Tips for Moth-ers

Giant silkmoth (Eudaemonia argus)

Now that we know the science behind moths, we can figure out various ways to observe the species in an area. One of the most effective methods of observing moths is to turn an outside light on. Whether the setup is ambitious or simple, one can sure to find some moths around it! This spring, my father and I built quite an elaborate mothing setup. Mothing, though not an official verb, is one of my favorite activities. One who participates in mothing is known as a moth-er, or a moth’er. In my setup below, I’ve taken a bedsheet, and sewn loops on both the top and the bottom of the sheet. In this way, I was able to bend two pipes, one for the bottom and one for the top, to make the sheet in a cylindrical shape. I connected the open side where the left and right sides of the sheets connect with safety pins and clothespins. On the top, I took another sheet, and used safety pins to pin a circular top to prevent the moths from flying into the light and possibly burning themselves.

I use a halogen lamp, although some other lamps such as mercury vapor lamps can work even better. If I had to add one thing to my setup, it would an ultraviolet black light as well. I put a heavy rock on every quadrant of bottom of the sheet to keep the sheet tight to the ground, so no insects would crawl under the sheet and into the light. This setup has been quite effective, and I’ve found moths on this sheet from various families. Even once, I was treated with an early morning visit by a cecropia moth (Hyalophora cecropia), a moth with the largest wingspan of native moths in North America! 

Some species of moths, notably the Saturniidae family, do not have mouthparts, and live off of fat reserves stored in their larval stages. However, for moths with mouthparts, one can go sugaring for moths. This method is also known as baiting. There are various recipes for sugaring, but a majority of them contain stale beer or rum, along with brown sugar, and rotten fruit. There must be enough brown sugar and rotten fruit in order for the mixture to be syrupy. If the mixture is too liquid, it will be difficult to “paint” onto the trees. A syrupy mixture is usually sticky enough to stay on the tree for moths to “drink.” A twist to this method is to dip a rope in the mixture and hang it. Moths in the genus Catocala with magnificent hindwings are very common visitors while sugaring.

Moon-lined moth (Spiloloma lunilinea) on a baited rope.

Since one observes moths sugaring at night, it is important to keep in mind to avoid shining a bright flashlight on them. Moths, like other insects, have a hard time seeing light in the red spectrum. Many people just place a piece of red cellophane over a flashlight and are able to avoid disturbing the feeding moths. To photograph them, a quick burst of camera flash should be okay and not disturb them too much.

Using pheromones is another way to attract male moths. The pheromone traps are usually for members of the Sesiidae family which mimic wasps. The pheromone “traps” are composed of the same basic chemicals as the pheromones released by female moths. The “traps” attract male moths which are fooled into thinking they have found a mate. Different species of moths use different pheromones to attract mates. Male moths can “smell” these pheromones from a great distance away since many have plumose, or bipectinate antennae. Plumose and bipectinate are terms used to describe the characteristic feathery appearance of many moths’ antennae. Females usually have reduced or lack bipectinate antennae. However, this rule is not always reliable, as some male moths may have the same reduced bipectinate antennae as females.