A royal visitor - a Monarch butterfly in our garden

It is autumn, a good time for planting shrubs - they have time to settle in with the rain and our relatively mild winters before the spring gales stress everything.  I had some swan plants ready as I want the garden to be more welcoming to Monarch butterflies next summer - none had visited our garden this year despite a butterfly-friendly abundance of flowers.  But I didn't have to wait till next summer - the swan plant foliage was being devoured already.  One hungry caterpillar was at work, its little black filaments waggling as it munched, the claws on the front legs seeming to direct the leaf to its mouth...

They might be fussy about what they eat (basically just milkweed plants thank you) but they are not what you would call fussy eaters - "eating machines" is one epithet.  The caterpillar (also known as a larva and called an instar if it is between moults) demolished much of the still modest sized swan plants, then disappeared.  Apparently they often go walkabout before the next stage.

Not too far away, the caterpillar had climbed into a plant of Ballotta pseudodictamnus, a pretty little shrub with grey-green leaves covered with soft white hairs.  Its rear prolegs were hooked into a dense white silk mat that it had woven on a leaf and the caterpillar, now called a pre-pupa, was dangling down, ready to go through its fifth moult to emerge as a green pupa.  You can see that change is afoot - the skin (exoskeleton) looks a bit more transparent, the pre-pupa is paler and lacking the healthy glow of the earlier instar.  Fortunately the autumn rains (hence raindrops) did not cause any problems. 

Next stage - pupa!

The soft stripey skin was shed to reveal the harder protective exoskeleton of the green chrysalis or pupa, blending well with the foliage - except for the bling.  Apparently the gold  and black band marks the end of the abdomen and the other gold spots occur over the thorax, the wing bases, and the eyes. When fully developed the butterfly emerges head first from the lower end of the chrysalis.  You can see the pattern of the wings through the transparent shell.

I had read that the pupation stage for a Monarch butterfly was about two weeks.  So when a month had passed, and the chrysalis looked black and lifeless, I had given up hope - it was too cold and wet I thought (the weather had suddenly changed.) 

And it turns out that the weather does indeed affect the pace of things.  The butterflies take longer to emerge (eclose) in autumn.  But if they survive the nastier autumn conditions they will then live much longer than their summer siblings.  They have a big task - keeping the population going by migrating and overwintering in warmer locations, ready to get started when winter is over. 

Not knowing this I had stopped checking, and I was very surprised one very wet morning, to see...

I am tempted to call this the "empty nest" - technically it is the "exuvium", the protective pupal exoskeleton no longer needed, metamorphosis complete.  So the butterfly had gone, just the imprint of its wings left behind.  But had it flown? How could it survive?  It was horrible weather - gales and rain and mist.  My heart sank.  I had read that cold and moisture can be deadly for them. 

But it is all relative.  I had forgotten that they are also tough little creatures.  They have been seen by glider pilots at 11,000 feet above ground.  And they are known (like glider pilots) to catch thermals which lift them up high to the strong winds - but only the wind heading in the right direction (how do they know?) for their migrations covering distances as great as the journey from southern Canada to central Mexico.  And then it didn't take long for me to catch a glimpse of orange through the tangle of grass being buffeted by the wind.

The imago - an adult Monarch butterfly.  Out only a few hours, apparently, with wings not quite completely expanded (butterflies emerge or "eclose" with rumpled little wings and haemolymph is pumped into the wing veins over several hours to expand and stiffen them) and sheltered near the empty chrysalis.  I was worried about how the wind was whipping the long brown leaves of the native grass (Carex buchananii) around and disturbing the butterfly's balance.  But somehow she held on, keeping down and away from the wind and rain.

She moved a little, occasionally fluttering her wings - but not very open.  This protected them from damage and anyway, butterflies need warmth to get moving, and there wasn't any!  But she seemed to be exploring - coiling and uncoiling her proboscis.  And those eyes - what does she see, I wonder.

You may ask - how do I know this is a female Monarch? 

I know because of her wing markings - the stripes on the wings of a female are thicker and don't have the spot on them which marks the males.  This moment was a rare one - a glimpse of her wings outstretched.  Mostly she barely moved and huddled, conserving energy and avoiding damage by sheltering down a bit and out of the wind, with raindrops on her antennae and her hairy thorax.  It didn't look promising for her.  But the next morning, she was gone. 

So - we were visited by a Monarch (butterfly) - and a monarch (human) of the future.  Her emergence coincided with a visit of William and Kate, royals from England (a hangover from our colonial past.)  The really wet weather has coincided with their visit - to the point that people from the drought beleaguered areas of Northland jokingly suggested that William and Kate go up there and take the rain with them.  If she has the chance, this lovely little lone butterfly may fly north too, and join the other overwintering Monarchs in a warmer part of New Zealand.