Looking for moths

Looking for moths is very easy. Many people just leave a porch light on and check what is attracted to the light. Others use blacklights and Mercury Vapor Lights that put out light in color spectrums that can be irristable to moths. Special fermented baits are also used to draw moths in. The Friends of the East Brunswick Environmental Commission has been holding Moth Nights once or twice a year since 2006 to explore and spotlight the nocturnal and seldom seen life around us. We use two methods to see what is flying in our parks; an extremely bright 175 watt Entomology Mercury Vapor Light and a sweet fermented mixture painted on tree trunks ie. what has been called “sugaring” for hundreds of years. The Mercury Vapor Light gives off light in wavelengths that are very attractive to moths and other insects, and the sweet mixture does the same through smell. We hang the light in front of a sheet suspended between two trees so that any insects that fly in toward the light have a place to perch so we can examine them. The sweet mixture is simply painted on the trees with a paintbrush an hour or so before dark. Many people who “sugar” for moths have their own special recipe and experimenting with different mixtures can be a lot of fun.

The best nights for “mothing” are in the summer on cloudy sultry nights with a chance of thunderstorms, but even mild late winter nights can be productive. Experiment, there is almost always something flying around…

My recipe for the sweet fermented mixture varies a little depending upon what I have at home but is essentially:

1 overripe banana or a can of peaches in heavy syrup (or both)

A few ounces of dark rum (tasted beforehand to insure freshness)

A bottle of dark beer (tasted beforehand to insure freshness) 

A box of dark brown sugar

A bottle of dark molasses

Mash the banana and\or peaches so that they are in little pieces

Mix the remaining ingredients together with the mashed fruit (use a container with a large open mouth for ease of getting the paintbrush in and out)

Put a tight lid on and leave in the sun for a few hours to a day 

Paint a 1 foot square area on tree trunks about 3 or 4 feet off the ground, the more trees the better

Check the painted spot every half hour or so, approaching very slowly (many moths will be skittish) and using indirect light from a flashlight. (one note of caution – the mixture will be attractive to bees and wasps the next day)

If you are taking pictures, shoot quickly and from as far away as possible and as many photos as you can, especially at the sugar bait (moths on the sheet are typically not as quick to fly). The flash and movements toward the tree are often enough to scare away any nectaring moths. However, they often come back quickly, so check frequently throughout the night.

Dave Moskowitz

East Brunswick, NJ