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.

Orange

Minettia inusta

I recently discovered a Facebook group for UK diptera (a fancy name for flies), which should help us to identify at least some of our more distinctive fly pictures – like this one, for instance. This is Minettia inusta, a small orange fly with distinctively patterned wings. It's said to be quite common in southern Britain, but ours is one of the very few records for Norfolk in the national database. My guess is that most people just aren't looking at little flies! Elsewhere in the world, it's widespread across the Palearctic (Europe, northern Africa, and Asia north of the Himalayan foothills). It's a saprophagous species, which means that it gets its nourishment from decaying organic matter, including carcasses. It's more common in grassland than other habitats, so I guess it's finding our pocket meadow to its liking. Other than that, I couldn't find any other information about the species. There's still a lot to learn about many species with which we share our planet.

Semaphores

Semaphore Fly (Poecilobothrus nobilitatus) – male

A visit to the pond last Thursday afternoon yielded an unexpected addition to the list: our first Semaphore Flies (Poecilobothrus nobilitatus). When you see a male in action, it isn't hard to guess how the species got its common name. He does quite the fandango around the female, waving those white-tipped dark wings to attract her attention, then doing a series of fast flights back and forth over her, flipping himself over in mid-air so that he's always facing her. If she's impressed enough, she'll mate with him. And apparently, this male had the right stuff! By the way, when I say "flipping over", this isn't something we saw ourselves; it's one of the fastest known animal turns on the planet, and human brains and eyeballs don't process quickly enough to see it. But scientists with slow-motion cameras have recorded it. To us, it just looked like he bounced back and forth from one side of her to the other, always facing her when he landed on the vegetation. These little flies are predators, feeding on a variety of small aquatic invertebrates, including tiny worms, water fleas, and midge larvae. They're common and widespread in southern England and Wales, and slowly spreading north as climate change warms the islands. Elsewhere, they're widely found across much of Europe. Now that we know they're around, we'll be watching for them. Adults fly from May to August, so we still have a few months to enjoy them.

The female lacks colouration on her wings.

Dagger fly

Empis livida

Right around this time of year, we start to notice dagger flies (aka dance flies) hanging around the composite flowerheads in the garden. The most regular of these is Empis livida, identified by its red-orange legs and the three dark stripes on its brown thorax (visible in the picture above). Females have clear wings (as below), while those of males are slightly cloudy. As you might guess from that wicked looking proboscis, this is a hunter-killer. It lurks around on flowers waiting to stab any unsuspecting insect that wanders by – though while it waits, it's more than happy to sip a bit of nectar from the flowers. They fly from April through July across much of England and Wales but are far less common in Scotland. Elsewhere, they're found throughout temperate and northern Europe, making them one of the most widespread flies in their genus. They've been shown to be quite effective pollinators, which isn't surprising, I suppose, considering their general hairiness (particularly on their legs) and their habit of hanging around on flowers. Their larvae are carnivorous, feeding on things they find in the damp soil and leaf litter where they grow to adulthood.

Mozzie

Banded Mosquito (Culiseta annulata)

Somehow, I never expect mosquitoes at this time of year. And yet, here's one I found yesterday, resting on a leaf near our little "rubbish bin lid" pond at the foot of the garden. It's a Banded Mosquito (Culiseta annulata), so named for its very stripey legs and abdomen. Those spotted wings are also distinctive. And it's huge, for a mosquito, measuring about a centimetre (i.e. nealy half an inch) from face to tip of wings. This makes it Britain's largest mosquito. The long proboscis (sticking straight out the front) and slender palps (the two angled things sticking out next to the proboscis) identify it as a female. A male's palps would be extravagently feathery. This one is missing half of her legs; she should have six, like all insects. Banded Mosquitoes are mainly nocturnal, resting during the day. They overwinter as adults, hibernating somewhere protected. As with all mosquitoes, only the female sucks blood. She'll feed on a variety of hosts, including (unfortunately) humans. Males feed on nectar, pollinating flowers in the process. 

According to our Collins Guide to the Insects of Britain and Western Europe, Banded Mosquitoes occur in many habitats, though always close to water. Females lay their eggs in a wide variety of watery sites; these can range from fresh to brackish, and can be clean or polluted, shaded or sunlit. Larvae and adults are all present year-round. The government's Public Health website says they're common and widespread throughout the UK, though ours is only the fifth record for Norfolk in the national database.

Migrant blowfly

Male Locust Blowfly (Stomorhina lunata) on Common Ragwort (Jacobaea vulgaris)

While wandering around in the garden recently, I spotted what I thought was a hoverfly I'd never seen before. I snapped a few shots and scurried to the house to get Mike, so that he could get some photos as well. However, when I tried to look it up later, I couldn't find it in our hoverflies field guide. So Mike undertook an internet search, and discovered that it wasn't a hoverfly at all. It's a Locust Blowfly (Stomorhina lunata). Once you know what to look for, it's a fairly distinctive insect. The combination of striped back (see below), banded abdomen (orange in males, grey in females) and "pushed out" lower face help to identify it. Adults feed on nectar and pollen, visiting a variety of flowers in the umbellifer and daisy families. But the larvae are voracious predators, specialising on the eggs of several species of locusts — including some that are serious agricultural pests. To date, there is no evidence that the larvae are predators of grasshopper species in the UK, so the occasional adults found here are all thought to be vagrants; they're widespread across much of Europe, Africa and Asia. It's amazing to think of such a tiny creature making its way across the English Channel, which stretches 21 miles at its narrowest point. They remain quite rare here, but sightings are increasing in southern England, and the species has been found as far north as Lincolnshire and Nottinghamshire. Quite an unexpected one to add to our list!

Wing wavers

Hawthorn Fruit Fly (Anomoia purmunda)

While I was weeding in the garden the other afternoon, my eye was caught by subtle motion on a spike of vegetation nearby. Looking more closely, I found a group of small flies waggling their patterned wings at each other and occasionally engaging in a bit of spirited head-butting, trying hard to shove each other off the leaf. I've never seen a behaviour like it! It's a Hawthorn Fruit Fly (Anomoia purmunda), one of the so-called "picture-winged flies". These little insects measure a mere 4.5 mm (less than 1/4-inch) in length, but their frenzied wing-waving makes them pretty noticeable despite their tiny size. Those wings are distinctively marked too, with a big black splotch near the base and a couple of thinner lines further out. Their eyes, green with two pink stripes, are characteristic as well. Females lay their eggs in hawthorn fruits (though they'll use a variety of other species if hawthorns aren't available). Interestingly, though they were displaying on a shoot of Greater Periwinkle (Vinca major), that isn't one of the known larval host plants. These little flies are reasonably common in the southern half of England and Wales, and from Europe right across the Palearctic to countries bordering the Pacific. Adults are seen between July and October, so we may get the chance to watch them do their wing-waggling/head-butting thing again.