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Monday, 9 December 2024

Radiating

Arthonia radiata

Now that the garden has settled into its winter hibernation, I have had time to go through some of the many pictures that I took of things this past summer. And amongst them, I found this shot of a new species for the garden – the lichen Arthonia radiata. This crustose lichen (so-called because it looks like a crust, i.e. flat and inseparable from the bark) belongs to a group called the "script lichens". It gets that name due to those scribble-like black marks, which are its fruiting bodies (called apothecia). Those marks can range in shape from rounded to linear to star-like; the latter shape gives it the common name of "asterisk lichen". Each colony is surrounded by a thin dark line, which is an area of the thallus (the "body" of the lichen) that contains only fungal hyphae and no algae. The thallus itself can range from white through pale grey or fawn to brown in colour, and is sometimes partially immersed into the bark. This is a common and widespread lichen across the British Isles, growing on the bark of smooth-trunked trees and shrubs.

Tuesday, 6 August 2024

Galling

Germander Speedwell Gall Midge (Jaapiella veronicae)
A number of the Germander Speedwell plants in the garden wear furry little caps these days – a clear sign that they've been attacked by the Germander Speedwell Gall Midge (Jaapiella veronicae). This tiny fly lays its eggs in the terminal bud of Germander Speedwell plants, or occasionally in the terminal buds of other species of speedwell. The presence of the eggs (one or two per plant) changes the development of those terminal leaves; they grow abnormally, becoming deformed, thickened and hairy. And they safely house one or two tiny, reddish-orange midge larvae. These galls are typically the only way most of us will ever know the midges are around. The flies themselves are so small that they're easy to overlook – a mere 2-3 mm (about 1/8-inch) in length. They are bright orange and stand on relatively long, stilt-like legs though, which might help in spotting them. The midge is common throughout the UK, found anywhere that Germander Speedwell grows.

Saturday, 3 August 2024

Six spots

Six-spot Burnet (Zygaena filipendulae)
While we sat working in the office the other day, Mike suddenly said "There's something red out there" and headed for the door. Sure enough, there was something red – a handsome Six-spot Burnet (Zygaena filipendulae), trundling around on Marjoram flowers near the sundial. This day-flying moth is the only burnet moth in the UK with six (rather than five or fewer) spots on its metallic green forewings. Those spots are a warning to potential predators that the moth is toxic; it's full of cyanide. Some of this comes from the food plants that the moth ate as a caterpillar. Preferred larval food plants, such as Common and Greater Bird's-foot Trefoils, are loaded with toxins which the caterpillars can safely metabolise for their own use. And if they can't get enough cyanide from their food sources, they can make their own! Such protection is so important to the moth's survival that males even present "nuptial gifts" of cyanide to females while mating; presumably, this helps to increase the survival rates of any resulting offspring. 

Six-spot Burnets are common and widespread across England, Wales and Ireland, but are mostly coastal in Scotland. Elsewhere, they range across much of Europe, and east into Lebanon and Syria. They flourish in grasslands (particularly those rich in flowers), and can be found from coastal cliffs and sand dunes to roadside verges, meadows and woodland clearings. Adults feed on scabious, knapweeds and thistles, all of which we have on the property; they clearly like Marjoram too. Caterpillars, when they're ready to pupate, build their cocoons high on grass stems. Hopefully our pocket meadow, with its bird's-foot trefoils and abundant grass stems for the caterpillars, plus various food plants for the adults, will prove appealing.

Wednesday, 31 July 2024

Shield bug

Woundwort Shield Bug (Stagonomus venustissimus)
A wander around the garden last week netted us an unfamiliar shield bug on one of the Common Ragwort flowerheads. Some quick research on the British Bugs website – an online guide to the UK's Hemiptera species – showed it to be a Woundwort Shield Bug (Stagonomus venustissimus). This is one of the UK's smaller shield bugs, measuring in at a mere 5-7 mm (about 1/4 inch). It's widespread across much of southern and central England, as far north as Yorkshire. It's much less common in western England and Wales. Elsewhere, it's found across most of Europe. The primary food source for its developing youngsters is Hedge Woundwort – hence the insect's common name – though they will also nibble on White and Red dead-nettles and Black Horehound. Given that we have plenty of the latter two "also rans" in our garden, perhaps we'll harbor some shield bug offspring in the coming months.

Saturday, 20 July 2024

Striped

White-lipped Snail (Cepaea hortensis)
While wandering around the garden last week, I discovered this handsome White-lipped Snail (Cepaea hortensishanging from the leaf of a Common Nettle (Urtica dioica) plant near the fire pit. The pale "lip" of its shell – the edge closest to where its foot emerges – quickly distinguishes it from the Dark-lipped Snail (Cepaea nemoralis) which featured on the blog several years ago. As with that closely related species, these snails can vary remarkably from one individual to the next. Some, like the one above, are marked with up to five bands of colour while others, like the one below, are a single solid shade, typically pinkish or yellow. Considerable research done on this genus of snails suggests that the wide variety of markings may serve two purposes: camouflage and temperature control. By blending in with their surroundings, and not looking like every other snail a potential predator might come across, snails with different markings might avoid being eaten. And snails with lighter coloured shells heat up less quickly than do snails with darker shells, which may explain why those in more open areas tend to be paler.

White-lipped Snails are widespread across the UK, and indeed across much of central and western Europe; they're also found along the coast of northeastern North America. Their habitats range from grasslands and gardens to dunes, clifftops and woodland, and they're known to reach altitudes of more than 2000 metres (6500 feet) in the Alps. Favourite foods include Common Nettle, Common Ragwort and Common Hogweed, so they're going to find plenty to munch in our garden!