What Is the Difference Between a Butterfly and a Moth?


Differences between butterflies and moths
There are several key differences between butterflies and moths. However, there are exceptions to most of these rules!

Butterflies and moths are amazing flying insects belonging to the order Lepidoptera. They share similar life cycles and look so much alike, it can be hard to tell them apart. Yet, if you look closely, you can identify them. Here are several differences between butterflies and moths.

  1. Butterflies are active during the day (diurnal), while most moths are active at night (nocturnal). Moths often use moonlight to navigate, which is why they may become confused by outdoor lights.
  2. Butterfly antennae are long and either knobby on the end or else straight. Moth antennae tend to be short and feathery.
  3. Butterflies rest with their wings folded upright above their bodies. Moths rest with wings open alongside their bodies.
  4. Butterflies and moths have different wing structures. In moths, the fore wing and hind wing on each side are connected by a joint called a frenulum. In contrast, butterflies have four unconnected wings.
  5. Butterflies have thin bodies, while moths have thicker bodies.
  6. Most butterflies are colorful, while most moths display duller, earthy hues. There are dramatic exceptions. Some butterflies are brown or have transparent wings, while some moths show vivid colors. Butterfly wings aren’t actually colored, but the tiny scales on the wings scatter light, making them appear colored. Moth wings also scatter light, but may contain some pigment molecules, too.
  7. Both butterflies and moths start life as an egg, which hatches into a larva (caterpillar). Moth larvae spin a silken cocoon, while a butterfly undergoes metamorphosis within a hard chrysalis. When adult moths and butterflies emerge from the cocoon or chrysalis, they pump fluid into their wings to spread them before they harden. They must assemble their straw-like proboscis to feed. However, some moths lack a proboscis and never feed as adults.

Exceptions to the Rules

Usually, it’s easy to tell the difference between a butterfly and a moth. But, there are exceptions. While butterflies aren’t mistaken for moths, some moths resemble butterflies. Examples include:

The Madagascar sunset moth has colorful wings like a butterfly, but feathery antennae of a moth.
The Madagascar sunset moth has colorful wings like a butterfly, but the feathery antennae of a moth. (photo: USGS)
  • Madagascar sunset moth (Chrysiridia rhipheus): Unlike most moths, the sunset moth displays bright colors and flies during the daytime. The bright colors warn predators that it is poisonous. The moth’s wings also rest upright, like those of a butterfly. However, it has the feathery antennae of a moth and emerges from a silken cocoon.
  • Promethea silkmoth (Callosamia promethea): Like butterflies, male silkmoths are active during the day. Females are active at night, but overlap the male activity period for a couple of hours. The male’s appearance mimics that of the poisonous pipe vine swallowtail butterfly.
  • Paysandisia archon: This moth flies during the day and has clubbed antennae. It holds its wings toward its body, like other moths.
  • Tetragonus: Moths belonging to the genus Tetragonus hold their wings upright, like butterflies. You can tell they are moths because they lacked knobbed antennae.

Difference Between Butterflies and Moths: Genetics

Scientists use molecular genetics to identify differences between organisms and to work out how they evolved. The resulting phylogenetic tree shows relationships between different species. Based on genetics, the differences between moths and butterflies is slight. Some butterflies are more closely related to certain moths than to other butterflies!

References

  • Mutanen, M; Wahlberg, N.; Lauri, K. (2010). “Comprehensive gene and taxon coverage elucidates radiation patterns in moths and butterflies”. Proc. R. Soc. B. 277, 2839-2848. doi:10.1098/rspb.2010.0392
  • Prum, Richard O.; Quinn, Tim; Torres, Rodolfo H. (2006). “Anatomically diverse butterfly scales all produce structural colours by coherent scattering”. The Journal of Experimental Biology. Cambridge: The Company Of Biologists. 209 (Pt 4): 748–765. doi:10.1242/jeb.02051
  • Scoble, M.J. (1995). The Lepidoptera: Form, Function and Diversity. Oxford, UK: The Oxford University Press.
  • Scott, James A. (1992). The Butterflies of North America: A Natural History and Field Guide. Calif.: Stanford University Press.

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