Silver-spotted Skipper

The end of July and it's Silver-spotted Skipper time again. That means a trip to Newtimber Hill and a morning searching one of the most productive butterflying locations on the Sussex Downs. Not having spent much time butterflying this year it was also a good opportunity to top up the year list with the downland species.

Sightings included Small, Large and Essex Skippers; Common Blue, Chalkhill Blue, Holly Blue, and Brown Argus; Small White, Green-veined White, and Marbled White; plus Painted Lady, Peacock, Dark Green Fritillary, Small Copper, Gatekeeper, Meadow Brown, Small Heath and a few micro moths. Not a bad haul but I was disappointed not to see Brimstone, Wall Browns and Small Tortoiseshell which this trip has delivered in previous years.

Silver-spotted Skipper

Silver-spotted Skipper

Some of the other butterflies seen today

Brown Argus

Common Blue

Essex Skipper - Black tips to the underside of the antenna

Green-veined White

Small Copper

A couple of the micro moths. There were a good number about but I couldn't get any clear shots.

Pyrausta nigrata

Pyrausta purpuralis

and a few from last week

Chalkhill Blue

Dark Green Fritillary

Dark green underwings but it is a Silver-washed Fritillary

Lighter coloured Silver-washed Fritillary

Large Skipper

Peacock

Small Skipper - orange tips to the underside of the antenna

I have missed a good few of the butterflies this year but visiting Newtimber for the Silver-spotted Skippers is one of the essentials for the year.

Beauty and the Beasts

The world of flies is truly fascinating. There are over 100,000 species world wide, with more than 7,000 recorded in the UK. The ability to identify them would require a lifetime of learning and endless patience - neither of which I have. I enjoy the challenge of identifying a new find, but I also end up throwing away dozens of pictures because I cannot spare anymore time researching them. However, I can always make time for the unusual.

The Beauty - Phasia hemiptera

Amazing colours on this fly. I spent a couple of hours trying to identify it, before I realised that I had seen it and photographed it before, but under different lighting conditions. The colours were there but not quite as obvious.


Reading up on colours in flies wings, it appears that there is another world of colour in flying insects. We do not see it but it is probably a key means of communication between flies, bees and wasps. Photograph a flies wing against a white background and it will probably appear as transparent, with no colour, as the reflected white light swamps the picture. Photograph it against a black background and with the correct lighting conditions and the colours become apparent.

I haven't yet pulled out any flies wings to try it out but there are good examples on the web. Have a look at this National Geographic article.


The picture below shows the three dimensional structure of the same flies wing, which I had not really noticed before. A quick check shows that there is a huge amount of research going on in this area. Clearly it has implications on manoeuvrability in man made flying objects.

Now for the beasts. Some of those flies that make you step back if they land close or fly near to you.


Robber flies, members of the Asilidae family and distant relative of the common housefly. These are amongst the top predators of the insect world. They feed on a wide range of prey, including other flies, beetles, butterflies, moths, various bees, dragonflies, damselflies, wasps, grasshoppers and some spiders. They wait in concealment and dart out to capture their prey using the long legs to hold them still. They then use a short, strong proboscis, to stab and inject victims with saliva containing neurotoxins and enzymes. These paralyze the victim and starts the digestion  of the victims soft tissues. The Robber Fly then sucks the prey dry.

Most are also capable of delivering a painful bite, so should be handled with care. Below is a Common Awl Robber Fly coming in at body length of about 15-17mm.


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Common Awl Robberfly - Neoitamus cyanurus

and a picture I have used before, of a Kite-tailed Robber Fly Machimus (Tolmerus) atricapillus with a body length of about 20mm.

Kite-tailed Robber Fly - Machimus (Tolmerus) atricapillus

The largest of the family in the UK is the Hornet Robber Fly - Asilus carabroniformis with a body length of about 25mm. Although the abdomen is a bright yellow colour giving it the hornet name, the robber fly is surprisingly well camouflaged, hence the difficult of obtaining a clear picture against its preferred background of cow pats.

Hornet Robberfly - Asilus carabroniformis 

Hornet Robberfly - Asilus carabroniformis

Nowhere near as big at only around 10mm but even creepier looking is this Ferruginous Bee-grabber. They are parasitic, the females will pounce on Bumblebee and Miner Bees depositing an egg into the bees abdomen where it hatches and feeds on its host. They can be found feeding on nectar, this one on bramble, although she? seemed more interested in passing bees than in the nectar.

 Ferruginous Bee-grabber - Sicus ferrugineus

And no blog on beasties of the insect world could go forward without a picture of the dreaded Clegie a member of the Tabanidae family. Robber Flies bite in self defence, bees sting in self defence but clegs bite just for the fun of it and it can be quite painful. To be fair the female needs blood in order to be able develop eggs and the male doesn't bite.

The female injects an anti-coagulant to ensure she can feed freely. You probably also get a dose of Equine infectious anaemia (EIA), also known as swamp fever, which is a viral disease that attacks a horse's immune system. There is no cure and no vaccine for this viral infection, which is caused by a retrovirus closely related to the HIV virus in humans. EIA is often fatal to horses but does not affect humans. Maybe not, but for many of us, something in a cleg bite can cause serious swelling and considerable pain for a few days.

The culprit - or at least one of the culprits.

Band-eyed Brown Horsefly - Tabanus bromius

More beasts than beauties but it's great fun finding and photographing them. Lets hope for a few more before the summer is out.

Narcissus Fly

Hunting in the garden for Hoverflies again. Found what I think is Meredon equestris a bumblebee mimic that also exhibits polymorphism and has at least four named variants and multiple examples with mixed characteristics. All very exciting although I don't think my wife was over impressed. It is also known by a number of common names Narcissus Bulb Fly, Greater Bulb Fly, Large Bulb Fly, Large Narcissus Fly.


The four named variants are Batesian mimics of different bumblebee species. This one probably closest to variant narcissi and would I assume pass as a Buff-tail or White-tail Bumblebee. We may not be completely fooled by its appearance but we cannot know what the predator sees and reacts to and the evidence does seem to show that Batesian mimicry does work.


Interesting though that the different variants must recognise each other as being of the same species as they still interbreed and give rise to the multiple examples with mixed characteristics.


Fortunately, as a species, it has a distinctive wing loop in vein R4+5 which can be seen in the picture below. Only one other British hoverfly exhibits this wing pattern and that one can be eliminated on leg colour.


As a bee mimic it is quite effective. The eyes are a bit of a give away but it's robust behaviour and flight pattern gave more of an impression of a bee than of a hoverfly and it had to be seen close up to confirm what it was. Listen out for the buzzing it makes, it is at a  higher pitch than the bees, making it a little easier to spot.

Merodon equestris

Now for something a little less complicated. White markings on black makes the Scaeva pyrastri below one of the easier hoverflies to identify. It is a migratory species with numbers variable from year to year.

Scaeva pyrastri

Scaeva pyrastri

The next is a Sphaerophoria of which there are eleven British species. Six of these have matched spots on the abdomen with the other five being banded as with this specimen. Given the body looking longer than the wings this looks like Sphaerophoria scripta which also happens to be the commonest and most widespread of the eleven species. Also referred to, for obvious reasons, as the Long Hoverfly.

Sphaerophoria scripta  Female

To confuse matters Sphaerophoria.scripta can also present with darker colours and matched abdominal spots which are the result of temperature variations particularly in the earlier spring specimens.

Sphaerophoria scripta  Male

There is only one British species of Syritta and with nothing looking similar the Syritta pipiens below is another hoverfly that is easy to identify. It is small and dark with a slender abdomen but the key feature is the greatly enlarged hind femora. There was a better picture of one of these in my 11 June blog but this one shows the markings on the abdomen which were not clear in that earlier picture.

Syritta pipiens

The example below shows whiter spots on the abdomen. Possibly an older and more faded specimen. Note also the two white triangles on the thorax just behind the head, a key identifier, these also appear to be faded.

Syritta pipiens

As the year moves on I am coming across a few new hoverflies. Below is Meliscaeve cinctella a new one for me and a bit unexpected in the garden as it is a woodland species. I checked the identification a couple of times and am reasonably confident. It is a widespread species and does occur in large numbers some years.

Meliscaeve cinctella

I have also included another picture Myathropa florea. This one a robust looking specimen and displaying a nice example of the "Batman" markings on the thorax.

Myathropa florea

The next hoverfly is probably a new one for me. It is certainly an Eristalis and in this case I think it is Eristalis arbustorum the Plain-faced Dronefly. The dark markings do not extend along the rear of Tergite two to enclose the yellow spots as seen on other members of the genus and there are no dark markings across the centre of the wings as found on E.horticola. It looks good but not a certainty.

Eristalis arbustorum - Plain-faced Dronefly 

The next one I have photographed before. Helophilus pendulus, known as the Sunfly or Tiger Hoverfly. It is unusual in that both male and female have the eyes separated on the head. To tell the sex of the specimen you need to look at the shape of the rear end which unfortunately in this case is not clear in the picture.

Helophilus pendulus 

The final specimen is Volucella pellucens - Large Pied-hoverfly. Again one I have photographed before but it is always a nice one to find.

Volucella pellucens - Large Pied-hoverfly

A Confusion of Bees

Not the correct collective noun for bees but rather an appropriate one for where I am at the moment. 

I thought bees would be easy. I’ve got the Field Guide, there are plenty of bees around the garden to practice on, and thanks to the lockdown I have had the time to study them. So what progress am I making. Well, I have managed to identify a few and I even have recognisable pictures for some but I have also taken hundreds of useless pictures and I have spent hours trying to identify what I have seen.

What have I learnt? I do now understand that bees are difficult to photograph, they move too fast, vibrate a lot and are the wrong shape for the narrow depth of field on a macro lens. I also realise that there are a lot of species that look very similar and when combined with variations in the markings within  species, very few map easily onto the drawings and pictures in my field guide.

I am not even sure that I can tell the difference between Buff-tailed and White-tailed Bumblebees. The queens, if I could see them, would be recognisable but workers are giving me real problems. My only hope is to spot a male White-tail with yellow face hair.

Anyway here goes - but please recognise my usual health warnings on the labelling of the different specimens.

Buff-tailed Bumblebee - Bombus terrestris

At a distance you think White-tailed but close up there is a narrow buff band between the black and white on the rear of the abdomen. My difficulty is, that I haven’t yet seen a specimen that I am really convinced is a true White-tailed.

Can’t really go wrong on the next one. The very distinct markings on the Wool Carder - Anthidium manicatum make it easy to recognise. This one was also easy to photograph as it appeared to be roosting in the shelter of the flower head.

Wool Carder - Anthidium manicatum

  

I found the next one a bit more difficult as there are a number of similar bees but in the end I came down in favour of the Clover Melitta - Melitta leporina

Clover Melitta - Melitta leporina

  

And another Carder Bee. This one looks good for the Common Carder – Bombus pascuorum.

Common Carder – Bombus pascuorum

I then had to check to see why you find Carder bees in two different families, The Wool Carder in the Megachilidae with leaf-cutters and mason bees whilst the Common Carder is a Bombus in with the Bumblebees. Apparently they both get the name Carder from their behaviour of scrapping hairs from leaves which they then bundle and carry back to the nest to use as a lining.

I had real difficulty photographing the next one The Green-eyed Flower Bee – Anthophora bimaculate. Easy to identify as it seems to be the only UK bee with green eyes but the one I was after was hyperactive. It favoured hovering whilst nectaring rather than landing on the plant and it only stayed for two or three seconds before moving on at speed. It was a case of predict where it was going next and wait for it to arrive. So three pictures of this one. None of them perfect but I can’t wait for it to return to the garden so I can have another go.

Green-eyed Flower Bee – Anthophora bimaculate

Green-eyed Flower Bee – Anthophora bimaculate

Green-eyed Flower Bee – Anthophora bimaculate

Another Megachiliade this one I think is the Patchwork Leafcutter Bee - Megachile centuncularis but I am happy to be corrected if anyone knows better. It seems to be running a high risk strategy in our garden as Sue is trying to identify what is causing lots of circular holes in the edges of the leaves on her new cherry tree.

Patchwork Leafcutter Bee - Megachile centuncularis

  

Three pictures for the next one as well. A shiny bum bee? After much delving all I can come up with is a possible Forest Cuckoo Bee - Bombus sylvestris, but it’s probably another Buff-tailed that has had a close shave with something!

Possible Forest Cuckoo Bee - Bombus sylvestris

Possible Forest Cuckoo Bee - Bombus sylvestris

Possible Forest Cuckoo Bee - Bombus sylvestris

  

The next one fits the description for the male Red-tailed Bumblebee – Bombus lapidaries. Unfortunately it didn’t stay around for long but it’s another one I would like to see back in the garden again.

Red-tailed Bumblebee – Bombus lapidaries

 I have one final bee and I have no idea what it is. A bumblebee and probably my old favourite the Buff-tailed but it is either very faded or or a colour variant. Nice looking bee though. 

It's probably noticeable that I am sticking mostly with Bumblebees. That is really driven by the fact that all the sightings were in my garden so the the species variety is limited. I need to get out into some different environments particularly if I want to see things like the Nomada bees. 

I have to say I am a bit worried by the the Andrena family the miming bees. I already have pictures of a couple but with a few exceptions they are going to be really difficult to identify. However rest assured, no bees are harmed or will be harmed in my pursuit of an identification.