Moths are maligned, ignored and considered more drab, less interesting than their glamorous butterfly relatives. National Moth Week (23-31 July) aims to dispel this and encourage people to explore and learn about these vital, sometimes vivid Lepidoptera with night lives that are poorly understood. Sure, some moths eat our fabrics, lay eggs in stored foods, and defoliate trees (see gypsy moth, humans made this disaster happen!). But others pollinate flowers, are important food for predators, or were introduced to control pests like tansy ragwort (a dangerous poisonous plant). Moths have amazing lives and fascinating bodies designed to blend into their environment or to confuse and harm predators.
- Moths are among the most diverse and successful organisms on earth.
- Scientists estimate there are 150,000 to more than 500,000 moth species.
- Their colors and patterns are either dazzling or so cryptic that they define camouflage. Shapes and sizes span the gamut from as small as a pinhead to as large as an adult’s hand.
Check out the luna moth’s wing tips resembling tapering “tails” in the photo above. These are used to decoy bat predators and can be bit off without hurting the moth. The photo below shows details of the round markings on the hind wings that confuse predators.
How to distinguish moths from butterflies
Moths usually rest with their wings either spread or folded back, butterflies hold their wings upright or open.
Plume moths tightly roll their wings when resting and resemble dried grass or twigs, thus avoiding notice.. They fly seeking nectar day and night.
This year the celebration spotlights underwing moths from the genus Catocala. There are more than 250 known species of Catocala. Their dull-colored forewings close to camouflage them while at rest. However, when they spread their wings, they reveal flashy hindwings with orange, red, white or blue markings. It’s thought that the underwing colors resemble a predator’s eyes and startle animals intending to eat the moth. Moths who fly at night need to be inconspicuous when they are resting in the daytime, easily visible to birds and other predators.
Moth antennae usually are broader, feathery or comb-shaped, while butterfly’s are clubbed at the tip.
A male moth uses his antennae to detect a female moth. Male giant silkworm moths have elaborate, feather-shaped antennae with hairlike scent receptors that allow them to detect a single molecule of a female moth's sex hormone from 7 miles away.
Moth caterpillars often have hairy bodies, spikes, and knobs (some butterflies also have spikes).
The word caterpillar is from Middle English catyrpel . They took it from Anglo-French catepelose meaning hairy cat. Some caterpillars are shaggy, some knobby, others spiny or a combo of all three.
Moths form cocoons spun from silk, often adding plant material or hair from their own bodies. (Butterflies form pupae from the hardened shell of the caterpillar’s body.)
Look around, day and night there are many marvelous moths living near you.
Some female moths don’t eat but exist only to lay mate and eggs. Other moths seek nectar and are pollinators of day- and night-blooming flowers. Learn more about moths from the Xerces Society’s blog Moths Are Cool. They offer simple instructions on making a light trap to observe night-flying moths and other night insects. To identify the moths near you use one of these guides to moths of specific regions from Butterflies and Moths of North America’s website. They have regional checklists, an image gallery, mapped sightings submitted by citizen scientists, and other resources for moth-ers.
Here are some moth features you might see.
Larval, cocoon and adult life phases of moths have clever disguises and sometimes toxins.
You might find two lives in one caterpillar.
i don’t want to leave you with that creepy image, so here’s one last amazing moth that is the first documentation of self-medication among insects.
Research found that tiger moths eat leaves containing alkaloids that help fight off internal parasitic fly larvae. Another way they evade predation is by making ultrasonic clicking sounds that interfere with bat sonar.
Go outside and look at moths and caterpillars. Don’t disturb them. They have lives, you know, and responsibilities.