Comma:  This is really a woodland butterfly that has had times in the past when it became quite rare.  However, since the 1960s it has increased dramatically in numbers and has spread northwards reaching Scotland in 2000.  It is now a familiar butterfly of woodland edges, hedgerows and gardens.  The butterfly is named for the white mark on the underside of the hind wing though on the other wing it will resemble a C which is part of its scientific name, Polygonia c-album.  The adult butterfly overwinters, presumably in sheltered places in its woodland habitat but not in our garages and outhouses.  On emerging from hibernation in late March or early April the males take up territories investigating any passing butterfly looking for females.  Pairing is believed to take place high in the woodland canopy after which the female prospects for suitably sunny but sheltered food plant.  In the past a much used foodplant was hop but now the main food plant is nettle but it has been found on a variety of plants such as currants, elms and willows.  The caterpillar feeds inconspicuously on the underside of the leaves of its food plant but by the time it reaches the last, 5th instar, its colouring has been transformed such that it now camouflaged looking like a white bird dropping.  The pupa is formed hanging amongst the vegetation of its food plant.  The adults of the next generation emerge in late May or early June.  These come in two forms – the normal darker form and a much paler form, hutchisonii.  The normal form feeds up on nectar and goes into hibernation in August.  The paler, hutchinsonii, mate and lay eggs that go through their caterpillar and pupal stages emerging in late August and September as a second generation.  These are the late season butterflies which will then, themselves, go into hibernation in late September or October.  There is, therefore, a mixture of one and two generations in its life cycle.

Photos   Robert Maxwell Wood    Peter Bright

Silver-washed Fritillary:   This magnificent, bright orange insect is close to the largest British butterfly and is certainly the largest in Somerset now.  This colouring is also why in some parts of the world this group of butterflies are called leopards. It is a butterfly of woodlands that have an abundance of violets growing around the moss-covered bases of trees, particularly oak.  Woods that are coppiced or thinned have an abundance of bramble, a favourite nectar source, as well as encouraging a good growth of violets. 

They spend a lot of time high in the canopy and feed on the abundance of honey dew on the leaf surfaces.  In some years these strong flying butterflies come into gardens using plants like Hebe and Buddleia as convenient nectar sources. The adults emerge in late June or July and may continue to fly into the middle of August.  They are fast and powerful fliers and the males patrol the woodland rides and canopy investigating any orange butterfly checking for virgin females.

If such a female is found there is a spectacular courtship flight with the male showering the female with pheromones from the sex brands on the front wings that show as dark lines along the middle two veins.  Following this the female seeks out patches of violets but having found them, then goes to a nearby mossy covered oak trunk base where she lays eggs, singly, in mossy crevices.  There is a fabulous colour variation of the females which is a deep bronze green colour called valesina.

It is possible that this dark colouration is favoured in poor summers as the butterfly warms up more quickly, but it is at a disadvantage in normal summers as the males take longer to find these unusually coloured females.  The newly emerged 1^st instar caterpillar eats its way out of the egg and immediately hides itself in a bark crevice where it passes the winter.  This could be why ash and beech woods are unsuitable lacking the appropriate moss filled bark crevices.  From early April the young caterpillar comes down to the woodland floor and feeds on the nearby violets.  When fully grown the caterpillar goes up a nearby plant to pupate a metre or two off the ground.  The next generation of adults emerge in late June providing another spectacle of summer in Mendip woodlands.

Photos    Peter Bright

 Dark green Fritillary:     This is typically a butterfly of windswept limestone grasslands but is also found on bracken covered hillsides, grassy dunes and a variety of similar habitats.  It is named for the green wash on the underside of the hind wings.  They need the sward to be of medium height so that heavy grazing, or complete lack of such, can make the violets that are its caterpillar food plant unsuitable.  It should be much more widespread across the Mendip scarp than it is but, it is doing well at Ubley Warren.   Single individuals have been seen on the Beacon and even in a Westbury garden over the last few years. 

With suitable grazing and clearing of gorse there is hope that the butterfly will return to the Beacon once again.  The adults emerge in June and will fly for much of July and perhaps into early August.  They fly strongly and can cope with their windy habitat and have a special fondness for purple flowers like knapweed as nectar sources.  The males will patrol large areas searching for virgin females investigating any suitably coloured butterflies.  After mating, the females will hide while their eggs mature and will then search out the violets growing in suitable places before laying near to them.  As with the Silver-washed Fritillary, the newly hatched caterpillar immediately finds a hiding place in which to hibernate.  Towards the end of March in the following year the caterpillar emerges from hibernation and seeks out violets on which to feed.  The later instar caterpillars are particularly black and spiky and may be seen travelling across open spaces seeking new supplies of violets. 

The blackness presumably enables the caterpillar to warm up quickly in its otherwise exposed and cool habitat. In a very tall grass sward it may, therefore, not be able to warm up quickly enough to survive.  In the middle of May or beginning of June the caterpillars will find hidden places to pupate and the adults will start emerging again from the middle of June.

Photos   John Ball    Peter Bright  Georgina Shuckburgh

Below are links to the data for the months March to June inclusive.  July and August will be added as we get there. The data for March to May have been posted earlier but you would have to chase about to make comparisons between months.  There is a separate file of Photo-voltaic generation totals for each month since 2010 which is a proxy for amount of sunshine.  An attempt is made to suggest which of the years has been sunniest and in which months.

2020.4.5 March max min rain and sunshine data 2006 to 2020  

2020.4.30 April max min rain and sunshine data 2006 to 2020

2020.6.1 May max min rain and sunshine data 2006 to 2020

2020.6.30 June max min rain and sunshine data 2006 to 2020

2020.6.30 Monthly kWh totals 2010-2020

Ringlet: This is a butterfly of the wider countryside whose caterpillars depend on the tall grasses of sheltered and damper places like hedgerows, field margins and woodland rides. It is one of the British butterflies whose numbers have been increasing and whose distribution has been expanding over the last 30 years. It is suggested that global warming and the reduction of pollution are both contributory factors. Reduced grass cutting of roadside verges and in places like churchyards are likely to be beneficial. The adults begin emerging in late June and this continues throughout July. The freshly emerged butterfly is a uniform rich dark chocolate colour with conspicuous white fringes to the wings. There are rows of spots on each wing which are most conspicuous from underneath with white centres surrounded by a yellow ‘ring’ which gives the butterfly its name. There is quite a lot of variation in how many spots and the brightness and shapes of the rings. They can resemble male Meadow Browns with which they often fly but lack the yellow patches on the underneath of the front wings and are a dark chocolate colour to the Meadow Brown’s milk chocolate! Males patrol the tall damp grass habitat searching for females. After mating the females lay eggs singly perhaps being selective of the dampness and condition of the grasses before seemingly scattering their eggs. The caterpillars are slow growing and when they reach the third instar in the autumn hide themselves away, overwintering in the bottom of a grass tussock. In the following spring they start feeding again and continuing their slow growth. By the beginning of June, the 5^th instar caterpillar forms a pupa hidden at the base of its grass habitat. After some two weeks the mature butterfly is ready to emerge. There is only one generation each year.

Photos Tina Westcott     Peter Bright

  Gatekeeper: This butterfly is found in all sorts of ‘hedgerow’ habitats using the grasses growing in the more shaded parts for their caterpillars to feed on. Brambles are a favourite nectar source. It obviously lives up to its alternative names the ‘Hedge Brown’ as well as ‘keeping gates’ in hedgerows. The butterfly is smaller than a Meadow Brown and is a much brighter orange colour. The males have a dark sex brand in the orange of the forewing which the slightly larger females do not have. The big eyespot on the forewing has two white spots to the Meadow Brown’s single one and on the underside of the hind wings the spots are white rather than black as they are in the Meadow Brown. Overall, it is a very handsome and almost unmistakeable butterfly. The first adults emerge in late June and may continue to emerge until late August.

The males are territorial chasing up any passing butterflies to check for females. After mating the female selects finer grasses growing in the shade of shrubs and inside hedgerows as egg laying sites. After hatching the caterpillar feeds and as a second instar hibernates hidden in the fold of a leafy tussock. In the spring the caterpillar continues feeding and growing and pupates in early June or later to emerge once more in late June or into July and August. There is thus only one generation each year. Look out for them now as they are just appearing.

Photos      Peter Bright