- a month of almost unremitting blue skies with little rain and soaring temperatures. On some days, we sweltered in temperatures in the high 20s.

Transcription

1 1 - a month of almost unremitting blue skies with little rain and soaring temperatures. On some days, we sweltered in temperatures in the high 20s. Above: Marbled Whites referred to in last month s Nature Notes continued in large numbers in Ashton Court Park until the middle of the month; I saw one passing through our garden and I encountered a few in Leigh Woods and Portbury Wharf Nature Reserve. Firstly, a little personal history. When, as a young teenager, I was living in Colchester, I was already a very active naturalist and in particular, a bird- watcher. When the Colchester and District Natural History Society was founded in 1953, I was one of the founder members and became a junior representative on the committee with a group of very distinguished naturalists. Among them was Tony Richardson who was an expert on aquatic life. Several of us were involved with clearing part of Distillary Pond, basing ourselves in the fine grounds of a nursing home called Scarletts. Some floating traps were made so that we could catch Moorhens and ring them. I was a bird- ringer in those days and catching Moorhens made a change from snaring huge numbers of Sand Martins and various thrushes in mist nets. Right: The fair haired youth rowing the small pint is me. Next to me is Neil Syer now deceased, and in the front photographing the Mute Swan is Tony Richardson.

2 2 Above: I demonstrate ringing a Moorhen for the press. In the middle wearing a cloth cap is the distinguished entomologist Joe Firmin, then Stanley Peck, Paddy Byrne, Neil Syer and Tony Richardson. We had many interesting field meetings and the adults in the society were a fund of knowledge from whom one tried to learn so much. Exhibitions were mounted in the newly formed Natural History Museum located in All Saints Church, where I used to sing in the choir and watch with fascination the organist at work. Tony Richardson and Paddy Byrne examine a specimen while I looked down a microscope at one of the exhibitions. Tony and I are now Vice- Presidents of the society and have long since left Essex. However, Tony has issued me with many invitations to go up and see his stamping grounds on the edge of Northampton and finally, I did so on the 3 rd of the month. So, here we are six decades later!

3 3 With the help of a few like- minded naturalists, Tony helps to manage Yardley Chase which is part of the vast Castle Ashby estate to the east of Northampton. Once used by the army, the chase is now a very fine wood mostly Oak, and a large number of ponds. We met a couple of Tony s friends, one of whom was Doug Goddard, and spent the morning looking for, among other species, Purple Emperor butterflies. By all accounts, it had been a very good year for them. Unfortunately, a brisk wind had got up in the night which made the woodland canopy a very lively place for flying butterflies! In the rides, where it was relatively calm, there was no shortage of Ringlets and Common Skippers (right). Meadow Brown (left) were also present. Doug regularly scanned the swaying upper foliage of the Oaks looking not only for the quick flying Purple Emperors but also for Purple Hairstreaks. The latter generally showed up as small silvery butterflies dodging around the canopy. Meanwhile on the edge of the drive, we watched a female Comma laying eggs on a Stinging Nettle.

4 4 Left: The Comma with the tip of her abdomen pressed against the nettle leaf as she deposits an egg. Right: The finely ribbed egg. Some of the tops of the nettles were tightly wrapped in silk. I had assumed that this might have been produced by a mass of small caterpillars of one of the butterflies, the larvae of which, feed on nettle foliage such as Small Tortoiseshells or Peacocks. However, I saw no evidence of caterpillars within these silken tents, but I did see spiders around them. I then twigged that they were spider nurseries. The spider was Pisaura possibly mirabilis. These are so- called wolf spiders which do not snare their prey in webs but hunt on the ground. The females can often be seen during the Summer carrying a ball of eggs on their abdomens. When they are about to hatch, the female attaches the package to a plant and weaves a protective tent around it so that the spiderlings are hidden from view. As an extra precaution, she stands guard. Right: The she- wolf guarding her nursery. She is apparently missing a couple of legs.

5 5 I noticed several of these pale bodied spiders on the nettles. Mark Pajak kindly identified it as a Candy- striped Spider (Enoplognatha sp.). It is a widespread member of the Therididae or comb- footed spiders. Left: The spider s eyes show up clearly as do the pair of fangs (chelicera). Hoverflies were few and far between. I was not even sure that this small shiny black fly was a Syrphid. When I checked the image I thought that it was one of the Cheilosia species. However, in the end, the yellow wing bases and the golden streaks ending in the yellow stigmas of this male pointed to Psilota anthracina, an uncommon hoverfly found in oakwoods in the Midlands, New Forest and Windsor Great Park. Another characteristic of this species is that, unlike other hoverflies, the there are no vena spurias or false wing veins. There are certainly none on this specimen. Our search for Purple Emperors produced a few very fleeting glimpses of individuals swiftly moving in and out of the oaks but nothing particularly satisfying. However, Doug did find a Wood White a delicate species that lives in small self contained colonies.

6 6 Left: A pretty fresh Small Tortoiseshell basking by a large pile of timber. On the way round, I was taken to some corrugated sheets which had been left to attract reptiles. As the sun beats down on them, it becomes very warm underneath and much to the liking of snakes and Slow- worms. Right: Under some, we drew a blank but one of them had a Slow- worm and a couple of Grass Snakes. Below: Neither a worm nor a snake, the Slow Worm is a legless lizard and far from slow when disturbed. This fine specimen slithered into the long grass very quickly when the corrugated iron sheet was lifted. We have seen 2-3 in our garden this year. We used to have many more but we suspect that they were predated possibly by a Badger that visited us nightly last Summer.

7 7 Above: The yellow neck band and absence of a zig- zag pattern down the body immediately distinguish Grass Snakes from an Adders. The tips of the forked tongue pick up scents in the air which are then perceived by the snake when the tongue is flicked into the mouth and the tips inserted into a sensory pit in the roof of the mouth called the vomero- nasal organ. It is the snake s method of smelling. Tony was very proud of his ponds and I wished to see some of his Damsels and Dragonflies. There are over a 100 in this part of the estate, many lined with Sallows. Purple Emperors lay their eggs on these plants and their larvae grow fat on the foliage. The army used to build ammunition stores in this wood and each one had a blast wall around it made by scooping earth and piling it up around the huts. Nowadays, these excavations are filled with water and make wonderful ponds brimming with wildlife. There were several kinds of Dragon and Damselflies that I hoped to see. Damsels were quite numerous hunting in the rides that we had been walking down.

8 8 Four- spotted Chasers (Libellula quadrimaculata) were by far the most numerous of the Dragonflies. Right: A Four- spot sitting on top of a stick projecting from one of the ponds with an empty pupal case below it. It probably belonged to a different individual. In fact, all of these predatory insects looking in wonderful condition, probably because they had only just emerged as adults from their larval bodies. Above: A female Four- spotted Chaser rests momentarily on a reed.

9 9 On one pond, we watched several Emperor Dragonflies (Anax imperator) hawking for small insects and possibly even Damselflies. They never settled and I attempted to obtain one decent in focus shot of one in flight. Their changes of direction are so random that following their flight paths was almost impossible. My best but very fuzzy photo is on the left. Here is a much better photo of a gorgeous male taken by my neighbour, Peter Kelly on his i- Phone at Ham Wall, on the Somerset Levels. The females have a greenish body. At the Yardley Chase, I spent some time trying to photograph a species that was new to me the Downy Emerald (Cordulia aenea). Left: Several of these dragonflies were seen but all were patrolling their beats and never landed. I managed to take a few very soft shots of one as it repeatedly passed me. There is just enough detail to see its metallic green body and eyes. Finally, we observed two of the smaller species; above is a Common Darter (Sympetrum striolatum).

10 10 Doug pointed out this Ruddy Darter (Sympetrum sanguineum) which has completely black legs. I did not manage to photograph it because it did not perch for long and so Doug kindly sent me his. Unfortunately, none of the Purple Hairstreaks came even remotely within range of my camera so Doug sent me a couple from his archive: above is a male with open wings, and on the left, a photo showing the silvery underside which you tend to see when viewing the flying high around the oaks. Luckily for me, Tony Richardson has had a lot of experience of Purple Emperors, and has even reared them in his house. To make up for my failure to photograph any on my visit, I am reproducing some images that he sent me all taken on film in On the right, is a female which does not show the purple iridescence of the male. After mating, the empress lays her eggs on Sallow.

11 11 When the eggs hatch, the tiny caterpillars hibernate during the winter, emerging to feed and fatten up before changing into a chrysalis. The caterpillars themselves have the appearance of slugs and are well camouflaged. Right: The chrysalis looking for all the world like a sallow leaf. Inside, the miracle of metamorphosis takes place where the tissue of the slug is transformed into an Emperor in all its glory. Below is a male showing its colours. The purple sheen is a structural colour caused by interference of light reflected off the scales. This powerful, charismatic butterfly has been much prized by Lepidopterists over the ages. Its habit of soaring and wheeling high above Oak woods makes it difficult to see properly as I discovered. However, the males do come down to take salts from faeces and puddles and even assemble on favourite trees where they are sometimes very approachable. Although widely collected in bygone days, the Purple Emperor seems to be doing well, and this year is a good one. Fermyn Wood in Northamptonshire is especially noted for this butterfly

12 12 Left: The underside of these butterflies is just as handsome as the top of the wings. I did see a flash of chestnut on a Purple Emperor that did descend into one of the rides that we were walking along. In all, it was an enjoyable day. In the hot dry conditions, blood- sucking Tabanid flies have been biting well, especially where the grass is long, The one below got stuck into me in Ashton Court Park on the 9 th, so I let her stay long enough so that I could photograph its wonderfully patterned eyes. It is a Cleg (Haematapota pluvialis) Above: pattern. A better view of the eye These flies find Sally or her blood especially tasty and if there are any biting insects around, they can be guaranteed to make a bee- line for her.

13 13 Left: Sally s left hand after she was bitten by a Cleg in our garden. People do vary in their reaction to the anti- coagulants that the flies inject into the skin to prevent the victims blood from clotting in the proboscis. It does not bear thinking about what one of the larger species would inflict on her. From the pointed shape of its abdomen, this big Horsefly (Tabanus bromus) photographed basking in our garden is a male and does not take blood. However, the hunting females are best avoided because their bite is painful. I know because one landed on my neck once! Note, the Cleg has variegated wings which are held like a roof over the body whereas this one has a typical fly resting posture and has transparent wings. Early in the month, I noticed a very small orb web on one of our Daturas (Brugmansias or Angel s Trumpets) that had been left outside. Although I expected to find a tiny Garden Spider hiding under one of the leaves, I discovered a small green spider in fact there were two. It was Arienella cucurbetina. This species is apparently our smallest orb web spinner and can be immediately recognized by the red spot near its spinners (see left the out of focus Poppy seed capsule gives an idea of the scale).

14 14 Subsequently, I found several elsewhere in the garden, and by coincidence, Nigel Simpson sent me a picture of one that he photographed on his land in Tydenham Chase (right). I wonder whether they have they been unusually numerous this year? Despite killing large numbers of Lilly Beetles, the larvae continue to munch into the foliage of Sally s Lillies. The plants continue to be littered with their droppings. However, a gardening magazine revealed something that I did not know about them. In fact, the larvae cover themselves with their own excreta as a form of camouflage. Beneath these glistening black turds is a pair of Lilly Beetle grubs. These are what is causing the damage to the leaves, not the scarlet adults. Left: A perky young Robin. Without his orange- red breast, it poses no threat to the adults because the species is fiercely territorial. The tits appear to have done well this year, judging by the number coming into our wall feeding station and bird bath in front of our kitchen window. This was taken on the 11 th.

15 15 Left and below: Poecilobothrus nobiliatus. The lily pads on the pond made good display grounds for these very small flies. In close up, they are rather splendid. Both of the specimens in the photos are males and they are characterized by possessing relatively enormous and bizarre penises. These are stowed away beneath the tips of their abdomens and can just be made out in the photos. The males joust and chase each other around and semaphore likely mates with their black and white wings. I attempted to capture this behaviour with my camera but failed to do so. A few Helophilus pendulus appeared around the pond but they were much smaller than usual this year. off prematurely. Jumping ahead to the 24 th of the month, a Common Hawker Dragonfly (Aeshna juncea) emerged from the pond but sadly, its wings had not inflated properly. When I first saw it, I thought that it was in the process of pumping its wings up. However some time later, it was in the same position and the wings were still crumpled. I noted that the right hand wings were in the sun and I wondered whether they had dried

16 16 I caught it in a pond net to see if there was anything that I could do but the wings were fully set. This is a close up of the amazing eyes of these aerial predators. They have a vast number of light receptors or ommatidia which gives them high definition vision. The wings of this attractive dragonfly were fully functional because it may well have flown across The English Channel. It is a Red- veined darter (Sympetrum fonscolombii) which briefly appeared in the garden on the 24 th. It is a frequent migrant to this country, breeding in southern Europe in shallow lakes and rice paddies. I do not recall ever having seen this species before.

17 17 Above: The stags of both the Red and Fallow Deer in Ashton Court Park tend to form bachelor groups outside the breeding season when the hinds are of no interest to them. The antlers are still in velvet and growing very fast. By the 11 th when these photos were taken, great swathes of grass had been cut in the park. However, stands of it had been left, thus preserving what wildlife it harboured. On the 12 th, I took to the air to take some aerial photographs of Leigh Woods to help The Leigh Woods Society make informed comments about planning issues, especially over Burwalls. Until recently owned by the University, it has now been sold for development. Above: Leigh Woods from over the harbour looking down the River Avon towards the Severn Estuary. The towpath along which Tony Cottrell walks daily can be clearly seen.

18 18 Above: Over Ashton Court Park s Red Deer enclosure. Above it is the golf course. The pale areas are where the grass has just been cut. The city stretches away to the right. I flew back to Doynton via Avonmouth and Filton, making a short diversion over Portbury Wharf Nature Reserve. Later in the morning, I walked around it. The visit was a little disappointing because I had hoped to find a good collection of Hoverflies and insects in general. A few Speckled Wood, a single Small Tortoiseshell and Gatekeeper Butterflies were present in the lane leading to the ponds.

19 19 Left: A Gatekeeper. Regarding Diptera, I noted the pilose Syrphid Cheilosa illustrata, and several Chrysogaster solstitialis (below). This little black hoverfly is easy to identify because of its large red eyes and smokey wings. This is a female with a comparatively wide frons separating the eyes. In the males, the eyes meet on top of the head. By one of the drains, some Ragworts were smothered in Cinnabar Moth caterpillars. The name is derived from the poisonous red mineral which is a source of mercury. Right: A Cinnabar Moth photo from the web. At all stages, they are toxic. The caterpillars take the distasteful alkaloids from the plants and incorporate them into their tissues. Their garish colouration advertises their unpleasant, if not poisonous properties. Only Cuckoos are not daunted by their looks because these birds are able to render the toxins harmless in their digestive system.

20 20 The caterpillars are apparently not averse to cannibalism if they have consumed all of the plants on which they are feeding. As they are voracious feeders, the moth has been introduced into various parts of the world in order to control Ragwort. Pastures covered with the yellow- flowered plants are useless for grazing because Ragwort is poisonous to cattle and horses, even when it is dried as in silage. Already, the very warm weather brought by The Spanish Plume was upon us. This tends to happen when the Jet Stream, the river of westerlies that marks the junction between warm air of tropical origin and cold air from the Arctic curves well to the north of Scotland. Hot air from North Africa and Spain is then drawn northwards to our latitude, bringing hot days and delightfully balmy evenings. Calm conditions stall the huge windmills at Avonmouth. Left: A female Leucozona laternaria. This hoverfly is very similar to L. glauca but the scutellum on the rear of the thorax is black but with a yellowish tip.

21 21 There was little of note on the ponds but this Pied Wagtail did conveniently perch on a post in front of the hide in which I sat for half an hour or so. Among the butterflies that I spotted, were a few Marbled Whites. Some garden observations are worth recording. Above: A large robber fly landed on our table while we were having lunch outside. It is a member of the Asilidae. These flies sit and wait and dart out to capture their flying usually other flies - when they come close enough. They have a strong proboscis which they use to stab their victims and their saliva contains a neurotoxic venom. Ray Barnett reckoned that this one might have been Machimus atricapillus. Sally cropped a small bed of mint and hiding behind them on a wall was a cluster of Daddy Longlegs Harvestmen. Formerly classified as Phalangids, they have now apparently referred to as Opiliones. Although often mistaken for spiders to which they are related, they are recognizably different.

22 22 The body is not divided into a distinct thorax and abdomen but both sections are fused into a cephalothorax (see left). Less obviously, there is only one pair of eyes rather than four pairs. The fabulously long legs are rich in sense organs enabling these predatory invertebrates to find their prey by touch. The flexibly jointed limbs then rapidly transfers the prey to the mouth where it is torn to pieces. On the 13 th, I discovered that one of the little green spiders (Arienella) that I referred to a few pages ago had constructed a cocoon which I presumed to contain eggs. This is illustrated in the photo on the right which I have cropped wide to include a very small aphid in the top left hand corner. This shows the scale. There were still two on the Datura but after I placed the plant outside for a short time to get some air, both of these tiny green spiders vanished.

23 23 A pair of Jays has been frequenting the garden and one of them has been attacking the apples. Although it has been dry with virtually no rain during the month, I cannot think that it is pecking the flesh for the moisture. I wonder whether it after the Codling Moth larvae. Despite the trap, quite a few of the apples seem to have been affected this year, especially the Bramleys and Peasegood Nonsuches. Whatever the reason, the Jay has destroyed quite a few which have been finished off by the Wasps. Right: Regarding the Codling Moth pheromone trap, I examined the sticky pad at the end of the month and was surprised that I had not caught more. The females are flightless and it is only the males which are equipped with wings so that they can search far and wide for a mate.

24 24 We were not the only ones beginning to swelter under the blazing sun! A young Blackbird sunning itself on one of our garden chairs. During the middle of the month, I paid a visit to Slimbridge to have a look at the flock of Greater Flamingos and their chicks. The Trust has a nice flock of this species and, apart from flying, all of the the bird s behaviour patterns can be seen at various times of the year. This year, in their new compound, they had produced over 30 youngsters and I was hoping to see some of them being fed. No such luck! Already the chicks were wandering around and there was an indication that they were beginning to form a creche.

25 25 The chicks were quite dispersed between the forest of legs but some had gathered into small groups. They had a long way to grow to reach adult size which they will do in just a few months. The chicks hatch with a much less decurved bill adapted to funnel regurgitated fluid food from the parents. This will ultimately develop into the characteristically hooked bill of the adult equipped with filters to strain crustaceans and algae from salt- rich lakes. The shape enables the adults to feed simply by dropping their long necks bringing the end of the bill into a horizontal position but pointing backwards.

26 26 Right: Baby bills! A pair of very young Greater Flamingos and below, a young Moorhen s bill is beginning to assume the dull immature pattern. I just missed a couple of Moorhens having a scrap. By the time I reacted, they were walking away from each other, their tails and wings raised in threat. This serves to show off their fanned tail with the outer feathers displayed as a V for victory perhaps or as and offensive threat. Some Black- headed Gulls were still had chocolate heads.

27 27 A walk in Leigh Woods at around this time revealed nothing much except a pretty freshly emerged Comma with nicely jagged wings. Down below Leigh Woods on the Avon Towpath, Tony Cottrell was having better luck on his daily walk. He sent me a large batch of his excellent photos of which I will only select a few. Left: Villa cingulate. This is not a Syrphid but a member of the Bombyliidae or bee flies. I found this species several years ago in Leigh Woods but had not seen one until this month when I spotted one in the garden which had disappeared by the time I got my camera. Left: The pretty Hoverfly with a very long name Xanthogramma pedissequum. Its dayglow yellow and black colouration is easy to miss because the fly tends to hang around near the ground. Its larvae feed on root aphids and found in ant s nests this it is sometimes referred to as the Superb- anthill Hoverfly.

28 28 Left: Another black and yellow species, Chrysotoxum bicinctum. This one has very long antennae for a Hoverfly. The two super Syrphids. On the Right: Volucella inanis... and on the left, Volucella zonaria. Both are Hornet mimics, the latter being the better one. Right: Epistrophe grossularia hovering. Tony obtained a couple of interesting species from other Diptera families.

29 29 Left: Conops quadrifasciatus which resembles a small Ichneumon Fly which is related to the bees and wasps. Right: Alophora hemiptera the name says it all. With their solid looking wings, they have the appearance of bugs. In fact, this is a parasitic fly and a member of the Tachinidae. Scarlet Tigermoths have apparently done very well this year. It is the hind wings which are bright red. It will come as no surprise that this showy daytime flying moth is very distasteful! And lastly, a male and female Common Blue Butterflies.

30 30 All of those photos were taken by Tony Cottrell. The one on the right was taken by John Burrell in his garden in Wembden, on the outskirts of Bridgwater. It is of an aberrant Ringlet Butterfly with a very pale right forewing. And this is another unusual one sent to me by Nigel Simpson in Tydenham Chase. Although hardly recognizable as such, it is a Silver- washed Fritillary but of the rare Valezina form. Below is Nigel s photo of a freshly emerged male for comparison. The dusky colouring of the dark form is controlled by a single gene which only finds expression in females. Apparently 5-15% of females are of the valezina type in larger colonies of this butterfly with the species main range. In the UK, it only occurs in the south. I also understand that males find these dusky females less attractive than the normal ones. Their behaviour is certainly different insofar as they tend to avoid bright sunlight, possibly because their dark colouration causes them to over- heat. THE END OF PART!