Happy National Moth Week!

National Moth Week is July 18–26, 2020

Published07/16/2020 , by Heather Cummins, gallery programs coordinator and Minnesota Master Naturalist

As an entomologist with an emphasis on moths, I must admit this week brings me much excitement and I can’t wait to share the wonderful world of moths with you.

National Moth Week (NMW) is a worldwide movement that began in 2012 to “celebrate the beauty, life cycles, and habitats of moths.” NMW encourages everyone, everywhere to become citizen scientists by contributing to global scientific data gathering for moths.

National moth week

Why Moths?

Moths belong to the insect order Lepidoptera (moths & butterflies) which makes up about 16 percent of all insect diversity (insects alone make up over 58 percent of the diversity of life on Earth!). Researchers estimate that there are up to 500,000 species of moths worldwide (roughly 150,000 of those have been described by science). These insects make up a large part of the diversity of life on Earth, and they can be recognized in their adult forms as moths, in their larval forms as caterpillars, or even in their pupal forms as they hide away in their chrysalides and cocoons.

When you think of a moth, what comes to mind? A drab grey or brown fluttering thing that flies aimlessly toward lights at night? You wouldn’t be alone in having that image be the first thing your mind goes toward when you hear the word moth. Fortunately, that hardly scratches the surface of moth appearances. They range from bright pinks and yellows to deep greens and rusty reds to having clear wings and resembling bumble bees or humming birds to mimicking wasps and so much more. Don’t believe me? Check out the “Searching for Moths” section below to learn some ways to start mothing right from home and see what diversity you find in your own neighborhood this week.

Not only are there hundreds of thousands of species of moths to feast our eyes on, but they also serve as excellent bioindicators and many species are pollinators. Bioindicators help us evaluate the overall health of an ecosystem. In the case of moths, when there is a high diversity of moth species, it indicates that there is high diversity of plants which, in turn, results in a higher diversity of other organisms (many of which rely on moths as a food source) in the ecosystem. Healthy ecosystems rely on a high diversity of species to maintain balance.

In a word, moths are COOL! We haven’t even gotten into some of the amazing behaviors and defense mechanisms they have, or taken a look at their caterpillars, but we’ll save those for future blog posts. For now, I hope you’ll stick with me this week and try out some mothing of your own. Read on for some tips and tricks.

Searching for Moths.

Looking for moths is as easy as turning on an outside light at your house or apartment building once it’s dark. Watch this video to learn more!

a white sheet hangs from a light at nightTo increase your success of seeing moths and to give them a place to land, try setting up a white or light colored sheet, rag, or towel and hanging it under the light. You could clip your sheet to a hanger and hang it on your light like in the photo to the right.

Once it’s dark you should slowly start to see some moths arriving at your light and resting on the sheet. Moths aren’t the only insects who are attracted to lights, though, so you will likely see a diversity of insects arriving at the light.

Don’t have a porch light? No problem! Try removing the shade from a table lamp and setting it up near the side of your home or building—adding a white or light colored sheet under it will again help attract moths and give them a place to land.

Prime mothing time is roughly midnight to 2 am. That’s not generally when the majority of us like to be awake, but don’t worry, there are some ways around that. When it’s time to go to bed, you can leave your light on overnight and check your sheet early in the morning (6 am or earlier is best)—you’ll likely still see some stragglers hanging around before they tuck themselves in for their daytime rest. 

Try setting out bait that you can check throughout the night or the next morning. There’s no “one true recipe” but most look something like this (if you don’t have all of the ingredients make substitutions with what you do have on hand and see how it works!):

  • 1 pound dark brown sugar
  • 2–3 tablespoons molasses
  • 1–2 chopped bananas
  • 1 bottle of dark beer (or enough to dissolve the sugar)

Mix everything together and use it right away or let it sit out in the sun for a day or two (covered so ants don’t get to it). Once you’re ready to use it, paint the bait lightly a few feet up from the ground on a tree or two (try different tree species to see if you get different moths at them)—if you do this in the same spot a few days in a row you might get repeat visitors!

If you’re feeling particularly adventurous, you could create your own moth light trap following simple DIY instructions like those shown here: http://www.lilacgrove.co.uk/diy-moth-trap/

You can also look for day-flying moths by looking in similar places you might look for butterflies—most moths are big fans of pollen and nectar just like other pollinators. Take a hike at a local park or walk around your neighborhood and look around trees, shrubs, flowers, and garden patches. I recently found this striking grapeleaf skeletonizer moth (family Zygaenidae; the caterpillars feed on grape leaves and leave them looking like skeletons) at Rice Creek North Regional Trail (photo below).

Black and red dayflying moth on grass

If you’re loving observing these remarkable insects and want to get deep into mothing, there are plenty of suppliers you can purchase equipment from. Check out BioQuip.com or LepTraps.com to get started.

Document moth diversity!

While simply observing moths is incredibly enjoyable all on its own, you can take your mothing a step further by contributing your observations to community science projects.

Here are just a couple ways to contribute, you can find additional projects a NationalMothWeek.org:

  • iNaturalist is one of our favorite overarching community science apps and it can help you identify the moths you find! The app is free to download and it’s as easy as 1-2-3 to use:
    1. See a moth (or any other living thing or sign of life like scat or feathers)inaturalist
    2. Take a photo of the moth
    3. Upload the photo to iNaturalist!
    • The app itself can suggest an identification for you if you are unsure and community members can confirm or correct the ID. Once enough community members agree on the identification your observation is considered research grade! During National Moth Week, any photos of moths that are uploaded to iNat will automatically be added to the National Moth Week 2020 observations project!
  • National Moth Week on Flickr is another great way to help document the diversity of moths around us. Scroll through the project to get a taste of the endless shapes and colors of moths right here and around the world.

And, with all of that in hand, I wish you all good mothing! and a fabulous National Moth Week! Let us know how your mothing goes by sharing and tagging us on social media @BellMuseum

Activity: Moth Bingo! 

How many of these squares can you complete?

left to right: found a caterpillar, uploaded a moth photo to inaturalist, saw an insect other than a moth at a light, found at least 5 different types of moth, saw a moth, accidentally swallowed an insect, caught a moth or observation, set up a light sheet at home, found a moth during the day