Aricia agestis, Brown Argus, butterflies in long grass, common blue, common knapweed, insects in long grass, keeled garlic, moths in the grass, Nursery Web spider, pisaura mirabilis, Polyammatus icarus, small hoverfly with snout, spider that makes web tents in grass
The weather up here in our part of North Wales has been variable this week. We have had a good bit of rain which has freshened everywhere up and just about enough warm sunshine to allow us to keep the faith that this is indeed high summer. It may not be the perfect weather for people here on holiday, but the local wildflowers and insects seem to be appreciating it.
Habitat: Long meadow grass
There is a whole other world existing in areas where grass is allowed to grow long and during the past couple of weeks I’ve begun to appreciate its importance as a home and a refuge for wildlife, particularly insects and spiders.
All journeys need a starting point and the following journey of discovery into the dimension of long grass began when I went to Bryn Euryn to see if a particular plant was in flower.
I’ve mentioned before that we have a few less-usual species of wildflowers growing in our locality and on Bryn Euryn this is the time to find one of them; the pink/purple flowered Keeled Garlic. I headed for the spot I had seen it in previous years and there it was, buzzing with bumblebees and more surprisingly attracting several beautiful little Common Blue butterflies.
I wondered at the attraction of this particular flower to the butterflies and thought perhaps they were just resting on the tiny flowers to sunbathe. A little later though I came upon another patch of the flowers with more Common Blues fluttering over and settling upon it, so maybe they were taking nectar from them. I was more than happy to see this many of the butterflies in the same place at the same time; I haven’t seen that for a long time.
I was not the only one to recognise the attraction of insects to the garlic flowers. Lurking on top of her tent-like web, built to protect her eggs and then babies, sat a long-legged Nursery Web spider.
Nursery Web spiders are the spinners of the many web ‘tents’ seen in grassy places at this time of year. They take their common name from the way in which they care for their offspring. The female carries her large egg sac beneath her body, held in her jaws. Before the eggs hatch she spins the silken tent around the egg sac and stands guard over them. She remains on duty until the spiderlings are big enough to live independently. The spiders are active hunters and search for prey amongst grasses and low vegetation.
Walking carefully through the long grass, every step seems to disturb a dry-grass coloured moth. They are so well camouflaged that should you manage to keep track of where they land, it’s not easy to find them again; then if you manage a picture of sorts identifying them afterwards is even harder. The one below, which landed on the pupa of a 6-Spot Burnet moth which I would otherwise not have spotted, maybe Crambus pascuella (?) As always, I’m more than happy to be corrected.
In places amongst the grass knapweed is beginning to open up it tight dark knots of buds to allow the purple brush-head of petals to escape. Knapweed is a hugely important source of nectar for a wide variety of insects, but more about the plant and its visitors later.
Long grass on dry slope of ‘downland’
The area of long grass at the bottom of the summit slope on the drier, chalkier downland side of the Bryn has a different character to the flatter, damper meadow area. Some species of butterfly you may see here, although found in other parts of the Reserve, show a definite preference for the conditions it offers and may be more numerous. It is especially good for seeing the smaller species that gain protection from predators amongst the grass stems and include Small Heath, Small Skipper, Common Blue and the less-common Brown Argus.
The larval host plant of the Brown Argus is Rock Rose, which has been prolific in its flowering here this year and the leaves of the plants are still evident in the ‘under-story’ of this grassy forest. I was once again lucky with the timing of my visit this week; after a few minutes of pursuing little butterflies through the tangle of dry grass laced across with long outreaching bramble runners, I spotted a newly emerged Brown Argus balanced on top of a dry stem.
It stayed perfectly still, wings outstretched for quite a long time and made no attempt to fly off although I was very close and holding the camera lens just a few inches from it. I was almost certain this was in fact a Brown Argus and not a female Common Blue, but was compelled to wait and hope it would close its wings for me to see its underside. It eventually obliged and although the angle it presented wasn’t the best, thankfully it did confirm its identity with its diagnostic pattern of spots.
Spot the difference:
Text & diagram from the UK Butterflies web site demonstrates the differences:
Of the two sexes, it is the female Common Blue that causes most confusion with the Brown Argus. The blue present in a female Common Blue is highly variable, with individuals ranging from almost completely blue through to completely brown. It is this latter colouring that causes the most confusion. Even so, the Brown Argus has no blue scales, but may give off a blue sheen from the wings and the hairs found on the thorax and abdomen. Another diagnostic is that the Brown Argus normally has a prominent dark spot in the centre of the forewings.
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Emily Heath said:
Fascinating! Thanks for all the wonderful photos.