This month (July), we have seen the appearance of many bright orange comma butterflies; the so-called, hutchinsoni form of Polygonia c-album. These lovely orange-coloured butterflies are the first brood to emerge, and are much paler – no so dark – than those that appear later in the summer. Their colours and markings are bright and vivid. They really are lovely butterflies. You would not see a more beautiful and colourful butterfly anywhere!
There are often two generations of this butterfly in England and Wales (it is also expanding north into Scotland). The first generation to develop and emerge in the summer, are the golden brown, or orange-brown hutchinsoni forms. They mate and give rise to a second generation, which usually emerge in August or September. These second brood commas are much darker (see below) – which probably helps then absorb more of the late summer sunshine – and this form, or morph, generally goes on to hibernate over winter.
These darker forms enter a state of diapause, before getting going again in the Spring, to mate and lay eggs, some of which develop to produce the wonderful butterflies we are seeing now.
If one stops to think about it, it is slightly strange – although not unusual for insects – to have two different forms like this. Some butterflies in the tropics have wet and dry season forms. We in our temperate clime have cold and warm season forms. They are both adaptations to the changing climate. It is tempting to think that the first, summer brood, are gayer and more carefree than the later, darker brood! Their bright and gaudy colours could be romantically envisaged as living for the moment and enjoying the joys of summer! They don’t have to worry about things like hibernation and cold! They can leave that to their darker, more serious descendants, who will have to contend with the rigours of winter.
I spent a few hours observing and photographing these butterflies at a nature reserve in Bedfordshire: Felmersham gravel pits. I was amazed by the behaviour of the males. They are incredibly territorial! This particular male (below) had a perch on the heads of dry grass plants (below), beside a woodland margin. He flew up to investigate any passing butterfly, but reacted mostly vigorously if it was another comma. The two commas – chased each other furiously – ascending in spiral flights to a great height. They often did this repeatedly. The male must have expended an enormous amount of energy flying, during the course of a day.
Remarkably, he always returned to exactly the same spot. Sometimes alighting on precisely the same grass head; or if not, very close by. This was his spot and he was going to defend it to the best of his ability (waiting for his lady to pass by!). He was not happy with my presence either, and flew up and round me whenever I approached. I imagined him feeling frustrated that he did not have the size or bulk to challenge me! But it did not stop him trying!
The comma males and females are slightly different, although I must confess, I struggle to tell them apart! The female is I think, slightly larger, but the differences are relatively small in the first brood.
Some of the other butterflies in the vicinity – getting chased by the commas! – were Red admirals. Here is one (below) perched high up, keeping an eye on the proceedings, looking down on the patch occupied by the comma!
I am an entomologist with a background in quarantine pests and invasive invertebrates. I studied zoology at Imperial College (University of London) and did a PhD on the population dynamics of a cereal aphid (Metopolophium dirhodum) in the UK. I spent 5 years with the British Antarctic Survey studing cold hardiness of Antarctic invertebates and 17 years with the Food and Environment Research Agency. My main interests now are natural history, photography, painting and bird watching.