Doreen Fogle: Moths … as pollinators?
While moths are not the best pollinators in the world, many of them do perform pollination services for our ecosystems and some are even the sole pollinators of some plant species.
“Moths?” you say, “those dusty, pesky, annoying bugs that eat my woolens, oatmeal, and my broccoli plants, and flutter endlessly around the outside lighting?” Yes, moths are one of the “other” pollinators. And many are quite interesting, too.
Honey bees and butterflies get a lot of credit for being the great pollinators. But there are so many others worthy of notice. My article of Oct. 21, 2017, titled Wild Bees: the Great Pollinators, pointed out the existence of the many types of native bees, their habitat needs, and their speed and great efficiency at pollination.
In addition to native bees, honey bees, and butterflies, there are the moths, beetles, wasps, flies, ants, midges, some birds, and bats, all known as the non-bee pollinators, doing pollination work.
Studies have been done to assess the value of non-bee pollinators. It has been found that while the non-bee insects are not as efficient at pollination as bees, they make up for it by simply visiting flowers more often.
Pollination effectiveness has been shown to increase with visits by non-bee insects. So it is wise for us to keep in mind the overall benefit our non-bee pollinators provide.
Many moths are nocturnal, pollinating the pale to white flowers, especially the very fragrant ones. They have smell sensors on many parts of their body and can smell flower nectar from many miles away!
The males can also smell the female pheromones from up to seven miles away. There is a story of researchers who tracked a moth who traveled 23 miles to find a female! Sadly for him it was just a pheromone solution.
That powdery dust from the wings of both moths and butterflies is actually tiny scales. If you handle them gently they can deal with the loss of some of these scales. They hear sounds with their wings. And the hairs all over their fuzzy little bodies give the insects a sense of touch, giving them information about their environment and the wind while flying.
The adult moths typically feed on nectar for fuel. Many have a long sipping tongue that stays coiled up in their mouths, which it dips down into the flowers that have abundant nectar. The flowers moths frequent include those that, in addition to fragrance, open in the late afternoon or night, have abundant nectar, and have a landing pad.
Flowers that would attract nocturnal pollinators would be morning glory, gardenia, pale colored butterfly bush, scabiosa, Sweet William, honeysuckle, Evening Primrose, and Jimsonweed.
Facts on moths
For many of the moths, their fat, hairy bodies brush against the pollen and they inadvertently brush it onto the next flower they visit. But there also moths that do not even have mouths as adults, living off the fat stored during its life as a caterpillar.
Nocturnal moths navigate by the light from the moon and stars when available, and rely on geomagnetic cues when it is not. The rays of light coming from the moon originate so far away that they are essentially parallel, providing rays of light the moths can use to navigate.
But when the porchlight is on, it emits light radially out from its source, confusing the moths’ directional abilities. That’s why we find them circling round and round, they are assuming the rays of light are parallel to each other.
Heck, they did evolve before the electric light bulb was invented. Once attracted to the light they don’t leave. So when they are circling around, exhausting themselves, they are not out feeding, finding their mate, or laying their eggs. But they do become food for bats.
A colored light bulb, preferably red, will not attract the moths’ attention. Or using motion lights that illuminate your path only when needed would help a lot to free the moths to do what they need to do.
Moths are closely related to the butterflies. Here’s how to tell them apart: butterflies have a knob-like structure at the end of their antennae, moths have either a simple filament without the knob or fern-like antennae.
Not all moths are nocturnal, many are about in the daylight. Some moths are quite colorful, not always dull and earth-toned, so you can’t rely on that as a distinction. There is also a sub-group of butterflies called skippers flying about. You can tell them by their squarish, furry bodies, their darting flight, big eyes, and they have a knob at the end of their antennae or a backwards curving hook.
Pros and cons of moths
Moths are insects and their larval stage is the caterpillar. This is the stage where they can become a pest. Cabbage loopers eating the cruciferous vegetables, tomato hornworms defoliating the tomato plants, and Gypsy moths denuding vast tracks of northeastern hardwood forests are all examples of moth larval destruction.
Controls such as hand picking and maintaining a good population of predatory wasps is helpful in the vegetable garden.
The Gypsy moths have not been controlled. They are imported and were released accidentally, and they continue to impact the forests. There are only one or two species of moth that eat our woolens and only one, a close relative, which eats our grains.
Some moths are the sole, specific pollinator of some plants. An impressive example of this is the yucca moth. There are several species of yucca and each has its specific species of yucca moth that does the job of pollinating its plant.
The Joshua tree is one example of a yucca plant. The female yucca moth lays her eggs in the yucca flower, careful to not lay too many so that there are enough resources for the young to survive. Then she visits the flower from anther yucca plant, to assure cross pollination, and she forms it into a ball and stuffs the ball down the stigma into the ovary to fertilize the flower, thereby ensuring the continuity of its offspring and its food source.
If you are out in the evening and you think you see a hummingbird, but it looks a little different, you are probably seeing a Sphinx moth. They are also called Hawk moths and Hummingbird moths, and there are many species of these.
There are over 200,000 species of moths that have been identified, and likely many more, whereas there are about 17,500 species of butterflies.
There are 11,500 species of moth in the U.S. Not only do many of these provide pollination services, but the sheer biomass in moth adults and larvae is a very valuable, protein-rich food for birds, bats, frogs, lizards, and small mammals.
Between pollination and supplying the food chain, moths are important.
Doreen Fogle is a Nevada County-based landscape designer with Delightful Gardens. She can be reached at firstname.lastname@example.org. Her website is mydelightfulgardens.com.
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