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August 2018  wildlife, from the Somerset Levels

August 28th 2018. John, Chris and I met up at one of the most interesting of local reserves this morning. We had been expecting a number of others but in the event this did not happen. They missed some exciting happenings, though not really what we had been expecting. Great Breach Wood on the Poldens, is famous for its butterflies, unusual ants and, surprisingly, dragonflies - as water is not in evidence. The day started grey and overcast, so we did not expect much, but better weather had been forecast for the afternoon. On the way in, we passed log piles edging the track (this area is owned by a commercial forestry company). On a stack of conifer logs, we watched numbers of ichneumons scouring the wood for signs of potential prey, though apparently without any luck. It was interesting that, although varying greatly in size, they were all of the same species, which preys on the wood-wasp, or Horntail, Urocerus gigas, a rarely-seen insect.

ichneumon Rhyssa persuasoria f

The places to search were the various clearings that had been made over the years. Sadly, the flower population has been much diminished by recent events, a long drought had brought flowers out but, just as quickly shut them off before their time. Two plants provided most of the insect sightings, Hardheads Centaurea nigra and Hemp-agrimony Eupatorium cannabinum. Both of these were well past their best, many on their last legs. Nevertheless, we came across some interesting insects. When I looked through these shots on the computer, I found that I had photographed one of the grasshoppers for which the reserve is noted. The black and white clubbed tip to the antenna is the giveaway point. It was good to spot the hoverfly Epistrophed grossulariae, not seen too regularly among its group.

Rufous grasshopper Gomphocerippus rufus

hoverfly Epistrophe grossulariae m

There were a number of tachinid parasitic flies on the remaining flower heads. They are beautiful in the armour plating of the outer skin, bristles jutting up from the top of the abdomen, the colours vivid.

parasitic fly Tachina fera f

While butterflies and dragonflies were largely absent, Hornets were much in evidence. Wherever we went, we found them hunting just above the foliage, darting in to a flower-head momentarily, then on again. The first were hunting conventionally, flying just above flower heads, dropping down for a brief search before flying on.

Hornet Vespa crabro w

We were surprised then to see another particular activity. They started diving down to semi-bare patches, scurrying around with vigour, sometimes flying only an inch or so above the ground, searching, but for what? They did not appear to have much luck,s time, always looking for fresh parts to examine. We took a great many pictures of Hornets this afternoon, both on the bare patches and in flight. At one point two of the insects met on a bare patch and briefly looked as though they were conferring, before they flew off.

Hornet Vespa crabro w

Hornet Vespa crabro w

Eventually John spotted what was going on and called us over. A Hornet worker had caught a grasshopper, of which there were a great many in evidence. She hauled it up onto a narrow stem and hung upside down by one leg to set about eating the unfortunate creature. We saw similar behaviour a week or so ago when another worker took her prey into a shrub and hung upside down while it ate its prey.

Hornet Vespa crabro w, with Meadow grasshopper Chorthippus parallelus

Hornet Vespa crabro w, with Meadow grasshopper Chorthippus parallelus

Hornets are most photogenic, with beautiful colouring and powerful shape. In previous visits to Great Breach Wood we have always come across them and on at least two occasions found and watched their nests. They must surely be nesting here to be found in such numbers, though we saw no evidence of this.

August 25th 2018. Today's entry is a portfolio effort, reporting on recent activities on number of days at the 'flats' outside my study. It is some since the recent short-lived burst of leafcutter bees' nest-building activity finished. There was next to no more for a while then, since the rain arrived, it has livened up somewhat. The volume of insect life has increased a bit, but also produced one or two highlights worth reporting. In many ways the most interesting has been the arrival of a tiny blue-green Jewel-wasp last seen on the logs some ten years ago. It is most distinctive, though varying in colour from all metallic blue to green. Size 6mm.

cuckoo wasp Trychrisis cyanea

The next arrival was a most distinctive cuckoo bee female with a long, pointed abdomen. Most years we see them on one or two occasions but they do not stay long. There are a number of species of which this is one of the most numerous in the country. The second picture shows the shape of the abdomen more clearly. They are preying on the nesting leafcutter bee Megachile centuncularis, hence the reason for its timing. Size, around 10-14mm

cuckoo bee Coelioxys inermis f

cuckoo bee Coelioxys inermis f

A small number of the little black, thread-like, Crossocerus wasps have started to appear once more, this species is among the commonest and most distinctive with its pale rings at the bottom of the tibiae. They are only around five or six mm long.

digger wasp Crossocerus elongatulus

Finally, the dashing and distinctive Ectemnius digger wasps have increased their presence. Once they are around, it is impossible to miss them with their splendid, brilliant black and yellow markings and large size - from 9-12mm.

digger wasp Ectemnius lapidarius f

digger wasp landing Ectemnius lapidarius f

August 17th 2018. It is a while since I last reported. An almost complete dearth of insects is responsible for that. Rain has come and gone, so plants look better, their leaves perking up once more, but few insects appeared to take advantage of the improved conditions. Indeed, the logs outside the study have shown next to no signs of life now that the leafcutter bees have completed much of their cycle. Today, a small group of us met at Chudleigh Knighton Heath, west of Exeter, off the A38. We had an excellent visit last year and decided to follow up at a different period. More particularly, we hoped to check the extremely rare ant Formica exsecta, and see if it was still in existence in the reserve? This ant has been present on the heath for many, many years but has been lost in other locations, where it had flourished previously. It seems it remains isolated, but relatively abundant here in this small patch of Devon, though the habitat looks no different to many others both in and out of the county. We found a small group of workers in lightly-shaded woodland within minutes of arriving, then watched a single worker for some while as it explored a bramble plant with great thoroughness. (This identification turned out to be incorrect. Although initial checks indicated F. exsecta, the back of the head appearing to be slightly concave, careful checks on the photos later showed that all the insects we saw and photographed were in fact F. canicularia, a much commoner ant).

ant Formica cunicularia w

ant Formica cunicularia w

ant Formica cunicularia w

F. cunicularia is virtually hairless on the alitrunk, has only a gentlly incised head; while the petiole scale has convex sides and is plump. F. exsecta has a deeply-incised head, an obvious few hairs on the alitrunk and hairy eyes - difficult to see. The petiole scale is constricted and thin at the top. My picture, taken many years ago, shows F. exsecta, illustrating some of the problems when jumping to conclusions out in the field. The two magenta lines point to the petiole scale and the obviously incised head

ant Formica exsecta w

Rose, John and I turned up, though more had been expected for this visit. We had hoped that Margaret was on her way, but sadly she felt unwell and had to cry off, as she had at Steart earlier. Rose did actually come on to Steart that day, but somehow we missed each other, though we must have been in the same location at much the same time. It appears she came across the same colony of small leafcutter bees we had spotted. Today's visit, while most enjoyable, confirmed our general impression of there being few insects around - as at home. Perhaps the most vivid confirmation of this came when we sat down and had our lunch in a field with some young bullocks - Devon reds naturally. These splendid creatures had not a fly around them, while their tails rarely twitched. Each bullock would normally be surrounded by a cloud of them at this time of year, the cattle constantly swishing their tails and twitching their skin to throw them off. Apart from the occasional Eristalis, the only other hoverflies were very small specimens of Sphaerophoria, one of which gave every appearance of being one of the less well-known species. We also spotted a conehead hiding behind a grass-stem, the first I have come across this year.

hoverfly Sphaerophoria batava f

Long-winged conehead Conocephalus discolor

Even in a situation like this, there is always a chance of coming across something interesting. We noticed a couple of perfectly circular small holes in a bare patch of sandy soil. These looked interesting, so I decided to put down my stool and watch them while the others went on. With a bit of wriggling, I fixed a position where the lens could concentrate on one of the holes. After some while, I realised that the hole looked different. It had gone a different colour, something was blocking it, though no detail could be recognised. It looked as if a plug had been forced upwards, level with the outside. Photographs were taken, blown up on the screen and It became clearer. The apparent blockage was the mouthpart and jaws of a Green tiger beetle larva, surrounding a sand-coloured centre, waiting to snap on anything that walked over the hole. I had read about this and searched for them in the past, without success. Now here it was, a piece of normally unseen natural history.

Green tiger-beetle Cicindela campestris larva

After a while the dark centre of the other hole changed to sand-colour also, the hole all but vanishing - another tiger beetle larva in waiting. Both were wary of any movement, darting back out of sight immediately. This find was a real bonus; well worth watching.

Green tiger-beetle Cicindela campestris larva

But that really was nearly all the excitement. My final sighting was a digger wasp searching the only bramble flower still open, all the rest had turned into dried-up, rather unappetising blackberries. A Common wasp was photographed tucking into some ripe fruit nearby. This summer, social wasps have been much in evidence after several years when they have rarely been present at home or elsewhere in the country.

mining bee Lasioglossum calceatum f

social wasp Vespula vulgaris w

Earlier, I saw a very occasional bumblebee and that was it. Enjoyable; but where were the insects?

August 7th 2018. The Somerset Invertebrate gathering was once more at the Langford Heathfield reserve close to Langford Budville. It was so good last year we thought another meeting at a different time would be worthwhile. John, Ron, Chris and I met at 11am by the layby on yet another fine, warm day, not as boiling hot as the previous few weeks. The countryside is still parched of rain but the further we drove towards the Devon border, the greener the grass, The reserve is very varied in habitat and seemed to have survived the worst of the drought, leaving some interesting habitat in good order. While the woods themselves may be of particular interest to beetle specialists, we found our enjoyment lay in the 'edges', following the main  path through this long narrow area. Most visible insects are generally to be found on the borders edging woodland and path. The immediate impression, as you plunge in through a tiny break in thick foliage is rather depressing, dark gloomy, bare; scrubby areas with trees crowding in around. First impressions were made worse when we emerged into the sunlight and the open area we remembered previously was smothered in bracken, with little life to be seen, though we had our first glimpse of a Silver-washed fritillary Argynnis paphia as well as the inevitable little hoppers. Luckily the next part opened into conditions such as we remembered so fondly. The grass was fairly low, open and not too thick, interspersed with a deal of flowering plants, particularly the essential Hardheads Centaurea nigra, loved by so many insects. We spent a deal of time looking round this area, finding much to observe and photograph. John demonstrated how sharp his eyes were, in pointing out interesting plants and insects and, even better, giving a running commentary to those of us who were finding plants with which they were not familiar. A great deal of the enjoyment of these gatherings lies in learning from each other, a process which continues, particularly over lunch. Bumblebees were found in good numbers here, though many Bombus pascuorum workers were really small, obviously victims of poor feeding in the larval stage. A variety of species were present, including B. terrestris, B. lapidarius, B. pratorum, together with numbers of cuckoo bumblebees, including B. bohemicus and B. vestalis.

bumblebee Bombus pascuorum w

bumblebee Bombus lapidarius m

bumblebee Bombus terrestris 

A few small mining bees turned out to be Lasioglossum, mostly feeding in the smaller yellow flowers, burrowing deep in the centres, smothered in pollen. Later we found a few Andrena flavipes, on the larger flowers. I was disappointed there were so few solitary bees in such perfect conditions, perhaps we were a little early for late summer broods?

mining bee Lasioglossum zonulum 

On our return through the same area in the afternoon, we found a few digger wasps had appeared. It is always good to pick out their black and gold colouring, so dramatic against the duller green and brown. Both Ectemnius lapidarius and E. continuus were observed

digger wasp Ectemnius lapidarius f

The really noticeable butterfly of this part was the Common blue Polyommatus icarus, such a cheerful colour. All were in very good condition, pointing to newly-emerged insects. The others spotted one ot two Brown arguses Aricia artaxerxes, Small heath Coenonympha pamphilus, Speckled wood Pararge aegeria, which complimented the bright colouring of more Silver-washed fritillaries. Hoverflies were less visible than I had hoped, but there were numbers of Sphaerophoria, as well as a selection of Eristalis species. One interesting find was the little picture-winged gall fly Urophora quadrifasciatus in a Hardhead, so colourful. It is not uncommon, but fascinating to watch as it flicks its zig-zag marked wings.

picture-winged gall fly Urophora quadrifasciatus f

picture-winged gall fly Urophora quadrifasciatus f

I could not but photograph another striking, though very common fly, as it posed beautifully, side-on. Most of us dismiss flies as creatures that irritate, while even entomologists often resist trying to identify them unless they are specialists, as many are so difficult. But there are numbers of colourful flies that ought to catch the eye of the photographer.

calliphorid fly Sarcophaga carnaria f

Everyone was intrigued by a small ichneumon which flew from flower to flower, searching, with its ovipositor thrust down, thinner than a hair, while its ovipositor sheaths stuck up held out of the way. They are fascinating insects to watch, restless and hard-working, twisting and turning to exert the right amount of pressure. How do they manage to keep the ovipositor straight so as to achieve this without buckling under the strain? One of the pictures, while not perfect, does show the ovipositor itself as it emerges from the pair of sheaths. Even the ovipositor is in fact a pair of perfectly-fitting components, designed to drill into hard surfaces by sawing the tips.

ichneumon spp. drilling for prey f

ichneumon spp. showing ovipositor and sheaths f

The next stage took us along a path provided with a splendid wooden walkway over much of its length, with interesting patches of shrub and vegetation along the sides. The more open aspects held numbers of Meadow grasshoppers, virtually the only species of grasshopper we have come across in recent visits. the only other members of this family were Dark bush-crickets emerging later in the afternoon.

Meadow grasshopper  Chorthippus parallelus

Dark bush-cricket Pholidoptera griseoaptera f

Last year, we found Hornets in the woodland edges,. We were pleased to see a few again on this occasion. One was sucking at a tiny sap-stream on an ash sapling, another catching some creature, then consuming it while hanging under a leaf, in an odd hunched-up position.

Hornet Vespa crabro w

Hornet Vespa crabro w

We came across a Tenthredo sawfly, so easily confused with a digger wasp, another was one of the dark sawflies, so tricky to identify. A pair of sharp eyes spotted a crab-spider holding its legs wide apart, hoping to catch some passing insect. Set against the flower head, it looked like some mythical creature praying for salvation.

Crab-spider Misumena vatia f

But, perhaps the best moments came on our way back. Ron was ahead of us, looking at something below, when we caught up with him. We had been hoping for a sight of lizards following the previous visit, when we found them enjoying the heat on a dead tree-stump. This was now covered in foliage, but lizards were using the walkway to sunbathe in the heat. In fact there was a family of mother and babies. The latter were really active, popping up from below, appearing and reappearing - great entertainment - a fitting end to an excellent visit.

Viviparous lizard Lacerta vivipara adult

young Viviparous lizard Lacerta vivipara

August 4th 2018. From any point of view, this year has been dominated by the ‘great drought’, following on from our rain-soaked winter. It has certainly dominated everything we have thought and done. As the garden has dried out and baked, our stock of insects has gradually disappeared, now almost nothing moves. Flowers appear and vanish at high speed in the heat  - we have recorded 33° on several occasions, while 28° at the end of the afternoon has become the norm, not just for a few days, but weeks on end. Our poor ancient dog has been flattened, as have I. During the last week or so, leafcutter bees have made an appearance at my drilled logs, after a long absence from members of the insect world. This time of year ought to bring a hive of activity at the logs. My favourite large yellow daisy plant, one of the great insect attractants, usually full of leafcutters of several species, has seen only one so far. Eventually we will be faced with floods and storms as the great heat ends and all will either be swept away or flourish once more, but of one thing I am convinced – it is getting hotter; both insects and ourselves are going to have to get used to similar conditions in summer. Outside, here on the Levels, it does not look so bad. Grass is green, unlike other areas without our high water-table, but flowers are largely absent and birds are in short supply. It is some while since I took my camara with me when walking the dog - not to be contemplated normally. It is implied wisdom that insects welcome sunshine and heat regardless – the hotter the better. This year, it not so. Any insect life appears when it is cooler, in the earlier part of the morning or, more particularly, as the direct sun moves off the flower-bed or logs, vanishing during the heat. It appears that our insects are as ‘British’ as we are, not enjoying the heat as much as we thought we did. How many people confess to wishing it would all go away and the rain arrive at last? It will be interesting to see what happens in years ahead.


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