Once you have collected your insects, the next step is to preserve them properly for future study and display. Various insects will require different methods of preservation; soft-bodied insects like larvae or termites are preserved in liquids while larger specimens are mounted on insect pins of varying sizes. Insects that are too small to be mounted on pins are glued to a triangular point.
Preserving Soft-Bodied Insects in Alcohol
Soft-bodied insects should be preserved in plastic or glass vials with alcohol (70%-85% isopropyl or ethanol alcohol is ideal). These insects include larvae, scale insects, termites, aphids, thrips, silverfish, mayflies and earwigs. Other insects can be preserved in alcohol as well (with the exception of butterflies, moths, and bee flies (bombillids) because the alcohol will damage their wings).
Insect pins of various sizes are available from entomological suppliers—we recommend getting size #2 or #3 as they’re good general-purpose sizes for most insects. Use only pins designed for pinning insects as other household pins may rust and damage your specimens.
Any insect large enough to be pinned without the risk of breaking or distorting it is pinned from the top (dorsal) side, straight down through its body. The correct point of insertion depends on the type of insect you’re pinning—some examples are illustrated below. Generally, the area is just slightly right of the midline of the insect’s thorax. You’ll want to pin the insect in the recommended location to reduce the risk of damaging important identifying characteristics.
An Essential Tool: The Pinning Block
A tool such as a pinning block is necessary to mount specimens at uniform heights while still leaving enough room on the pin available for data labels. Check out this video on how to utilize this useful tool:
Pointing is an option for mounting insects too small to pin through the thorax. Using this method, the insect is glued on its right side onto a small triangular strip of cardstock. Cardstock or other similarly weighted white paper is preferred over copier paper as it is sturdy enough to support the specimen glued to it.
Cut or punch out the points you need (point punches are a handy tool available from entomological suppliers that make this process faster), then insert an insect pin through the broad base of the triangle. Use a pinning block to set the point to the correct height. With your forceps, carefully bend the narrow tip of the point down—this is the surface where you will apply a small drop of glue to attach the insect. Be careful of how much adhesive you use so you can avoid unnecessarily covering insect parts with glue. Next, carefully maneuver your insect with your forceps into a position where you can gently affix its right side it to the flattened tip of the point. You can then adjust the position of the insect before the glue sets. Check out the video below on how to properly point an insect: