Artemesia aphids

Absinthe Aphids (Macrosiphoniella absinthii) on Shrubby Wormwood (Artemesia arborescens)

When I looked out the office window the other afternoon, I noticed a dark smudge at the top of one of the Artemesia plants in the herb garden. Intrigued, I ventured out for a closer look and found these colourful aphids (photographed by Mike). A sniff around the internet led me to the amazing Aphids ID website run by the folks at Influential Points. This site packs a serious punch. It has detailed ID information for hundreds of species, with some great pictures as well. Sifting through the plant list (you can search for potential aphids IDs by checking the plants on which they're feeding) quickly led us to our list's latest addition — the Absinthe Aphid (Macrosiphoniella absinthii). Its one of only 25 species of aphid that Carl Linneaus himself named, in the 10th edition of his seminal work, Systema Naturae. As is suggested by its name, it's typically found on Absinthe plants. We don't have Absinthe in the garden, but we do have a close relative — Tree Wormwood (Artemesia arborescens). And that's where these little creatures have made themselves at home. They feed only on the upper parts of various Artemesia species. All of the insects you see in the picture are female. Like other aphids, this one typically reproduces parthenogenically. For most of the year, females give birth to only to other females, which are clones of their mother. And those newly-born females are already pregnant with clones of their own. In the autumn, some males will also be produced, and these will then reproduce sexually with some of the females. This allows for a bit of gene mixing (provided, of course, that they're not just mating with their sisters).

These little aphids are unexpectedly colourful; many aphids solidly green or brown or grey. The bold pattern may help to make the aphids less obvious to passing predators by helping to break up their outline. Alternatively, it may aposematic, indicating to potential bird predators that the aphids are toxic; the compound thujone in Artemesia plants render the aphids inedible to birds. The two little spikes sticking up from the aphids' back ends are called siphunculi (or cornicles); they're tubes that exude a defensive fluid if the aphid is threatened. The pointy "tail" is known as a cauda; the aphid uses it to flick away its excrement (also known as honeydew because of its high sugar content). Unlike some aphid species, this one is not guarded by ants. This species naturally occurs from northern and central Europe, north Africa and the Mediterranean region east to Siberia and Iran, and has been accidentally introduced to the US, Canada, and Argentina. Our record appears to be the first for East Anglia — how exciting! Of course, it could also just mean that most people aren't looking...

Marmalade

Male Marmalade Hoverfly (Episyrphus balteatus)

Now that we're nearly to summer — though our recent weather seemingly belies that fact — we're starting to see plenty of the little orange Marmalade Hoverfly (Episyrphus baleatus). With its small size, distinctive orange colour, and two black bands on each abdominal segment (one thick, one thin), it's a relatively easy species to identify. Males can be told from females by the size and shape of their eyes; females' eyes don't meet at the top of their heads, while males' do. Reputed to be the most common hoverfly species in the UK, Marmalade Hoverflies are found in gardens, grasslands, farmland and open woodland across the whole of the islands. The combination of easy identification and widespread distribution means it's one of the few hoverfly species to have a common name.

Marmalade Hoverflies are widespread across much of the Palearctic, from Europe and north Africa right across northern Asia. They're seen year round, even here in the UK. Though they breed in large numbers here, we also occasionally get massive numbers migrating from the continent. A friend in Cromer reported the massing of hundreds along the sea front this past week, for example, which may have come across the North Sea. Adults are nectar feeders, particularly fond of flat-topped flowers, including Tansy, Cow Parsley and Ragwort. The larvae feed on aphids, which makes them a very welcome addition to the garden. They're also a major form of biological control of aphids in commercial crops, helping to suppress dozens of species. Females lay their eggs (2000 to 4500 of them in a lifetime) on the underside of leaves near aphid swarms. Given the number and variety of aphids we're finding here, they should have a good buffet of options to choose from in our garden!

Rattle

Lesser Yellow Rattle (Rhinanthus minor)

Most of what's in the garden either pre-dates our arrival or has been planted in one of the developing flower beds. An exception is our burgeoning colony of Lesser Yellow Rattle (Rhinanthus minor). We sprinkled seeds of that native species onto one of the rank, grassy banks along the edge of the property, in the hopes that it will eventually help to suppress the vigorous, tussocky grass growing there. This handsome flower is one of the so-called "broomrapes"— semi-parasitic plants that get some of their nutrients by tapping into the roots of their neighbours. Lesser Yellow Rattle photosynthesizes, using its green leaves to convert the sun's energy like other green plants do. But its roots also seek out and tap into the roots of its most vigorous neighbours (typically grasses), and that will help us to control the grass without having to spray herbicides or mow regularly. And that should help us to improve the bank's biodiversity.

Lesser Yellow Rattle is a widespread annual in sunny areas of grassland and farmland across the British Isles; it's also native to much of Europe, northern North America and western Asia. It germinates in early March, pushes strongly serrated leaves from black-spotted stems that can rise to nearly half a metre (18 inches) in height, and blooms between May and September. Its yellow, tube-like flowers extend from fat green calyxes (the pale green structures in the photo above), and are particularly favoured by bumblebees. After the flowers have been pollinated and fade away, tiny seeds develop in the now-brown calyxes. These seeds give the plant its common name, because they rattle around in their casings when the plant is brushed against. The plant also serves as the larval food source for a couple of rare moths, neither of which we've seen here yet. With any luck, maybe someday, the moths will follow.

Cockchafer

Male Common Cockchafer (Melolontha melolontha)

When we run the moth trap these days, we're catching a fair few Common Cockchafers (Melolontha melolontha), also known as May Bugs. They're a bit of a pain, really; they bumble around in the trap, crashing into the moths and generally stirring things up. For those who don't run moth traps, these are the large insects that buzz loudly around the garden at dusk and crash into lighted windows on late spring and early summer evenings. Despite their large size (males can measure nearly 1.5 inches long, females slightly smaller), they're harmless to humans. Plants, though, are another story. The beetles actually spend most of their life underground. For three years, they live as fat, brown-headed, white grubs, munching on plant roots. They're particularly fond of grasses, including cereal crops. Considering that we're trying to get rid of much of the rank grass in our garden (slowly, of course), we're not too worried about their presence. And the neighbouring carrot and sugar beet fields shouldn't be much affected either — which is good, because the beetles are capable of pretty significant crop damage. They used to cause tremendous damage to forests and agriculture in Europe. Heavy pesticide use led to them being nearly exterminated by the mid-1900s, though their numbers have been slowly increasing again.

Adults emerge between May and July, feeding on flowers and leaves. The strange name has nothing to do with chickens or body parts. It dates to the 1600s, and means "large, vigorous chafer", a chafer being this sort of large beetle. The combination of black pronotum (the section just behind its head), brown legs, brown elytra (the hard cases that cover its wings) and long, pointed "tail" (not visible in the picture above) help to identify it. The number of fronds on its feathery antenna indicate whether it's a male or female; males have seven fronds, females only six. Common Cockchafers are widespread across much of the British Isles, though less so in northern England and Scotland. They're found in a wide range of habitats, from grassland, heathland and coastal dunes to woodlands, farmlands, gardens and wetlands. We'll be catching them in the trap for a few more months!

Pink Elephant

Large Elephant Hawkmoth (Deilephila elpenor)

Checking the results on the morning after we've run the moth trap all night is a little bit like opening presents — we never know quite what we'll find, but we're always hoping it will be something good. And finding a hawkmoth in the trap definitely qualifies as good. This gorgeous creature is a Large Elephant Hawkmoth (Deilephila elpenor), so named because its caterpillar supposedly looks a bit like an elephant's trunk. I say "supposedly" because you need a fair bit of imagination to think so. The adult is a real stunner, a vision in pink and green, the latter fading to yellowish as the moth ages. They're a good size too, measuring about 1.5 inches (nearly 4 cm) long with a wingspan of nearly 2.25 inches (60 cm).  Presumably it was drawn to our garden by a good nectar source. It feeds at night on honeysuckle flowers, which are currently blooming in all corners of the property — including a big patch right near where we put the trap. They'll also feed on other tubular flowers.

This common species is found in gardens, heathland, open woodland, hedges and rough ground. The female will lay her eggs on bedstraws, willowherbs, and fuschias, all of which are present in the garden. Widespread throughout England and Wales, Large Elephant Hawkmoths have expanded north through Scotland and greatly through Ireland since the 1980s. It's common in central Europe and its range extends across much of Asia as far as Japan. Since the adults fly from May through August, this will hopefully be the first of many we see this summer.

One hundred

This marks the 100th post about the garden and our slow process of converting it to a wildlife haven. We've made some good progress over the past couple of years, adding lots of pollinator-friendly plants, leaving sections of grass to grow long (leading to an explosion of grasshoppers) and coddling along some of the native flowers that have returned to the property.

The resulting increase in insects, birds and mammals visiting the property has certainly been encouraging. We've documented 905 species as of this week, with more to come as we comb through the lists to see what we've forgotten to add. The main thing we've learned though, is how much we don't know! There are whole orders of arthropods we haven't yet been able to wrap our brains around (ants, aphids and woodlice, we're looking at you).

Doing research for the posts has been good fun, and has led to us learning lots of new facts, even about species we thought we already knew well. We hope you'll continue to share the journey with us. There's plenty more to discover out there!

Sorrel

Procumbent Yellow-sorrel (Oxalis corniculata)

We currently have a whole community of small, creeping plants thriving on the gritty soil of our driveway. This one is the Procumbent Yellow-sorrel, also known as Creeping Woodsorrel. It's another clover relative, like the Lesser Trefoil I introduced you to a few weeks ago. Its sunny, yellow flowers rise a mere inch or two off the ground, and its maroony-purple, trefoil-shaped leaves paint splashes of colour all along the edge of the drive. Rumour has it that the leaves are sometimes green, but all of ours are the rich colour seen in the picture above. The whole plant forms a little mat up to 15 cm (6 in) or so in diameter, with a small number of five-petalled flowers rising from each mat. This little annual (sometimes a short-lived perennial) prefers dry, open places, so our unimproved drive suits it perfectly. Introduced into the UK in the mid-1600s from the Mediterranean region, it's now fairly common across England and Wales, less so in Scotland. It's still often found around human habitation, but has also escaped into the wider countryside, where it has now naturalised.

Intriguingly, it seems that the plant may actually be native to southeast Asia, brought to Italy (intentionally or not) by traders. It is now found across much of the world, even on sub-Antarctic islands! Packed with vitamin C, it has been widely used for culinary and medicinal reasons. Its leaves are said to taste of lemons, and various parts of the plant have been used to treat everything from diarrhoea and wounds to scurvy, hookworms and arsenic poisoning. It has known antibacterial properties. It's a known hyperaccumulator of copper, and can be used to remediate contaminated soils. It's often considered to be an invasive weed in garden centre stock and urban gardens, spreading itself around by explosively flinging its seeds in all directions. Fortunately for the pollinators, which appear to greatly appreciate it, we don't care where it crops up.

Red

Large Red Damsel (Pyrrhosoma nymphula)

While working at my desk this morning, I spotted a movement towards the window and found this Large Red Damsel (Pyrrhosoma nymphula) perched on a candle holder on the windowsill. She must have come in through the office door, which had been open to the day's sunshine. I gave her a poke so that she'd crawl onto my finger, and carried her out to the garden, where she promptly flew off. Fortunately, she was easy to spot when she landed, so I was able to get the above picture while she rested in the sun. This is one of Britain's earliest-emerging damsel species, first appearing in the UK in March or April, with a flight period that extends through September. They're common and widespread across the British Isles, much of Europe and down into north-western Africa. Though they're found in a wide range of wetland habitats, they're most common in well-vegetated standing water, and typically avoid running water. Though we don't have a pond in the garden (yet!), there's a reed and bulrush-ringed pond only a few hundred metres from our property that this damsel may have come from.

Black legs, red lines along the edges of the thorax (the section of the dragonfly behind the head) and small black spots (called pterostigma) in their wings help to separate Large Red Damsels from the much less common Small Red Damsel, which is the only other red damsel in Britain. Damsels have ten abdominal segments, which range a bit in size; these are numbered starting from the head end of the insect. The patterns on those segments can be used to differentiate between males and females, and between individuals of similar-looking species. I can tell this is a female because of the size of the black patches towards the posterior end of her abdominal segments, and because of the yellow rings seen at the joins between those segments. It took this female more than a year to reach adulthood. Last year, she would have been an aquatic larva in a pond somewhere. Once she emerged, she spent 9-15 days fully maturing, and will spend a total of 40 days or so feeding on small flies, looking for a mate and depositing her eggs before succumbing. How cool that she spent part of her time hanging out in our garden — adding a new species to our list!

Missing sectors

Missing-sector Orbweb Spider (Zygiella x-notata)

While rummaging around the part of the garden near the house recently, looking for likely suspects to photograph, I came across this spider strolling unsteadily along the windowsill. It was a rather chilly, windy morning, so she might have been a bit cold. For whatever reason, she was in the open rather than hiding away, so I was able to get her picture. This is a Missing-sector Orbweb Spider, named for its habit of leaving an empty section in its otherwise normal orb web. (Think Charlotte's web with the radial lines missing in one of the upper sections.) A single thread crosses this empty section from the center of the web to its edge, where the spider sits in a retreat it has built there. The thread acts as a signal line, with its movement alerting the spider, which is holding the thread between its front legs, to the presence of any prey caught by the web. This line allows the spider to zip quickly to the middle of the web without having to negotiate sticky threads. Interestingly, if the plane of the web varies from the angle of the signal line by more than 40 degrees, the spider doesn't leave a sector missing. Presumably, that's because it can parachute in on the line without having to worry about getting caught in its own web.

In most examples of this species, the pattern on the abdomen is silvery-grey with darker edges; in fact the spider's other common name is Silver-sided Sector Spider. (This particular individual appears to lack that colouring.) The silver comes from very thin crystals of guanine beneath the spider's skin — the same substance as that found in fish scales. While the silver of a fish's scales help to camouflage it from below, scientists aren't sure how such colouring helps spiders.

As with most of the spiders we've been able to identify so far, this one is very common and widespread across Britain. It's found across pretty much all of Europe and the Middle East, as well as along both coasts of North America, throughout the Japanese islands and in other scattered locations in Asia and South America. This species is nearly always found in association with us humans, and we have undoubtedly carried it around the world with us. It's particularly common in the upper corners of window frames and doorways, occasionally venturing as far as roof eaves and fences, or even into garden bushes. It's also regular around boats and docks. Away from humans, it's sometimes found near cave entrances. As the British Arachnological Society posits, perhaps it moved from caves to houses with us!

Checkers

Male Orange-tip (Anthocharis cardamines)

One of the early-season butterflies that has made quite a splash in our garden this spring is the unmistakable Orange-tip (Anthocharis cardamines). Somehow, they weren't on our butterfly list until this spring, though I'm sure we must have seen some before then. This year, however, they've been hard to miss! Mike got the nice snap of the male above; it's certainly easy to see how it got its common name. The female (pictured below) is a bit tougher to identify. From above, she looks very similar to the Small White. Underneath, though, is a different story. The green-and-white checkered pattern (found on the underside of both males and females) is unique among Britain's breeding butterflies, and shared by only a few closely-related species elsewhere in Europe. The Orange-tips are in our garden thanks to our burgeoning stands of Garlic Mustard, which we've left specifically to attract them. Both that and Cuckoo-flower are favoured larval food plants. Other crucifers (members of the cabbage family) are also used to a lesser extent, but caterpillar survival isn't thought to be good on those plants.

Orange-tips are now common and widespread across most of the British Isles, having surged north well into Scotland over the past 30 years. Their range extends throughout Europe and across temperate Asia as far as China. Although they prefer damper habitats, such as the banks of streams and rivers, woodlands and hedgerows, they'll readily visit gardens too. Adults are on the wing between April and July. Females lay their tiny eggs, which turn bright orange as they mature, near the developing seeds of the host plants. When the caterpillars emerge, they eat first their eggshell, and then any nearby unhatched eggs — eliminating the competition. By July, the caterpillars will pupate, remaining encased until the following spring, when they emerge as adults.

Female