Emperor Gum Moth

22 November, 2009

Emperor Gum Moth - Opodiphthera eucalypti adult male
Emperor Gum Moth - Opodiphthera eucalypti adult male
Image: Mike Coupar
Source: Mike Coupar

Question: Has the emperor gum moth declined in numbers recently?

Answer: The Emperor Gum Moth, (Opodiphthera eucalypti), is a spectacular species of moth that is found over most of Australia and has been introduced to New Zealand. It can be quite variable in colour ranging from grey, through straw-coloured, to almost brick red.

The caterpillars feed on a variety of species of gum, but will also feed on other plant species. The caterpillars need to consume enough food to complete the transition from caterpillar to moth and also to sustain the adult moth as the adults do not feed.

While the larvae of this species can cause some damage to trees with their eating of the leaves this species is not usually associated with widespread damage. The Emperor Gum Moth is a food source for large birds and is also parasitised by a number of insect species.

This species of moth used to be commonly seen in the larval form, as the caterpillars are large and quite spectacular with their colour scheme and spiky protuberances.  Anecdotal evidence suggests that the caterpillars were more common a generation ago and the question has been raised as to the availability of any studies or proof that the numbers of this species are falling. While we have not been able to find any concrete evidence of their decline, some people of an older generation have reported that the moths both in the adult stage and as larvae are much less common now than when they were children.

The European Wasp is a predator of many native species including the Emperor Gum Moth caterpillars. The Senior Curator of Entomology at Melbourne Museum believes that the European Wasp has unfortunately had a huge impact on the population of this species in some areas.

Comments (73)

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Doug & Alison Retchfrod 6 March, 2014 14:08
We have just discovered 3 Emperor Gum caterpillars in one of our gums in the back yard. This is the first time we have ever seen them on our Surrey Hills Victoria block in 34 years.
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Steve ryan 13 February, 2014 17:13
We found one in our front yard before Xmas we had a caterpillar on our house We lost him for a while but found a cocoon on the timber of our window today it is on the wall of our house in Frankston Victoria the biggest moth I've seen around here
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Holly 30 December, 2013 08:40
Last spring (2012) we had a gum tree full of these larvae, most of the the cocoons are still on the tree. My children and I have been waiting a long time to see them transformed, yesterday we found an empower gum moth in the driveway, alive! We were fascinated as we had never seen the larvae or moth before. A quick google led me here to learn about them. I hope we find some more.
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Craig 6 December, 2013 21:44
Today I found 5 large emperor gum larvae on some gums at a nursery I work at in dingley Victoria. I saved them from being sprayed (they should have been sprayed about a week ago but the rained stopped that and apparently not long after I took them someone came to kill them) I was going to let them go on a tree my bro and I used to pick to feed these little guys when we had them many moons ago but after reading up on them I feel like I saved them from one death only to send them to another I'm now thinking about keeping them until they turn into a moth, then let the moths go. What do people think about this?
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Neisha 20 October, 2013 13:23
Hi, We have a huge population of these caterpillars at our kindergarten. The children find them very fascinating. Just wondering if you have any resources we could use with the children to extend their intrest in the caterpillars and moths? Thanks
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Bron 11 March, 2013 22:04
I'm in coburg, victoria and thanks to the internet have discovered we have about 7 emperor gum caterpillas on a small gum in our back yard. They are lovely, big and healthy. Hopefully the wasps dont find them and they survive to moth stage.
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Paul Swiatkowski 10 February, 2013 21:30
I have undertaken a breeding program and to date have had over 1000 fertile eggs from a base of about 30 pupae. The problem always was coordinating emergence which seems to be more related to day length than anything else I have just hatched a couple of hundred helena gun moth caterpillars, which are closely related to the emperors and would like to make them available primarily to schools but not exclusively if others are interested. They are relatively easy to rear if you have access to fresh young gum leaves They are all currently either second or third stage caterpillars. The biggest problem to date has been polyhedral virus Please feel free to pass on my Email to anybody who is interested. I only want to cover postage and handling via express post for obvious reasons.
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francois 18 August, 2013 23:34
Hi paul, i saw that you have already reared this caterpillar this year. It will be great if you could respond me. I have some cocon and a female which is born yesterday evening had begun to laid this night. i didn't saw the pairing with a young male and this morning the pair was separated. My first female have done the same thing few days ago. what do you think? Why this females laid for their first day? Is it usual with this specie like with the automeris to have quickly pairing. Best regards, francois
Alan Hopkinson 15 June, 2013 20:00
Hi Paul Do you still have any of the O.helena pupae. I would love to have a few. I have not seen this one in the wild.
Lee-Ling B 18 November, 2012 21:15
I'm raising 9 emperor gums. They are about 15 days old. About five of them have she'd their first skin. What they do is not move or eat for about a day and then they shed their skin. I have two caterpillars that had dent moved for about 2 days. Then today I watched them as they started shaking their heads extremely violently. They kept doing it for about 30 mins. All of a sudden they just stopped nearly at the same time and they kinda just flopped on the leaf and didn't move for ages. I thought they were shedding their skin, which they might be. But when I picked up the leaf they were on to have a look at them, they just fell right of the leaf as though they were dead! I don't know what to do. They are still at the bottom of they box because they are still too small to pick up!!! Are they dead? If you know something please tell me. It has been 8 hours or smthing and they r still in that awkward position they fell in...
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Discovery Centre 22 November, 2012 09:46
Hi Lee-Ling, our Live Exhibits manager has said it appears your caterpillars are dying of insecticide poisoning. What you describe is the classic behaviour demonstrated when caterpillars ingest poison either from an aerosol spray or through the plant. Aerosol sprays work immediately and quickly lose their potency, but plants bought from large nurseries or hardware stores have often been treated with systemic insecticides that can last six months or more.

Small parasitic wasps often attack Emperor Gum caterpillars, but they tend to have an effect only in the later stages of development. The caterpillars are also susceptible to disease such as nuclear polyhedral viruses, but the symptoms for these are very different to those you described.

Nick Hughes 13 November, 2012 15:42
I grew up in Beaumaris, a leafy bayside suburb of Melbourne in the 1960's/70s. Eucalyptus trees were everywhere and they were literally weighed down with emperor gum caterpillars (and another species of caterpillars which we called 'spitfires'.) Show and tell at primary school often involved bringing a shoe box full of gum tree leaves laden with these fantastically iridescent green caterpillars.
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Kerryn M 24 October, 2012 22:18
I have been trying to find out what type of caterpillar we have in abundance that is falling from our gum trees like rain. It is the first time in the six years that we have lived on our property that we have seen these caterpillars and our chooks are eating them and I was worried that the might be poisonous. I think that they may be the caterpillars of the emperor gum moth. How can I tell for sure?
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Discovery Centre 25 October, 2012 11:58
Hi Kerryn, the Discovery Centre can identify specimens for you and let you know a bit more about the habits and possible dangers once they are identified. Contact us through our Ask the Experts Identifications page and we'll do our best to help you out.
David Giomi 20 October, 2012 22:07
We were camping at lake Eldon last week and I have a picture of one sitting on a can of olive oil. Was supprised to see it as I remember back in the 70s they were all over the outer northern suburbs of Melbourne. The last time I found one in my garden at Templestowe lower was in 93.
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Sandra 13 October, 2012 22:38
I live in baranduda (near Wodonga) in victoria an have just Found a beautiful sandy coloured emperor gum moth sitting on my back door. We have only lived in the area for a short time and we marvel at the wildlife literally at our back doors.
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Vicki Griffiths 9 October, 2012 00:25
I was excited to find this large Moth in my friends backyard Marion Bay, Tasmania. What a beautiful creature it is and thank you for all the information on here it was so interesting to read about this magnificent moth, the information for Natalie was helpful as I also had the same question,thanks.
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Diane Baker 16 August, 2012 13:45
I live in Talgarno which is near Wodonga Vic. I planted some new gum trees on my property about 2 years ago & today I found bunches of black caterpillars hanging in the forks of the branches & many of the leaves either completely eaten or full of holes. The bunches of caterpillars are about the size of a closed fist with caterpillars all on top of each other they are about 5cm long. I am wondering if these are harmful to the young trees.
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Brian 3 October, 2012 03:36
The fists of black caterpillars you're referring to are probably the lava of the saw fly and are commonly known as "spitfires" for their defensive behavior when provoked where they squirt acrid fluid to repulse a would be attacker! They are social live as a family group (the fist you speak of)of siblings which all hatch and live together until they pupate.They actually communicate with each other by tapping their rear ends as they move around their tree! http://www.youtube.com/watch?v=LYwkC0XqrA8
dorcas 12 September, 2012 10:47
I am also wondering what these fists of black caterpillars are on gum trees, what do they turn into?
Discovery Centre 16 August, 2012 13:54

Hi Diane, Museum Victoria has a free Identification Service. If you send us a photograph of your caterpillars, we would be happy to identify them for you. Large numbers of caterpillars feeding on a single young tree may cause the tree to become stressed. However, if the tree is otherwise well-established and healthy, it should recover.

Ej 12 June, 2012 06:23
are these Common in Michigan during the Summer?
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Discovery Centre 14 June, 2012 12:26

Hi EJ, Brenda from Michigan asked a similar question on the 25th Mar 2010. Please have a look at the answer we posted for Brenda.

Lisa Chapman 3 March, 2012 08:55
We have just found two of these caterpillars in Whangarei NZ,very beauitiful to look at but did take me a step back when i first saw it never seen anything like it.Glad to have finally identified it.
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Natalie 22 February, 2012 08:43
Thanks to your website I was able to identify this beautiful creature. I have found an adult emperor gum moth and I am in Hamilton, New Zealand, this is the first time I have ever seen one. It is very docile at the moment I hope it is not about to die...what should I do?
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Discovery Centre 23 February, 2012 15:24
Hi Natalie, adult Emperor Gum Moths do not live for very long; after emergence from their cocoon their sole purpose is to mate and lay eggs, the adults do not feed. So it may be that your moth has already mated or if not the best thing to do is leave it outside as it will be keen to try and mate.
Shaun 21 February, 2012 19:00
The other day we found 1 was like Christmas because the last time I saw a gum was probably 13 years befor today we are caring for it gonna try breeding doing research and such best looking out of all the caterpillars I've found to this day
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Nikki 5 February, 2012 15:31
I came across one of these on South Bank in Melbourne today. I've never seen one before, took a few pictures and now your website has enabled me to identify it.
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Doug W 23 January, 2012 11:45
About four years ago I was delighted to find 22 large Emperor Gum caterpillars in a small gum tree in my back yard. {Melbourne South East} ... Back in the 1950s I was a great fan of these caterpillars . So I called my grandson who was very keen to come around the next morning . That evening I found two possums in the tree feasting on the caterpillars . All I had to show my grandson the next day was one half of a large green caterpillars. "Beware of possums" .
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vera 22 January, 2012 20:01
I'm located in the Southern Highlands and today found an exhausted female on the side of our house, with what I suspect are the last of her eggs. I am hoping that she laid the majority on the huge gum tree nearby. After hearing about the gorgeous caterpillars I will have to take some time to look around in the near future
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Raekwon 10 January, 2012 07:46
6 days ago me, my brother and my friend found some bull ants EATING an emperor gum moth and they had eaten its wing so we took it inside put it in a box, next to a light, with wet eucalyptus leaves, it laid 41 eggs over 1 day and 2 nights then we left myrtle ford and it died
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Big Nick 30 December, 2011 13:26
Found two of these on the surf coast in Victoria. I believe they were a mating couple, as one of them was particularly bright (colour used to attract females). I spotted them in the daytime, and they were extremely dosile (they wouldn't move when I touched them). Does this signify a particular stage of their development? Have they laid eggs and are now ready to die?
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Discovery Centre 31 December, 2011 11:59
Hi Nick, it is quite likely that the moths will die soon after mating. Adult Emperor Gum Moths are usually found between November and March but don't feed; they mate, lay their eggs over several days and die. 
john mcinerney 26 November, 2011 16:53
trying to id an orange caterpillar 6to7 cm 1cm dia. no stripes or spots. can you help. comes into house when rains.
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Discovery Centre 27 November, 2011 09:17
Hi John, Museum Victoria has a free Identification Service. If you send us a photo of your caterpillar we'd be very happy to identify it for you. Alternatively you can bring the spider into the Melbourne Museum Discovery Centre for us to examine.  
Marita Coxhead 18 November, 2011 19:16
Hi...3 nights ago a huge beautiful moth flew into our laundry. We have never seen one like it before so I took some photos, watched him for a few minutes and we then set him free. I have just searched and discovered it was a Emperor Gum moth. We have a huge Gumtree next to the house and about 30 down the back of the farm. Perhaps there will be some Caterpillars in them. We live in Ararata, Taranaki, New Zealand
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Discovery Centre 19 November, 2011 11:09
Hi Marita, the Emperor Gum Moth is thought to have been introduced to New Zealand via imported hardwoods and has slowly expanded its distribution. This site has some information.
Jacqueline 28 October, 2011 15:41
I believe an adult Emperor Gum Moth landed in our garden today. We are on the mid north coast of NSW. Talk about HUGE!
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Norma Toland 9 July, 2011 16:15
I found the Emperor Gum moth in Gig Harbor Washington. I took pictures of him.
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christina loras 30 May, 2011 08:16
Can any one tell me how long the Moth usually takes to pupate? A Year 3 pupil has had a pupating moth for more than 3 months.
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John Kean 22 March, 2011 13:36
As well as fluctuating in relation to environmental conditions, the occurence of Emperor Gum Moths is probably a function of memory and history. I remember seeing a few as a kid around Bentliegh c. 1961, they made a huge impression on me I will never forget those fat Caterpillars, my nose was much closer to the leaves back then, I spent a lot of time with other kids in trees, staying quiet so as not to upset the old lady who lived next to the vacant block where we played
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Neil McCormack 17 March, 2011 17:31
I have an original gauche painting of an Emperor Gum Moth sketched in 1843 by my g'g'g'g'grandmother. she was Charlotte Atkinson nee Waring, an accomplished artist & naturalist & mother of Caroline Louisa. Is it of interest to know that he species were around Sutton Forest inSydney region at that time. It is very well done & almost an exact likeness to the photographs on the web some 175 years later.
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Roly Barrett 5 March, 2011 16:55
Some friends of mine who live at Wollongbar on the Far North Coast of NSW have just had a tree FULL of these Emperor Gum moth caterpillars. They collected a few and watched the process of pupation with great interest as we had no idea what they were until now. HOWEVER, the caterpillars they had were very large (from my experience), jet-black, had fluoro-yellow stripes down their sides joining orange tubercles and white protuberances (the hairy bits sticking out in clusters like cactus hairs). They looked amazing and there was a tree-full. The tree they were feeding on was a native white-bean or cedar thing.
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Michael Fox 3 March, 2011 10:07
I found a male Emperor Gum Moth at Gerringong ( on the South coast of NSW) last night. It's the first of this species that I've seen for at least 30 years. It's been a hot, tropical spring and summer here. Insects are having a bumper year. I'm very relieved to see that this species is still hanging on.
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Holger 22 February, 2011 09:58
I too used to have them as pets many years ago and had not seen them for at least 30 years but to my delight I found about 10 happily munching away near birdsland reserve between lysterfeild and tecoma.
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will trueman 20 February, 2011 21:35
i grew up in balwyn and remember collecting them at the back of the rsl hall on a pepercorn tree. in the mid 1990's i saw a gum tree in albert park with caterpillars on it. about that time saw the larvae of its close relative helaena on a gum at trawool. id from the lack of turbecles on it. in 1997 i moved to townesville and used to often see them at night near lights at the bohle supermarket. definitely emporer gums, not the similar syntherata moths. on holidays last xmas in victoria i spotted a moth in daylight on a tree at polly mcquinns weir near strathbogie and the childhood memories came flooding back.
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geraldine adams 10 February, 2011 21:11
WOW, it seems these beautiful caterpillars i remember collecting at school are making a return.Just this evening it was like winning tattslotto to find an emperor gum caterpillar while walking here in Ballarat,mind you,unforunately he was already deceased.But still excited !!
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Martin Lagerwey 30 January, 2011 16:01
Hello I located some caterpillars at Coldstream and collected about ten. They pupated and one, having only a foam box to use collected the foam and made a white pupal case. To my surprise they have mostly emerged already. I have one female caged outside and she attracts several males at night.
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Talia 24 January, 2011 11:55
About a month ago (december 2010), my brothers and I found around 40 fully grown caterpillars at Lake Eildon. So we brought them home and they started to cocoon. I think it was about one week later they were all in cocoons. I have been researching up about them and from what I have found is that the moths can emerge any where between 4 months and 10 years. But this morning (Jan 2011) i have had an Emperor Gum Moth emerge. it has only been 1 month since they cocooned, so I'm wondering if it's unusual for it to hatch so quickly?
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Discovery Centre 26 January, 2011 13:40

Talia

 

Good to hear from you again. As a population, Emperor Gum Moths seem to have a built-in range of emergence times, so some will emerge sooner, others later, some in years that are good for moths and others in years that are not so good. This way they hedge their bets against bad years and the overall population survives and, particularly in the good years, prospers. 

In a good summer, however, especially an early warm summer, the first generation may go through its life cycle quickly, leaving time for a second generation before autumn. 

This means they can emerge from the cocoon in as little as a month, although this is rare. As you've said, it's more likely to be between 4 months and 1-2 years. 

Keep up the good work. 

Margaret 20 January, 2011 12:05
Hi, my daughter found, and photographed on her phone, an emperor gum moth by a road near Hobart - I believe these moths are not often seen in this state.
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Discovery Centre 21 January, 2011 11:38
Hi Margaret, the CSIRO website shows the Emperor Gum Moth as occuring in mainland Australia and also in Tasmania but it is hard to find good information as to their numbers in Tasmania. The Tasmanian Museum and Art Gallery may have a better idea of the distribution of this species in their state.
Di McGauran 5 January, 2011 21:02
I was absolutely thrilled to find a dozen large emperor gum caterpillars on a young flowering gum at our beach house in Phillip Island. I have not seen them since I was in primary school 50 years ago. They lived in the peppercorn trees of West preston state school.
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Paul Swiatkowski 29 December, 2010 22:26
I would love to be able to raise a few of these caterpillars again. It seems we have given up too much to introduced pests and urban sprawl If anyone has access could they please contact me. I live in St. Albans Victoria
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Willow 16 December, 2010 07:56
Hi, yesterday we found a large emperor moth, a little worse for wear, and the kids put it in their insect box, and it proceeded to lay eggs. We have a shoe box full of silk moth catapillers at the moment which we feed mulberry leaves. Can you please tell me which kinds of eucalyptus leaves we should feed them when they hatch- are any species poisonous to them?
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Discovery Centre 22 December, 2010 09:32
Hi Willow, the adult moths have no mouthparts and so don’t feed at all. The caterpillars feed on just about any type of gum tree and while there are some gum species that they may not particularly like, there are none that are poisonous to them. They will also feed on Peppercorn trees (Schinus molle), Birches (Betula species) and Liquidamber. The best option is to offer small branches of several gum trees you have locally and see which one they like best.

One thing you need to keep in mind with Emperor Gum caterpillars is that they will readily drown themselves in jars of water you might use to keep the branches in. Make sure the top of an open jar holding branches is blocked by sponges or something similar that the caterpillars can’t get past.

Julie and Jamie 15 December, 2010 21:13
We have just found many emperor gum caterpillars on a young Angophora costata tree in our yard in Mount Martha. I too have not seen these beautiful caterpillars since I was a child (decades ago!). For the first time my son is discovering these lovely caterpillars. Maybe the recent rains have something to do with their reemergence?
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james 2 December, 2010 18:45
I am sooooo sad that I never got to see the loads of caterpillars my dad saw as a kid. Though I did manage to find only one tiny emperor gum caterpillar. This does show that not all of them survive. I reckon there should be a council to get rid of those pesky wasps.
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Amanda Beet 22 November, 2010 16:37
My sons found a tree at the bottom of their school which is covered in these guys. I hadn't seen them since I was a kid more than 30 years ago when they were really common - kids in class used to have them crawling all over themselves having forgotten how many were poked into pockets on the way to school! We are going to try to raise one in a box the way I did all those years ago. I had wondered why I hadn't seen one in years, wretched wasps!
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Jess 19 October, 2010 08:01
We recently found an emporer Gum Moth here at our worksite In victoria Australia, we had some pretty bad weather this day and he was out of energy and was nearlly going to end up in a pool of water, i gently moved it away to a covered place and got our Enviro Engineer Jo to come and have a look, she picked him and took him inside and gave him a rest, after about half hour he was back to his happy self again and Jo let him go back into his natural environment, we were all very pleased to know we all helped in some way.
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andrea 1 May, 2010 00:21
QUESTION April 30 2010 I found a large cocoon about 2 months ago at Seabrook Beach in New Hampshire. This morning it hatched!It was surprising not only because I forgot I had it but because of the enormous moth staring at me when i was doing the dishes! I discovered it is an emporer gum and i was wondering what i should do with it?
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Discovery Centre 4 May, 2010 15:27

Hi Andrea, if you still have the moth, capture it with a large container so as not to damage the wings, and release it outside.

Anthony Darby 23 April, 2010 00:31
I suspect Brenda is confusing one of the many species of large American silk moths, like Anteraea polyphemus with the emperor gum moth. Anthony
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Barry Wright 12 April, 2010 10:51
HELLO IS THERE ANYTHING FURTHER FROM BRENDA? I WAS TOLD BY FRIEND THAT THERE ARE VERY FEW INSECTS THAT WENT WITH OUR EUCALYPTS TO OTHER COUNTRIESSO THUS THEY DO VERY WELL
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Discovery Centre 14 April, 2010 09:41

Hi Barry, we didn't receive any images from Brenda. You are correct that a number of Australian insects such as longicorn beetles and some weevil species cause damage to Eucalyptus plantations in America. This is because many of the predators that help to keep their numbers under control in Australia are absent in America. Other Australian insects such as the Cottony Cushion Scale have also made it to America and cause damage to the American citrus industry.

Brenda s. Collett 25 March, 2010 09:35
I live in Michigan USA. I found a coccoon last fall. I brought it in my house all winter All winter. What came out was the most beautiful moth I ever saw an adult emporer moth. Are they common in Michigan? II just wanted to know. Can you tell me. I feel Blessed to have witnesses such beauty. Thanks from Michigan USA.
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Discovery Centre 25 March, 2010 11:25

Hi Brenda,

The Emperor Gum Moth is a species that is native to Australia and has been introduced to New Zealand. We are not aware of it being officially recognised as being present in America. If you are able to take some good quality images please feel free to send them to discoverycentre@museum.vic.gov.au and we will have a look at them for you. Alternately you may also want to contact your local Museum to see whether there are any moth species in Michigan which may appear similar.

Linda R 14 December, 2009 21:02
I was amazed to find over a dozen very colourful caterpillars on young gum trees near Seninis in the Moondarra National Park this weekend. Now thanks to information on the web, I'm certain they are early stages of Emperor Gum Moths. Only with photos could I appreciate how brilliant they are. Other then controlling any wasp nests we find, what can we do to help ensure ongoing survival of these beautiful creatures?
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Discovery Centre 22 December, 2009 11:47

Hi Linda,

The staff in the Live Exhibits Department have suggested the best thing is probably to leave them where you saw them. Some of the individuals may not survive but hopefully enough will make it to adulthood to breed.

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Alison 27 November, 2009 15:34
Yes, I clearly remember seeing heaps of emperor gum caterpillars! Big fat aqua giants - they were very spectacular. I'm very sorry to hear the wasps have had such a devastating impact. Next time I see one of those horrid wasps, I'll try extra hard to kill it (painlessly of course!)
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Pauline Borg 22 November, 2009 12:06
When my children were little (30 years ago)one of the most interesting things we did was keep a dozen emperor gum moth caterpillars in a large aquarium, feed them and watch them pupate and turn into moths.They were very common then.(West Preston) Haven't seen a caterpillar or moth in at least 10 years-would love to do this activity with grand-daughter, but not much hope of that.
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tina abels 30 December, 2012 20:51
Hi Pauline, I live in Seatoun have just found a gum moth in my garden. Sadly it is not alive, i have nere seen one b4 Cheers Tina
Maxwell Campbell 24 October, 2012 11:40
Most of the eucalypts trees, liquid amber trees and peppercorn trees in suburbia would support one or more generations of emperor gum larvae in the Spring and Summer each year until the mid 90s. My native garden had loads of them each year and my children delighted in following their growth and metamorphis. Cup moths were similarly abundant. I observed first hand that European wasps attack and dismember the caterpillars with great efficiency. My patio was covered in the guts of the unfortunate caterpillars. Since that event I have not seen either caterpillar in my garden or in the trees along my street. I haven't seen any for many years. I also European wasps preying on emperor gum caterpillars near Yarra Glen in 2008.