Old World Swallowtail (Papilio machaon) butterflies are one of our northern European beauties, not that common although I do usually see a fair amount in the garden during the spring and summer. I see even more of their unmistakeable caterpillars on my dill, which self seeds about the place and I allow it to do so because not only is it attractive in flower but because it is one of the host plants of the butterfly larvae (along with fennel and carrot). Weeks ago I found 4 tiny Swallowtail caterpillars but just a few days later they were no longer there. So when I came across two more on the dill in the veg patch, I felt the need to step in and give them a helping hand.
Suddenly next year's project became this year's as a bucket with dill and two caterpillars was brought indoors. I then had to hurriedly do a little research into caterpillar housing, and improvise!
I think the best way to document their journey so far is to show each caterpillar separately, as they are each at a different stage of development. This all started on 1st September.
Here is 'Little Guy' for want of a better name for him. This is taken through the glass of the preserving jar that I'd put him in! I lined it with kitchen towel and put some muslin fabric over the top to keep things out (what I'm not entirely sure) and allowing air in. At this point he (I don't know that he's a he of course) was very tiny.
|Little Guy 1st Sept|
To start with neither caterpillar seemed to do much; for the first few days they seemed to sit around not eating or pooing much and I thought it had all gone horribly wrong and that they were going to die, and that the kitchen windowsill (out of sunlight) was not a suitable environment. I realise now after Big Guy had a moult that Little Guy had also done so during this time, and they seem to go rather quiet and not eat a lot in the time leading up to this. They also eat their own skin after shedding it so that accounts for them not needing to eat so much of the dill that I give them fresh twice a day. They seem to eat their skin very quickly and I haven't yet witnessed this, so they could easily be moulting without me noticing - even though I am looking in on them often, but I can't help the hours that I may be outside during the afternoon or at night.
This is the next stage, known as an instar, of Little Guy's development, on 4th September. He has clearly changed colouring and was growing, little by little.
|Little Guy 4th Sept|
|Little Guy 5th Sept|
|Little Guy 6th Sept|
|Little Guy 8th Sept - he's actually still quite small|
On the 9th it started to get interesting! I discovered him just after he'd moulted. What I had thought was a bit of frass turned out to be the head capsule! I didn't realise until I had zoomed in on the photos that I took. Within half an hour Little Guy had eaten his skin (damn, missed it!) but had left the head capsule, which warranted closer examination.
|Little Guy moult and head capsule - 9th Sept|
|The head capsule against a millimeter measure|
|Closer up, showing the hairy bits!|
So this is where I'll stop documenting Little Guy and turn my attention to Big Guy now and show his stages through this same time span. Big Guy was clearly quite visible out in the veg patch on the dill flower, and was at about the same stage that Little Guy is now.
|Big Guy out in the garden 1st Sept|
Big Guy was put into a slightly larger container - in the absence of anything more suitable at the time he went into a plastic barquette/punnet that peaches and nectarines are bought in, again with a muslin sheet put over the top.
This was the first moult that we witnessed by Big Guy on the 4th. At this point I didn't know what happened next so some hours later was surprised to see that the moulted skin had disappeared. Obviously I didn't know at that point about the head casing either. You can see in the following two photos that the head casing (top right of the moult) is still attached to the rest of the skin.
|Big Guy moult 4th Sept|
|Here, now that I know what I am looking at, is the head capsule|
still attached to the rest of the skin.
By now Big Guy was starting to look like the caterpillars that I'm used to seeing on the dill during the summer months here. This is their grown up colours and markings. (I do apologise for my lack of scientific terminology but it's all new to me and I've only learnt a few words so far, like frass, instar and eclose!)
|Big Guy 5th Sept against the windowsill|
|Big Guy being measured on 8th Sept|
I did wonder why he seemed in a bit of an odd position until I flipped him over by mistake and saw he was clutching a bit of dill stalk - he looks so cute like this and didn't seem bothered lying there whilst I took photos! It's great to see their truelegs up their top end (the right) and prolegs on the rest of the body. (OK, I admit, I just looked that up. It does sound more professional than 'feet' and 'sticky pads', which is what I originally wrote!)
|Big Guy clutching his dill stalk|
There ends Big Guy's journey for the moment, because at this stage enter onto the scene New Guy, who I found out in the veg patch! I couldn't help myself but bring him in as well......
|New Guy 9th Sept - exactly the same size as Big Guy|
Now I will make a start on Part 2 and let you know progress in due course, as already there have been more changes. I realise now how important it is to document this all as although day by day not a lot seems to happen, over the course of a week or so, it actually does, so I need to keep on top of what is going on or I'll be totally lost.
To be continued!