Sunday, 15 May 2011

Corpse on the cob

This week's blog looks at the magic of spiders' webs - and how to do a CSI-style corpse survey. There's information on bringing spiders' webs back to the classroom for study. Oh, and some bleating about a woman on her wedding day. Funding news too.

Picture the scene. It involves a human being, a young successful twenty-something, on her wedding day. After ten years she’s worked her way up the ladder. She owns her own house, mortgage paid. She’s going for the full-hand: car, house, job, soon marriage and then kids. Today is the day - she gets herself prim for the biggest day of her life. For her, life starts now.

She climbs out of the car, walks up the steps to the church. And then… and then…

…She gets stuck in a massive sticky web? She gets bitten by an enormous eight legged fang-laden spider four times her size? She dies a slow and painful death…? Well, yes. If you're an insect. In the insect world, young lives in the prime of life are lost each day.

Don’t believe me? Well, go to your nearest pond and study the spiders’ webs. Tragic tales like those above are festooned all over them at the moment. Rites of passages ruined. Maiden flights foiled. Metamorphoses wasted. Spiders fed.

In the waters below these webs, aquatic larval stages have been gorging themselves on prey (or plants) before they burst forth out of the pond to the stuttering buzz of virgin wings. The spiders must think some satanic deity is paying out.

Caddisfly larvae are my favourite – their larval cases are made from whatever’s in the pond (grasses, twigs, leaves, mud, polystyrene), all cut to shape and glued into an intricate moveable cave (it’s even inspired artists in the human world). Each larval caddisfly species has its own fondness for materials: some like thin twigs specially aligned (Limnephilus rhombicus), some have a love of big leaves (Phacopteryx brevipennis), and some even have a thing about tiny ramshorn snailshells (Limnephilus flavicornis).

As a tool for inspiring people about the value and awe-inspiring power of freshwaters, I’d say caddisflies feature as high as frogs. Maybe higher – they just need more publicity.

But back to those spiders' webs…

What’s in your pond?

So, as I was saying, spiders’ webs that have been flung near ponds are rich pickings if you want to see which insects were living in the pond as larvae (and which may be present again next year). At this time of year many webs are full of caddisfly adults (honestly, go and look). After all that effort of making a larval case to live in, plus the whole metamorphosis thing, it’s shocking how many die so early. Such is life / Life…

Their webs are full of the adult life stages of other things too – mosquitos, small hoverflies, even moths (Brown China-mark Moth is quite widespread).
Who’d have thought that spiders, in their blood (hemolymph?) lust, would inadvertently create a survey tool for wildlifers to use to understand what’s in their pond. Clever little nightmares, they are.

A web-tool for engagement?

When I scour spiders’ webs for insect treasure part of me gets sad about the waste of such larval potential. I think of the woman on her wedding day, predated. A small part of me feels her pain. If I’m honest though most of me is excited and inspired about it all. Actually it’s the same boy-like awe and excitement I still get when imagining dinosaurs killing one another or a great white shark ripping apart a torso. Is this just me? Am I disturbed? Maybe.

Perhaps using spiders’ web as a study tool might help young boys (particularly) to engage better with nature? It sort of fits alongside the ‘Deadly Sixty’ mentality which grabs young people so well. (I hear the sentence, “I’ve seen that on Deadly Sixty!” on most days). Try it out and let me know how you get on.


I’ve never attempted it, but there is apparently a way to bring spider webs back to the classroom (or the study/lab/garage workbench) for further study (and maybe to satisfy an artistic urge or two). Bizarrely it involves hairspray. In Nick Baker’s excellent, clear and informative The First Time Naturalist, it says you can spray the web with spray paint a couple of times (to harden it up), then hairspray (to make it sticky). Then it’s a case of carefully lining up a bit of card and pushing the card through the (now sticky) web. Not sure how long it would preserve the insects caught within the web – certainly long enough to get your microscope out for a further look I’d say.

Give it a go! If anyone’s got any pictures of your web exploits let me have them – I’ll post them on Twitter (@juleslhoward).

Right, that’s me done – from life in webs, to the web of life, spiders have certainly grabbed my interest of late. Hope they do yours!


Only one national one to speak of this month – but might be a good one…

Ideas Fund Green is provided by Ideas Tap, a not-for-profit organisation, bringing young, creative people together and offering cash funding, opportunities and a portfolio to showcase work. The aim of the scheme is to realise creative projects that either address green issues or are produced in an environmentally sustainable manner. Up to £5,000 is available.

Until next week, Jules

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