Monday, July 18, 2011

A Jekyll & Hyde moment...

Note: Apologies to anyone that has recieved e.mail notification of an old entry from January, I have no clue as to why blogger decided to re-send this old posting
                                                                                                      Robert Louis Stevenson wrote his novel of dual personality in 1886 and although the struggle in this case was between good and evil, it's what sprung to mind whilst watching one of the most extraordinary transformations I have been lucky enough to witness thus far. 

Nature has always enthralled and enthused me with its seemingly, unending secrets. Like the universe we all inhabit, it holds many mysteries that only reveal themselves by virtue of putting in the time and effort to discover what may have been there all along, for millennia, most likely, but have remained hidden to all but those that actively seek them out.

If that's sounds a little pious or even sanctimonious it's not meant to, I'm just trying to express my thoughts as to how we can all see nature's hidden secrets but you do need eyes and mind wide-open. You will miss so much by rushing through the countryside on a route march. Take your time and let nature infuse you with it's bounty!

Acclaimed singer/songwriter Yusuf Islam wrote "Maybe there's a world that I've still to find?" 

Preamble over, I'll get to the nub of this blog entry; in essence it's all about time spent observing what is no doubt a common enough occurrence and will take place hundreds, if not thousands of times a year up and down the country. 
And yet... how many will have been privileged enough to have witnessed it first-hand?

The Small Tortoiseshell Butterfly just like all butterflies and moths has four main stages of life; Egg (Embryo)-Larva-Pupa-Adult (Imago), it is the third stage that I am dedicating this blog entry to, the pupa; or to be more precise, following the progress of a larva as it changes into a pupa.

To try and build a timeline and also condense this into a blog-sized tale, I'm posting a few shots that are not best quality being stills that I've cribbed from the main movie but do illustrate how the sequence all began.
After watching the larva feeding itself in preparation for what follows, at around 5.15pm on Saturday evening I saw that it had attached itself to a stem of the nettle plant it had been calling home for the past few weeks. 
Once attached safely, it curled up into the position you see in the above photograph.

Four hours later, the only real change was that the larva had begun to uncurl itself a little. It was still almost motionless and remained so for quite a while.

'Quite a while' became in reality 17 hours. At around 2pm on Sunday the larva seemed to be head-down at an almost vertical position and had started to twitch a little.

It was at this point the transformation proper seemed to be under-way.The first short clip I'm posting shows how much movement had begun inside the larva.

Click on the arrow to start movie clip
(E.mail subsribers: You will only be able to view the movie by visiting the blog. It will not show in an email.)

Eventually the movement became more and more exaggerated  and pronounced with what appeared to be contractions and almost convulsions, as the pupa struggled to free itself from the larva.

Click on the arrow to start movie clip
(E.mail subsribers: You will only be able to view the movie by visiting the blog. It will not show in an email.)

It did feel like the struggle between Jekyll & Hyde with the larva starting to sway with the force of a completely different being trying to emerge from within.

Although I was captivated by what was happening here, I began to feel like an expectant father; willing it on with every contraction, even shouting "C'mon...push!" at one point. It did seem to be having some difficulty with emerging. Not as much difficulty as I was experiencing with trying to make sense of just what was happening. I was unable to fathom just how it was possible for something to become a completely different 'thing' in such a short space of time.

Sir David Attenborough even struggled to find the words to describe this momentous quirk of nature. He described it as a stage in a butterfly's life when it does not feed and in which the larval body is broken down into a kind of thick soup.
Clusters of cells survive this breakdown and then fed by the 'soup' they start to grow and multiply, eventually developing into the adult insect. 

And so here's the main course today.....the full movie of the whole event. It was filmed (videoed?) on my little Panasonic Lumix camera and so the focus isn't spot on at all times, as you would expect. But it does capture a magical 8 minutes; probably one of the best 8 minutes I've ever spent in fact... 

Click on the arrow to start movie clip
(E.mail subsribers: You will only be able to view the movie by visiting the blog. It will not show in an email.)

Watching this unfold was a real education for me. Something I didn't ever expect to see and will probably now never forget. It is these little things in life that we take for granted, often not even stopping to consider how!

Watch closely the very end of the movie and notice how the emerged pupa twists and turns until it frees itself from the larval skin that eventually drops to the ground. Not only is it spinning around, but it turns in alternate clockwise and anti-clockwise directions.

For those of you who don't feel you want to watch the whole 8 minutes, there's a high-speed version that I've included too. I won't be expecting anyone to use this version though. You'll all be interested enough to want to see the full monty right? Don't you touch that button! .....leave it!

Click on the arrow to start movie clip
(E.mail subsribers: You will only be able to view the movie by visiting the blog. It will not show in an email.)

Another surprising thing to me was just how much detail is visible at this early stage. After all the pupa will be another few weeks before it's ready to split open and reveal the adult insect.

Using Sir David's analogy of the 'soup' I was struck by being able to make out both the eye socket and the antennae detail already formed. The following is another still from the movie and I've enlarged this one so that you can see exactly what I mean.

The whole thing once fully emerged looked like this....

After a couple of hours drying out and hardening it looked like this...

By this morning (Monday) it had taken on a wonderful golden tone that this following photo doesn't really do justice to. It looked like it had been painted gold.

And so that my friends is where this marvellous story ends. Or does it? Will I become luckier yet and capture the adult butterfly as it emerges in a few weeks time? I'll try my best but don't hold your collective breath!

Until the next time then...

Friday, July 08, 2011

Where have all the insects gone?

It does seen to have been a strange year for insects and bugs thus far. I've been saying so since May really and having talked to friends and contacts about their experiences, we all agree that the timing has been very unusual this season.

Early flowers and the hot weather through April/May seems to have confused the insects and following on as it did from a harsh winter, has only added to the problems with for instance, favourite food plants being in-flower too early.

However, nature has a way of sorting these things out and it's not all doom and gloom.
As usually happens, what's negative for one species, becomes a positive for another.
Having been troubled by my lack of invert finds recently, the past few days have seen a real augmentation to numbers with a sudden proliferation of bug and insect eggs and nymphs.

Emerging Ants

I found these tiny ants as they were emerging from the eggs when I moved a stone on a woodland pathway. The adults were very quick to react to being disturbed and immediately began to pick up the youngsters and move them to safety. I replaced the stone having taken this shot of them.

Next up were these little woodlouse nymphs. It struck me on finding these, just how many species emerge in white; I wonder why it seems that so many are pale at this stage and only later get their true colour? After all, we as humans don't usually undergo a colour change as we grow (unless you're Michael Jackson that is).

Juvenile Woodlouse 

The nursery-web spiders have been busy too and if you look in the long grass in almost any meadow at this time of year, you'll probably see a small 'nursery' full of youngsters. Each nursery contains too many spiderlings to count but there will be well over a hundred . 
Nursery-web Spiderlings

Urrrrgh! Spiders! Yes I know there are many of you for whom the mere sight of a photograph of an arachnid is enough to induce a cold sweat. You'll be pleased then that we're about to replace the Urgh! factor with the Ahhh! factor.

A Green Shieldbug Nymph

This miniature bug illustrates nicely my point about an increase in the nymphs that are starting to appear now. Whilst in previous years there have been plentiful supplies of numerous species to record and photograph, until now, they have been a rare sight this year.

This creature (about 4-5mm) is a second instar of the green shieldbug, the first being even smaller and instead of the green seen on this one, would be a kind of pinkish tone.
There are in all 5 instars before it becomes an adult and each one looking quite different to it's predecessor. For instance, take a look at the photo below.

This one is a fourth, or possibly even final instar-nymph and as you can see bears little resemblance to the second instar.

Adult Green Shieldbug

The last photo here shows the adult. This one was taken at the end of last season and it's already in it's winter colours. During the spring and summer it would be green.

Rhagonycha fulva
It's this kind of behaviour that's responsible for the explosion in insect numbers and it'll come as little surprise to you that one of the names this little cantharis beetle has is the 'Hogweed Bonking Beetle' Also referred to as the common red soldier beetle.

My sister, who sometimes accompanies me on my evening or weekend bug-hunts has her own name for it, to her it will always be the 'Bloodsucker'  They do not suck blood of course, and the name seems to have derived purely from their colouration.  And yet....people are still frightened by them and react with waving arms and shouts of "Urgh! One of those bloodsucker things" 

My interest in insects has taught me many things, and a strong contender for top position amongst those would be just how unreasonable most folks act around our insects. The truth is that most will not harm you in anyway and those that look to be the biggest threat are often a harmless critter disguised as a 'killer' as a means of defence against predators.

I suppose I should at this juncture be providing the answer to my little puzzle set in my last blog entry?
I should.....but I don't think I will just yet. 

If you've been wondering (and why would you?) just what the larva of this beetle looks like, then wonder no more as the next photo is just such a thing.
Cantharis Beetle Larva

Not to be confused with this following photograph of a larva. This one is actually the larva of a glow worm. These are fascinating creatures and becoming scarce in some areas. There is a great website dedicated to them where you can read all their lifestyle; including things like, only the female glows and she turns out her light after mating. The glow worm only lives for about 14 days, and other interesting things.

A Glow worm Larva

Finally, another species of shieldbug that has been busy egg-laying in the last couple of weeks is the Woundwort Shieldbug-Eysarcoris venustissimus. With the fully grown adults only managing a paltry 5-7mm, you can perhaps imagine how minute the eggs are and the difficulties of getting reasonable shots of them?

I tried my best to get some photographs as a record of the species and below is the best of the bunch. Not one of my best photos I agree but considering each of the eggs would be not much more than a millimetre across, acceptable.
Perhaps next year I'll try some shots using a reversed prime lens to get closer and bring out more detail.

Woundwort Shieldbug Eggs

I'm keeping an eye on the areas where these were found, as there were quite a number of eggs, and I'll hopefully be able to share with you in a later blog entry pictures of the emerged bugs. The little 'eyes' on these eggs suggest to me that they'll be emerging any day now.

The puzzle then? The photo was of a Burnet Moth pupa. In this case, probably a 6-spot.
They are usually to be found attached to a stem of grass, quite why this one was lying on the ground I'm unsure.
However, all being well it would in time morph into the moth pictured below.

Congratulations if you got the correct answer :)

6-Spot Burnet Moth

Until the next time then....