Butterflies vs. Moths

How do you tell a moth from a butterfly? In distinguishing butterflies from moths, there are some generalities you can follow to figure out what sort of lepidoptera you are viewing. Obviously, there are exceptions to almost every rule but if the specimen you are watching meets several criteria for moth or butterfly, you can be fairly safe in your assumption.

Day vs. Night: Most butterflies are diurnal and fly during the day. Most moths are nocturnal and fly all night and during transition periods like dusk and dawn.

Colors: Many butterflies have brightly colored wings. Many moths have more drab colored wings.

Different Antennae: Butterfly antenna are slender and have club shaped tips. Moths have tapered or wide feathery antenna that do not have club shaped tips

How they Fold Their Wings: When at rest most butterflies hold their wings folded together vertically over their bodies. Butterflies have brighter colors on the tops of their wings and duller colors on the underside. Moths rest with their wings extended, wrapped around their bodies or pressed against the support on which they are resting. Moth moths have dull colors on the upper side of their wings.

Warming Up: Butterflies often warm their bodies by basking in the sun and absorbing solar radiation. Moths fly at night and have no access to solar radiation. Many moths with shiver their wings, which causes their flight muscles to heat up and provide warmth for their bodies.

Body Shape and Scales: Butterflies tend to have slender bodies in comparison to their wings. Their scales are pressed tightly against their wings forming a smooth surface. Many moths have stout bodies and their scales give them a furry appearance on their wings and bodies.

Sense of Smell: Butterflies “smell” with sensory organs in their feet and also with their antenna. Moths “smell” with their antenna.

Wing Movement: Butterflies have 4 wings that can move independently of each other. Moths have four wings but they are linked together and the fore and hind wing move as a set. The wings are linked by a bristle on the hind-wing (frenulum) and hook on the forewing (retinaculum) that keep the two wings moving as a unit.

Moths are More Numerous: There are over 700 species of butterflies north of Mexico. In the same area there are ten times that number of moth species which are far more diverse in form, structure and choice of food plants.

Specialist vs. Generalist: Most butterflies are specialists when it comes to host plants and will usually only consume a small group of closely related plants. Many moths are able to consume a much broader range of host plants.