Moths. The word often conjugates “pest” while the word butterfly ignites a whole different reaction. Moths dredge up a foreboding sense of larvae wiggling through the flour. Though related to butterflies – they share the same order Lepidoptera – moths are the ugly ducklings compared to their bright and colorful relatives. Everybody loves butterflies, but you might be hard pressed to find someone who shares an enthusiasm about moths. Case in point: when was the last time you went to a moth and hummingbird exhibit or heard about a wedding where moths were released as part of the ceremony?
Well, they say every dog has its day, and the moths have their own National Moth Week. It's held annually the last full week of July and it celebrates the beauty and diversity of these mainly nocturnal creatures. Special events are held across the U.S. and in other countries throughout the world to document distribution and habitat use of moths by citizen scientists like you and me.
I used to hold moths in low regard. I considered them prey items of bats, owls, amphibians, nighthawks, poorwills and other creatures of the night. They were the source of “weevils” burrowing through open bags of flour and the culprits that ate holes in my wool shirts. Their caterpillar stages are a huge food resource for songbirds, but I didn’t really look at them the same way I looked at butterflies. But that was long ago and since then I’ve changed the errors of my way.
Moths are pretty cool and, compared to butterflies, are far more abundant. In North America there are an estimated 1000 species of butterflies compared to 11,000 species of moths. Worldwide that’s about 28,000 butterfly species to more than 110,000 species of moths. Of course, these numbers vary depending upon species or variety levels, but the idea that there are a whole lot more species of moths is the take home message.
Moths tend to be more nocturnal than butterflies, but some are diurnal, flying during the day. Both pollinate flowers, but unlike their colorful daytime cousins, moths search for those flowers that open at night like yucca, Indian tobacco, datura, some types of phlox and other flowers that tend to be white in color. Like the yucca moth in the Southwest whose life cycle is dependent upon females laying their eggs in the yucca flower’s ovary while the moth is pollinating the flower. The developing larvae feed upon some of the maturing seeds before they emerge to pupate. Not all moths are nocturnal, but most are.
Some other general characteristics may be used to separate the moths from the butterflies. Moths hold their wings in a tent-like fashion or to the sides like a plane protecting their abdomens while butterflies often hold their wings upright, vertically over their backs, or at an upward angle when landed. Butterfly antennae also tend to be club-shaped at the tip, whereas moth antennae are feathered or saw-toothed at the tip. Again, most but not all. Moths also have a structure called the “frenulum” which can join the forewing to the hingwing for increased power during flight.
Butterflies larvae wrap up in a chrysalis to pupate before emerging as adults. Moths spin a cocoon enveloped in a silk coating while the butterfly’s chrysalis is hard and smooth. Some moths pupate a few inches underground or wrapped in leaf litter. Again, not all.
During National Moth Week, started by New Jersey entomologist David Moskowitz, private individuals or organizations host “mothing” nights. The goal is to attract, identify and discover what species of moths are flying in a particular area. These family-friendly nights can be an adventure of discovery or a chance to learn from the experts. It doesn’t take much to attract moths, it’s figuring out what types show up.
In the backyard, a simple moth attractant is to turn on a porch light and see what is flying around the light. A small butterfly net helps with capturing individuals, just remember to be gentle and try not to injure the moth. That fine powder-like substance that comes off of their wings isn’t dust; it is minute scales that cover the wing.
Another idea is to insert a black light bulb into that porch light or set up a handheld blacklight outside aimed at a hanging white sheet. Clotheslines work well here or run a string between some trees and hang the sheet from the string. If you can anchor the bottom of the sheet to the ground, this gives a nice taunt surface that the moths can land on and to observe them without the sheet flapping and scaring the moths away. A camera helps record the different species that visit the light and can be used by experts to help identify the moth – if you need help.
A third idea is to “fish” for moths with bait. Nothing fancy like a fishing pole is needed, just some mashed up bananas, peaches, brown sugar, stale beer or whatever you have on hand. The pasty bait mix is left to ferment for a few days and then painted on trees to attract the moths. Moths don’t have noses, but can detect odor molecules through their antennae. You can also add maple syrup, honey, fruits or other sweet smells to attract the moths. Apply the mix to tree trunks, about chest height, then wait and check the trees a few hours after sunset to see what moths have shown up. Use a flashlight to discover the moths; covering the lens with some red cellophane helps soften the light and not scare the moths away. Remember, too, to be quiet as moths can hear and will flee if they feel threatened. A combination of bait and lights works well because some species of moths will be attracted to the bait over the porch light.
Once the moths show up, the fun or challenge depending upon your view point is to try and identify them. There are several field guides in print or websites that offer ways to identify the moths. Some will be easy, their distinctive color and shape lend to a solid ID, but others might take some time. Try to photograph the ones that show up and these can be submitted through different websites like iNaturalist or some of the listed resources below. And what a conversation starter when you share that you went mothing last night, unusual reactions guaranteed.
Here are a few recommended resources depending upon your location:
Discovering Moths: Nighttime jewels in Your Own Backyard by John Himmelman.
Peterson Field Guide to Moths of Northeastern North America by David Beadle and Seabrooke Leckie
Caterpillars of Eastern North America: A Guide to identification and natural history by David Wagner
Website: http://pnwmoths.biol.wwu.edu. Pacific Northwest Moths provides information on more than 1,200 species in the Northwest. The site also offers an interactive identification guide to help key out your backyard visitors.
Website: www.bugguide.net. Print out the guide to silhouettes to help determine which family a particular moth is in.
Website: http://www.discoverlife.org/mp/20q?guide=Moth. Use the search key to help with identification.
Website: http://nationalmothweek.org. This site lists events across the U.S. and indicates if they are private or public outings. The public outings provide great opportunities to learn about mothing and moths in general, and some of the private ones are families or friends out camping and may be open to visitors dropping in to see what all the weird lights are about.