Friday 30 December 2016

The Miracle of Emergence

My Madagascan Moon Moths (Argema mittrei) have begun emerging.  Its an exciting moment when you realise the process is underway and you get the chance to witness the sequence of events as it happens.  For those of you who have never had the chance to see this, we managed to get the camera set up and did a bit of time lapse photography, so here goes ...

 

The sequence starts after the moth has emerged from the cocoon - it will climb to try and get in a suitable space where it can hang downwards.  This one is hanging from a cocoon (you might notice its not a moon moth cocoon, this is an Atlas cocoon that was hung up in the emerging cage).  The wings are really shrivelled to begin with, and very soft.  They can be easily damaged at this stage.  The moth pumps fluid into the veins and the wings will start to unfold and expand.



Here you can see the forewings and the hindwings expanding.  You can start to see the long tails becoming visible too.

 

Once the wings are pretty much full size, the tails really start to lengthen.  You can't quite believe how long those tails are going to become when you see it at this point.

  

Those tails just seem to keep growing and lengthening ....



I thought the camera was adjusted to the right distance, but those tails are so long, we had to pull back a little further to fit them in to the shot!



So there's the final side view, and just one more front view to show the moth fully emerged.  This one is a male - the females have shorter tails and less feathery antennae.


 

The process you can see here took around an hour in total.  Emergence can be a lot quicker in other moths, but those tails take a little while to fully extend.  The moths usually emerge in the morning and then sit quiet for the rest of the day, so that the wings have time to harden before evening, when they may well become active and start flying.

There are a lot of things that can go wrong and result in a moth with stunted, shrivelled or deformed wings - it can be due to the caterpillars being inbred or just not very healthy, eating bad quality food, or some disturbance at a crucial stage of its development whilst inside the cocoon, or being too cold or too dry at the point when it begins the process of emergence.  Knowing all the things that can potentially go wrong, makes it all the more satisfying to see the process when it goes right. 

Now, if one of those female mittrei would emerge, there might be a chance of pairing them!!


Sunday 18 December 2016

Eri Silk, Part 2

So my wet mass of silk fibres has dried, and with a little teasing out, it looks a lot better than it did last night.





















In amongst the fibres, there are some of the innermost layer of the cocoons still visible.  These don't always degum very well, they feel very papery.  I usually take the larger bits out during the process of carding - here are the fibres ready to card.



























And here is what they look like after carding.






















There are some nice long, silky fibres combed out, but lots of bits too - if I had more of the fibre, I could pull out the smoother, silky pieces and spin them up separately to produce a finer and more even yarn, but there's not that much fibre, so I don't want to waste it.  I'm going to spin the lot, so it will be a bit uneven and slubby.  That's what we call a textured yarn!  I decided to spin it on the hand spinner as there is only a small amount.  Here is the completed spun thread.


 

The next step is to ply it - I did this by cutting the thread in half and twisting the two strands together,  Plying makes the yarn stronger and evens it out a bit too.  So here is my finished yarn.  Its turned out a nice ivory colour, but silk takes up dyes really well so I'm not sure yet what this will end up as.  Its not a huge amount, but its not bad from just 14 cocoons.








Saturday 17 December 2016

Making Eri Silk



I decided today to process the cocoons of my Samia ricini x walkeri.  There are not that many of them, but they range in colour from bright white, through beige, to golden orange.  I really like the golden orange ones, but I wasn’t sure whether that colour would remain in the silk.  In some of the silkworm varieties with bright yellow cocoons, they still produce white silk, because the colour is in the sericin (the glue that holds the cocoon together) rather than in the silk filament.

 Here's what I'm starting with.

 

The first step is to clean out the cocoons.  Although the moths have emerged, this doesn't mean the cocoon is empty.  Inside is the shed skin of the caterpillar, and the empty pupal case.  Its a bit fiddly opening up the cocoons and removing all the detritus, but if you leave it in, then you end up picking bits out of the silk all the way through the process, so the cleaner the cocoons are at the beginning, the better. You can see some of what I’ve removed in this picture.

 

It doesn't really matter if you cut open the cocoons to remove the bits inside, because its not essential to keep the fibres unbroken.  I start the process of making the silk by putting the cleaned cocoons into a saucepan of hot water, with a bit of stergene and washing soda added.  I then push the cocoons under the water to get them really wet, bring the water to the boil and simmer very gently.  Some people say you shouldn’t boil the silk, but especially with the wild silk, nothing much seems to happen if the water doesn’t get sufficiently hot.   
 
 

The cocoons will start to soften and loosen, and if you push a kebab stick in, you can see the fibres unravelling and the cocoons breaking down into a mass of threads.

 

When they get to this stage, I rinse them out in warm water to get rid of the soap and washing soda, then give them a final rinse in some water with citric acid added to it (or you can use vinegar instead)- this is to neutralise the alkalinity of any washing soda that might be left behind.   At this point, it looks and feels really soft and,  well ... silky!

 
After rinsing, I squeeze the excess water out and leave it to dry.  It doesn’t look quite so appealing at this stage.  I am a little disappointed that I have lost that really bright orange colour -  its mostly a mix of pale gold, ivory and white.  
I am going to leave it now to thoroughly dry out, before moving on to the next stage, turning it into carded fibres and silk thread.

Thursday 15 December 2016

The most stunning silkmoth?



The postman brought me a great parcel today, it contained ten cocoons of the Madagascan Moon Moth, Argema mittrei.   The cocoons are silvery and netted, really pretty.  These ones have been cut open to check the pupae inside.  If you know what to look for, you can see not just if the pupae are alive and healthy, but also whether they are male or female, and whether they are close to emergence. 
 
There are four males and six females in my batch -  this pupae is a female.You can see the body of the moth, the feathery antennae curving downwards and the shape of the wings that are crumpled up inside there.

 


It may not be too long before some of these emerge, but in the meantime, here’s a photo of a male moth from a couple of months ago.  Its on my daughter’s hand, so you can get an idea of the scale.   

 

They are the most amazing and gorgeous creatures.  We managed to see these in the wild in Madagascar a few years ago.  As far as I know, the cocoons are not known to have ever been used to produce silk in Madagascar, but if you process the cocoons, it certainly looks like useable fibre.  Its a lot thicker and coarser than some of the other silks, but now I have a few more cocoons, I will have a go at spinning it up when they become vacant.

 

They don’t use the Argema silk in Madagascar, but I have since found out that there is another moth native to the island that has been used for silk production.  Its not a Saturnid, but a member of a different family, the Lasiocampidae.  When I looked up Borocera cajani online to find out what it looked like,  the caterpillar sounded very familiar and here’s my photo of it  - I didn’t realise at the time the significance of this caterpillar.   

Its very well camouflaged, but when disturbed, out come these four big, orange tufts of stinging hair.  In some parts of Madagascar, they are trying to reforest upland areas with native plants, including the foodplant for this caterpillar.  Harvesting the cocoons and turning the silk into scarves is making a real difference to the lives of the women of the villages involved in this conservation project.  They are getting the opportunity to earn an income sustainably, whilst improving native habitat.  If you are interested, take a look at the video at  www.feedbackmadagascar..org/eng/whatwedo/projects/proj_silk.php.  I’d love to go and see this for myself and find out about it firsthand.


Wednesday 7 December 2016

And more moths ...



I still have a few caterpillars from my second lot of Samia of unknown race (possibly Samia wangi).  The remaining caterpillars are pretty big and it shouldn’t be long before they are ready to pupate.  The colours on them are fantastic.
 

Most have spun up already and I have a nice batch of cocoons.  I was wondering if they would go into diapause and I could have a break until the weather warms up and the vegetation starts growing again.  With the recent cold weather we have had, the privet really isn't the best and that has to have an effect on the health of the caterpillars.


But no, this morning I had a newly emerged female moth.  She is very pretty -  I’m guessing it may not be long before I have a male to join her.  I already have eggs from the ricini x walkeri batch.  Looks like I will be having a busy time again soon.  The good news is I won’t have to wait too long to process that silk ....