Small cabbage on lavender

Butterflies in winter

You may be surprised to discover that butterflies are around during the winter but just in different forms.

Unlike mammals, who are warm blooded, butterflies are cold-blooded and rely on external sources of heat to survive. Butterflies gain their warmth by basking in the spring and summer sun, so when the temperature starts to drop, life becomes a problem for them.

Britain has fifty- eight species of butterfly. Nine of these spend winter as an egg, thirty-two spend it as a caterpillar, eleven as a pupa, and six as adult butterflies.

The Red Admiral butterfly, which has become quite a common sight during the British winter, does not enter dormancy but will become active on warmer winter days.  So, if you see a butterfly in midwinter, it’s likely to be the lovely Red Admiral.

Butterflies don’t really hibernate but go into a dormant state. The lift cycle of a butterfly involves four stages: egg, from egg to caterpillar, from caterpillar to pupa (chrysalis) and finally to an adult. During the autumn and winter a butterfly will go into a dormant state regardless of what stage of their life cycle they are in.

Eggs, larvae, and pupae are usually hidden away in winter so if you do encounter a butterfly during the winter then it’s either an active adult such as the Red Admiral or a dormant adult like the Brimstone or Small Tortoiseshell.

As soon as our weather deteriorates and becomes damp and dull then species will try and find a dry place to rest. Our houses appear a safe place to overwinter but in fact when we turn the central heating up then any dormant butterflies may awaken prematurely by our high indoor temperatures. To them it must appear that spring has returned.

These butterflies are confused and no doubt the householder is too. How can we help these beautiful creatures survive? The best answer is to try and rehouse them into a suitable location. Catch the butterfly carefully and place it in a cardboard box, leave in a cool place, for around half an hour to calm it down. After this time, try and coax it out of the box and into an unheated room, porch, shed, garage, or outhouse. Please ensure wherever you choose to place the butterfly, it needs to be able to escape when spring finally comes.

If you find a butterfly that isn’t moving in your house, then our advice is to leave it alone.  It has entered its dormant state and is best left where it is to ride out the winter months.  As soon as warmer weather arrives it will awaken and move outside.

Butterflies are great to have around. Not only are they mesmerizing to watch, but they are also extremely beneficial to the environment.

Why not try and attract them into your garden with flowering shrubs like Buddleia, Lavender, and Hebe. Buddleia isn’t called the Butterfly Bush for nothing – this easy and fast-growing shrub is loved by butterflies but a word of caution, it can be highly invasive. These three shrubs can all be planted in a container, so if space is limited, give container gardening a go!

Written by Angela

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