August 2017 - notes from the Somerset Levels

August 29th 2017. Our invertebrate gathering took place this morning at Langford Heathfield, a 226 acre reserve run by the Somerset Wildlife Trust west of Taunton. John, Una, Tony and a new member, Chris H from Taunton, joined me in the lay-by looking into what appeared dark, dense scrub and woodland. In fact it is woodland-based, but has numbers of clearings and meadows at the far end. Although other parts did not enjoy much sunshine, we were lucky with plenty during the day. As a result, there were plenty of insects flying and we had a really succesful day. Our good results were almost entirely in the open clearings most of which had Hardheads Centaurea nigra flowering across the area, in profusion. One particularly pleasing and notable find were numbers of Hornets Vespa crabro feeding among these, patrolling up and down. They were too restless and quick for succesful pictures but their bright colouring shone among the flowers. it is good to report that these insects have become seen more frequently in recent years. It is interesting to find that the largest numbers of records were among hoverflies. This particularly so since such reords have been so sparse this year. Plenty of species were represented, among which were species not normally spotted. The very first of these was a small black hoverfly with yellow banding. It looked familiar, but was not what we had imagined. It turned out to be Dasysyrphus tricinctus, which none of us had ssen before, though it is said to be common.

hoverfly Dasysyrphus tricinctus m

hoverfly Dasysyrphus tricinctus m

hoverfly Cheilosia scutellata f

hoverfly Cheilosia variabilis m

hoverfly Platycheirus podagricus m

hoverfly Eristalis abusivus f

hoverfly Epistrophe nitidicollis f

hoverfly Sericomyia silentis f

hoverfly Melanostome scalare m

hoverfly Meliscaeva cinctella f

hoverfly Sphaerophoria interrupta f

hoverfly Volucella pellucens f

Common lizard Zootoca vivipara

Common lizard Zootoca vivipara

Sloe bug Dolycoris baccarum

Mining bee Lasioglossum zonulum f

bumblebee Bombus terrestris m

August 25th 2017. We spent some time on what is usually both an unproductive and rather dull walk - perhaps because we have marched down Jack's drove in all weathers. This time it was quite different and I came back with some interesting pictures. The first of these was from my favourite category - insects in flight. You take the shot and wonder what it will look like in critical detail on the computer. When it hits the spot, I think how amazing it is that autofocus can get it so right!

 bumblebee Bombus pascuorum m

 hoverfly Rhingia campestris

 hoverflies Rhingia campestris m

This tiny little ichneumon was given away by the continual nervous movement of its antennae, forever searching for chamical signals wherever it was. I can only hope that one of my friends may be able to help identify it. It is marvellous when you get home and blow it up on the computer, to see that the lens has captured the most delicate shapes of its structure. I still finfd it an amazing feeling when all this is revealed on the screen.

 A very small ichneumon, Ichneumonidae

The angle of the light and the creature on the flower can readily alter the appearance of hoverflies such as the various Eristalis species. This picturte makes the insect look completely furry, other shots show the much more typical makings quite clearly. In this case the particular give-away points are the colour of the middle tibiae and the strong black facial stripe.

hoverfly Eristalis nemorum m 

 A small ichneumon, Ichneumonidae

From previous experience, I suspect this ichneumon may be a Clistopyga species but again I shall be seeking help elsewhere.

August 24th 2017. A further hundred or so pictures have been added to the flight gallery. Click on Birds in flight - waterbirds 1 & 2.

I spent more time than I should have, watching the digger wasps at the logs this morning. They were is full swing, really active, searching every potential nest. It is always a challenge to see if it is possible to catch these tiny insects in flight, hopefully when they pause for the briefest moment in the hover. I can only marvel at the technical wizardry of my ancient equipment when it works - D300+years-outdated Sigma 180 macro. I am putting the pictures in without identificaion other than that they are all Crossocerus spp., but hope to come back later with some names. They are difficult to recognise but a combination of timing, leg colour and jizz may bring some reults. Not that it really matters; they are fascinating creatures portrayed in their daily lives, images that ought to live on.

digger wasp Crossocerus spp.

digger wasp Crossocerus spp.

digger wasp Crossocerus spp.

digger wasp Crossocerus spp.

digger wasp Crossocerus spp.

digger wasp Crossocerus spp.

digger wasp Crossocerus spp.

digger wasp Crossocerus spp.

mining bee Colletes daviesanus f

hoverfly Baccha elongata m

August 21st 2017. Our daily walk took us down to Catcott Fen edges. Most of the herbage was dry and unproductive for insects but not entirely. A flash of black and white, with bright colour between was a tiger moth flitting around. Fortunately it stopped to allow some pictures, for it turned out to be the distinctly unusual Jersey tiger.

Jersey tiger moth Euplagia quadripunctaria

August 17th 2017. It is interesting to look at progress with the leafcutter bee nests. This shot shows one log which clearly is their favourite. A nextdoor log has not taken their fancy at all, though everything looks similar. These are a mixture of Megachile versicolor and V. centuncularis nests. The colour of the closure starts as green and changes with age.

 Leafcutter bee nests, Megachile spp.

August 15th 2017. Our invertebrate group met this morning at Fontmell Down in Dorset, between Shaftsbury and Blandford. This reserve is large, set on a great sweep of the great chalk Downs which cascade steeply down to the valleys below. There is a car park at the top and the only slightly off-note was the noise of great numbers of small aeroplanes taking off into the wind just overhead, working at their hardest and noisiest. This must depend on the direction of the wind but was at its loudest this day - with many people enjoying the flights in perfect conditions. The whole day was all but cloudless, giving marvellous views over to the west. The very first sight of the day was a Red kite Milvus milvus sailing across the green and over the horizon. It came back regularly during the day as did various Ravens Corvus corax and a Peregrine Falco peregrinus way up above us, almost out of sight. But our aim was at insects and in particular the butterflies for which the place is noted. By the end of the day only two of us had located these, way down below at the very bottom of the slope and they had a good and succesful time although they ran out of time not long after finding the spot. I concentrated on the insects on the vegetation along the side of a stony little lane running down off the car park, as did we all to start with. This proved highly succesful. We had a good attendance; John M. and John B., Nigel, Robert, Malcolm from Langport, Rose from Bideford,  Margaret and myself. The chap who had suggested the meeting, Peter, had to rush off north because of family sickness and, sadly, had to miss it, but sent me a description of what to expect. The list of sightings proved exciting, starting with something quite unexpected. Right at the start, the lane produced a number of large bees that reminded us of Honeybees Apis mellifera, but were coloured quite differently, dark-skinned and hairy.

Black honeybee Apis mellifera mellifera f

After a some research I am certain they are honeybees, but our rare native Black honeybee Apis mellifera mellifera, described  as extinct by one person on-line, though there is evidence it is being found in numbers of places in Britain, where it was the original native honeybee. They are said to be hardier, with smaller populations which overwinter more readily. It has been said they may be the best bet for future populations better suited to our climate than the more fasmiliar insects (which were also present and gave a comparison on site). A huge dark fly then caught our attention, the massive Tachina grossa, not often spotted.

fly Tachina grossa f

There were also a few hoverflies to my great relief, as they have been so absent recently. Various Cheilosia, Eristalis and a single Dasypoda albostriatus were among those seen.

hoverfly Cheilosia pagana f

At this point Robert brought out his bat-detector and immediately heard a great burst from a Roesels's bush cricket, just a foot or so away, though it took us ages to actually see it sitting on a grass stem in full sunlight. As soon as the sun dimmed momentarily, the cricket stopped its song, as if cut off by a knife. We were to find others of this once-rare insect at different points in the lane, all the way down.

Roesel's bush-cricket Metrioptera roeselii

Knapweed flowers Centauria were attracting numbers of leafcutter bees, the majority Megachile willughbiella, though a similar but miniature female Hoplitis claviventris visited briefly - too quickly for a picture.

leafcutter bee Megachile willughbiella f

It was good to come across a few mining bees on the knapweeds, as well as various yellow flowers in the edges of the path.

mining bee Lasioglossum prasinum f

mining bee Lasioglossum prasinum f

mining bee Halictus tumulorum f

A couple of species of Ectemnius digger wasps were busy on the umbels, both E. continuus, often the most visible species, and E. lapidarius.

digger wasp Ectemnius continuus f

digger wasp Ectemnius lapidarius f

As in many places this year, the commonest bumblebee was Bombus terrestris, but the next busiest was Bombus lapidarius.

bumblebee Bombus lapidarius q

Although I had hoped to see some of the more unusual butterflies, the most obvious were Brimstones Gonepteryx rhamni, mainly females, but that may be because they are so large and obvious.

Brimstone Gonepteryx rhamni f

The others had more luck with different species when they trekked down to the bottom, traversing slopes that are too much for me nowadays. I sat at the top, where it plunged over a lip, for half an hour, looking over that extraordinary panorama, enjoying the view, the warm sunlight and the various birds crossing over. Eventually, I spotted Robert and John at the extreme bottom, where they struck entomological gold, right at the end of the day. At least they know now where to go on their next visit. But, a fitting end to a most enjoyable outing over the Somerset/Dorset border.

John & Robert, Fontmell Down

August 13th 2017. Just a brief update to yesterday's entry. We removed the dead dove as it grew dark last night. This morning a number of the doves were seen walking round the spot where the youngster had died. They had a quick look and then flew away.

A further 25 pictures have been added to the Birds in Flight gallery. Click on Birds in flight.

I spent a glorious time in front of my log trap-nests after lunch. The original attractions were the leafcutter bees hard at work on one particular log. What made this even more fascinating was that the bees were Megachile versicolor, in place of the earlier M. centuncularis, though still working on the same particular log, but a different set of holes.

leafcutter bee Megachile versicolor f

leafcutter bee Megachile versicolor f

leafcutter bee Megachile versicolor f

leafcutter bee Megachile versicolor f

But that was by no means the end of the story. A brightly-coloued Ectemnius digger wasp was spotted searching some of the holes on another log alongside the first. But it turned out to be a species only very occasionally seen here, E. lituratus. It was a good opportunity to take numbers of pictures, including a couple in flight, about to land.

digger wasp Ectemnius lituratus f

digger wasp Ectemnius lituratus f

digger wasp Ectemnius lituratus f

A single queen ant appeared on a log and peered in and out of holes before vanishing off to find a male from the hordes that have been appearing from one of our cupboards in the last couple of weeks.

ant Lasius niger q

Several species of ichneumons visit the logs regularly, but It was particularly interesting to see a new species hard at work beside and into one of the nest holes. It was impossible to identify from my sketchy knowledge but it is possible it could be one of the Apechthis species? The overal colouration and the stubby ovipositor look familiar. I must ask a friend who knows far more about such matters.

ichneumon f

Very few cuckoo, or jewel, wasps have been seen at the logs this year but there was a fine specimen around today. The problem for the photographer is finding them stationary for even a second - they dash frantically from hole to hole incessantly when they are present.

cuckoo wasp Chrysis mediata

Finally, my lucky shot of the day. Whenever the little black Crossocerus wasps appear, I cannot resist trying to catch them in flight as they search from one hole to another, sometimes hovering momentarily. This little insect is around 5mm long, on the smallish side, near invisible against the dark shadow round the logs. Yet the camera has locked on in remarkable fashion, using autofocus set to the approximate posion expected.

digger wasp Crossocerus annulipes f

August 12th 2017. We have had a small family of Collared doves Streptopopelia decaocto feeding in the garden recently. This afternoon we noticed that seven or eight doves had gathered on the ground or in a nearby tree. They appeared concerned at something out of sight behind the tree trunk. We went and looked and found a young dove lying on the ground, able to move its head and wings but dazed, possibly disorientated. We left the bird there, hoping it would recover. An adult dove sat in a low branch of the tree looking down, while the others were on the ground near the injured bird. The old adult sat there for much of the afternoon and we thought the injured one showed more signs of life. However, later the youngster died, rolling over onto its back in a last convulsion. We think it might have crashed into something, affecting its balance. As soon as the bird died, the other doves disappeared and have not been seen since. Who says that birds do not have feelings? Clearly those birds cared for their relative and were extremely upset at events. It was a sad moment.

August 10th 2017. An interesting day devoted to leafcutter bees, both on the moors and in the garden.Catcott Fen saw numbers of leafcutters on a thistle in a very windswept spot. They were engaging in tha typical method of pollen collection with the abdomen raised up and the hind legs trasferring it to the hairs beneath on the sternites as the picture shows.

leafcutter bee Megachile centuncularis f

The next picture was taken on a gient daisy plant in our garden. At this time of year, it is hugely attractive to a variety of insects, bumblebees, hoverflies and leafcutter bees in particular. Up to four different species of the latter may be seen at times.

 

leafcutter bee Megachile willughbiella f

Finally, a second species for the year was seen finishing off its nest in the logs. This an elaborate and intricate process with the insect bringing in leaf after leaf to construct each cell, then the final two or three to seal off the entrance. It is really hard work and they take infinite pains to get it just so.

leafcutter bee Megachile versicolor f

August 8th 2017. Photography took place totally within the garden today. The sun came out in the afternoon and the purple variety of the butterfly bush Buddleja davidia was fully out, attracting many insects. Within feet of this, I found a Volucella zonaria sitting on a friot tree, the first of this exotic insect I have ever seen. From a distance, it stood out with the richness of the colouring, reminiscent of a Hornet Vespa crabro.

hoverfly Volucella zonaria f

hoverfly Volucella zonaria f

Nearby, a close relative, Volucella pellucens, stood out against the purple of the butterfly bush like some brilliant tropical insect.

hoverfly Volucella pellucens f

There were a few Eristalis hoverflies feeding there also, some of the earliest I have seen this year.

hoverfly Eristalis tenax f

Numbers of butterflies were also present, some looking overcome by the richness of the nectar - drunk? This particular one was a slightly strange, washed out colour.

Red admiral Vanessa atalanta

The last notable find was a wonderfully bright bumblebee. Almost certainly a male Bombus pascuorum but it could as readily be a male B. muscorum - they have been seen in the garden previously. The colours are beautiful. The difference lies in the presence or absence of black hairs at the wing roots and the sides of the abdomen.

bumblebee Bombus pascuorum m

Finally, on a thistle in the hedge, a leafcutter bee was photographed, the first of the year for Megachile ligniseca, known from previous years to be a garden inhabitant.


leafcutter bee Megachile lignisec m

August 6th 2017. In the morning, the logs provided some interesting watching. Several leafcutter bees were hard at work constructing their nests, some just finishing off the final capping, others delving away inside.

leafcutter bee Megachile centuncularis f

leafcutter bee Megachile centuncularis f

In the afternoon, we went down to the end of Jack's drove, on Tadham Moor. It has been very disappointing this year, few bees, other aculeates or hoverflies. Now, the umbels are certainly busy but with none of these insects. Muscids, Green bottles and numerous small flies are the bulk.

flies on umbel

It seems early, but masses of Hedge bindweed flowers Calystegia stepium are now the main floral interest. Numbers of bumblebees visit them but the principle beneficiary is the hoverfly Rhingia campestris, found sitting at the base of so many of their flowers.

                                                              hoverfly Rhingia campestris f                                                              

Walking back, I managed to photograph one of the bumblebees in flight.

                                                              bumblebee Bombus pascuorum                                                          

August 5th 2017. Maddie and I decided on a walk at the southern side of Chilton Moor. It is a good and interesting walk when it is dry - not so good in winter. This period of summer can be interesting, as thistles are prominent by the side of the drove at present, and should attract bumblebees. Teasels Dipsacus fallonum are out at present, such unusual flowers, popular with numbers of insects. I have been meaning to check the more conventional-looking thistles, but have not got round to it yet. Must remember to do so during my next visit.

                                                                       Teasel Dipsacus fullonum                                                                     

There were numbers of bumblebees on these plants, mostly Bombus pascuorum and B. terrestris, working hard at collecting their pollen and sipping the nectar.

                                                          bumblebee Bombus pascuorum                                                           

Leaving the drove, a wild screaming was heard high up in the sky. A buzzard, young I would guess, sailed over then perched behing some trees, still calling. I suspect it was hoping its parents would still feed it. 

Common buzzard Buteo buteo

Later, in early evening, I wandered round the garden and took some pictures of various bumblebees, close-up, always fascinating to see the detail.

                                                              bumblebee Bombus terrestris                                                              

                                                            bumblebee Bombus terrestris                                                              

August 4th 2017. A rather disappointing visit to Ham Wall in the afternoon produced little to see but it was good light  and the colours were interesting. It was very crowded, being close to the first weekend of school holidays, but everyone was enjoying themselves and the further you walked, the less people came or remained long. Indeed the island hide was almost empty for much of the time. Unfortunately, though to be expected when so many birds are in eclipse, there was not much to be seen. A few shoveler Anas clypeata were feeding in front. It is difficult to see what the sexes were in this intermediate plumage. They are alweays worth photographing though.

                                                                          Shoveler Anas clypeata                                                                         

There were a few little birds around and one, A Reed warbler Acrocephalus scirpaceus was amongst the most obliging, popping out periodically to sit among the outer reeds.

                                                   Reed warbler Acrocephalus scirpaceus                                              

The other notable event was spotting a newly-emerged Comma butterfly Polygonia c-album just below the rim of the hide. The colouring is superb.

                                                                  Comma Polygonia c-album                                                                  

August 1st 2017. Our invertebrate group had a most succesful outing to Stoborough Heath and Hartland Moor in Dorset, with sunshine throughout our visit, though much of the rest of the country had patchy rain at the same time. John, Robert and I drove down to meet the others, by courtesy of John, picking Robert up en rounte. Rose and Margaret were already there, exploring the heath. One or two others had been expected but never made it. Because we were a bit late, we thought we spottted the others over across the boggy ground and the others decided to walk over there. Those people turned out to be strangers but John then came across a real rarity in the wet area, to everyone's delight. Large marsh grasshoppers Stethophyma grossum were spotted among the tufts and plants in the bog. These large grasshoppers have become extremely rare in recent years. They appear to have vanished completely from our Somerset moors where they used to live. This made it particularly a good start for our visit. While they were away, I decided to sit down in front of the layby where we met. This has always been a prime spot to see Dasypoda hirtipes, that extraordinary mining bee with the huge, bushy pollen brushes on the back legs. At first sight this was not too promising, as there was a strong wind - which often stops most insect activity - while there were few 'volcanoes' to be seen. The nesting sites of these bees are characterised by a cone-shaped pile of fine sand capped with a circular hole. A bee went into one of these, eventually came out and, in due course, returned with a load of pollen.

mining bee Dasypoda hirtipes f                                                                                       © robin williams

mining bee Dasypoda hirtipes f                           © robin williams

I sat for ages and realised eventually that its head was just visible, well below the rim. I managed a photo but the bee still did not emerge then, quite unexpectedly, it reached up and pulled the sand in until it had filled the entrance with loose sand - the bee still underneath. A few minutes later, nearly all the volcanoes were seen to have done the same thing - no holes were visible and no bees flew. Strange behaviour, for the sun remained out.


mining bee Dasypoda hirtipes f                           © robin williams

mining bee Dasypoda hirtipes f                           © robin williams

It was interesting to see a number of flies hanging round the nest entrances and, eventually, going down inside, always making certain the bees had just left to collect more pollen. These were Leucophora species, Anthomyiidae, kleptoparasitic on solitary bees and, clearly, on Dasypoda. They are not that visible, well-camouflaged on the multi-coloured sand and move slowly and unobtrusively.

fly Leucophora spp.                                                                                                            © robin williams

A brief foray into the heath opposite yielded a single hoverfly Leucozona lucorum on some brambles but no sign of others, by then the wind was really whipping over the surface.

hoverfly Leucozona lucorum f                              © robin williams

After lunch, sitting on the grass behind the lay-by, we moved over to the tramway at Hartland Moor. Again, it appeared unpromising, with the wind whistling straight down the track. Walking on towards the little hide, we came across Bee-wolf Philanthus triangulum nest-holes in the pathway and two or three older ones that may well have been those of the rare Purbeck mason wasp Pseudepipona herichii, with the typical separate pills of spoil washed away. A couple of times, a sand wasp Ammophila sabulosa made a brief appearance, dodging in and out of the edges of bare sand and heather.

sand wasp Ammophila sabulosa                          © robin williams

Three types of heather Ericaciae were in flower, a splendid sight, ranging from pale lavender to rich purple. Returning along the trackway, the large patch of bare sand round a water-tank brought out a single bee-fly Bombylius minor, busily searching for suitable nests into which it would hurl its eggs. It was altogether too fast for me this time, so no picture. While the others searched more widely on the heath, I walked back down the track and settled on my rucksac-seat alongside what appeared to be active Bee-wolf nests. They were! Within minutes, three or four appeared, flying in and retreating, then settling beside the nests. Most were males, waiting for females to appear, some even hovering over nest-holes, appearing to try and see what was going on inside.

digger wasp Philanthus triangulum m                © robin williams

One nest had a Honeybee Apus mellifera lying abandoned on the top, beside the open hole. Eventually a rather larger Bee-wolf flew in, landed nearby and edged its way towards this nest, ending up beside the Honeybee. All this took some time and, fortunately, Margaret and Rose had caught up and were watching it all through their close-up binoculars. The drama increased as our female twisted and turned alongside the paralysed Honeybee before dragging it down inside with one last heave, too quick to record the moment when the bee disappeared completely.

digger wasp Philanthus triangulum f                  © robin williams

 

digger wasp Philanthus triangulum f                  © robin williams

 

digger wasp Philanthus triangulum f                  © robin williams

 digger wasp Philanthus triangulum f                  © robin williams

digger wasp Philanthus triangulum f  & honeybee Apis mellifera                           © robin williams

Walking back, we could not help reflecting on how much this formerly amazing entomological area had changed in recent years. The formerly largely bare sand banks are now nearly covered with Bell-heather Erica cinerea. There may well be insects underneath but they are longer visible. I suspect many will not find it hot enough and will have moved on. For all that, it had been an enjoyable and rewarding day all round. It was raining at home.






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