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Butterflies and Moths


About butterflies and moths

Butterflies and moths are insects with four large and colourful wings. About 130 species of butterflies live in Alberta and breed wherever there is suitable vegetation.


Butterflies and moths can vary greatly in size. For example, Alberta's smallest butterfly is about 15 millimetres (a little over half and inch) from wing tip to wing tip, while the largest is over 10 centimetres (4 inches).

Economic impact of butterflies

Except for the cabbage butterfly, whose caterpillar destroys many garden vegetables, few butterflies are of economic importance.

Butterflies and moths in winter

In Alberta, most species overwinter either as pupae or adults.

Reproduction and growth

Butterflies and moths grow and develop through a series of stages.

Stages one and two: from eggs to larvae

  • Butterfly and moth larvae, commonly known as caterpillars, hatch from eggs. Caterpillars grow larger by a series of moults, or skin-sheddings.
  • The caterpillars of some butterflies feed on only one kind of plant. In turn, caterpillars are often food for predators, especially birds.

Stages three and four: from pupae to adults

  • Caterpillars turn into pupae when they have reached their largest size. The pupa is a resting stage before the final change into a butterfly.

Butterfly and Moth Species at Risk

Some butterfly and moth species populations are in decline in Alberta. One aspect of butterfly and moth species that may make them particularly vulnerable is their interdependency with certain types of plants.

For example, if agricultural activities such as livestock grazing or food crop production limit the range of certain native species of plants, the butterflies and moths that depend on such plants as part of their life cycle can be affected.

In this section of the website, one such species at risk, the Yucca Moth, is profiled. See:


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Updated: Jan 8, 2014