Moths of Alaska

Whats the difference between butterflies and moths?

Moths and butterflies are very much alike. They are both insects in the Lepidoptera Order. They lay eggs that hatch into caterpillars. The caterpillars go into a "pupal" form that later turn into the adults that can fly. When they are in the pupal form, moths wrap themselves in a silky cocoon. Butterflies form a chrysalis, with a thin "shell." That's the real difference-- how they pupate.

That doesn't help much, does it? When you see a moth or butterfly flying around in its adult form, how can you tell them apart? People talk about the shape of their bodies, the colors on their wings, how they hold their wings, size, and what time of day they fly. Those things aren't reliable at all. With Alaskan Lepidoptera, the most reliable characteristic to look for is the antenna shape. Butterflies have little knobs on the ends of each antenna. Moths have plain or feathery antennae that don't have any knobs. The wood tiger moth (below, left) has simple antennae. The rusty tussock moth has feathery antennae.

So look for clubbed antennae. If you see clubs, its a butterfly. If you don't, it's a moth. You have to look closely!

Alaska has more kinds of moths than butterflies. There are only a few here, but more will be added. Check back.


Click on the thumbnail pix to see them bigger

Wood Tiger Moth
Parasemia plantaginis

 Rusty Tussock Moth
Orgyia antiqua 

 Spear-Marked Black Moth
Rheumaptera hastata

Herald Moth
Scoliopteryx libatrix

Great Brocade Moth
Eurois occulta

wood tiger moth

rusty tussock moth

spear-marked black moth

Herald Moth

Wood Tiger Moths are small, attractive, and somewhat variable in appearance. They are found throughout northern Europe, northern Asia, and western regions of North America. They prefer low altitudes near the sea coast and boggy areas. They fly during the day, especially the males. They overwinter in the larval form. You will find more information on this species of moth here and here. Caterpillars of this species feed on a wide range of woody plants, and can do considerable damage.We know that the pictured rusty tussock moth is a male, because the females are about six times larger and virtually wingless. They remain with the cocoon after they emerge, and use pheromones to attract the males. They lay eggs on the cocoon. Eggs overwinter.

Spear-marked black moths have been very numerous in the Anchorage area and interior Alaska this year (2004). Larvae feed on birch, and other woody plants. They can damage vast area in the forests.

There is extensive information about this species at this link.

Herald moths overwinter in the adult form, and are therefore among the first moths flying in the spring--"the herald" of spring. Adults are attracted to sweet fruits. Larvae feed on leaves of alder, aspen, birch, poplar, and willow.

You can find additional info on this species here and here.

This large attractive moth ranges through North America, Europe and Asia in northern coniferous forests. The larvae feed on a variety of trees and shrubs, but tend to be fairly harmless in most areas of their range. Partially grown larvae overwinter before completing their life cycle.

For more info, try this link.


 Other Alaskan Invertebrates

 Butterflies of Alaska

  Dragonflies of Alaska

 Stonefly in Alaska

Spiders in Alaska

  butterfly link