Yellows

The family Pieridae includes the yellows. These yellow butterflies particularly the brimstone is probably where the term butterfly (butter coloured) originated from.

  Brimstone  Gonepteryx rhamni

  Clouded Yellow Colias croceus

Brimstone  Gonepteryx rhamni

The brimstone appears very early in spring, particularly in this part of Cornwall, where it can be seen in January. These butterflies over winter as adults and will have just come out of hibernation.

With the name brimstone, one would presume that the butterfly would be sulphur yellow. This is only true for the male as the female is a greenish white. Both sexes have a small orange dot on each of their wings. The wings are not as rounded as the other Pieridae species but are more leaf shaped.

Photograph by Alan Griffiths

Brimstones have one brood a year. Their caterpillars are bluish green with two thin yellow lines running down the length of their body. The food plants are buckthorn and alder buckthorn. Caterpillars turn into chrysalises in mid summer and emerge as adults by August.

Clouded Yellow Colias croceus

This is the commonest of the three species of Clouded Yellow to be seen in Cornwall. It like the others, is a migrant species and numbers do vary. In some years they arrive in very large numbers.

The uppersides are a yellowish orange with black edging. The forewings have a central black spot, the females have a central orange spot on the hindwings.

The undersides are yellow and bordered by a line of spots. The forewings have a central black spot while the hindwings a central double white pupiled spot.

There is a single brood and in good years two. They do not have a high success rate with overwintering as adults but can succeed as caterpillars and pupae. The foodplants include clovers and lucerne.

Photograph by Alan Griffiths