Species of the Month

These beautiful, delicate butterflies have a wingspan range of 45-50mm. The males are easy to spot as they have distinctive orange tips to their white wings, which acts as a warning to predators not to eat them. Mustard oils that have built up from the plants the caterpillar ate make them distasteful.  

The female has black tips to their wings, so they are not so noticeable amongst the foliage while they lay eggs and therefore don’t need the warning orange tips.  

Both sexes have a beautiful, mottled pattern on the underside of their wings created by green and yellow scales, to camouflage them against flowers and leaves when resting with their wings closed. These butterflies can sometimes be confused with green-veined whites or small whites.  

The adults feed mainly on crucifers such as cuckooflower, garlic mustard, bugle, charlock hedge mustard, hairy rock cress, large bitter cress, winter cress and turnip. They will also feed on dandelions, bluebells, greater stitchwort, ground ivy, hawkweed, ragged robin, red campion and vetches.  

Males are more active than females as they flit along searching for a mate and will fly for long periods without stopping to rest or feed. As the female is more focussed on egg-laying, she is less active and found near the foodplants.  

There is generally one single brood each year, although if spring is very early and warm there may be a small second brood.  

The adult female locates a plant by tasting it with her feet and lays a single pale green, long, thin, bottle shaped egg (0.6mm x 1.2mm) at the base of the flower head. She chooses particular plants to ensure the caterpillars have the right food to eat, which include the flower stalks of cuckoo flower, hedge mustard and garlic mustard, but in gardens they may also lay on honesty and sweet rocket. She lays a single egg because the larva is cannibalistic.  

The caterpillars are about 31mm long, pale orange at first but become blue-green with a white line down each side. They eat their eggshell on hatching and will also eat any other orange-tip eggs it finds. They feed mostly on the seed pods of foodplants between May and July, although will also eat the flowers and leaves.  There are four moults, and the larval stage lasts between three and four weeks. The caterpillar travels a long way to find a suitable place to pupate.  

After the caterpillars’ final moult, the chrysalis develops. It is about 23mm long and is initially green but turns olive brown after a month and looks just like a thorn so is superbly camouflaged. Inside this the caterpillar is transforming into an adult. The chrysalis overwinters, giving the orange tip a head start over other species, hence why it is one of the early butterflies of spring.  

• Historical names for the orange-tip include lady of the woods, prince of orange, and the white marbled butterfly. 
• The orange-tip is a good ‘indicator species’ for studying the effect of climate change because it is common, widespread and easy to identify.  

The population and distribution of orange-tips is widespread throughout England, Wales and Ireland, but it has been extending its range and is now well established in Scotland.  

Adults can be on the wing from early April until July, although their emergence varies depending on the weather and temperature and could even be as late as the end of May  

Spot them flying along hedgerows, meadows and woodland margins looking for a mate or flowers for nectar or for laying their eggs on.   

If you have a garden, the best thing you can do for orange-tips is to grow their foodplants cuckoo flower, hedge mustard, garlic mustard, dandelion, honesty and sweet rocket so there is plenty in flower for them to nectar on in spring from April to June. 

As orange tips overwinter as a chrysalis on or near the stems of their foodplants, it is also important to leave these in place throughout winter and not be tempted to clear them until the temperature rises and they have had a chance to emerge.  

You can also help by not using chemicals in the garden. 

You might also like to record your first sighting on Natures Calendar and be part of this long running phenology citizen science project.  The list of species you can record has been carefully selected by scientists to help us understand how wildlife is affected by weather and climate change. 

If you already have a wildlife-friendly space, please apply for one of our awards. By proudly displaying this, you will help us encourage more people to help orange tips and lots of other Dorset wildlife!