Butterfly Basics

Have you ever wondered how butterflies know which flowers to visit for nectar? Did you know that butterflies smell with their antennae and taste with their feet? Like all living things, butterflies use their basic senses to explore their world.

SIGHT

Adult butterflies have large compound eyes made up of thousands of tiny lenses called ommatidia that help the butterfly see a wide range of color and motion. They can sense polarized light, which tells the direction the sun is pointing, and ultraviolet light (light beyond the range of human eyesight) reflected from flowers. They also recognize floral patterns called nectar guides, which can sometimes be seen as darker-colored patterns leading into the throat of a flower. 

Gulf fritillary butterfly closeup by Flickr user Mike Keeling under CC BY-ND 2.0

SMELL/TASTE

Butterflies have sense receptors called chemoreceptors in their antennae, feet, and other body parts to help find flower nectar and to identify specific plants in which to lay their eggs. When a butterfly lands on a plant, these chemoreceptors can sense the presence of dissolved sugars like those found in flower nectar. When the taste sensors are activated, the butterfly will uncoil its proboscis to consume the nectar it has detected. By just landing on a surface, a butterfly can taste if something to eat is available.

Female butterflies have specialized chemoreceptors to help them find the right host plant. Female butterflies have tiny spines on the backs of their legs that are used to drum against a plant leaf and release juices from the plant. These juices or the plant surfaces are tested or tasted by chemoreceptors at the bases of the tiny spines and can determine if the female butterfly has found the right host plant for her eggs. Some species of butterfly like the Monarch will test a host plant with all six legs before beginning to lay eggs.

Butterflies also use chemoreceptors to find potential mates that release pheromones, which are hormones that the butterfly can recognize. 

Red Admiral  by Flickr user John Flannery under CC BY-ND 2.0

TOUCH

Butterflies sense touch through hairs, called tactile setae, located all over the body. They use these hairs to sense wind, gravity, and the position of their own body parts while flying. 

Karner Blue closeup by Flickr user USGS Bee Inventory and Monitoring Lab under Public Domain

HEARING

Some species sense sound through veins in their wings, reacting to changes in sound vibrations. A few species of butterflies make sound by rubbing together body parts. While the sense of hearing is not well-developed in butterflies, there is still much research to be conducted to understand the role of sound for butterflies. 

Red Cracker by Flickr user Robb Hannawacker under Public Domain


How are butterflies and moths ALIKE?

Both BUTTERFLIES and MOTHS have:

  • ​an exoskeleton

  • ​three body parts (head, thorax, abdomen)

  • six jointed limbs

  • two antennae

  • ​a life cycle consisting of egg, larval (caterpillar), pupal (chrysalis [butterfly] or cocoon [moth]), and adult stages

  • ​membranous wings covered with pigmented scales

  • ​the taxonomic name Lepidoptera, which means "scaly wings"


      How are butterflies and moths DIFFERENT?

      In general, BUTTERFLIES:

      • are diurnal (active during the day), so they can use their colorful wings to attract mates and deter predators
      • have two smooth antennae that terminate in knobs (or clubs) that they hold out and forward
      • ​rest with their wings closed and directly over their backs (unless they are sunning)
      • ​have thinner bodies which are not overly fuzzy
      • pupate in a hard chrysalis
      • comprise about 750 species in North America and about 17,500 species worldwide
      In general, MOTHS:
      • are nocturnal (active during the night), when light levels mean that only drab or pale colors show up well
      • have two thread- or plume-like antennae with no knobs at the end
      • rest with their wings spreads flat or pitched over their thorax and abdomen (and sometimes tuck their antennae alongside their bodies)
      • have fatter, stockier bodies, and are often noticeably fuzzy
      • pupate inside a cocoon, which they spin out of silk and sometimes nearby materials like leaves​
      • comprise about 12,000 species in North America and about 160,000 species worldwide