Butterfly Of The Month: April – The Brimstone


Peter Martin writes:

The Brimstone butterfly is regarded as the “harbinger of spring”, as the male is so noticeable due to its “brimstone” colouring when it flies strongly after its winter hibernation. Females are a more whitish-green and are, therefore, often mistaken for Large White butterflies.

This is a particularly good year for the Brimstone, as I have already seen them in the garden on several days. One year, I saw 14 on one day at Fleet Pond Nature Reserve.

After courtship, the female lays her eggs singly under a young leaf or on a stem of Alder Buckthorn or Purging Buckthorn. Between April and early July, a single female may lay 200 to 300 eggs. After about ten days, each egg will hatch and the resulting green caterpillar rests along the mid-line of each leaf when not chewing holes in it. Due to its green camouflage, it is often easier to spot the holes than the caterpillar itself.

On reaching full size, the caterpillar pupates by suspending itself under a leaf. This too is well camouflaged, until the yellow colour of its wings show through just before the beautiful butterfly emerges. The new generation of butterflies can be seen on the wing from mid-July onwards.

Brimstone butterflies can live ten months or more, if we include the hibernation period. They spend the winter in hollow trees among the fronds of ivy, where their colour blends perfectly with the leaves.

Odd Commas, Peacocks, Small Tortoiseshells or even Red Admirals may be brought out of hibernation by the warm and sunny days during the mild winters that we now experience, but it is the Brimstone that really demonstrates that spring has arrived.

Picture credit here.

Visit this blog in May for information about the Orange Tip.

Peter Martin has acted as author for a booklet entitled “Blackwater Valley Butterflies” which contains photographs of all 32 species found in this area together with information about their life-cycles. Copies are available for £2.50 plus £1.00 p.p. from Blackwater Valley Countryside Partnership, Ash Lock Cottage, Government Road, Aldershot, Hants. GU11 2PS. (Cheques should be made payable to B.V.C.P.).

8 thoughts on “Butterfly Of The Month: April – The Brimstone

    1. Thanks for getting in touch with us! The blog posts are usually a mixture of future events, descriptions of regular activities we carry out and items that reflect the individual interests of FPS members (butterflies, photography etc). We also encourage guest posts from members of related organisations eg RSPB. A lot more goes on at the pond than may perhaps be initially imagined, and one reason for setting up the blog was to increase awareness and appreciation of this.

      We are always on the lookout for new ideas so please get back to us if you think that something useful is missing and we’ll do our best to take this into account!

    1. Hi Ampers

      Thanks for the interest. The picture of the butterfly is not ours, it’s from Wikipedia. The credit link is given at the bottom of the article.

      Hope this helps, all the best


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