Saturday, 18 July 2015

August 2015

‘How did you spot that?’ is a question I’m often asked when I see something interesting in the undergrowth.  Indeed, it is a question I’ve often asked others when they have found something I didn’t see.  The simple answer ‘Well, I was looking for it.’ - is rarely true.  Most of the time when you spot something, it is because you saw some movement that attracted your attention.  Walking round Rye Harbour reserve, out of the corner of my eye I caught sight of a bird flying into a tree, and heard a familiar call. I scanned the tree for a while before I saw the barred breast of a cuckoo.  The cuckoo rarely sings on an open perch and often tucks itself in amongst leafy branches, which explains why many more people have heard a cuckoo than have ever seen one.  So when I pointed it out to my companion, they said – ‘How did you spot that?’

When it comes to the insect world, you may well spot some movement – a butterfly opening its wings, for example.  But insects are very wary of predators which may also spot movement, so they tend to keep still as far as possible.  If you are interested in insects then there is a tendency to walk slowly and scan bushes or the ground, and quite often you may not be aware of how you saw one.  It may have been a shadow on a leaf, or a tiny splash of a colour other than green.  (Or it may be green like the tortoise beetle that looks just like a flat blister on the surface of the leaf!)
Tortoise Beetle

Just recently I saw my first woundwort shieldbug -
 Eysarcoris venustissimus.  Now, before you congratulate me, you’ll probably want to know what a woundwort shieldbug is.  It is a bit like the common green shieldbug that you’ll find on your runner beans sucking the juices from them.  It is smaller though, in fact it is only about 6 millimetres long. (That’s quarter of an inch in old money.)  It also has exquisite purpley bronze colouring on its back and shoulders, and a black and white connexivum.  (Entomologists like to give posh names to various bits of their chosen group of insects and connexivum is shorter than saying the pie-crust edging round the back and sides of the abdomen of a shieldbug, and I wish I’d never mentioned it now!)

Woundwort Shieldbug
It’s a beautiful insect though, and I certainly can’t say I was looking for it, because before I saw it I didn’t even know that they existed, and it was just the magnification provided by the camera’s viewfinder that allowed me to identify it as a shieldbug.  It was only when I got the photos back home, and looked it up in the field guides that I knew exactly what it was.  It is called the woundwort shieldbug because it lays its eggs on hedge woundwort and the nymphs feed on the leaves.    Hedge woundwort is an attractive plant with spikes of purple flowers and horrible smelling leaves.  Plants that have …wort in their name were once used medicinally, so woundwort was probably once used to heal wounds.   The woundwort shieldbug also lays its eggs on white dead-nettle which is closely related to woundwort.
The eggs hatch out into nymphs, which is a shieldbug’s way of getting round all that dangerous caterpillar and chrysalis stuff that many other insects go through.  The nymphs are mobile and more or less similar to the adult insect, but smaller and they can’t fly or reproduce.  To grow they have to shed their old exoskeleton and puff themselves up to expand the soft skeleton underneath, which then hardens again.  They will go through several of these instars, as each stage is called, before they emerge from the last stage as an adult with wings and reproductive bits.

So how did I spot it? – I haven’t a clue.  I was looking for bumblebees at the time.  Maybe I just knew that there was something beautiful and interesting down there, because I find that if you keep your eyes open, there usually is.

No comments:

Post a Comment