Black and white

Great Pied Hoverfly (Volucella pellucens)

One of the less common hoverflies we've seen in the garden is also one of Britain's largest. The Great Pied Hoverfly or Pellucid Hoverfly (Volucella pellucens) has made only a handful of appearances over the years, including one this week. It's one of island's largest flies, measuring 10-15.5 mm (i.e. around a half inch) in length. It's round with a bold white girdle around an otherwise shiny black body and eye-catching dark marks on its wings. Found from May to October, they're especially common in June and July. This female will have been looking for a place to lay her eggs. She'll search out ground-dwelling bumblebees or social wasps to deposit her eggs in their colonies. When the eggs hatch, the hoverfly larvae drop to the bottom of the colony, there to nibble on various waste products (dead bees/wasps, dropped foodstuffs, other insects, etc.) and the occasional bee or wasp larvae. When fully grown, the larvae migrate outside of the colony to pupate in the soil. Adults feed on nectar and pollen, preferentially visiting bramble (genus Rebus) and other white flowers. Widespread across the whole of the British Isles, they're primarily found in woodland and along woody hedgerow, though they also regularly visit gardens. Outside of the UK, they're found across Europe and the Palearctic, as far as Japan.

Stripey fly

Xanthogramma pedissequum

The generally chilly weather we've had this spring seems to have put a bit of a damper on insect numbers in the garden, but I found this unfamiliar hoverfly warming itself on a south-facing leaf yesterday. It's Xanthogramma pedissequum, and it's new for the garden. The yellow striping along the edges of the thorax (the fly's "shoulders", if you will) is distinctive, as are the triangular yellow spots on near the fly's "waist" (tergite #2, if you're being specific) and the dark leading edge to the wings. This handsome insect is most common in the summer (particularly in June), but can be seen as early as March and as late as the end of September. It's a widespread southern species, common south of a line between the Wash and southern Wales, with scattered records as far north as central Scotland. Though primarily a grassland resident, it is sometimes found along paths in more wooded areas. Much of its life history is little known, but its larvae are thought to live in the nests of black or yellow ants. It typically flies close to the ground and feeds on low-growing flowers, but is most often seen, as this one was, perched on foliage somewhere. It's the first new insect of 2022!

Wasp mimic

Two-banded Wasp Hoverfly (Chrysotoxum bicinctum)

One of the more distinctive hoverflies to visit our garden is the eye-catching Two-banded Wasp Hoverfly (Chrysotoxum bicinctum). It's a wasp mimic – and quite a good one at that. The combination of the two yellow bands across its black body, its long antennae, and the chocolate-brown spots on its wings is diagnostic; no other UK hoverfly shares those features. We often find these hoverflies on the Field Bindweed flowers along one edge of the garden. They prefer sheltered grassy areas, especially those near shrubs or trees. Adults fly from May to September, peaking from mid-June to August. Surprisingly (considering that they're widespread across lowland England, and occur throughout Wales and as far north as the north coast of Scotland), little else is known about their biology. The larvae are thought to be associated with ant nests, where they may feed on root aphids being "farmed" by the ants. There's so much still to be learned about many of the world's smaller creatures!

Faker

Lesser Hornet Hoverfly (Volucella inanis)

While wandering around the garden the other evening, I found a big hoverfly climbing over the Common Marjoram (Origanum vulgare). Though it was nearly the size of the Hornet Mimic Hoverfly I profiled a few months ago, this one was clearly different, with much more yellow on its distinctively broad abdomen, and a dark brown, rather than chestnut-coloured, thorax (the part of the insect just behind its head). It's a Lesser Hornet Hoverfly (Volucella inanis), another of the UK's larger hoverflies. What looks an out-of-focus photo artefact around its eyes is actually a thick coating of hairs on its eyeballs – and how it can see through such a thicket is beyond me! It also has plumose antennae, which is a fancy way of saying they're branched like feathers rather than hairlike or paddle-shaped, like those of most hoverflies.

Like its larger cousin, the hoverfly mimics a wasp in an attempt to deter predators that might be put off by the possibility of getting stung. From its former stronghold in southern England (particularly around London), it has expanded its range across much of the country in the last 30 years, now reaching as far north as Yorkshire and beginning to edge into Wales. Despite the expansion, however, it's still listed as "infrequent and local" outside of the London area. Like all hoverflies, the adults are nectar feeders. The larvae, however, are predatory; the female lays her eggs in a wasp or hornet nest, and the hatched larvae feed on the wasp or hornet grubs. Adults fly from June to September, but are most common in early August. They're typically found in gardens and along roadside and hedgerows. Elsewhere, they're found across southern Europe and northern Africa.

Thunder thighs #2

Thick-legged Hoverfly (Syritta pipiens)

We've been struck this summer by the relatively low number of insects in the garden compared to years past. Hoverflies in particular are notable by their absence, with only a fraction of the hordes we saw last summer. Despite that, I'm still racking up new species. The Thick-legged Hoverfly (Syritta pipiens) is one that Mike spotted last year but I managed to miss. This slim little nectar feeder is one of the smaller hoverfly species, measuring only 4 to 7 mm (about 1/8 to 1/4 of an inch) in length. Those bulging hind femora – its "thighs" – are distinctive. The combination of its hefty femora and the dusty grey sides to its thorax (the part of the fly right behind its head) are diagnostic; no other British hoverfly shares those two characteristics. It's a common and widespread hoverfly, found right across the UK, though missing from the highest and most exposed locations. Larvae develop in damp, rotting compost, silage and manure. Adults fly primarily in the late summer and into the autumn, with numbers sometimes augmented by arrivals from the continent. They feed on many different flowers, and can be abundant on Common Ivy (Hedera helix). We'll have to keep an eye on our small ivy patch this autumn to see if they're still around then. Britain's Hoverflies says the males can be quite territorial, facing off and shoving each other back and forth until one finally gives up. That could be amusing to watch!

The eyes have it

Eristalinus sepulchralis

Last week, a strikingly different hoverfly caught my eye as I wandered around the garden. Unlike most of the "regulars" which I have learned to identify, this one was dark, with dull buff, rather than yellow, markings. But the biggest surprise was its eyes. They were speckled. I knew right away what that meant; I had finally seen my first Eristalinus. A quick check of Britain's Hoverflies: A Field Guide yielded the species name – Eristalinus sepulchralis. This is another species that Mike spotted last year but I missed. Like all hoverflies, it's a nectivore as an adult, visiting a wide variety of flower species and undoubtedly finding a nice buffet in the garden. The "rat-tailed" larvae develop underwater, so perhaps our new pond will provide an appealing prospect for potential breeders. The larvae feed on micro-organisms that break down wet, rotting vegetation. The species is essentially a lowland species of Wales and southern England, though there are scattered records from lowland Scotland as well. Elsewhere, it is widespread from Europe right across the Pacific Ocean. It has undergone a substantial decline in the UK over the past decade and a half, so we're happy to find them here, and hope they like the place enough to stick around.

Check out those speckly eyes!

Fake hornet

 Hornet Mimic Hoverfly (Volucella zonaria)

I finally connected with Britain's biggest hoverfly – the Hornet Mimic Hoverfly (Volucella zonaria) – on one of our flowering shrubs this week. Mike saw several in the garden last year, but I managed to miss every single one of them. It clocks in at a chunky 15.5 - 25 mm (up to an inch) long, which is pretty big for a hoverfly. It looks (and sounds) remarkably like the European Hornet, which helps it to avoid being eaten; most predators won't mess with prey that might sting. The hoverfly, however, has no sting. It spends its adulthood sipping nectar from a variety of flowers, while its larvae live inside wasp, hornet, and bumblebee nests, eating waste and debris. Hornet Mimic Hoverflies first arrived along the south coast of England in the late 1930s. By the 1940s, a population had become established, primarily around London. Since 1995, its range has expanded greatly as climate change warms the UK, and it is now regular across the southern and southeastern England, with scattered records as far north as Scotland. Adults fly from May until November (though primarily in July and August) so we have plenty of time to see others.

Beaded

Male Beaded Chrysotoxum (Chrysotoxum festivum)

The hoverflies are certainly swarming around the flowers these days, and we're finding all sorts of new ones for the garden — including this very distinctive Beaded Chrysotoxum (Chrysotoxum festivum). The colour hasn't really come across in the pictures, but those paler stripes have an almost neon green tinge. The yellow bars on the sides of the thorax (the part of the fly that its wings attach to), the rusty wings with their darker spot, the long antennae (for a hoverfly), and the bold "D" in the middle of its back are also eye-catching.  The adults feed on nectar and pollen, and are said to be particularly fond of thistles and umbellifers, both of which we have in abundance in and around our property. As with many species of hoverfly, the larvae are carnivorous; they're thought to specialise on aphids that feed on plant roots. The Beaded Chrysotoxum is found in grassy areas, heaths, and open scrub, primarily in the southern half of Britain. In Essex, it's apparently particularly common on post-industrial waste sites! Though widespread in Britain, it's still not particularly common; with our sighting, there are only eight records for our half of Norfolk in the national database, for example. Its population has increased since the 1980s and its range has expanded northwards since the early 2000s, with records from as far north as Scotland, mostly along the coast. Elsewhere, it's found in much of Europe, and across Siberia to the Pacific coast, with disjunct populations in Japan and northern India. It flies from May to September, with numbers peaking in June and August. Plenty of time to see another one or two, with any luck.

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!

Batman

Myathropa florea

Another day, another hoverfly! This one is Myathropa florea, and though the books say it flies from May through November, we just spotted the first one for the garden on a water butt near the kitchen. It was quite an eye-catching insect, waggling its yellow-furred backside up and down as it sat near the rain-soaked cover of the container. Like many hoverflies, it's a wasp mimic; the yellow and black marks on its body presumably deter potential predators afraid of being stung, though the fly doesn't look very wasp-like to us humans. Like the other hoverflies we've managed to identify so far, this one is common and widespread across most of the British Isles. It's also one of the easier to identify. It shows the same strongly-looped vein as Helophilus pendulus (R4+5, particularly visible in the right wing above), and the black patch towards the back of its thorax (the part of the fly that the wings attach to) rather resembles the "Batman" symbol. Given the width of its rounded backside, it's probably a female; males are pointier at the end of their abdomen. Though typically a woodland species, it is opportunistic, and will breed anywhere it can find a suitably wet habitat for its "rat-tailed" aquatic larvae — including, apparently, the occasional water butt. Adults feed at a variety of flowering plants, but are particularly fond of umbellifers, like the towering 8-foot high fennel plants that currently loom over our herb garden. Hopefully, that means will be seeing this handsome wee beastie again!

Striped Pajamas

Helophilus pendulus

We've had an extraordinary number of hoverflies in the garden this year: what seems like hundreds and hundreds of many dozens of species. They're proving quite challenging to actually identify, principally because when I look them up, it turns out I've taken the picture from the wrong angle, or there's some bit of vegetation covering an important ID feature, or the fly is just a little too far away, or some other equally frustrating development. This time, though, I have enough of the "right bits" to identify this particular hoverfly. It's Helophilus pendulus, a common and widespread species found right across Britain and Ireland. It flies from April to November, with numbers peaking in July. I found a couple of them today — one feeding on a Common Cat's-Ear flower, the other sitting quietly on a bit of log in our tiny pond (in reality an upside-down garbage pail lid buried in the grass).  The photo above is from earlier in the summer, when I found another individual resting near the same pond. This species is often found near shallow water, where its larvae, widely known as "rat-tailed maggots", live among decaying vegetation.

The striped thorax of this species is pretty unusual; only a handful of British hoverflies share that feature. The noticeable bend in one of the veins in its wings, visible near the tip of the fly's left wing in the photo above, is also distinctive. The combination of those features, plus the thin black stripe on the fly's face, its dark antennae, the dark lines between the blocks of yellow on its abdomen, and the dark band on its back tibia (the middle section of its leg) covering less than half of the tibia's length help to clinch the ID. This is a male, as determined by broadness of the yellow markings on its abdomen, and the less-pointy shape of the abdomen's tip. One species down, dozens and dozens to go!

Imposter

Merodon equestris

So, it's a bumblebee, right? You'd be forgiven for thinking so, since this imposter looks rather like the bumblebee it's mimicking. But you'd be wrong, because this is actually a fly — the hoverfly species Merodon equestris, to be precise — and looking like a bumblebee is its way of potentially avoiding predation. Known colloquially as the Greater Bulb-Fly, this is probably an introduced species, since it wasn't reported in Britain until the 1800s. Its larvae develop in and feed on daffodil bulbs (as well as the bulbs of a host of other species), so it may have originally stowed away in daffodil bulbs imported from Europe, where it's common and widespread. Greater Bulb-Flies can be quite variable in colouration, with somewhere between 4 and 7 different named varieties (experts disagree on the exact number) mimicking the patterns of several types of bumblebees. This one appears to be the form bulborum, which mimics the Red-tailed Bumblebee. They're most common in late May and early June, but are found from mid-March right through until the middle of October, so we're likely to see a few more before the year is out. Maybe we'll spot one or two of the other varieties as well!