butterfly
butterfly, (superfamily Papilionoidea), any of numerous species of insects belonging to multiple families. Butterflies, along with the moths and the skippers, make up the insect order Lepidoptera. Butterflies are nearly worldwide in their distribution. Although their larvae may be destructive to certain plants, butterflies are major pollinators of the world’s wild and domesticated flowering plants, and all stages of their life cycle are important to local food webs. For more detailed coverage, see also Lepidoptera and list of butterflies and moths.
The wings, bodies, and legs, like those of moths, are covered with dustlike scales that come off when the animal is handled. Unlike moths, butterflies are active during the day and are usually brightly colored or strikingly patterned. Perhaps the most distinctive physical features of the butterfly are its club-tipped antennae and its habit of holding the wings vertically over the back when at rest. The lepidopteran life cycle has four stages: egg, larva (caterpillar), pupa (chrysalis), and adult (imago). The larvae and adults of most butterflies feed on plants, often only specific parts of specific types of plants.
Major families
The butterfly families include:
- Riodinidae, the metalmarks, found chiefly in the American tropics.
- Nymphalidae, the brush-footed butterflies, the largest and most diverse family. The group include such popular butterflies as the admirals, fritillaries, monarchs, zebras, and painted ladies.
- Hesperiidae, the skippers.
- Hedylidae, the American moth-butterflies (formerly considered a sister group to Papilionoidea).
Butterfly declines and conservation
A major study published in 2025 found that populations of butterflies across the United States are in serious decline, with total butterfly abundance having decreased by 22 percent from 2000 to 2020. The study found dramatic population drops for many individual species across all North American butterfly families: more than 100 species had declined by more than 50 percent, and more than 20 species had declined by more than 90 percent. Numerous other studies have documented regional declines throughout the world, indicating a widespread and serious problem. Pervasive pesticide use, including insecticides that directly kill or weaken butterflies and herbicides that kill the plants they rely on, habitat loss, and anthropogenic climate change are the major drivers of these losses. Access to pesticide-free habitat—wild areas as well as native plant gardens at homes, schools, and businesses—with abundant host plants for caterpillars and nectar plants for adults can help stabilize and support struggling butterfly populations.