Hard-bodied insects have an outer exoskeleton with their soft parts on the inside. These insects will keep for decades after drying. Although some will fade, many will keep their original color.
However, soft-bodied insects such as aphids, lice, mayflies, and termites, as well as immature insects such as caterpillars, and wasp and beetle larvae, have to be preserved in alcohol solutions. You can use either a 70% ethyl or isopropyl alcohol solution; denatured solutions, available from your local pharmacy, will work fine.
Because specimens will often change color and shrivel when kept in an alcohol solution, insects need to be dipped in boiling water for 30 seconds before being transferred to the alcohol jar. Another option is to kill the insects in a special fixing solution known as a K.A.A. solution. To make a K.A.A. solution, mix one part of kerosene, two parts of white vinegar, and ten parts of 95% denatured alcohol in a glass container. For better results, substitute glacial acetic acid, available at photo supply stores, for the vinegar. You can also buy fixing solutions from many science catalog dealers.
It's easier to study soft-bodied specimens that have been dipped in a K.A.A. solution because the specimens uncurl and swell up. Specimens shouldn't be left too long in a K.A.A. solution, though, or they will burst. Small insects need about 30 min. and larger insects, like caterpillars, need 2-3 hours. After the insect has been fixed in the solution it should be transferred to a vial or other small container with a 70% alcohol solution. The container should then be sealed tightly with a stopper. Force an insect pin through the stopper, then withdraw the pin slowly. This �burping� releases air that has been trapped air in the vial. For larger specimens, replace the original alcohol in a day or two, then reseal and re-burp the container.
· 1 decade ago