The sight of literally thousands upon thousands of butterflies floating through the air is a magic few of us are blessed enough to experience and those of us who do, carry the magical experience with them forever.

In the northern mountains where I live, a butterfly species called pieris brassicae — more commonly known as the ‘large cabbage white’ — does exactly this at least twice a year and each time on a warm day after periods of refreshing rain. The first mass arrival of these fragile insects is usually during mid-spring, the second in early summer, with often a third mass ‘birthing’ taking place during or towards the end of the summer monsoon.

With an average wingspan of between 57 and 70 mm, these short-lived butterflies are very common from Lahore northwards and is often found enjoying the company of pieris canidia, which is otherwise known as the ‘Indian cabbage white’ and which is so very similar in appearance that it is extremely difficult for an amateur to tell the difference.

The large cabbage white is — as the name implies — mostly white in colour with the underside of its hind wings being pale yellow in colour and, on top of both wings are two distinctive black spots that are highly visible on the female of the species.

These fragile butterflies lay up to 20 dark yellow eggs on the food plants of their choice. They have a special taste for members of the ‘brassicae’ family of plants and this includes mustard, cauliflowers and, of course, the cabbages from which these pretty butterflies get their name!

They generally lay their eggs on the underside of the plant leaves and when caterpillars hatch out; these are a blue-green in colour and, until they start making serious holes in the leaves, can be difficult to see. The caterpillars can destroy entire cabbage crops quite quickly, gobbling up the leaves until only the plant stalks are left and both commercial farmers and home gardeners have come to dread the sight of cabbage white butterflies of any description, as butterflies lay eggs, the eggs hatch out into hungry caterpillars and trouble is inevitable.

In their natural habitat of forests, woodlands and other wild places, these butterflies are a magnificently welcome sight and their caterpillars make little impressions on the particular wild plants they prefer to eat. It could be that they do eat all the leaves off one plant but, in an ecologically balanced environment, nature can deal with this and affected wild plants often regenerate themselves quite rapidly so that balance and harmony are maintained.