Post by trembo3578 on Feb 27, 2011 22:58:50 GMT -8
I know many of the lepidoptera collectors on here work with adult forms of the different species but I was wondering if anyone had any known means of larva preservation. I have heard that freeze-drying is the only method that will work. I also read that a less expensive type of home freeze-drying (http://peabody.research.yale.edu//jls/pdfs/1960s/1969/1969-23(1)43-Flaschka.pdf) could also work.
Does anyone have any information from personal experience about larva preservation?
You can either take their guts out and blow them up with a stick while you dry them over a flame, this works great for Lasiocampidae, stuff with lots of hair but not with pigmented skinny caterpillars.
The other method at home is putting them into your freezer at home in an OPEN container and waiting for the famous Freezer burn, I think 1,5 years in freezer and the specimen should be ready, you see that will take a lot of time.
The other method is getting a proffesional freezer dryer. Both museums where I work have got one, they did not yet let me put my hands on it as I had nothing valuable to freeze dry bu after my first collecting trip to the tropics I will sure make a few nice series of all instars of a few species ;D
Last Edit: Feb 28, 2011 1:04:36 GMT -8 by nomihoudai
Post by Chris Grinter on Feb 28, 2011 12:42:55 GMT -8
Well, in my opinion the only reason to collect caterpillars is for morphological work. In that case, you should carefully photograph the specimen while living, and then quickly boil the specimen for a minute or two before placing into 95% EtOH - letting it stand for a day or two, and then replacing that ethanol with 70% for permanent storage. The colors do not fix well, but the specimen will not turn black. No reason for a ridiculous freeze-dryer when you can just take a photo instead!
There is another method for fixing the colors in the field, and it's called XAA (Xylene acetic acid). It's a nasty mixture of Xylenes and Glacial Acetic Acid (both available at a hardware store). You mix the xylenes slowly into the GAA until a while cloud forms in solution. Then you add a little more GAA to bring the solution back to clear. At this stage any small amount of water will trigger this cascade effect, making the reaction more effective at sucking water out of anything you place into it. Add a caterpillar in the field live and the solution turns white - sucks the water out of the caterpillar after a few minutes - and you can then place into EtOH for preservation. The colors fix pretty well this way, and the caterpillar turns rigid and keeps its natural shape. However, this acid mixture is really nasty and will give you a pretty bad burn!
The easiest and cheapest way to preserve/dry larva for collection is to dry them using silica gel and a freezer. I know people who have used this method a lot and the results are very good (not to say impressive).
I have been able to preserve large caterpillars using silicon caulking. I kill the larva using my acetone killing jar and then using a sharp razor knife, carefully make a small slit on the under side, just in front of the anus. The internal fluids are squeezed out as much as possible and then using a needleless syringe I fill them full of silicon caulk. I put a pin through them and position them on a spreading board so the caulk dries in the desired shape. I have done many hairy and smooth skined larva this way and had them retain their color. I don't see how to post pictures to this reply or I would show you some of them.