The weather is starting to warm, the sun is getting higher in the sky and the days are lengthening. Now is the time that spring butterflies appear. Some of you may have already seen a Brimstone, which is a very distinctive bright yellow in colour and is one of the first butterflies to stir from winter hibernation. Many butterflies overwinter as dormant caterpillars, but a few like the Brimstone spend the winter as adult insects, hiding away in secluded places until the warmer weather arrives. It is thought that it is the Brimstone from which the word butterfly was derived, because of its bright yellow colouring.
Other butterflies which start to appear in the early spring include the Small Tortoiseshell, the Peacock, the Comma and the Red Admiral. All of these butterflies, like the Brimstone, have spent the winter as adult insects. The Comma finds dead leaves to hide in, no surprise as its camouflage both in terms of its colouring and wing shape is superbly adapted to blend in with dead foliage. The Peacock, and Small Tortoiseshell lie dormant in garden sheds, attics and other sheltered spaces during the winter. By contrast the population of Red Admirals in Britain is made up of a mixture of native insects, born and bred in the UK, and butterflies which have migrated from continental Europe. Some migrate southwards during the autumn but increasing numbers are overwintering in Britain possibly due to climate change and our increasingly milder winters. Red Admirals do not enter a proper dormant state like Peacocks Tortoiseshells and Brimstones, but tough it out by roosting on bad weather days and take to the wing even during the winter months, provided there is sufficient sunshine and the temperature is high enough.
Spring days when there is plenty of sunshine will bring all of these species out on the wing. The insects prefer sheltered spots where the temperature may be one or two degrees higher. Their priority is to replenish their energy stores diminished during the winter and they seek out nectar sources such as fruit blossom, heathers, primroses and rosemary.
As we move into April, other common butterflies such as the Orange Tip, Small White, Large White, and Green Veined White start to appear. These butterflies have spent the winter as pupae so make their entrance slightly later as their emergence is thought to be triggered by factors such as the length of daylight.
The early butterflies are always a welcome sight as a signal that warmer, longer days are ahead and that summer is on it’s way and boy do we need that tonic now!