Some nature lovers confuse moths and butterflies, two interesting flying insects of the order Lepidoptera. Although most people associate moths and butterflies as close cousins, with the same four-stage life cycle and complete metamorphosis, they actually have many differences when examined in more detail, such as in appearance and behavior. So what are they? Are there any exceptions? We’ll get to that soon.
In terms of appearance, butterflies are colorful, have a hard chrysalis, and thin bodies; while moths are duller (more earthy hues), have a silky cocoon, and thick bodies.
Cocoons and chrysalises are both protective coverings for insects’ pupal stages, but differ in structure. Cocoons are silk casings spun by caterpillars as pupa; caterpillars secrete silk threads from spinneret glands for the woven structure.
In contrast, chrysalises are hardened outer skins of butterfly caterpillars during pupation; there’s no silk involved-instead, the exoskeleton transforms into a rigid case before metamorphosis, protecting the developing butterfly inside.
Butterflies have long straight or clubbed/balled antennae, closed-upright-resting wings, and no wing hinges (no frenulum);
Moths have short feathery antennae that are often tapered or leaf-shaped, their wings rest open along their bodies, and their upper and lower wings(forewing and hindwing) are joined by a row of hair-like structures called the frenulum. Hair seems to be ubiquitous for many moths, as a possible adaptation to evade bat echolocation. Something to note is that although butterfly wings have color, they aren’t actually colored-instead they have tiny scales that scatter light; meanwhile moth wings, while also having this same structure, may contain some additional pigment molecules.
Another thing to consider would be that moth vs butterfly wing colors are adaptations to the insects’ lifestyles-moths need daytime camouflage as they rest, and bright colors aren’t required for nighttime activity (they use pheromones instead); while the diurnal butterflies use bright colors for mating or warning predators.
The main behavioral difference is that moths are nocturnal or crepuscular(active at dawn and dusk), while nearly all butterflies are diurnal(active during the day). Relating to this, moths often use moonlight to navigate, which explains their confusion with outdoor lights.
Of course, since there are always exceptions, here are some of the outliers to look out for:-several moth species are daytime-active, and a handful of butterflies are night-active:
- Diurnal moths include the Hummingbird Hawk-Moth (Maccaglossum stellatau), Cinnabar Moth (Ixtia jacobacae), Six-Spot Burnet (Zyaena filipendulae), White-lined Sphinx Moth (Hyles lineata), and Clearwing Moths (Sesiidae family),
- Nocturnal/crepuscular butterflies are Northern Pearly Eye (Enadia anthedan), Common Glider (Neptis sapphs), Chocolate Demon (Aacistroides nigrita), Malayan Night Fliers(Elymnias caudata)
- Some butterflies hold their wings folded like moths, such as the skippers of family Hesperidae
- Hawk moths pupate in exposed pupa rather than cocoons
- The Madagascar sunset moth is a “double exception”, with bright colors, diurnal behavior, and upright-resting wings. Tetcagenus moths also hold their wings upright.
