If you’re catching a live insect to preserve, putting it in alcohol for at least 10 minutes will kill it while also cleaning it. But also keep in mind that it’s usually fairly easy to find dead insects that are still intact if you’re willing to look around for them. You may get better preservation results with living soft-bodied insects (like caterpillars, grubs, and larvae) by putting them in boiling water for 1-2 minutes. After that, transfer them to a container of ethyl or isopropyl alcohol. [2] X Research source
If you’re interested in doing a more detailed preservation process that’s closer to what professional entomologists do, skip this step and check out the “Advice for More Detailed Preservation” section of this article before proceeding. While it’s definitely more time-consuming, the detailed process reduces the chance of the insect rotting inside the resin and increases the visual appeal of the insect’s appendages.
Check the specific safety recommendations for the brand of resin you’re working with. Insect preservationists typically use one of several brands of clear polyester casting resin. [5] X Research source
Stir slowly so you don’t add lots of air bubbles into the resin. These will show up in the finished product. It’s impossible to completely clean out the mixing container once you mix resin in it, so always opt for something you can throw out. However, do not use a styrofoam cup or bowl, since it may react with the resin.
Pour slowly to cut back on the number of air bubbles you introduce into the resin. Ice cube trays work okay for smaller bugs, especially if they’re made of silicone instead of hard plastic. Silicone molds made specifically for resin casting are available online and in some craft stores. Try these if you need shape and size options that you can’t get with baking molds.
While poking with the toothpick to check the thickness of the resin, take the opportunity to pop any air bubbles that are near the surface.
If the insect floats freely, the resin hasn’t set up enough. Carefully remove the insect and wait a few more minutes before trying again.
As the resin begins to thicken over the following 20 minutes or so, you can use a toothpick to pop any air bubbles that appear. Don’t try to pop bubbles once the resin becomes gelatinous.
No matter how careful you’ve been, there will almost certainly be some air bubbles trapped in the resin. Just accept them as part of what makes your preserved insect unique!
If the insect is too small to cut open, or you’re just not interested in cutting it open, use a needle to inject the abdominal cavity with alcohol. If you don’t take this step, the innards may potentially rot while the insect is encased in resin, which does not totally prevent air penetration. If this happens, the abdomen may shrivel up, discolor, and possibly ooze out some unpleasant-looking gunk!
Make sure you arrange the insect exactly as you want it to dry within 1 day of its death. If you wait too long and try to move the parts of the insect, they are likely to break off. For insects with delicate wings, pin down thin strips of wax paper over the wings to hold them in position. Don’t put pins through the wings. Insect pins are available online and at some craft stores. Avoid using regular household pins if you can, since they might rust and discolor your insect specimen. If you leave the insect out to dry without pinning it, its appendages may twist, curl, and shrivel in undesirable ways.
Once the insect is rigid, carefully remove the pins so it’s ready to be encased in resin.
