PRESERVING ADULT ODONATA SPECIMENS FOR THE MOS

Mark O'Brien

A number of MOS membershave asked about the proper procedures for preserving adult Odonatafor the MOS. This is one of those topics that are near and dearto my heart as a collections manager. I try to make specimenslast as long as possible with a minimum amount of intervention.Once any insect specimen has been properly preserved, it shouldlast indefinitely. However, the hard part is getting the specimenpreserved in a fashion that will provide maximum usefulness andthe best longevity. Mold and insect pests are problems that Ihave to contend with. Encasing something in acrylic plastic willcertainly protect it, but the specimen is pretty much uselessfor anything but a cursory examination. What is important forthe preservation of adult odonates is to observe the followingfor best results:

1. Kill the specimenas quickly as possible.

2. Dry the specimenas rapidly and completely as is practical.

3. Keep the specimenin a dry place protected against pests.

I have had specimenscome in from several sources that were moldy. In each case, thespecimens were not quite dry and were stored inside the clearplastic envelopes that we use for permanent storage. The specimenshad been killed via other methods instead of with Acetone. Ifyou are not using Acetone, I'd rather that you left the specimensin glassine envelopes or paper triangles.

Acetone has become thechoice method for killing adult odonates and for assisting inthe rapid desiccation necessary for good preservation. Acetonedissolves the fats and absorbs the water from specimens, and preventsthe specimens from rotting, as is typical for other methods. Acetoneis also readily available at hardware stores, and a gallon willlast for a season's heavy collecting. I don't recommend freezingspecimens, because the colors become muted, and the specimenswill give off that rotten smell unless quickly and thoroughlydried. The fats also stay with the specimen, which causes thespecimen to darken. Some people still use ethyl acetate or cyanidefor killing specimens. There is a problem with the specimens dyingwith the wings in strange positions using those killing agents,and again, fats are not dissolved from the body, and color preservationis not as good. However, if you can only use a regular killingjar, ethyl acetate is preferred. Remember that the specimens stillneed to be in glassine envelopes. Otherwise, their wings willbe askew when you remove them from the killing jar.

Here is the procedure thatyou should follow:

1. After capturing thespecimen, place it in a glassine envelope (translucent paper,not clear plastic) (these are provided free of charge by the MOS)with the wings folded OVER the back, so that the specimen slidesinto the glassine envelope headfirst. If you have a Band-Aid box,you can store the specimens in that until you are ready to preservethem. Make sure each envelope has a collection number so thatyou can match up the specimen with your notebook. In lieu of anumber, the complete data can be written on the glassine envelope,or penciled in on a small card that is left in the envelope.

2. Snip a corner off the envelopeto allow the acetone to rush in and drain out easily. Then, dropthe enveloped specimen into the jar of acetone. A 32-oz wide-mouthjar works fine for this. I recommend leaving the jar inside acoffee can that is just slightly larger to protect it. Drop thespecimens in at the end of the collecting period - or end of theday.

3. Store the specimenin acetone for about 12 hr and then remove and let dry completely.Make sure that you work with the acetone in a well-ventilatedarea. Use rubber gloves if you are handling the envelopes withoutthe aid of forceps. Leave the specimens in the glassine envelopesfor shipment to the MOS.

Specimens in glassineenvelopes, dried after removal from acetone. Note field note numberson envelopes.
 
 



Above: Two other techniquesfor recording data with the specimens. L ó a printed cardinside; R ó written data on the outside of the envelope.Use a Micron Pigma Pen©, India ink, or soft pencilto write data on the envelopes, as they'll be in acetone. Don'tuse ballpoint pen!

4. Dry the specimensin a well-ventilated area. DON'T use the oven, and do not microwave!Leaving them in the sunlight for a couple of hours will work fine.DO NOT transfer them to the clear plastic 3 x 5 envelopes at thistime.

5. Store the specimens(after they are completely dried) in a plastic shoebox or similarcontainer. If you are unsure if they are fully dried -- a weekshould suffice to fully dry them out. If you are undecided onwhat to do, just keep them in glassine envelopes, and we'll transferthem to 3 x 5 envelopes.



L: A Band-Aid©box with papered specimens inside. R: a jar of acetone with specimensin envelopes.

6. When you are readyto ship the specimens to the UMMZ, place them in one of the small3 x 5 boxes furnished by the MOS and make sure nothing is rattlingaround by cushioning the specimens with tissues or toilet paper.Tape the box closed, and enclose it inside a larger box that leavesabout 2" of padding on each side. Use whatever cushioningmaterial you have available.

MINIMUM INFORMATION TO PROVIDE:STATE (MICHIGAN), COUNTY, TOWNSHIP, FEATURE (lake, creek, preciselocality), DATE, COLLECTOR. Of course, you can add other information.

By following the abovemethods you should be able to preserve specimens with good colorretention that will not mold or turn dark with body fats.



last updated 02-23-2005