The insect order Lepidoptera includes moths and butterflies and is the most recognized group of insects in the world. Perhaps this popularity is due to the wide range of colorful wing patterns that adult moths and butterflies display. These wing patterns range from brightly to dull colored, single- or multicolored, simple to highly intricate designs, but all wings have one thing in common—microscopic scales of “color”. Thousands of microscopic scales cover the two pairs of wings that most moths and butterflies have, and these scales easily rub off like dust in your hand (Figure 1). The presence of scales is the key character that distinguishes the moths and butterflies from nearly all other insect orders, and certainly contributes to the beauty and popularity of Lepidoptera.
One goal of this publication is to help Washington residents recognize all life stages of Lepidoptera and to distinguish adult moths from butterflies. There are over 1,200 species of moths in Washington State (Pacific Northwest Moths 2017). This publication seeks to help Washington residents recognize and appreciate the biggest and most spectacular moths native to our state.
Moths versus Butterflies
A general rule of thumb is that moths are active at dawn, dusk, and at night, while butterflies are active during the day. Thus, moths tend to be more subdued in coloration, while butterflies can be very bright and colorful. Not all moth colors follow these rules, as a few moths are not only bright and colorful, but active during the day. Moths tend to have thick and sturdy bodies covered with hair, while butterflies have thinner bodies.
Moth Life Cycle
All moths and butterflies go through complete metamorphosis, or a change in shape and size from egg to larva, larva to pupa, and finally from pupa to the adult stage.