I have two buddleia bushes at the bottom of my garden. They’ve been in flower for a couple of weeks and, on the odd occasion when the sun shines, I stroll down to check them for insects.
The buddleia is sometimes called the butterfly bush and the mauve flower spikes are irresistibly attractive not only to butterflies but also to other nectar loving insects like bees and hoverflies.
I’m not sure of the reason for the attraction, obviously the nectaries of the flowers are very productive but I suspect there are other factors, including colour. I’ve noticed that mauve flowers, wild knapweed for example, are singled out by nectar-eating insects. Anyway, the two buddleias in my garden are attractive and I planted them specifically to attract butterflies.
And the other day they attracted a rarity, a butterfly called the comma. Twenty years ago this would have been a very exciting event because commas didn’t breed in Ireland then and the only records were for very occasional vagrants that blew across the Irish Sea and most of these seemed to end up in Northern Ireland. However, in 2000 a small group was discovered breeding in the Raven Nature Reserve in Co Wexford and since then populations have established at several other locations in the east of the country.
Commas belong to a butterfly family called the vanessids which contains some of our largest and most colourful species. The other Irish vanessids are the peacock, the red admiral, the painted lady and the small tortoiseshell. The comma is about the same size as a small tortoiseshell, though not quite as brightly coloured, and the edges of its wings are what the books call ‘scalloped’ but are probably more accurately described as ‘ragged’. It gets its name from curious white marks on the underside of each hind wing which are the shape of the punctuation mark.
They were once widespread in England, Wales and southern Scotland, though not in Ireland, but in the mid 1800s there was a catastrophic decline and they ended confined to small numbers in a handful of counties on the border between England and Wales. The caterpillars used to feed on the leaves of the hop plant and it’s believed a sharp reduction in hop growing was the cause of the decline.
Then in the 1960s they began to make a spectacular comeback, bucking the trend of most butterfly species. Nobody’s quite sure of the reason for the comeback, although global warming has been suggested. It seems more likely that the caterpillars evolved to learn to eat the leaves of stinging nettles, like the other vanessids, and lost their dependence on hops. Anyway, the happy outcome is that this species has spread to Ireland, where there are now half a dozen breeding colonies, and there’s a new butterfly on my buddleia.
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