil and you might have noticed I use the word Pupae when referring to moths and Chrysalis when talking about butterflies and this is because Moths and Butterflies have separate terms. Pupa and chrysalis mean the same thing, but the reason why Butterfly pupae are always referred to as chrysalids comes from coloration. Moth pupae are almost always a type of brown and look drab in comparison to the usual shiny and metallic butterfly pupae. The word chrysalis actually originates from the word chrysos which means gold and refers to this metallic sheen but we’re getting pretty off-topic so let's take it back (rewind affect).

 

The caterpillar of a Hickory Horned Devil is possibly one of the coolest-looking Giant Silkmoth caterpillars I’ve ever seen and there's a good reason why it got the name Hickory Horned Devil. The final instar of this caterpillar is a bluish-green color with 4 small black spiny appendages on each body segment, except for the tail and the first three segments including the head. Replacing these black spines at the front end are four large red and black-tipped devil like horns that protrude from the two segments directly behind the head of the caterpillar. It almost looks like a rams head but with four horns instead of two. The head and last body segment are both red in color and the thorax section has two large black dots where those large devil horns come out. Its six true legs are also red in color making this thing truly fearsome. Aside from looking super intense, these guys will also sometimes raise their heads and shake them to scare you, but this caterpillar can actually do no harm. To be honest it's one of the more docile ones. You can pet all the spikes and have them crawl all over you and you’ll be fine. Similar to many other menacing-looking animals it has to look that way if it wants to survive because otherwise it's got nothing.  

Another thing is that these caterpillars also happen to be one of the world’s largest, reaching a length up to 15cm. Yes it actually out sizes the caterpillar to the world’s largest moth by at least 2cm. I will of course be showing pictures of everything on the instagram page so I recommend people to follow that or the facebook page because I forward everything there as well. 

Hickory horned devils do indeed feed on hickory as a primary host plant, but they also feed on other plants such as walnut, butternut, persimmon, sumac and sweetgum, and the caterpillars primarily feed during the night when they’re still small and vulnerable. During the day these young caterpillars curl their bodies in the shape of a J to look like bird droppings. This actually works well for them because the coloration on their early instar/molts is black with a brown smudge. As they get larger and scarier they also get more active during the day and will be munching on leaves nonstop. 

Adult moths do not feed on anything at all. In fact, all Giant Silkmoths have no functional mouths once they reach adulthood and live purely off the fat they gained as a caterpillar.

Most Giant Silkmoths also go through a stage of hibernation known as Diapause in the entomology world, and the regal silkmoth actually hibernates in the winter underground as a pupa regardless of where it's raised, but the growing season might be shifted a bit depending on which part of the country or world you are in. 

I say world because you can actually breed these in other countries like the Netherlands for example. Many people love to raise giant silkmoths and its not uncommon at all for people to get insects from outside countries to raise for fun. Certain restrictions apply of course if there is an ecological concern but that will be listed by the supplier.  

Once the moths eclose from their pupae they get ready for flight in the case of a male or they get ready to use pheromones in the case of a female. As with all Giant Silk Moths, the female moth will not fly until after she’s mated and will actually hang where she eclosed and release a pheromone trail through her scent wand. It’s called a scent wand but it is not at all like a fairy wand or some other magic controlling stick. Think of it more like the mechanics of a highlighter pen, but when the tip of the pen is exposed to air it leaves a strong scent trail. The females moths can choose when to make themselves available by exposing their scent wand and it is in fact as quick as clicking a highlighter pen. The males have huge antennae for this very reason, because males are constantly on the move hoping to pick up a scent trail that will lead him to a mate. Females have much thinner antennae but usually have heavier bodies because of the hundreds of eggs they carry and they have the all powerful scent wand. 

 

Now there is another species of Horned Devil which is actually called the Pine Devil and this species of Regal moths feeds exclusively on pine trees and the color of the caterpillar actually matches the branches of the trees they feed on. This makes them different shades of brown with black markings but the body shape is essentially the same as the famous hickory horned devil. The moth is the same shape as well but the coloring is much more bland. It kind of looks like the walnut moth got left in the toaster too long or something like that, but you can see the images on the instagram and facebook page. 

 

If you are interested in Learning how to raise hickory horned devils I Highly recommend checking out Bart Coppens youtube video. He goes in-depth about how to raise these caterpillars among many other exotic giant silkmoths. I watched it to make sure it was legit and I’m happy to report he knows what he’s doing.