Small, crafty, eats geraniums

The Common Geranium Bronze butterfly is widespread, and can easily be attracted into suburban gardens.

By Justin Bode

Common Geranium Bronze, showing its intricate wing markings (Photograph: Justin Bode)

Cacyreus marshalli, colloquially known as the Common Geranium Bronze or the Malvabloutjie, is native to South Africa and one of our most common butterflies. It is found frequently in gardens as the larvae feed on different species of geraniums or pelargonium, as the common name implies (malva  is Afrikaans for geranium).

Planting a few specimens of geranium or pelargonium will thus attract these butterflies into your garden.

Common Geranium Bronzes have been observed along the provincial road traversing Verloren Valei, but without several surveys it is not possible to state whether it is common on the Reserve.

The species is on the wing all year in suitable localities, but only in summer in cooler regions of the country. The female lays the eggs singly on or near a bud or young seeds of the host plant. The eggs hatch after about six days, and they pupated after about 30 days . The adult butterfly emerges from the pupae after 13 to 19 days.  Larva have been killed by Apantales sp. in the 3rd instar; and by small tachinids and small braconids in the final instar.

These are small butterflies—the males’ wingspan is 15-23mm and the females’ 18-27mm. Nonetheless, they have evolved some nifty protection in the form of eyespots and false antenna on their hind wings as a defence mechanism to confuse predators. The wings are brown/ bronze with a white border outlining the wings. The underside is a grey-brown with darker bands interlaced with white, creating an intricate pattern.

The species is now resident in Europe, notably the Mediterranean area—its French name is brun des pelargoniums. In those regions, it is considered a pest to locally cultivated Geranium and Pelargonium species. It is thought to have been transported accidentally to Europe in the latter part of the 20th century.

Lepi-Map distributipm of Common Geranium Bronze

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