Resin as a preservation technique

I can't find any copyright-free resin pictures! so here's a fossilised spider preserved in natural resin -i.e. amber. CC image by Elisabeth.

Several people have asked me recently about preserving their specimens in resin. It's not the traditional thing for taxonomic collections. But if it does what it needs to do - i.e. preserve the specimen while still enabling you to examine all its important and distinguishing features - then it's probably hard to argue with.

I can only imagine attempting small things like beetles and spiders. Little floaty seaweeds in resin look great in my imagination but the technique wouldn't be very practical for anything much bigger. (and you probably want your entire collection to match aesthetically). I can see resin's appeal because spiders do tend to get all scrunched up in alcohol - perhaps it's easier to spread all their legs out in resin(?).

The main issue seems to be - does it still allow you to see the fine detail that allows you to show you've identified it correctly? If you can get this to work, then that's excellent. But it might take a bit of frustrating experimentation. Followed, hopefully, by success and general elation. But perhaps by you getting cross because you've ruined your specimen. So perhaps don't try things out on something you've only got one of.

I've got a tiny bit of experience with resin, but not with setting creatures in it (it's Art, innit). So I do know that you'll probably want 'crystal resin' because that's completely colourless. The stuff I used was cheaper but practically opaque. You have to buy a tin of resin and also a tiny bottle of stuff which reacts with it to make it set (the catalyst / hardener).

You'll also have to think about molds.  I bought a few for my artwork but they weren't cheap, and most of the commercial shapes were far too cutesy. In the end I improvised something I could get for free, but they sometimes got hopelessly stuck, which wasn't ideal.

I also know that resin heats up a bit when it cures, and that can lead to problems with specimens. The only student I can remember that used resin found his spiders went a bit shrivelly. But perhaps this was because they contained moisture, perhaps they could be freeze-dried first? And I believe you can get a problem with 'silvering' which might be related to the shrivelling, when a gap appears between your creature and the resin. I don't know how it will affect the colours of your creature - perhaps that depends what it is.

I also know that resin really stinks and you'll have to find a well-aired place to deal with it (I would suggest the labs but we've not got a fume hood - other people's labs do, but you'll have to fit round the classes).

I found this video on youtube which is interesting because they essentially make their own mold, based on a cut bit of perspex. But they do have an awful lot of bubbles in there (despite their insistence otherwise). And I'm not totally convinced by the opaque edges. And the insects are all curled round. "Oh" I thought, "perhaps you could pin them first." But then if you're going to pin them... why not just pin them, not resin them (not that that would apply to a spider). Don't forget you've got to attach a label somewhere too.

I spotted this guide by Rhys Brigida who loves encasing spiders in resin. He's American, so everything's dollars and ounces, but it should give you some inside information from someone who's tried it with spiders (albeit mostly large ones).

So. This could be worth some experimentation, and much reading around on the internet will probably help. But only if you're feeling super keen, because traditional methods do work and might be less aggravating. I think it might drive me a bit mad. A big question will be - do you have the extra time to get good at it, and will it be worth the possible extra marks if you can do it well? Remember the important part of this assignment is the identification, not just the presentation.

But I do wish you the best of luck if you want to try.

Asteraceae in September / October

Bristly Ox-tongue (CC image Brocken Inaglory)

I've been keeping a casual eye out for Asteraceae recently and there seem to be plenty about still. If you want to do your collecting now, and to improve your botanical identification - I think I'd be tempted to choose this as my group.

This week I've seen (on campus and at the sides of roads):
Daisy (Bellis perennis)
Common Knapweed (Centaurea nigra)
Bristly Ox-tongue (Picris echioides) - it's very bristly and has lovely feathery hairs in the pappus.
Creeping Thistle (Cirsium arvense)
Yarrow (Achillea millefolium)
Mugwort (Artemisia vulgaris)
Oxeye Daisy (Leucanthemum vulgare)
Common Ragwort (Senecio jacobaea) 

So that's eight already - and that was without trying terribly hard. So if you pick the Asteraceae and get cracking I think you could make a very healthy collection, quite easily!

I think you should be able to easily find a few more at the moment without going to any specialist habitat - species like Groundsel, Tansy, Feverfew, Gallant-soldier, Hemp-agrimony, Pineappleweed, Scentless Mayweed, Spear Thistle, Greater Burdock, Dandelion, Nipplewort, Cat's-ear, Autumn Hawkbit, Perennial / Smooth and Prickly Sow-thistle. It'd be easy to double your species count to sixteen or even more.

All these would be along roads, on wasteground and in generally 'weedy' and unkempt places. There'll be a couple of species which appear in the early spring: Colt's-foot and Butterbur. Plenty to choose from. I'd say anything that's listed in Rose's Wild Flower key is fair game (assuming it's not got an asterisk * to say it's rare and protected).

You'll need a hand lens to see all the detail on your plant. We do have some but I recommend buying one -  you can get a perfectly decent one for £10+ which'll last you a lifetime (plus you don't have to get squeamish about holding something right up to your eye that a million other sticky-fingered student have handled).  There are lots of places to get one, I could suggest NHBS or Watkins and Doncaster but there are many other options. x10 is generally enough magnification for botany.

General thoughts on collecting

Finnish entomologist Johan Sahlberg and his botanist wife Mimmi, just before they left on their honeymoon field-trip in 1873. Photograph by Antero Saalas.

 The Legal bit: Technically, you should only collect where you've been given permission by the landowner. Realistically, if you collect a sprig of grass from a roadside, no-one is likely to demand you are thrown in jail. But bear it in mind that under the Wildlife and Countryside Act, it is illegal to uproot any wild plant without permission from the landowner. 'Plant' includes algae, lichens, mosses, fungi and vascular plants. You don't need to uproot anything of course, just take parts of it. If you haven't got permission to be on someone land, you shoud confine yourself to public land and footpaths, or else you could get in trouble for trespassing, and that's before you've picked a thing. It doesn't hurt to be following the Countryside Code in general.

It is quite complicated in law, because there's no single law that covers such things. You do have some rights as a 'forager' which have built up around collecting plants for food. The British Mycological Society have some sensible advice regarding picking fungi but you'll find there's increasing worries about people collecting large amounts of mushrooms and then selling them to fancy restaurants (selling things on is not really in the spirit of traditional foraging).

Also, it is very tempting to want to go to a nature reserve to collect - after all, that's surely where all the nature is? Actually, you'll find you can collect a remarkable number of species from uncontroversial places. If you really do want to collect at a nature reserve, you should ask first. In my experience they may give permission - just contact the relevant Wildlife Trust (etc.) and explain you are doing a taxonomic collection for university and only want a specimen or two of common species. Reassure them that you will not be digging anything up, least of all their rare species. Always take the minimum amount of material necessary wherever you are.  

 There's more advice in the Wildflower Society code of conduct. You might also want to read the Botanical Society of Britain and Ireland's code of conduct. It encouragingly says "Collecting small amounts of plant material for identification purposes, for private herbaria, for research or as voucher specimens is usually acceptable, except in the case of protected or Red List species. Indeed, collecting is often necessary if botanical expertise is to be developed."

 The Amateur Entomologists Society has similar advice concerning invertebrates. Although I feel pangs of guilt killing them, the main threat to species in this country is habitat loss. The code points out that "collecting should always be limited to the minimum necessary for the purpose intended, as well as by full compliance with legal requirements relating to particular sites and species."   

It is rather unlikely you'll come across rare species (the clue being in the name). Surprisingly, very few are specifically protected by law. Obviously, if you're in a reserve where one exists, you should make yourself aware of its appearance and avoid collecting any.

In short, use common sense and all will be well. Stick to public places and no-one will threaten you with a shotgun. Develop a casual demeanour and learn to shrug off the strange looks the public will doubtless throw you. Never be without a plastic bag or collecting pot. The latter is the best bit of advice I can give you :)

 

The Health and Safety bit: 

If you look at the course guidance on Blackboard, you will see that before going out collecting it requires you to send a risk assessment to Katy. This is not so onerous, as there is a generic version on Blackboard - you just need to go through it and remove anything irrelevant to your own situation, and perhaps add in anything extra. 

For example, you can delete any of the chemicals you won't be using for preservation. You've survived this long so presumably you are good at common sense - but here's a recap anyway-

Take someone with you (it's more fun, besides).
 Let someone know where you're going and when you ought to be back (a map and a phone are useful too).
Especially if you're like me, take a snack and something to drink so you don't pass out in a ditch.
Take your medicine with you if you suffer from some life-threatening illness (now I feel like I'm talking to my mother).
Take some sensible clothing and footwear with you (and now I am turning into my mother).

Fill in your details on the form - send a copy to Katy and keep a copy for yourself.
Then you can go forth and start collecting.

Entomological suppliers

CC image by Anaxibia.

 I was thinking it might be best to be like the BBC and not openly advertise any particular companies. But let's face it, if you want entomological pins or something similar, you can't just pop down the supermarket, your options are limited. So I'm going to point you at a couple of the bigger more obvious companies.  But "other entomological suppliers are available."

 Watkins and Doncaster

and Anglian Lepidopterist Supplies

both stock all sorts of pins, boxes, lenses, nets, scalpels, beetle glue, you name it. The Watkins and Doncaster site is easier on the eye, but they don't include VAT until you check out, so you only think it's cheaper until then.

Something I've discovered recently and am consequently evangelising about is this type of very light forceps - they help you pick invertebrates up without damaging them. They're not exactly cheap (I got mine somewhere cheaper on ebay... Dutch ebay actually), but I have found them useful.

I do have some glass vials you might like for collecting / display, and don't forget that I can make you up some invertebrate preservative (70% ethanol, 10% glycerol and 20% water). I've also got ethyl acetate if you want to make a killing jar. Also little crystals of naphthalene (moth balls) to put in with your insects to deter nibblers. And plenty of spreading boards you can borrow if you're doing moths.

Presenting your lichens

Graphis scripta, not known for legibility. CC image by Ed Uebel.

The packet method is traditional for long-term storage of lichens. So you could hand them in in packets arrayed one behind the other (in taxonomic groups) in a box - like this picture of a moss herbarium at Yellowstone National Park. You can make the packets the same way as the ones you used for collecting. This is the traditional style preprinted envelope I used for handing in samples on a lichen course I attended. This has got more than the bare what, where, when and who information,  - but as long as you include at least those either on the envelope or a separate label, you'll be fine.

But lichens are aesthetically pleasing and most if not all students who've collected them in the past have gone for a more open display. You could put them in a single clear-fronted case, or in lots of little boxes, or perhaps fasten them to a piece of mountboard, or make some kind of more naturalistic 'lichen diorama'. It depends how sober or creative you want to be. I just can't find an example of such a thing on the internet, which is distressing, and all previous lichen collections here have been proudly taken home by their creators. I look forward to taking a photo of yours.

And this being a taxonomic collection, you should make efforts to arrange them taxonomically in your display. But lichens are a bit strange because they're a symbiosis between two types of organism - a fungus plus an alga or cyanobacteria. Taxonomists have named and arranged them according to the fungal part of the relationship. If you want to know what the other part is, Dobson often says. It can be useful to know for identifications, because one of the photobionts, Trentepohlia, is orange not green when you scratch the lichen's surface.

When you're learning to identify lichens, it's really helpful to divide them by form: crustose, squamulose, foliose, fruticose... but those aren't taxonomic divisions and your display shouldn't be organised on that alone. It would be better to include the name of the family, and divide them like that.

I recommend using the Natural History Museum's Dictionary of UK Species to ensure you have up-to-date names and the correct family information.

If you have any questions, please do come and ask me, and bring your specimens!

Long tailed tits frequently use lichen in their nest building. CC image by Alan Shearman.