Phasmid Preservation Techniques (part 1)
Well I finally got round to doing this! It was about time I emptied my freezer a bit. I do this because it keeps the insects from rotting until I find a time to preserve them. I will hasten to add I don't freeze healthy insects just to pin them - all the specimens I preserve have died naturally, but I do occasionally do euthanasia when a moult goes wrong, or with some species that take a long time to die (this can happen with Heteropteryginae, sometimes taking weeks).
The insect in this demonstration is an adult female Anchiale sp. from Malaita. She moulted to adult, but failed to start feeding and died a few days later (the rest are doing fine). I picked her because she's a large phasmid, so will be easier to show techniques. Also she's winged, so that's covered as well.
Here goes...
A: Pins. You can never have too many. I use stainless steel entomological pins from Watkins and Doncaster as they don't rust, but it depends how serious you want to get;
B: A good sharp pair of scissors - these can be substituted with a sharp scalpel, but I find scissors are easier for larger insects;
C: Fine nose tweezers - perfect for eviscerating and stuffing large and small insects (if you're patient!);
D: 2 setting pins - you don't really need these, but I find the long wooden handles useful for manipulating parts of the insects, rather than buggering about with fiddly pins;
E: Cotton wool. I use pleated rather than the balls or such, just because I find it easier to tear up into small wads. All personal preference really;
F: Polystyrene board and tissues (not pictured) - to stop the mess getting on your best tablecloth;
G: An insect. Rather essential to the whole process.
2 - First cut:
Using the scissors (or scalpel) make an incision between the mesothrax and the 1st abdominal segment. We will be removing most of the viscera through this hole.
3 - Cleaning out:
Once there, grab hold of the gullet with the tweezers and gently tug it. the head of the insect should bend forward - if it doesn't you haven't got hold of the gullet, so try again. A (delicate) sharp pull should snap it clear and allow you to remove it in one piece.
Voila! As you can see, it's completely empty. Normally there'd be quite a bit of chewed food in this.
As this is a large insect, We're going to make a second incision further down the abdomen (in this case between abdominal segments VI - VII). This will facilitate removal of viscera.
The flesh in the abdomen isn't as easy to remove as the thorax. It's a bit time consuming as you can only pull small amounts out at a time. However, do as good a job as possible and you won't have too worry too much about the whole insect turning black and rotting.
Job done!
4 - Stuffing:
Tear up small pieces of cotton wool and begin to gradually stuff the body of the insect. You should be quite careful when doing this, as the pigment is easily rubbed off of the inside of the exoskeleton. Don't pack the insect too tightly or you might rupture the sides. Also, you won't be able to get a pin through the thorax!
What we're going for is an even stuffing to try to emulate the body of the insect while it was alive.
Huzzah! You can see where some of the pigment has rubbed off on the abdomen. Silly me.
5 - Pinning:
This bit is by far the easiest bit, but can take time to master the symmetry and such. First get the insect into roughly the right position you want (also allowing space for the wing we're going to open)...
...like this!
The first pin goes through the mesothorax, slightly to the left. If you've overstuffed the thorax with wool it will be very difficult to get the pin through and you might rip the underside. If this is happening, un-stuff the thorax and try again.
