I am sorry to everyone for the late post. Things at NGRREC are really picking up, and we are going into a very busy part of the year. From now on, we’ll only be posting one blog on the first Friday of every month. Now, to the subject of the week. MOTHS!
Butterflies are beautiful and brilliant, but moths are magnificent too. Moths can be equally as beautiful and have evolved incredible ways of avoiding hungry predators. Today, we are going to shed some moonlight on these incredible insects.
Moths, like butterflies, start life as eggs which hatch into caterpillars. They spin a cocoon and then metaphor into a beautiful moth (Figure 1). The instars you see in the diagram are different stages of the caterpillar’s development. Ever wonder how to tell a butterfly from a moth? That can sometimes be tricky. As scientists discover more butterflies and moths, the lines between the two become less obvious. Some ways to help decide are size, color, and wing shape. Most moth species, but not all, are nocturnal, and they tend to hold their wings in a way that hides their abdomen while butterflies do not1.
Moths are usually smaller and less colorful, but there are definitely exceptions1. The Callosamia promethean or the Promethea Moth (Figure 2) is a large and wonderfully beautiful native moth that could be mistaken for a butterfly if it did not have the large, fuzzy body and fan-like antennae. This lovely moth’s caterpillars can be found on a variety of tree species; happily munching away on birch, wild cherry, lilac, tulip poplars, white ash, and others1,2. As with several other species, once this moth emerges as an adult, it does not eat. Males use their large antennae to smell out the females, and mating is the only goal for this moth during this life stage. Last summer, I gently scooped a female up off the sidewalk and put her back up into the tree. She fluttered to a couple different branches and then settled out of sight.
Moths are not only beautiful, but they are an essential part of our ecosystems. The caterpillars provide food for our native birds. Even species that eat seeds or fruits feed juicy caterpillars to their growing babies who need the protein. They also serve as pollinators for several plants. Not all moths stop eating as adults, and as they fly from flower to flower, they carry pollen and help the plants reproduce (Figure 3). There are many moths whose caterpillars only eat one kind of plant, and the adult also only feeds and pollinates that one plant. While they flutter about in the night, they might also end up feeding our local bats. Bats find moths with their echolocation, but some moths have evolved ways of avoiding detection or jamming their signals.
One way moths make an escape is to fake out the bat with long flowing tails on their wings (Figure 4). These confuse the echo the bat hears, and they end up biting at the tails instead of moth’s body. Another cool evasion technique where moths fall out of the air to avoid being eaten is explained in the following video.
Bats are not a moth’s only predator. Spiders will also take a moth as dinner, but one moth in particular has had enough and calls the spider’s bluff. When confronted by a jumping spider, the metalmark moth flares its wings and extends its legs. In this position it looks an awful lot like another spider3, and it may even jump. In the following video, you can even see the spider raising its legs in a territorial defense posture; thinking it has to defend its space against another spider.
So moths are pretty darn cool. There is so much more I could say about them, but I’ve run out of space. If this has peaked your interest in the moths in your backyard, I encourage you to visit BAMONA (Butterflies and Moths of North America). You can learn what species are in your area, get region checklists for a mothing expedition, and report your findings.
If you would like to go mothing, visit www.mothnight.info for some great options for attracting them.
When you do find amazing moths, take a picture and identify it. Keep a list and report it to help promote moth conservation. For help identifying adults or caterpillars use www.discoverlife.org or the BAMONA website. I hope you are as excited about these beauties as I am. Happy mothing! See you again June 3rd.