Category Archives: Hoverflies

The disappearing dove

Every year millions of migrating songbirds heading from Africa to Europe get blown out of the sky by weird people with shotguns. That combined with the policy in the UK of destroying habitat at an alarming rate is making life impossibly possibly difficult for some of our iconic bird species, one of which is the turtle dove (Streptopelia turtur, Dansk: turteldue).

But last summer I was exploring one of my regular haunts, Milton Country Park, on the northern edge of Cambridge, on a warm Saturday morning and the air was buzzing with insects including this handome hoverfly known as the ‘footballer‘ due to its rather fetching black and yellow striped thorax. This species is common in England reaching a peak in July which is when I snapped this individual.

The footballer hoverfly – Helophilus pendulus

And hoverflies aren’t the only abundant insects to be found in July. Milton Country Park is also home to mumerous species of Odonata, the dragonflies (Anisoptera) and damselflies (Zygoptera).

Common blue damselfly – Enallagma cyathigerum – perched on a seedhead

The Park has 4 big lakes:

MCP map

…and a few other streams and pools, and despite the abundant human presence it remains a haven for some properly exotic wildlife including a bittern that appeared for a week or so last year, and the occasional osprey stopping off on migration from sub-Saharan Africa to breeding sites further north in the UK.

The great crested grebe (Podiceps cristatus, Dansk: toppet lappedykker) isn’t an exotic migrant but it’s a beautiful bird and can always be found here:

The grebe was almost hunted to extinction because its dense feathers were coveted as a substitute for fur. But it has recovered and can now be found on lakes over most of the UK. The one above is an adult and the one below still has the striped head markings of a juvenile.


But getting back to the point, the undoubted star of the show on this trip was the turtle dove:

The turtle dove is in very serious decline, I believe we have lost around 97% of our breeding population and it is anticipated it will become extinct in the UK by 2020 as it’s also under increasing pressure in Europe. The reason for its catastrophic decline is that it feeds on seeds from cereals and other plants and both of these are a scarce commodity in the fields of the UK at the time the doves need them.

So the birds arrive here in the UK exhausted after a heroic migration across the Sahara and the Mediterranean. And those that avoid the gun-toting imbeciles in southern Europe arrive here to find there’s not enough food. So as it takes them a long time to rest and feed and get back into breeding condition, they only have time for a maximum of one brood per season before they have to head all the way back. And this enforced curtailment of there breeding window means they just can’t sustain their numbers.

They arrive back in the UK from around mid April so I’ll try to capture some more photographs before they finally stop coming here all together.

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The birds and the bees

Insects have been hit hard by climatic aberrations in recent years and on my meanderings around the Cambridgeshire countryside this year numbers of bees and butterflies sightings have been down compared to previous years. It’s now the middle of June and I saw the first dragons of the year today; two damselflies. I also read this week in ‘The Guardian‘ newspaper that a third of managed honeybee colonies in the USA were wiped out in 2012. This article makes very sobering reading. And it’s a similar story in Europe, but in Europe neonicotinoid pesticides, which have been implicated in colony collapse disorder, have been banned for two years to evaluate their effect on honeybees. My concern is that the onslaught on the bees is complicated and removing one variable may not show a significant effect in the limited two year duration of the ban. But I hope it does!

Early last month the sun finally broke through and gave us some insect friendly weather and it was remarkable how quickly the microfauna emerged.

Beefly – Bombylius major

Beeflies are found over large parts of the globe and can be seen hovering in sunny glades from the springtime. The narwhal of the Dipteran world, the spike looks fearsome but is only used to probe flowers for nectar, there is  no sting. Beeflies procreate by flicking their eggs into the entrance to the burrows of wasps and bees where the larvae feed on the grubs of the occupants.

A pair of hoverflies doing their best to rectify the decline in the insect population

I think these hoverflies are ‘Eristalis pertinax’ but I’m not certain. It was good to see them though, especially as they were taking their biological responsibilities so seriously.
Addendum: on the subject of climatic aberration mentioned at the top of this post I just found and read with increasing concern this link:

http://robertscribbler.wordpress.com/2013/04/12/human-climate-change-is-wrecking-the-jet-stream-uk-met-office-calls-emergency-meeting/

which my blogging buddy Sam posted on her excellent WP blog ‘Science on the Land‘. This provides a chilling insight (in every sense) into why the weather in the northern hemisphere is behaving the way it is. And it doesn’t look as though it’s going to get any better folks.

Anachronous insecta

A few posts ago I showed you some of the spider I encountered in the short spell of good weather we had in the late summer and early autumn. I think maybe some species were making hay whilst the sun was shining because there were also a lot of hoverflies around at that time too. And here are  three of the species I found. It’s the wrong time of year to be posting about hoverflies, hence the title of the post, but I haven’t been able to get out with my camera so I reckon a hoverfly post is better than none at all! Identifying hoverflies can be tricky because there are species which look very similar to each other and I’m no expert, so I hope my identifications are accurate but if any of you spot an error please let me know.

Eristalis tenax

Eristalis tenax is a type of hoverfly known as a ‘drone fly’, so called because they mimic honey bee drones. They are common throughout the UK and the females, which mate before overwintering and laying their eggs in the springtime, can be seen in any month of the year because they emerge from hibernation to feed when the weather warms up sufficiently. The larvae of this species are called ‘rat-tailed maggots’ and feed in sewage outflows and rotting carcasses – the more putrid it is the more they seem to like it! They are aquatic and the reason they are called ‘rat-tailed’ is that they have an extendable tube which can protrude up to around 5cm which they poke out of the water and use to breath air.

Tapered drone fly – Eristalis pertinax

The tapered drone fly is so called because the male has a tapered abdomen which is visible on this individual. It is otherwise a similar species to E. tenax and it’s larvae are also known as rat-tailed maggots. Apart from the taper it’s also distinguishable from E. tenax by it front legs which are pale.

My favourite hoverfly I found this year is this one:

The footballer – Helophilus pendulus

It’s called ‘the footballer’ because it’s colours are likened to a football shirt. It’s scientific name means ‘dangling sun lover’. The larvae of this species feed on detritus and have been found in wet manure, drains and in very wet sawdust. It’s widespread throughout the UK and can be seen throughout the summer in bright sunny locations in hedgerows. Despite the unsavoury but indispensable habits of the larvae of all of these species they transform into the most handsome adults.

I haven’t done a dedicated Christmas post this year so here’s wishing you all a very merry Christmas and a happy and healthy 2013!

Correction – Volucella zonaria

In my post ‘Backyard Safari‘ from September 15th I included this photograph of a magnificent hoverfly which I identified as Volucella inanis:

I subsequently received a comment from Roger Morris of the Hoverfly Recording Scheme (HRS) to let me know that I had incorrectly identified the fly and it is in fact Volucella zonaria. So thanks to Roger for putting me straight.

When it appeared in my garden I mistook it for a hornet, it’s our largest hoverfly and I’ve seen it described as a ‘hornet mimic’. The adults feed on flowers such as buddleia which may be why it appeared in my garden, and the larvae feed on the detritus which accumulates in the cavity at the bottom of wasp nests. It wasn’t recorded as resident in the UK until the 1940’s when it appeared around London and then spread across the south of England to the west country. It’s population is still most dense in the south east but it is regularly recorded in the east Midlands with occasional recordings in the northwest of the country.

Back yard safari

A couple of posts ago I described my Fenland safari and since then I just happened to have had my own ‘back garden safari’! Lots of colourful creatures have been stopping by to refuel.

I’ve previously expressed concern for the depleted populations of insects, in particular butterflies and dragonflies, due to the mad weather we’ve experienced in the UK this year, but in the last couple of weeks there have been some great sightings outside my back door.


Common darter (Sympetrium striolatum) female perched on the clothes line

The dragons have been late to appear but since the last week in August there have been common darters regularly alighting and migrant hawkers hunting overhead.

And of course it’s that time of year when the arachnids are most in evidence, and my garden is festooned with garden spiders, there are webs attached to every surface: walls, plants, windows… everywhere.

Garden spider female, Araneus diadematus, despatching her prey, a small fly

The female garden spider has a bulbous abdomen which is adorned with the fabulous diadem that gives the species its name. The male is smaller than the female and has a flatter, kite shaped, abdomen, but he also carries the diagnostic markings. A couple of years ago I posted about the perilous love life of the garden spider, suffice to say the sex life of the male can be dramatically and terminally curtailed if he fails to show the lady sufficient respect!


This garden spider male set up home inside the bedroom window – until  the resident arachnophobre found him and relocated him

As well as the spiders, the occasional cricket strolls by, and this little chap was taking shelter under a sunshade from the unseasonally hot weather last weekend:


Oak bush cricket – Meconema thalassinum – the male of the species. The female has a long, upturned ovipositor protruding from her rear

The oak bush cricket is quite a small example of the genre, they are 13-17mm long and are carnivorous, feeding on small insects. They live on the edge of woods and in gardens and appear from July into the Autumn.

Also putting in a welcome appearance was a common buzzard, Buteo buteo:

The buzzard has been one of the birds which has really bounced back since the more stringent controls on of agricultural pesticide use were introduced in the 1980’s. I’d never seen a buzzard until I was in my 20’s and even then it was the occasional sighting in the wilds of west Wales or down in Cornwall. But they can now be seen over all of England – even from my garden.

Hoverfly – Volucella inanis

Hoverfies rarely have common names, they’re simply known under the generic name ‘hoverfly’. And V. inanis is no exception, at least as far as my research reveals. There was great excitement when it first buzzed into the garden because at first glance we thought it was a hornet due to it’s size and its yellow and red colouration. And it was a whopper! They can grow up to 15mm long and this one was one of the bigger ones. It eventually settled and posed rather obligingly on the edge of the rabbit run while I snapped a portrait, and it is a very handsome fly. It has an interesting breeding tactic too laying its eggs in the nests of other social wasps, including hornets – which probably explains its size and colour scheme – where they hatch and feed on the larvae of the host.

Comma – Polygonia c-album

I waited expectantly for this comma to open its wings and show the gorgeously ragged orange symmetry, but it didn’t. So I had to content myself with this silhouette of it perched on a cooking apple.

Insects and molluscs

Over the last couple of weeks I’ve been out and about photographing wild flowers, and of course the raison d’etre of flowers is to produce the reproductive cells of the plant in order to ensure survival. And as plants are immobile they rely on other vectors to connect the male and female parts, that can be the wind and the rain but many flowers are exquisitely evolved to attract one or more species of insect to carry the pollen to the ovum and effect fertilisation.

So in the course of photographing the flowers some of them were hosting a pollinator or two:

Tree bumble bee – Bombus hypnorum

This tree bumle bee was sipping nectar from the flower of the white deadnettle. It’s one of the insects that is strong enough to get to the back of the flower and take the nectar. Flowers have evolved in this way such that the insects have to pass the stamen, which is where the pollen, or plant sperm, is produced. The stamen is made up of the filament and the anther, and foraging insects brush against the anther picking up pollen which they carry to the next flower where it is deposited on the female part of the plant – the ‘carpel’, and fertilisation ensues.

There are various species of bees in the UK but only around half a dozen common ones. Bees are in trouble in this country and no one seems to know why, both honey bees, which live in colonies, and solitary bumble bees are dying out at an alarming rate.

Buff tailed bumble bee – Bombus terrestris

The buff tail above was in a particularly poorly condition and had tiny mites crawling on it’s body so I imagine it didn’t do much more pollinating.

Soldier beetle – Cantharis rustica

The soldier beetles are related to the fireflies and they get their common generic name from one species which is bright red and is therefore named after the ‘redcoats‘ – English soldiers from days of yore. The larvae and the adults are carnivorous, the larvae feeding on insect eggs and caterpillars and the adults on aphids. They also feed on nectar and can therefore pollinate too.


Black slug – Arion ater

Alot of people have an aversion to slugs because of the damage they can do to fruit and vegetables, but this chap was out in the field making a meal out of a couple of dandelion seedheads. I don’t think they contribute much to pollination and they are predated by frogs and toads and also hedgehogs. Although I’ve heard that if too much of a hedgehog’s diet consists of slugs, parasitic worms living in the slugs can get into the lungs of the hedghog and kill it because its lungs fill up with fluid. Which sounds pretty unpleasant but I guess it’s not the fault of the poor old slug!


Brimstone moth – Opisthograptis luteolata

The brimstone moth is a splendid creature with a wingspan of 32-37 mm. It’s common and widespread across the UK. In the warmer climes of  the southern UK there can be three generations in a year but in the north there is only one brood per annum, and adults can be seen on the wing between April and October. The caterpillars feed on various trees and bushes including hawthorn and blackthorn.

A couple of weeks ago after days of rainfall which had moistened everything I found a 50m stretch of verge which was crawling, literally, with hundreds of yellow and brown snails.


Brown lipped snails – Ceppaea nemoralis. Just a few of the hundreds that were making the most of the damp conditions

The ‘lip‘ of the snails in their name is the front edge of the shell which can be seen in the next two pictures and is lighter brown on the yellow one and a much darker brown on the brown one:

Snails are predated by songthrushes. They pick up the snail by the fleshy part and crack the shell on a handy stone. Some years ago I was sitting at home on my own reading a book and everything was very quiet. I heard ‘tap tap tap’ on the front door, but when I went to answer it their was no one there. So I went back to my book. A few mintes later I heard the same tapping and again there was no one there, so I opened the door to have a look up the street and rather than a visitor there was a collection of broken snail shells on my front doorstep. It transpires the tapping I’d heard was a songthrush using my front doorstep as an anvil to swing the snails against and hammer open the shells!

Insectivora

The hedgerows and the edges of country paths are home to an immense variety of small creatures, especially those which aren’t in the firing line for agricultural chemical spraying, and it can be easy to overlook them.

Last weekend I spent a morning chasing insects around and I followed a red admiral butterfly into a thicket of nettles where it sat tight with it’s wings closed. Over the next twenty minutes it very briefly opened its wings, but only partially, but enough to enable me to see that its colours were pristine:

And then it opened them fully, and the colours really were sumptuous:


…well worth half an hour stood in a nettle bed!

But I thought the half hour definitely wasn’t wasted when I looked down at my feet and saw this cluster of peacock caterpillars eating nettle leaves:

I moved to one side to get some pictures of the caterpillars, and fortunately after I’d spent some time doing that the red admiral was still in situ.

Peacocks are hardy butterflies which can be found over most of the UK including the Shetland Isles and can be found hibernating in garden sheds. They emerge from hibernation at any time of year if the weather is warm enough, they mate in March and lay eggs then the caterpillars can be seen from the middle of May into July.

Not only are they hardy, they are quit beautiful too. A close look at their wings reveals a fabulous array of brightly coloured detail:

Male peacocks hold fort in their territory and wait for passing females to pass by when they fly up to greet them and attempt to mate. Male and female peacocks are very difficult to tell apart and watching the males performing this courtship behaviour is one way to differentiate the genders.

And close to the same spot I was looking at the flowers and I spotted this hoverfly cleaning his eyes:

…and this beetle wandering over a convulvulus flower, I don’t know what it is but it has gorgeous colours:

The brambles in the hedgerows were also full of bees in the sunshine, many species of honey bees and bumble bees were harvesting nectar from the flowers:


White tailed bumble bee flying from flower to flower feeding on bramble nectar

And than this marvellous creature was hunting in my kitchen last week:


Violet ground beetle, isn’t he magnificent!

Violet ground beetles are carnivorous, as are their larvae. They hunt at night and hide up during the day under log piles or other cool dark places. They eat a variety of insects, including a number of species that gardeners would be glad to be rid of. They’re big beetles, around 3cm long, and they have irridescent blue or violet edges to the thorax and wing cases. So don’t use chemicals in your garden – let these guys get rid of your pests!

And now I’m looking forward to some warm sunny July days when the surrounding fields are full of butterflies. I’ll share some more insect photographs with you then.