Q.
What solution can I use to preserve nymphs and adult insects?
Art Flick used distilled water and formaldehyde, but I don’t
think I can buy formaldehyde. I am presently using “isopropyl
alcohol,” but I know that is not a good preservative. John Kosick
A.
The most commonly used preservative for aquatic
insects is 80% ethanol. This does a pretty good job
for long-term storage, although some folks add 1% Ionol,
an antioxidant that helps preserve color.
Another preservative widely used by aquatic insect
collectors is Kahle’s fluid. It is made up of ethyl
alcohol (15 parts by volume), formalin (6 parts),
glacial acetic acid (1 part), and distilled water
(30 parts). The benefit of Kahle’s fluid is that
it penetrates tissues rapidly before decomposition
begins, kills quickly, and preserves color well.
However, the Kahle’s fluid should be drained before
permanent storage in 80% ethanol.
All-in-all, I’d recommend sticking with 80% ethanol.
If you have a question, please feel free to contact me.
~ C. E. (Bert) Cushing, aka Streamdoctor
105 W. Cherokee Dr.
Estes Park, CO 80517
Phone: 970-577-1584
Email: streamdoctor@aol.com
The ‘Stream Doctor’ is a retired professional stream ecologist and
author, now living in the West and spending way too much time
fly-fishing. You are invited to submit questions relating to
anything stream related directly to him for use in this Q & A Feature
at streamdoctor@aol.com.
Originally published April 12th, 2004 on Fly Anglers Online by Robert Younghanz.