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Monday, 29 July 2019

Twig mimic


This marvelous creature is a Buff-tip — a moth that mimics the end of a broken birch twig. It's an amazingly effective camouflage, even if we humans do happen to notice the furry little feet. We've pulled a few from our moth trap this summer, and it's a treat every time. (We've run our lighted trap overnight several times this summer; the light sits over a box with a clear top that traps the moths inside until we have the chance to examine them. We release what we've caught without harming them.) The Buff-tip is a common and widespread species here in Britain, found in hedgerows, parks, gardens and woods. The caterpillars feed on the leaves of lime, birch, hazel and willow; we only have one willow in the garden, and thus probably won't be finding too many caterpillars. Adults fly from late May through July, so we may not be seeing too many more adults this year either!


Sunday, 28 July 2019

Gatekeeper


The last few weeks have seen the emergence of a host of Gatekeepers (Pyronia tithonus), small brown and orange butterflies that seem particularly drawn to the grassy part of our garden. They flit along the paths and over the ripening grass flowers in their dozens, always close to the ground and often chasing each other. The one in the picture above is a male, identified by that curving brown "hook" in the forewing, which the female lacks. She's less orange, and has an identifiably different pattern underneath her wings. Gatekeepers were named centuries ago for their habit of visiting the flowers that grew around the gates tucked into hedgerows around agricultural fields. They're still found in such areas, as well as scrubby grasslands (like our pocket meadow), country lanes and woodland rides. They're often found in the same areas as Meadow Browns (Maniola jurtina) and Ringlets (Aphantopus hyperantus), two other butterfly species which we've seen in our pocket meadow as well. In the UK, they're found primarily in the southern and central counties of England and Wales, but they're slowly expanding their range northwards. On cloudy days like today, they tend to spend most of their time spread-eagled on a leaf, a flowerhead or the ground; they're a lot more active on sunny days. Adults feed on nectar from many flowers, but the caterpillars feed on grasses — so Gatekeepers of all ages should be happy at our place!

Monday, 22 July 2019

Herb Robert


The lovely Herb-Robert (Geranium robertianum) has planted itself all around our garden, from flower beds and plant pots to cracks in the pavement and gaps near the door sills. It's a typical wild geranium — an annual (occasionally biennial) with delicate pink flowers, and pungeant foliage. The deeply cut leaves, which go red in the sun or on older plants, are distinctive. The Royal Horticultural Society rates it as a bit of a weed, due to its habit of explosively flinging its abundant, small seeds in all directions; it has certainly spread itself around the property since we moved in! It is found in a variety of habitats, but prefers shady areas and typically doesn't occur on acid soils. It flowers from May to September.

Herb-Robert is native to most of Europe (though missing from the extreme north), and has been introduced to eastern North America and western Washington state. It is reputedly named for a French abbot and herbalist, Robert of Molesme, who lived around the turn of the first millenium. He undoubtedly used the plant medicinally; it was prescribed to treat diarrhea and to control bleeding, and may also repel insects. Perhaps it's working — we have little problem with mosquitoes and fleas here!


Sunday, 21 July 2019

Slimed


Any time we get a bit of rain, we get a sudden irruption of Garden Snails (Cornu aspersum) on the walls of the house. They slither their way around, looking for plant material to nibble — and for other snails to mate with, presumably! They can be a problem in a garden (or agricultural field) if their numbers grow high enough, but that hasn't been an issue here yet. That might be because we have a number of Song Thrushes in the neighborhood, and they're well-known gourmands of snails. We do find slime trails regularly across the paving stones near the driveway, but whether the snails or their cousins the slugs have made them, we're not sure.

Like most land snails, the Garden Snail is a hermaphrodite, producing both male and female gametes. They fire love darts at each other during the mating process, though we haven't seen any evidence of those. These "darts" are covered with mucus that appears to help prime the recipient's female sex organs to receive the donor's sperm. They mate for hours (!!) then produce up to 80 tiny, pearly-white eggs, which they lay into sheltered areas such as cracks in the soil.

The Garden Snail (dubbed the "Brown Snail" in parts of the New World) is native to Europe, from the British Isles south to the Mediterranean, as well as northern Africa and east to Asia Minor; it has been widely introduced (intentionally and otherwise) to much of the rest of the world. While sometimes considered a pest, as it is primarily a herbivore, it is also consumed by a variety of birds, mammals (including humans), reptiles, amphibians and insects. In other words, it definitely has a place in our wildlife garden.

Saturday, 20 July 2019

Yes, grasshopper


We're developing a "pocket meadow" in our garden — an area of about an eighth of an acre that we mow only once a year. We have trails running around the edges of it and a few running through it so that we can easily access various bits of it, but most of it is untrammeled. Why? To aid and abet those species losing their habitats elsewhere. Last year, we heard four grasshoppers (four individuals, not four species) in our garden for the whole of the summer. This year, the second of our "no mow" regime, we've already had dozens and dozens. Scores of instar grasshoppers (nymphs not yet fully grown, so nearly impossible for us mere mortals to identify) leap out of the way every time we walk the paths, and (best of all) we're hearing several species trilling from the grasses.

Most common so far has been the appropriately-named Common Green Grasshopper (Omocestus viridulus), which has a long stridulation that sounds like a free-wheeling bicycle or someone quickly rubbing their hands together. They're heard from late May (in balmy springs) or early June. Below, I've linked to a recording I made late last month; click the red arrow to hear it. (Be sure to have your sound turned up, or all you'll hear is the Eurasian Blackbird!) According to our copy of Grasshoppers and allied insects of Norfolk, by David Richmond (yes, we're nerds), this species is previously unrecorded in our 2km square, though that may have changed since 2001, when the book was published. Common Green Grasshoppers occur in a variety of habitats, including unimproved grasslands like ours, roadside verges, woodland rides (a British term for a horse riding path through the forest) and old commons (public lands formerly used for grazing). They're less common along the North Norfolk coast than in the rest of the county, so we're pleased to have them here.


Adult male Common Green Grasshopper (Omocestus viridulus)

Friday, 19 July 2019

Migration wave


Several days ago, we had a mini-invasion of white butterflies. Most were the resident Small Whites (whose picture I haven't yet managed to snap), but a few were immigrant Large Whites (Pieris brassicae) like this one, driven north by the gentle southerly winds that had been blowing for days. The broad black tip to the upperwing, particularly how far it extends down the back edge of the wing, helps to distinguish this species from its smaller cousin, while the dusting of dark scales on the underside of the hind wing and the bold black spots on the upperside of the forewing mark it as a "first brood" female. Unlike some British butterflies, Large Whites have multiple broods per year. They fly from March to late October, and occur throughout the British Isles; elsewhere, they're common and widespread across northern Africa and all of Europe, the Middle East and in Asia as far as the Himalayas. Their diverse habitats include virtually anywhere their larval host plants occur, and adults are particularly fond of thistles and knapweeds.

As larvae, Large Whites can become serious pests of Brassicaceae species, including cultivated crops such as broccoli, cauliflower, kale, mustards, horseradish, etc. While their damage tends to be fairly limited in Britain, they are capable of causing the near-complete loss of crops in localised areas elsewhere in the world. Fortunately, none of our neighbouring farmers have planted such crops this year, and we don't much care what they nibble here in the garden — within reason of course!

Wednesday, 17 July 2019

Peacocks


Mention to someone that you've just seen a Peacock in the garden, and their mind is probably filled with visions of a sizable blue-green bird with a spectacularly impressive tail and a penchant for shaking its booty. But there's another creature with the same common name — the handsome red butterfly Inachis io. It's a common and widespread species across much of Europe, including nearly all of the British Isles. (They appear to reach northern Scotland only as migrants.) Since they hibernate overwinter as adults, Peacocks start showing up as early as March on balmy spring days, but their main flight season is between June and August. This adult was feeding on Lemon Thyme (Thymus x citriodorus) in our herb patch; they're also very fond of Buddleia. The larvae feed on nettles, of which we have plenty growing in some of the rougher corners of the garden. Hopefully, we're helping to boost the local population!

With wings closed, they're a lot less eye-catching!

Tuesday, 16 July 2019

Waxed paper


It's been quite a while since we've featured a lichen on the blog. This one is Parmelia sulcata, sometimes known as "Hammered Shield Lichen" or "Waxpaper Lichen" because of its appearance. Dobson's Lichens field guide says that it's "grey to glaucous white" in colour, but it always looks distinctly bluish-green to me. The brownish tips to the lobes, which are ridged and overlapping, and the network of faint, white lines along which the soralia develop are distinctive. (Soralia are the structures that hold the soredia: bundles of fungal and algal cells which break off to form new lichen colonies.) And it really does look like a bit of hammered metal. The underside is dark-brown to black and covered with a mat of rhizines, which are the fungal filaments that help to attach the lichen to its substrate.

There are quite a few colonies sprinkled around the garden, mostly on the Japanese Cherry tree and on the slowly-rotting wooden garden bench. This lichen, which is a great example of a foliose species (the name given to lichens that are flattened and leaf-like), is common species throughout much of the world. It grows abundantly on trees and rocks across most of Britain and Ireland, particularly in the lowlands. People in various parts of the world have used it to make dyes (it produces a reddish-brown colour) and medicines.

Wednesday, 3 July 2019

Tiny lives


While checking things out at the back end of the garden a few weeks ago, I spotted a number of these little moths — one of the so-called "micro moth" species — hanging out on some of the flowers. They're Cocksfoot Moths, Glyphipterix simpliciella, so named because the tiny caterpillars spend most of their time feeding on the seeds of Cock's-foot (a rank grass) and later pupate in its stem. Given that we have a few scattered clumps of that grass in our pocket meadow, that may be where the moths have come from. These are very small moths, measuring only 3-4 mm in length (about 1/10th of an inch) with a wingspan of maybe double that. Though they're often found in large groups on flowers (up to 20 at a time, according to several references I've read), they're so minute that they're easy to overlook. They're common over much of Britain and Ireland (and the western Palearctic), and are especially fond of buttercups. Fortunately, we have lots of those growing among our meadow grasses, so the moths, which fly from May to July, should find plenty to keep them happy here.