Carding techniques by James McGill

Preparing for carding

Clean your beetle before carding it if necessary. It makes identifying things like Helophorus (Helophoridae) easier. Clean glabrous, greasy beetles with ethyl acetate or isopropyl alcohol. Ethyl acetate seems to remove dirt better. However, for species where you are interested in the pubescence (especially small staphs) ethyl acetate MUST be avoided as it leaves all the hairs matted. The best bet with these is to tear off tiny slivers off tissue paper and twist them; then holding them in forceps brush the individual fibres over the pubescence. With a bit of persistence this will restore the natural arrangement of the hairs. If the beetle is particularly greasy (as often occurs if the wings were extended in death and you have removed them) then brushing it with distilled water before using tissue paper can be helpful. It is often easier to finish cleaning a small staph when it is carded, however beware breaking off the appendages in the process.

I use an artist’s brush to tease out the appendages of most beetles (size 0, 9 mm tip), except for the most awkward customers. Forceps can cause a lot of damage, particularly when you are a beginner, so are a last resort.

Carding

I use a binocular microscope for carding all but the largest beetles.

Pin the mounting card first. You can then pin the mounting card into a piece of plastazote to give a secure base for gluing the beetle. Otherwise the whole card will tend to move as you adjust the position of the appendages. It also eliminates the risk of damaging the beetle when you push the pin through the card.

Use different glues for sticking the body of the beetle to the card and gluing the appendages down. A stronger, thicker glue for the body (e.g. fish glue) will make it easier to position the beetle and be more likely to keep it in place. A thinner glue (I use gum arabic, which is marketed as a watercolour binder) will enable you to slide the legs around easily. It can be re-wetted and stays flat if you want to adjust anything.

Smaller beetles (less than 3 mm) need very little glue to stick them down, otherwise some of the legs get glue on them and become impossible to move. However, too little glue and it can have dried out already before you’ve been able to transfer the beetle to the card. To move the beetle onto the card quicker than with forceps, submerge a brush (size 000, 5 mm tip) in water then touch it onto tissue paper to drain off the excess. Then touch the damp brush onto the elytra and you should be able to lift the beetle up. Now dip another brush in your glue. If you pick up too much, or it isn’t on the tip, get rid of the excess on the brush holding the beetle and shape a small amount on the tip. You don’t want a blob of glue on the card as the beetle will tend to tip to one side or the other, and the glue is more likely to get on the legs. You need a short, flat glue patch. As soon as this is applied to the card, immediately place the beetle down. I would aim to stick between the mid and hind coxae.

To help arrange the beetle’s legs symmetrically, if right-handed glue the legs on the left side of the beetle first with the mounting card rotated 90 degrees to the left. Then card the legs on the right hand side with the card pointing forwards normally. Reverse if left-handed. With a completely relaxed specimen it should be possible to flatten the tarsal claws in the same plane as the tarsi (manipulating the specimen in a few drops of distilled water on a glass slide while cleaning it is the best time to test this). This is a small detail but makes setting the tarsi much easier.

For most specimens, before setting the antennae I apply a small amount of dilute glue and stick the head/jaws down (or the tip of the rostrum in weevils). This keeps the palps visible if necessary and prevents the head moving as the specimen dries which inevitably distorts the antennae as well. With staphs I also stick the abdomen down, as this tends to telescope inwards and lift as it dries, even on dissected specimens.

To card the antennae you need a very dilute, thin glue. First extend the antennae by stroking out the terminal segment with a brush. You may need to use forceps but it is very easy to snap them so avoid if possible. With the antennae roughly in position, brush the smallest amount of water (damping the excess off on tissue first) at and just beyond where the last antennal segment will rest. With a bit of luck or encouragement from the brush the antennae will sit in position held by the last segment. Now you can see exactly where it needs to be glued, transfer a small amount of glue to the area just beyond the last antennal segment. It should soak back down around the segment. If at all possible avoid getting glue on any other segments than the last. You will probably need to adjust the position of the antennae at this stage but it is easier to do than describe. Practice on something like a Philonthus (Staphylinidae) which have antennae like a string of beads that can be stretched out nicely. It is much harder to get the same results on carabids.

Finally, James comments “I also think some mention of patience might help put early struggles into perspective – my carding only improved gradually over two and a half years”.


3 Comments

  1. Alan Rowland says:

    James

    I am keen to make a start but need to start buying supplies. I have Watkins and Doncaster’s catalogue and can identify everything needed – except pins sizes. Can you please advise which pins are best for carding?

    Regards

    Alan

  2. markgtelfer says:

    Alan,
    I use these:
    E6861F Continental s/steel nylon head pins No.4
    Size: 38mm x .55mm

    Though I buy bulk direct from entomoravia.eu rather than Watkins & Doncaster.

    Obviously the length you get depends on the depth of your store-boxes/ cabinet drawers. “Continental” pins (38 mm) are increasingly the standard but won’t fit in antique cabinets.

    The No. 4 pin (0.55 mm diameter) is a good rigid pin for carded specimens but if you’re doing any direct pinning you would be better to get some thinner pins. The thinner the pin, the bendier they are.

    Mark Telfer

  3. Alan Rowland says:

    Mark
    Many thanks, I will follow your advice. Hope to see you on Lundy some time too.

    Alan

Leave a comment