Moths serve a purpose; numbers are declining


By Johnna Siegrist

Darke County Parks

Moths are often overlooked. Although viewed as pests, these insects actually serve a vital purpose in many ecosystems.

Moths outnumber butterflies by more than 10 to 1. In the United States, there are approximately 12,000 species of moths, compared to only 750 species of butterflies. Ohio alone has recorded around 3,000 species of moths and 140 butterflies. Moths can be as small as a pencil tip, to as large as a songbird. The Stigmella maya is the smallest moth in the world that is found in Yucatan, Mexico, measuring only 1.2 millimeters (0.05 inches) in size. The Atlas Moth, with a wingspan of 27 centimeters (10.6 inches), is the largest moth in the world and can be found in the Eastern Hemisphere.

What is the difference between moths and butterflies? Most butterflies are diurnal (active during the day), while most moths are nocturnal (active during the night). However, some species of moths are diurnal, like the hummingbird clearwing moth, which can be found in Ohio. There are also physical features that separate moths from butterflies. Moths tend to have thicker bodies that are covered in hair-like scales that give them a fluffy or furry appearance. Butterflies, on the other hand, often have slender and sleeker bodies that are less furry in appearance. When they are at rest, moths will rest their wings horizontally on their body, while butterflies will hold their wings upright in the air. Another difference between butterflies and moths is the shape of their antennae. Moths will have feathered or saw-edged antennae, while butterflies’ antennae are slender with bulbs at the tips.

What do moths eat? Well, it depends on the current life stage of the moth. Moth larvae, or caterpillars, are herbivores, consuming mostly plant leaves. They are known as shredders since they can break down organic matter, which releases carbon into the atmosphere. They also enrich the soil by turning plant parts into humus, which allows small detritivores to break down the humus, returning nutrients into the soil. Moth caterpillars are often regarded as pests due to their destructive feeding habits. There are only a few species of moths that will consume cotton in their larvae phase, and they have been declining in number. Adult moths will feed on sap or nectar. Some species are carnivorous and will consume small insects or snails in their adult or larvae phase. Some adult moths do not have mouthparts, so they cannot eat at all. Species without mouth parts live long enough to reproduce over a few days to a week.

Moths play an important role in pollinating numerous plants because they consume nectar. They are not specifically designed for pollination, but will pick up pollen on their legs and bodies and transfer it from flower to flower when they are feeding. They are not very efficient pollinators, but due to the number of flowers that they visit in a single night (or day), they can pollinate a large number of flowers. Some recent studies have shown that nighttime moths may be more efficient pollinators than bees. Some plants rely on moths solely for pollination. Since many moths are active during the night, they are vital to the survival of many plants that open their flowers at dusk or during the night. These flowers are typically lighter in color and are very fragrant. The lighter-colored petals reflect the moonlight better, making its visibility to moths much better. The strong fragrance of the flowers also helps attract moths since they have a keen sense of smell. Moths do not have noses, so they use their antennae to detect odor molecules in the air. Their antennae are so powerful that males can detect a female from 7 miles away.

Moths have declined in population 33 percent since 1968. Over 20 species have become extinct since the start of the 2oth century. The Garden Tiger and its Woolly Bear Caterpillar (brown and black fuzzy caterpillars in the Farmer’s Almanac used to determine winter climate) have declined 90 percent since 1968. You can help moths by growing a diverse selection of shrubs, plants, and trees. There are certain plants that moths need for egg-laying and ones that provide nectar for adults. Planting these plants will help the species of moths that are declining. Try to avoid bug zappers. These devices often harm and kill more than just mosquitoes; moths often fall victim to them as well. Keep old leaves, branches, and tree stumps to provide habitats for moths and other animals. Covert dead zones into areas with native plants, trees, and shrubs. Reducing light pollution helps protect moths from the concept of “like a moth to a flame”. If lights are needed, use yellow-colored bulbs instead of white ones. Leave caterpillars be. Understand that they provide a food source to over 115 Ohio songbirds and that they will transform into a butterfly or a moth someday.

For information about upcoming programs and events, visit or call the Nature Center at 937-548-0165

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