-prepared by Bastiaan M. Drees, Professor and Extension Entomologist
Although there are many techniques to mount butterflies and moths, below is a description of the one I prefer. All techniques described have their strengths and weakness’ but all follow a few basic plans. Furthermore, some modification may be necessary, depending upon the characteristics of the specimen being mounted.
Collecting, Killing and Storing Specimens
After netting a butterfly in an aerial net, the best way to KILL IT is by pinching its thorax (middle body segment) between your thumb and forefinger. This technique takes some practice to learn the proper pressure, but it will stun the specimen immediately and prevent it from damaging itself. The stunned specimen can then be slid into an envelope or a paper triangle as shown in Figure 2, with its wings over it’s back. Butterfly specimens can be kept in this condition indefinitely in a box with moth balls or other insecticide to protect specimens from damaging dermestid beetle larvae and book lice, until they are “relaxed” for mounting. Alternatively, freshly papered specimens can be kept in a plastic bag in a freezer until they are mounted, eliminating the need to “relax” the specimen before mounting since frozen specimens will relax as they thaw.
Relaxing Dried Specimens
After insects are dead, they become extremely brittle. However, dried specimens can always be relaxed and mounted in any desired position. The only potential drawback is mold. Relaxing jars can be made from jars, plastic boxes, or any other airtight containers. These containers are partially filled with sand or paper towels and then water is added to make conditions in the box very humid. The only other concern before adding dried specimens is adding a substance to prohibit the growth of mold on the specimen. The ideal fungicide is chlorocresol, sold through chemical supply houses. Some companies have specialized “relaxing fluid” such as Glanz relaxing fluid distributed by Bryanston Corp., N.Y. However, in a pinch, Lysol can be used. The time required to relax a specimen will vary and depend upon the specimen’s size, the level of humidity in the relaxing jar, and the storage temperature. Don’t be impatient. However, if any mold begins to form, remove the specimen immediately. If you are in an extreme hurry or can not find a mold inhibitor, the specimen can be relaxed in one minute by holding its body in a pan of boiling water, being careful not to get the wings wet or burning your fingers.
Pinning the Specimen
After relaxing the specimen (Fig. 1), remove it from its envelope carefully using forceps (Fig 2). Holding the specimen by the thorax, force an insect pin through the middle of the body between the wings (Fig. 3). The wings may be forced backwards in order to insert the pin far enough through the body. After the pin is through the body, it is often helpful to force the wings down briefly with forceps. This step makes the specimen easier to manipulate once it is on the mounting board. Next pin the specimen onto the mounting board being certain to keep the side of the butterfly, where the wings are hinged to the body, just above the surface of the mounting board (Figs. 4 and 5). Also, be sure that the Din is straight up and down in the middle of the mounting board’s groove.
Mounting the Wings, Body and Antennae
When the specimen has been properly placed on the mounting board, wings can be folded down using strips of paper and pins (Fig 6). Avoid touching the wing surfaces with your fingers which would rub off scales. Once both pairs of wings are pinned down, move the front wings forward individually or both at the same time to avoid twisting the body around the pin (Fig. 7). Be certain to only insert pins into the wings behind larger veins to prevent ripping the wings. Move the front wings forward far enough so that their hind margins form a nearly straight line (Fig. 8). Move the hind wings forward underneath the front wings enough to match patterns, but not so far as to obscure color patterns. Next, pay attention to antennae and the abdomen, pinning them in their proper positions (Fig. 9). Check the overall position of the specimen and make any adjustments necessary before placing wider strips of paper over the wings to keep them from curling up during the drying period (Fig. 10). Drying time will depend upon specimen size, temperature and humidity. Drying can be sped up by placing the specimen underneath a lamp. After the specimen is dry, carefully remove the pins and discard the paper strips. Reusing these strips may result in the loss of scales from the wing surfaces.
Storage of Mounted Specimens
Keep mounted specimens in tightly closed boxes with moth balls or paradichlorobenzene or other insecticide to prevent dermestid beetle larvae and book lice from feeding on the body parts. If the specimens are kept in glass frames or domes, keep them out of direct sunlight to avoid fading of colors. Always keep specimens in low moisture conditions to prevent mold from growing on the specimen’s body. Stored properly, specimens will last for years and years.