Many moths will come to lights at night, but if you really want to sample the species in an area, you should try sugaring for moths. Sugaring or baiting is an effective and fun way to attract moths to an area. The bait is usually a mixture of fermenting fruit, sugar, and alcohol.
When sugaring for moths, you apply the bait mixture to tree trunks, fence posts, stumps, or other structures, usually around dusk. After dark, you visit your bait sites at regular intervals of time to collect or photograph any moths. You can try sugaring for moths any time of the year, but you'll have the best results if the temperature remains above 50°F. Warm, muggy nights are ideal for baiting moths.
Making a Sugar Bait for Moths
Every moth enthusiast or entomologist I know has their own favorite recipe for sugar bait. The key to effective bait is making a concoction with a strong odor to attract the moths, and a sweet taste to keep the moths around. Finding a mixture that yields good results may take a bit of trial and error on your part. Start with this basic recipe, and modify it to your liking.
Basic Sugar Bait Recipe to Attract Moths
- brown sugar
- overripe bananas
- beer (stale beer is preferable)
We're not baking a cake here, so there's no need to measure anything. Making a good bait for sugaring moths is more a matter of consistency than it is of proportion. You should try to achieve a consistency thick enough to keep it from dripping, but thin enough to spread with a paintbrush. Crush up the ripe bananas and mix them in. Use enough beer to dissolve the sugar. Stir it all together until you have a thick but fluid bait mixture.
Some people prefer to age their sugaring bait, by letting it sit at room temperature for a few days. This will allow it to ferment, which will make the bait all the more attractive to the moths. If you choose to do this, don't put your mixture in an airtight container. Use a loose-fitting lid, or cover the container with a paper towel held in place with a rubber band. If you have any stale or skunky beer around, here's your chance to put it to good use. Moths don't mind stale beer.
Other Sugar Bait Ingredients
Really, the fun part of sugaring for moths is creating your own perfect bait recipe. Try some of these ideas to modify the basic recipe, and see what works best to attract moths.
- dry yeast - if you're going to let your mixture sit and ferment, this may be a good addition to try
- sweet liqueurs, like schnapps
- white sugar – can be substituted for brown sugar
- maple syrup
- rotting watermelon – some moth enthusiasts swear by watermelon, claiming it's the best moth attractant you can find
- fermenting peaches, pears, or apples
- black treacle – a sweet syrup produced when sugar is refined
- cola – some people like to simmer the cola, stirring in sugar and perhaps some molasses until it dissolves
- orange soda – open it and let it sit for a while, so it goes flat
Applying the Sugar Bait to Attract Moths
Now that you've mixed your sugar bait, it's time to do some mothing! You'll need a paintbrush to apply the concoction. A 3-4" width paintbrush is ideal for this purpose. Take your mixture to the area where you hope to collect moths, and choose a few tree trunks or fence posts that are easily accessible. Paint the mixture on these locations, making about a 12-inch square (smaller, obviously, if the tree trunk isn't that wide) at eye level. If you're planning to photograph the moths, keep that in mind when applying the sugar bait. Make sure the ground is clear of debris or undergrowth, so you can collect or photograph any moths easily. I recommend sugaring the trees around dusk, so the scents of a fresh batch of bait are wafting through the air just when the night-flying moths are waking up from their naps.
When you're applying the bait, remember that other insects (Ants, anyone?) may enjoy a sugary snack, too. If you want to find moths, you need to be careful not to spill the bait solution as you walk around the area. Don't let the bait mixture drip down the tree trunk, either. You need to make a nice, neat square of sugar bait, without creating trails for ants to follow. If it drips, it's not thick enough and you should go back to the kitchen. Adding molasses will usually do the trick.
Some people recommend using the bait mixture as a barrier, to keep hungry ants from reaching the bait square intended for moths. Try painting a ring of the sugar bait around the tree trunk, several feet below the moth bait, and also several feet above the moth bait. This should effectively intercept any ants, and keep them preoccupied and away from the moths.
Checking the Bait for Moths
Now it's just a matter of sitting and waiting for the moths to find your irresistibly stinky bait. You'll probably notice the most moth action between the hours of 10 pm and 1 am, but check your bait sites every half hour or so. Be careful you don't spook the moths! Don't shine your flashlight directly at the moths. Flashlights with a red filter, or with red LED lights, will make it easier to observe the moths without disturbing them. Keep your flashlight pointing down toward the ground as you approach.
As moths in the area detect the scent of the bait, they will fly to the site to investigate. You'll see moths resting on the areas where you applied the bait. You may be able to photograph a moth unfurling its proboscis to sample the sweet snacks. If you're collecting moths to preserve, have your killing jar ready!
- Discovering Moths: Nighttime Jewels in Your Own Backyard, by John Himmelman
- Sugaring for Moths, Catocala website, accessed November 19, 2012
- Sugaring for Moths, University of Washington, accessed November 19, 2012
- Sugar Baits for Moths, National Moth Week, accessed November 19, 2012
- Sugaring for Moths, Michigan Entomological Society, accessed November 19, 2012
- Attracting Moths, Staffordshire Moth Group, accessed November 19, 2012