Everyone has an insect that defines their summer. It might be the wasps hovering around the drinks in the garden or the whine of a mosquito that has found its way into your bedroom and is disturbing your sleep. But for me, and many other folk, the insect that typifies summer days is a beautiful butterfly fluttering around the lavender, buddleia or one of the many other nectar rich flowers.
In recent years, especially this year, the anxiety regarding the decline of insects has greatly increased. This is a result of emerging evidence, including one long-term study in Germany, that reveals a severe and continuing decline in every type of insect. The current numbers show a 75% reduction overall in the number of insects across the board.
But perhaps we shouldn’t panic about low numbers of butterflies just yet. Every year there is a BIG BUTTERFLY COUNT run by the Butterfly Conservation Society that shows that butterfly numbers of all species do vary greatly from year to year. Butterflies are affected by the weather at each stage of their complicated life cycle; A very cold winter or spring can kill eggs and overwintering pupae, but a hot dry summer allows better survival and reproduction, meaning numbers build up through the summer, and with a mild winter, good populations of many species will emerge the following year.
This year many people reported an absence of butterflies when they expected them in May and June. This is likely to be because of a very cold March and early May. Around The Fold the typical spring butterflies were out in abundance, especially the lovely orange tip. Now the meadow browns have come in great numbers and we are finally seeing the summer butterflies, Cabbage Whites, Gatekeepers and the dramatic Marbled White all in numbers that are greater than last year.
What we have not yet seen around Bransford are the Red Admirals, Small Tortoiseshells and Painted Ladies. Again, perhaps we need to be patient. Overwintering individuals emerged from their hibernation sites in sheds and log piles in spring and their caterpillars are turning into pupa ready to emerge as a summer brood very soon. Indeed, we have seen the first bright Small Tortoiseshells already.
Painted Ladies are another thing altogether. This amazing and lovely butterfly migrates from its overwinter site in Morocco, and although a few fly 4000 Km to the UK, most stop and breed in Spain and France before the next generation resume their long journey North. Therefore, when Painted Ladies arrive in your garden depends largely on the winds and weather over our European neighbours. Some years very few arrive, other years they arrive in their millions and travel all the way to Scotland. We are currently expecting a bumper year as record numbers have been recorded on their way North from France (19th July) so look out!!
Then there are those butterflies we rarely see, either because their food plants on which the caterpillars live have become rare due to habitat loss or disease like dutch elm disease (White Letter Hairstreak), or because they live high in the tree tops like the Purple Emperor. A few species of butterfly live in just a few tiny colonies scattered around the British Isles and you will never see them in Worcestershire. There are certain species only found on the Isle of Wight for instance or along the coast in the North of the British Isles.
Finally I must say, do not expect to see some spring butterflies in the summer. The glorious Red Admiral, one of my favourites will turn up almost at any time throughout the year even in November, since it is both partially migratory coming over the Channel at times on favourable winds, plus it is a hardy butterfly and can even sometimes overwinter as a caterpillar and breed twice in a season.
Now log onto the Big Butterfly Count 2019 and do your first butterfly survey!
Keith Falconer July 2019