Butterflies have fascinated people for centuries! Some of the oldest butterfly collections in museums today have specimens from the 1700s - including species that are now extinct. (A note of caution: many species of butterflies have plentiful populations, but make sure you don't collect too many of the same species or kill rare ones without considering first.) To start your own collection of these beautiful Lepidoptera (the insect order that butterflies and moths belong to), you'll need some basic collecting equipment. A sturdy butterfly net is essential, and a spreading board, insect pins, and a display case are helpful tools for making a quality collection.
How to Use a Butterfly Net
When trying to capture a butterfly with a net, move slowly until you are in range. Position the net under the insect, then swing your net upward and turn the handle so that the net flips over and the captured insect cannot escape. If you bring the net over the insect and down to the ground, raise the end of it so that the insect can fly to the closed top, then stick a container under the net and carefully move your butterfly down into it.
Identifying Butterflies & Moths
This step can come after you've brought the specimen home, but often it's helpful to identify it right away, so you can remember where you found it. A field guide like the Butterflies & Moths Golden Guide can help you identify many common species, or you can try an Audubon guide with color photos of 600 species. Using a guide, find out what type of plant the caterpillar of that species eats, then check any of those plants in the area for tiny butterfly eggs on the underside of the leaves. (And come back later to see the caterpillars!) If you decide to identify your captures when you get home, make a note of where you found each one and what plant or flower it was feeding on.
The first step of the identification process is to determine whether your capture is a butterfly or a moth, the two groups of Lepidoptera. Sometimes they are very difficult to tell apart, but in general moths have plump, furry bodies, are more dull in color, are active at night, and have wings spread flat when resting. Butterflies, on the other hand, usually have smoother bodies, brighter colors, are active during the day, and fold their wings up over their backs when they land. Another important difference is their antennae - butterflies have slender antennae that form a club shape at the end. Moths tend to have feathery antennae and very few species have clubbed antennae.
How to Use a Killing Jar & Relaxing Jar
For all insects that you want to keep in a collection, the easiest way to kill them is to use a killing jar. You can make one of these by putting cotton balls soaked in rubbing alcohol or ethyl acetate (a more hazardous chemical - use caution!) into a glass jar. For best results, though, use ethyl acetate in a killing jar made for the purpose. The ethyl acetate will work more quickly than rubbing alcohol and the jar has a plaster cartridge to soak up the fluid so the insects don't get wet.
Butterflies, because they are so fragile, sometimes batter themselves in a killing jar so it is better to first stun them by pinching their thorax - the central part of their body. It might take a little practice to get the method down just right, so try it out first on common moths or butterflies that you aren't concerned about keeping for your collection. After you stun the butterfly, you can also carefully fold its wings over its back and put it in a glassine envelope.
Don't leave the butterfly in the killing jar too long. Use forceps, if you have them, to carefully take the butterfly out. Either pin the butterfly immediately (see steps below) or store it, with wings folded, in a glassine envelope.
Before you spread the butterfly (unless it hasn't yet stiffened), you need to to "relax" it. Make a relaxing chamber by setting a damp rag inside an airtight plastic container. Set the butterfly inside, cover it with 2-3 damp (not dripping) paper towels and close the lid. You can leave the butterfly inside the glassine envelope. The butterfly should soften in 2-3 days if you keep the cloth and paper towel damp. When the butterfly has relaxed enough for you to gently move its legs and antennae, it's ready to be spread.
How to Use a Spreading Board
For butterflies and other large winged insects, you should use a spreading board and insect pins. Carefully insert a pin through the right side of the thorax. Pinch the thorax to spread the wings enough so you can pin it. Place the butterfly's body in the groove on the board - it varies in width for different-sized insects. Gently press the wings down so they lie spread out flat, then put a thin strip of paper over each wing and pin the ends of the strip to the board. (Be careful not to pin through the wing itself.) This will hold the wings flat until they dry out. The drying process may take up to two weeks.
When the butterfly has dried, remove the paper strips, but don't try to remove the pin through the thorax! Use that pin to mount it in a display case.
How to Mount a Butterfly
For any insect collection, it is essential to know the name for each insect that you find! With a good identification guide, you should be able to find the scientific and common name of each one. Write or print out a small tag (card stock or other thin cardboard works well) with the name, and attach it to the pin that you use to hold down your insect. You may also want to list the date and place where you found the insect (e.g., in the garden, April 13, 2005). If you can, collect two specimens of each species and mount one to show the colorful top of the wings and the other to show the more camouflaged underside of the wings.
Collecting butterflies is a fun and rewarding summer activity, and a mounted butterfly collection has both scientific and artistic value!