Nature Notes
Quite A Number of Moth Species Are Active in Daylight
By Patricia Martin

I recently received a note from a friend of mine describing an unusual sighting. Feeding in the garden of his house was a moth that was seen briefly and flew away quickly, only to return shortly. His description is as follows: "It fed actively in the sunlight, just like and almost the size of a hummingbird, with a thick furred body, double, fast beating wings that were almost transparent, a distinct mock-bird tail (too short), antennae slightly furred like a moth's, but then a butterfly's too. It uncoiled its long butterfly tongue into flower after flower." He further goes on to call it the duck-billed platypus of the moth world. It was a hummingbird or clearwing moth.

Moths and butterflies are the most popular and easily recognizable of all the insects. It's funny that though there are at least 150,000 species of moths compared to only 15,000 species of butterflies, butterflies seem much more popular with people. There are more books about butterflies, more songs, more poems, and have you ever heard about a "moth house?" Perhaps this is because of some of the moths' behavior. In German the word for moths is "nachtschmetterlinge," meaning night butterflies, referring to the fact that the majority of moths fly at dusk or during the night. But this characteristic is not true of all moths. Quite a number may be seen during the daylight. In addition, while it's true that some species of moths are harmful, destroying crops, fruits, trees, and woolen goods, most moths are harmless, playing their role as pollinators of flowers, aiding in the propagation of plants.

Hummingbird Moth or Clear-Wing Moth

There are some general characteristics that help tell a moth from a butterfly, but there is not one single feature that separates all butterflies from all moths. In general, moths fly at night, butterflies during the day. Many butterflies are brightly colored and many moths are dull colored. Most butterflies hold their wings upright over their backs, while most moths rest with their wings flat. The butterfly antennae are knobbed at the tip, but moth antennae are either featherlike or plain. Because butterflies fly during the day, they're much more dependent on sight and color to attract them to flowers. Moths, on the other hand, often depend on their sense of smell to find flowers or a mate, as they often fly at night. The antennae, which are feathery, detect odors. Of these two groups of insects, moths are much older, with the fossil record indicating that they appeared at least 140 million years ago, while the earliest record of butterflies occurs about 40 million years ago.

Moths and butterflies have a number of similar characteristics. They need to be warm for their bodies to work properly. When the air is cold, they rest. One reason moths are hairy is that the hair helps them keep warm at night. Adult moths and butterflies do not eat to grow larger. They use their food to warm up their bodies in order to keep them functioning properly. Most of these organisms get their food from the nectar of flowers, which they drink through a long tube called a proboscis. The proboscis is curled up when the butterflies and moths are not eating.

Moths and butterflies have a similar life cycle. Both of these groups of insects lay eggs that hatch and develop into caterpillars. Caterpillars are hungry creatures that eat voraciously, sometimes shedding their skin several times. After the caterpillars grow sufficiently, they begin to develop into a pupa, which may be encased in a cocoon. It is in this non-moving stage that major changes occur. The pupa changes into an adult butterfly or moth.

The hummingbird, hummingbird clearwing, or clearwing moth (Hemaris thysbe) that my friend saw is one of a group of North American species with large, clear areas on both the fore and hind wings. The clear areas appear as scales and wear off soon after the moth emerges from its cocoon. The clear areas are surrounded by dark, red-brown borders but the wing bases and front half of the body are olivegreen. The front half of the heavy body of this moth is lighter in color than the darker, rear portion. The wingspan of this moth is one and a half to two and a half inches and it is found around trees and in lowlands. The caterpillar of the hummingbird moth is plump, yellowish-green with pale stripes along the back and a yellow and green tailhorn. In its caterpillar stage it likes to feed on hawthorn and other related species.

The adult moth feeds during the day on nectar from a variety of flowers. Their behavior often mimics that of the bumblebee, darting from flower to flower on quickly moving wings. A close Eurasian relative of this moth, the hummingbird hawkmoth, is often mistaken for a hummingbird because of its flitting from flower to flower and its rapid wing movement. These moths have a very long proboscis for sucking up all that nectar. The hummingbird moth is found across the eastern half of Canada and the United States.

This is one of a couple of unusual moths that have appeared on Mackinac this summer, and there are others that I'm sure I never even heard about. Keep an eye out for them.

Trish Martin is a yeararound resident of Mackinac Island, has earned a master's degree in botany from Central Michigan University, and owns Bogan Lane Inn.