The Emperor Moth is a fascinating, large insect that captures the attention of many nature enthusiasts. These moths are best known for their vibrant, colorful wings and their impressive size. They are primarily nocturnal, which means you’ll most likely find them flying about at night.
Imperial Moth caterpillars come in a variety of colors and can grow to an astonishing 5.5 inches in length. As they develop, their appearance changes, making it an interesting process to observe. Not only are these caterpillars noteworthy for their size, but they also transform into stunning adult moths that are impossible to confuse with other species due to their unique patterns and colors.
An essential aspect to consider about the Emperor Moth is the selection of host plants on which they lay their eggs. These plants play a crucial role in the life cycle of these moths, and understanding their connection to specific host plants will offer valuable insights into their survival and reproduction.
Emperor Moth Overview
Saturnia Pavonia
The Emperor Moth, scientifically known as Saturnia pavonia, is a large and attractive moth species belonging to the Saturniidae family. Noted for their vibrant colors and bold patterns, these moths are especially fascinating for their unique appearance.
Distribution and Habitat
Emperor Moths are widely found across the British Isles, including England, Wales, Scotland, and Ireland, as well as in other parts of Europe. They inhabit various ecosystems such as heathland, moorland, and woodland, showing a preference for areas with birches and fens. Some typical habitats include:
- Heathland
- Moorland
- Woodland (especially with birches)
- Fens
Conservation Status
Thankfully, the Emperor Moth is not considered an endangered species. Their conservation status in most regions is stable, mainly due to their relatively wide distribution and adaptability to different habitats. However, it is essential to continue monitoring their populations and ensure the preservation of their habitats for their continued survival.
Appearance and Characteristics
Size and Wingspan
- The Emperor Moth is a large and impressive moth
- Wingspan ranges from 3 to 4 inches (7.5 – 10 cm)
The Emperor Moth is a large and visually appealing species. With a wingspan that ranges between 3 and 4 inches (7.5 – 10 cm), it is one of the most eye-catching moths native to the UK and Europe.
Colour and Markings
- Males have mostly brownish-grey wings
- Both have large eye spots on their wings
- Eye spots are striking and resemble rings
The overall colour of the Emperor Moth varies slightly between males and females. Males typically have brownish-grey wings, while both sexes display large, striking eye spots on their wings, which resemble rings. These eye spots help ward off predators by acting as a defense mechanism to confuse or scare potential attackers.
Sexual Dimorphism
- Females have more rounded wings
- Males have more pointed wings
- Males have feathery antennae
- Females have less feathery antennae
Emperor Moths exhibit sexual dimorphism, with males and females having unique physical traits. Their wing shape is one such distinction, with females having more rounded wings, while males have slightly more pointed wings.
| Feature | Male Emperor Moth | Female Emperor Moth |
|---|---|---|
| Shape of Wings | Pointed | Rounded |
| Antennae | Feathery | Less Feathery |
Antennae are another sexually dimorphic feature in these moths. Males sport feathery antennae, while females possess less feathery antennae. This difference plays a role in the moth’s reproductive success, as the male’s feathery antennae help them sense and locate the pheromones released by females during mating season.
Life Cycle and Behaviour
Eggs and Caterpillars
Imperial moths lay their eggs on the foliage of host plants. The eggs hatch into caterpillars, which have a wide range of appearances and can grow up to 5.5 inches in length.
Some key features of imperial moth caterpillars include:
- Large size
- Variability in appearance
- Feeding on host plant foliage
Pupa and Adult Moths
After the caterpillar stage, the imperial moth enters the pupa stage. The caterpillar forms a cocoon and becomes a pupa, eventually emerging as an adult moth.
Characteristics of pupa and adult moths:
- Pupa development occurs within a cocoon
- Adult moths have a beautiful and variable appearance
- Adult males have more feathery antennae than females
Feeding and Predators
Imperial moth caterpillars feed on the foliage of a variety of host plants. They are considered generalists, as they will consume almost any type of plant material.
As for predators, some common ones include:
- Birds
- Small mammals
- Carnivorous insects
Conservation Status
There is currently no specific conservation status for the imperial moth. However, their population, like other moths and butterflies, can be affected by habitat loss and pesticide use.
Comparison: Imperial Moth vs. Miller Moth
| Feature | Imperial Moth | Miller Moth |
|---|---|---|
| Caterpillar Size | Up to 5.5 inches (large) | Smaller than imperial moth |
| Caterpillar Diet | Foliage of various host plants | Mostly grasses and grains |
| Adult Moth Size | Large | Smaller than imperial moth |
| Adult Moth Flight | Mostly nocturnal | Mostly nocturnal |
| Predators | Birds, mammals, insects | Birds, mammals, insects |
Food Sources and Habitats
Woodland Rides and Heath
The Emperor Moth prefers living in woodland rides and heath areas, where they find ideal food sources. Some of the moth’s preferred food plants include:
- Heather
- Bramble
- Blackthorn
- Hawthorn
These plants provide an excellent source of nutrition while allowing the moth to camouflage itself with its surroundings.
Hedgerows and Field Margins
Hedgerows and field margins are another suitable habitat for the Emperor Moth. These areas usually contain a variety of woody plants, such as:
- Sallow
- Sallows
- Other shrubs
These food plants are crucial for the growth and survival of the moth throughout its life cycle.
Sand Dunes and Moorland
Finally, sand dunes and moorland provide yet another ideal habitat for the Emperor Moth. Here, the moth can thrive among a variety of plant species while staying close to nature. The list of food plants found in this habitat includes:
- Heather
- Bramble
- Other native plants
| Habitat | Food Plant Example 1 | Food Plant Example 2 |
|---|---|---|
| Woodland Rides | Heather | Bramble |
| Hedgerows | Sallow | Sallows |
| Sand Dunes | Heather | Bramble |
By understanding the various habitats and food sources of the Emperor Moth, we gain a better insight into this beautiful butterfly’s behavior and preferences.
Miscellaneous Information
History and Classification
The Emperor Moth belongs to the Saturniidae family, and the species was first classified by Carl Linnaeus. They are considered large, showy insects that are known to fly at night. Caterpillars of this moth can grow up to 5.5 inches and display a variety of colors, from light to dark green and brown shades.
Some features of the Emperor Moth include:
- Large size
- Yellow wings with spots and speckles
- Highly variable caterpillar coloration
Mating and Pheromones
For mating, Emperor Moths use pheromones to communicate. Male moths have more feathery antennae, which helps them to detect these pheromones in the air and locate females for mating. Mating usually occurs at night, aligning with their nocturnal nature.
Comparison of Male and Female Emperor Moths:
| Feature | Male | Female |
|---|---|---|
| Antennae | Feathery | Less feathery |
| Flying Time | Night | Night |
Although not a primary predator, owls may occasionally prey on Emperor Moths due to their nocturnal activity. As these moths fly and mate primarily at night, they can be difficult to observe and photograph, making pictures involving them a challenging but rewarding achievement in the world of science.
83 Comments. Leave new
I’m no expert, but are you sure this is not the Mopani worm or some relative of it?
Thanks for the reply 50/50, after many months. I found this caterpillar on the grass in my garden in Johannesburg. When I discovered, after a week, that my whole Kiepersol tree was invaded, I was so shocked! They eat, but every single leaf on this tree! After they’ve eaten and fully grown, they bury themselves under the soil for the next stage, before becoming a giant moth. I also thought it was a Mopani worm, and googled it, but no, not a Mopani. Does anyone know a short name for this creature? Except for the African Emperor?
Found 25 in Featherbrooke Estate Krugersdorp
Happy Thanksgiving!
You may want to take this up with Bill Oehlke, but the forewing on this specimen doesn’t seem quite dark enough to me to be H. dyops and looks more like Heniocha marnois. I am not certain about this so I would ask Bill.
Thanks for the suggestion. I will contact Bill Oehlke
I would like to be in contacrt with the person who submitted Heniocha marnois image. Please ask them to contact me at oehlkew@islandtelecom.com or provide me with the person’s email. Thanks
Bill Oehlke
Also Spotted in Pretoria South Africa in April 2013 beneath a Kiepersol tree. All of them fell off the tree and was moving to the West side of the stand.
Hi, I’ve just spotted a load of these in Sierra Leone on a mining site camp…thought I would share
Eyespots, wonderful!
I also thought, “Bird Attack!” when I saw this butterfly. This red-tip hedge (of my neighbors) is patrolled by a mockingbird who was singing nearby while I took photos. I wonder…
Eyespots, wonderful!
I also thought, “Bird Attack!” when I saw this butterfly. This red-tip hedge (of my neighbors) is patrolled by a mockingbird who was singing nearby while I took photos. I wonder…
Observed dozens feeding in a Kiepersol tree in Northwold Johannesburg. Amazing.
My garden has just become invaded with these. There must be about 100 roaming around. The unfortunate part is because they wiggle like snakes, I am petrified 🙁
There is no need to be frightened. They are perfectly harmless.
Dear WTB
Thank you so much and for such a speedy response!
The photographs you may of course use.
I will direct my sister to the photos of the adult moth which is different in colouring from the ones commonly seen, which are pinkish in the eyes and the margin patterns and generally all over buff coloured. Where as the one shown in the related posts is yellow and brown and much lighter all over.
I will let you know if she has any more information.
Thank you again.
Regards
Anita
Please send any photos of the adult moth you might have or might be able to take. It would be an excellent resource to be able to include photos of the caterpillar and moth on our site, especially as there is so much taxonomic revision being done regarding species and subspecies that are very local in distribution.
Dear WTB
Thank you so much and for such a speedy response!
The photographs you may of course use.
I will direct my sister to the photos of the adult moth which is different in colouring from the ones commonly seen, which are pinkish in the eyes and the margin patterns and generally all over buff coloured. Where as the one shown in the related posts is yellow and brown and much lighter all over.
I will let you know if she has any more information.
Thank you again.
Regards
Anita
We are on holiday in Keurbooms and there are dozens of these caterpillars on a small tree in the garden, the neighbour says they are here every year ~ poor tree is denuded!! Got some amazing photos though 🙂
Please send the photos using our standard form by clicking the Ask What’s That Bug? link on our homepage.
I have seen these caterpillars for the first time. The “water tree” in front of my house is invaded by them and has no leaves left. They are digging holes in the ground and I am worried that the tree is damaged. Obviously if these are moths I’m soon going to have an invasion plaque of giant moths. How can I get rid of them?
Allison
Hi Allison,
We do not provide extermination advice.
I have seen these caterpillars for the first time. The “water tree” in front of my house is invaded by them and has no leaves left. They are digging holes in the ground and I am worried that the tree is damaged. Obviously if these are moths I’m soon going to have an invasion plaque of giant moths. How can I get rid of them?
Allison
Hello,
We found these interesting insects at the restaurant I work at in Port Elizabeth, there is a small garden area next to the function area and they came inside, was a mission to collect them but eventually managed to get them all we hope. We are all wondering if they are poisonousor not, a few of us handled them and a couple of guys managed to get themselves pricked by the spines.
Sincerely
Troyé
Dear Troyé,
African Emperor Moth Caterpillars are not poisonous. They are actually edible.
Hello,
We found these interesting insects at the restaurant I work at in Port Elizabeth, there is a small garden area next to the function area and they came inside, was a mission to collect them but eventually managed to get them all we hope. We are all wondering if they are poisonousor not, a few of us handled them and a couple of guys managed to get themselves pricked by the spines.
Sincerely
Troyé
Dear Troyé,
African Emperor Moth Caterpillars are not poisonous. They are actually edible.
Hi, I just found about 50 in my neigbours fig tree. They are munching all the young leafs. Shame poor plant. If they burry themselves do they come back and eat on that tree again?
If they bury themselves, it is to pupate before emerging as Moths. The Moths do not feed.
I have thesenasty looking catterpillars in my garden.
They don’t bug, pardon the pun, me as much as scare me with their armour like body.
I am scared they get into my roof and start feeding on the wood.
Am I over-thinking this?
Please let me know, as I would hate to exterminate something harmless.
Thanks!!
Emperor Moth Caterpillars feed on leaves, not on wood, so your roof is safe. According to Wikipedia: “Food plants Bauhinia spp, Croton spp, Harpephyllum caffrum, Cussonia spp, Celtis spp, and Ekebergia capensis. In DR Congo the larvae feed on Sarcocephalus latifolius, Crossopteryx febrifuga and Dacryodes edulis.”
I have thesenasty looking catterpillars in my garden.
They don’t bug, pardon the pun, me as much as scare me with their armour like body.
I am scared they get into my roof and start feeding on the wood.
Am I over-thinking this?
Please let me know, as I would hate to exterminate something harmless.
Thanks!!
I live in Amanzimtoti in Kwa Zulu Natal, South Africa which is subtropical and last year we also had lots of these beautiful caterpillars in the garden and they too were on our Kiepersol (cabbage) tree, they had a wonderful feast and moved off. I thought they were stunning and picked a couple of them up for some photographs, (after I checked they were not poisonous.) Nature makes some amazing creatures.
If you have any nice images, you can submit them using the Ask What’s That Bug? link on our site.
I currently have a whole collection of the African Emperor worms eating my tree. I was totally shocked when I first saw them. Very happy they will turn into stunning moths. They are welcome to stay and graze 🙂
The leaves will grow back after your caterpillars pupate. The caterpillars are also an important food source for birds and other insectivores.
Our cussonia trees are also invested with these ghastly emperor caterpillars. They are also creeping around on our patio and in the garden and we have to keep our little Jack Russel inside all the time. They are causing a massacre of the leaves of the cussonias and I really want to get rid of them. Am going to pour ant poison around the trunk of the tree. We have been living six years here and have never seen them before. Is it the drought that have brought them here? See you provide no eradication advice, but surely there is something which can be sprayed which is environment friendly?
Insect populations change year to year depending upon weather conditions and food supplies. We are not sure why you are being so troubled this year and you have seen no evidence of Emperor Moth Caterpillars in previous years. You are correct that we do not provide extermination advice.
I found this caterpillar by my house,and it`s not eating or moving.It`s is night time at my house so it might sleeping,but I don`t know.I`m waiting for it to make a cocoon,then I`ll let it fly away.Can you tell me what it eats please.I would be sad if it did not eat. Thank you Bug Man ,Jake
Chances are that if the caterpillar left its food plant, it was to search for a place to pupate. At that time, the caterpillar stops eating.
Thanks.How big is it usually when it stops eating?
We are in Ballito and just noticed thousands of them eating away our tree there are big ones and smaller ones as well as some with eggs on them. Thought I wanted to exterminate them but after reading these comments we will leave these beauties to graze.
Thank you Bugman! Great website. We saw a lot of these African Emperor caterpillars purposely crawling along the grass and tarmac in our church carpark. We kept collecting them and putting them into the flower beds to keep them from being run over but they weren’t co-operating! It was obvious they were looking for a place to pupa. Our toddler group were fascinated by them! What beautiful creatures.
The caterpillars arrived virtually overnight again in the same kiepersol tree at the same time of the year in Northwold, Johannesburg. After about a week they disappeared again virtually ovennight. The tree is stripped bare in places ant the ground underneath thick with droppings—–but no caterpillars.
Very curious about this bug my dad found the exact same moth/butterfly in france is this normal ? Is this bug dangerous ?
The Pine Emperor Moth is not found in France, though it is possible there was an escape from a breeder.
Interesting to hear the news ab out the emperor moth caterpillars, I feel that they do the tree a favour as while they eat they also create fertiliser, and as most of these creatures depend on some sort of tree they seldom do that much harm to the tree as to destroy the tree altogether, they need to feed themselves again next year, you could say they are subsistence farmers of a sort.
We like your philosophy.
TOTALLY agree! They are fascinating aren’t they?
HI There, We live in Pretoria South Africa, and have the same infestation of the gorgeous caterpillars in our kipersol tree. I have picked a few and put them in a box (with some kipersol leaves) to take to school. Do you think they would pupate if the don’t have soil? I would love to see them change to moths. My children are fascinated as are we.
I would never spray these caterpillars or kill them. The trees will come back and shoot new leaves anyway. I am just so happy we still have interesting creatures to find in our garden in the city.
They are so big at the moment they almost look like they are ready to change.
So exciting!!
We have a recent posting of Emperor Moth Caterpillars from Nigeria and a follow-up posting that includes images of pupation. Perhaps you can take a few hints from those postings.
HI There, We live in Pretoria South Africa, and have the same infestation of the gorgeous caterpillars in our kipersol tree. I have picked a few and put them in a box (with some kipersol leaves) to take to school. Do you think they would pupate if the don’t have soil? I would love to see them change to moths. My children are fascinated as are we.
I would never spray these caterpillars or kill them. The trees will come back and shoot new leaves anyway. I am just so happy we still have interesting creatures to find in our garden in the city.
They are so big at the moment they almost look like they are ready to change.
So exciting!!
I noticed one of these caterpillars yesterday. ( in Port Elizabeth) Today we saw more then realised they were coming down the tree trunk, lots of them! What we originally thought were little berries fallen on the ground must be caterpillar poop 🙂
We discovered dozens of these caterpillars on a milk wood tree in our garden in Grahamstown Eastern Cape South Africa. After a while they move onto the ground looking to bury themselves under the grass. How long do they take to chrysalis then emerge as moths? Very beautiful little creatures. Make sure to let everyone know they are totally harmless and a sign of healthy environment. Don’t kill them. They are a part of the ecosystem probably food for birds and bats
Just spotted a few of thoses emperor catappilers in Grahamstown Eastern Cape.
They look so cute .
Just spotted a few of thoses emperor catappilers in Grahamstown Eastern Cape.
They look so cute .
Good day! I just found a Emperor Catepillar and would love to keep it and show the cycle to my son but I am not to sure whats the best way to keep it save and feed it???
Plse Help!!!
Good day! I just found a Emperor Catepillar and would love to keep it and show the cycle to my son but I am not to sure whats the best way to keep it save and feed it???
Plse Help!!!
I am from South Africa in Kwazulu Natal.
We have a whole stack of them in the neighbours tree. saw them yesterday feeding away and they get so fat they fall off onto the lawn. We live in Port Alfred, Eastern Cape. Glad to hear they are harmless. Scary looking for sure.
They might be dropping to the ground so that they can burrow beneath the surface to pupate.
I collected a few fro my kids to watch change into moths, I collected soil and added some of the leaves fro them to eat, they unfortunately all shriveled up and died.
We visited near Bela-Bela and a nasty caterpillar got hold of me. Stung me in the neck. Havpie a severe rash.. Local told me it was a caterpillar, althtough I did not see it. Do you know more about it, and how long will rash last?
Why would the moths move into our ceiling and use the light fitting as a door? I’ve noticed the caterpillars for the first time this year in our Pretoria, South Africa, garden and now they hang around in our kitchen. Could the handful of indoor plants be the reason? We also have not used any poison in the garden since we’ve moved in 5 years ago.
We don’t know why these caterpillars moved indoors.
Hello. I live in South Africa. This is the first time I have ever come across this species of moth : Pine Emperor Moth.
It seemed to be struggling to fly. I attempted to rescue it (from being trodden on / eaten by cats).
Do you have any advise on how to care for it?
image:
https://www.facebook.com/photo.php?fbid=1699080297062531&set=a.1459387831031780.1073741831.100008817318811&type=3
See that it’s warm has a bit of water/moisture and keep it away from the cat, a bit of cheese is also a good idea, some of them actually like candy floss.
Hello. I live in South Africa. This is the first time I have ever come across this species of moth : Pine Emperor Moth.
It seemed to be struggling to fly. I attempted to rescue it (from being trodden on / eaten by cats).
Do you have any advise on how to care for it?
image:
https://www.facebook.com/photo.php?fbid=1699080297062531&set=a.1459387831031780.1073741831.100008817318811&type=3
Found one in our garden yesterday, (to my six year old sons delight) We are situated in Naboomspruit (Limpopo) I have never seen anything like it. Really a beautiful creature, but scary in a way.
I have had the same experience but all the caterpillars have had wasp eggs attached to them and will surely be devoured before they can pupate and become moths again
Found one of these caterpillars in my garden this morning under the peper tree. Took photos and then carefully relocated it to the reserve across the road.
Nearest pine tree is about 800m away. Don’t know how it got to my garden.
Lovely colours. Would love to see what it becomes.
I’m located in Kleinmond, in the Overberg region
Found one of these caterpillars in my garden this morning under the peper tree. Took photos and then carefully relocated it to the reserve across the road.
Nearest pine tree is about 800m away. Don’t know how it got to my garden.
Lovely colours. Would love to see what it becomes.
I’m located in Kleinmond, in the Overberg region
I found one in my garden in port elizabeth
Don’t use insecticide. Nature knows best
We are in Pretoria, Akasia. Our house is in a place called Chantelle. These worms scare my wife. They are looking fierce of course. Could you tell me what their common name is and any African name (any of the South African languages) if they have any?
Seeking information, defiantly a cabbage tree caterpillar. But no Kiepersol tree nearby? all making here way to somewhere? Where are they going? can they feed on other trees? how long till they become a moth?
Can you please tell me how long between starting the pupa stage to the orchard swallowtail butterfly emerging.
The one on our curry leaf plant has been in pupa for two days.
I was surprised it was on the curry leaf plant as we also have dwarf lime and kaffir lime nearby.
It most likely left the citrus to pupate on the curry plant. We would estimate two to three weeks.
Can you please tell me how long between starting the pupa stage to the orchard swallowtail butterfly emerging.
The one on our curry leaf plant has been in pupa for two days.
I was surprised it was on the curry leaf plant as we also have dwarf lime and kaffir lime nearby.
Ifound them in kitale Kenyalast year so many and they disappeared. Now they are back
I have just seen them in Natures Valley.On a tree that I don’t know but there were probarly like 50+ of them In one tree!
We have hundreds of these which return to the same trees each year. Some of them have what look like white eggs all over them. Can anyone tell me what these are?
Some species of large caterpillars, especially those in the families Saturdiidae and Sphingidae, fall prey to parasitoid Brachonid Wasps that lay eggs inside the developing caterpillar. The Braconid larvae feed on the non-vital internal organs, eventually emerging and forming pupae on the Caterpillar, which alas, will not survive the parasitization.
Found many of these in a tree I had to cut down in Pretoria East. Couldn’t believe how big they are!
So excited. Just found the orchard swallow tail caterpillar on our lime tree. How long till pupa