Wednesday, 19 December 2012

Amazon & Wildguide: Britain's Hoverflies

I have heard from various people that their Amazon order for the WILDGuide has been cancelled. I have investigated with our publishers and they don't understand what is going on either. They suggest that the likely reason is that there have been several delays and that as a result Amazon may have a process that kicks in to cancel orders. But, in truth we just don't know why this is.

As an update, Rob Still, the designer is expecting to receive page proofs in the near future. Assuming they are ok, then the button will be pressed and the presses will roll. After that it is an agonising wait for the container to reach the UK and then  for the books to reach distributors (including me!).

So, whilst the book won't be in Christmas stockings this year, it can be expected to accompany your Easter Eggs - just in time for the new field season.

Happy Christmas everybody!

Wednesday, 12 December 2012

Dipterists Forum Summer Field meeting 2013

It has been quite a challenge finding accommodation for next summer's field meeting. I have finally reached a solution with a venue based at Lancaster University that I hope will be OK.  We will be in self-catering accommodation, which is a bit of a departure from recent years.  However, my feeling is that it should be a good venue and that we will have a great time.

What I am struck by is the note I got back from Peter Chandler who reminded me that this next summer would be the 40th anniversary of the first field meeting. That calls for a celebration I think! It is hard to imagine that the field meetings started so many years ago and that several members still attend meetings!

My first meeting was in 1985 when a group visited Charterhouse in Somerset. As my memory serves me, the cook failed to turn up and Jane Stubbs and Christine McLean took on the role of cooks. My goodness how we owe them for that effort. It was a bit of an ordeal for me as a relative novice surrounded by people with lots of experience and including several (lots) of well-known 'names'. I only stayed for three nights I think, and during that time I made several lifelong friends - Roy Crossley, Mike Pugh, and Austin Brackenbury immediately spring to mind because they were so friendly and welcoming.

Today, the composition of the group has changed but I like to think that its general behaviour is much the same. If you are a novice you will be welcomed and embraced in a group rather than being left to fend for yourself. It is anything but elitist and many of us remember our first trip as novices surrounded by much more experienced Dipterists. We remain very egalitarian and welcoming.  The meetings were originally devised as a means of both training and square-bashing. These days we are far less avid square-bashers and far more avid proponents for developing people's interests. If there is a pub, we will even find time to go there! Speaking personally, all I want to see is people having a great time and looking forward to next year's meeting with old friends. My test for a meeting is to hear people saying - 'see you next year'.

Now, of course, that raises the question of whether it is an 'old' group? It is not. Last year in Scotland we had members aged 25 to 70+ attending. But nobody is old or young - it is just a group of friends on holiday. Ken Merrifield describes it as 'Alan's Holiday Club' - and he is not far wrong. Having said that, I must comment that there are times on DF meetings when it seems like 'last of the summer wine'. Who knows which bog Malcolm will fall into? And it is not just Malcolm - I have been known to end up sitting in a river with my haul of flies drowned rather than asphyxiated!

Forum field meetings are open to all entomologists who want to visit interesting places, although as a rule we tend to be better suited to daylight hours rather than those who favour the night and scaly jobs!

Come and join us. We will be in Lancaster from 6-13 July 2013 assuming all goes well.

A favourite photo of mine - Eric Philp and Stuart Ball bird-watching at Martins Haven, Pembrokeshire - who said we have to look at flies?
A retreat into Rob Wolton's barn during the Forum visit to Devon in 2011. It rained that day!

Saturday, 8 December 2012

Hoverfly Wildguide - it is at the printers!

I got a call from Stuart this morning (well actually yesterday morning if one is pedantic). He had spotted a quite significant glitch in the book after it had gone to the printers! A quick mail to Rob Still with the bad news. Oh goodness we hope this can be corrected and the printers are not too quick off the mark.

A couple of hours later and a further call from Stuart - apparently Rob had spotted the problem and had corrected it before he sent the book to the printers. Relief!

Well, it has been a long process but we really have got to the end of what we can do. Once the book arrives I have a fair block of work sending out pre-publication copies to the 120 or so people who took up the Dipterists Forum offer we made so very long ago - was this early 2011??? I think those that took up the offer will actually have done pretty well because the book is around 20% bigger than when it was advertised, and it is also RRP £24.95 as opposed to £17.95.

I look forward to seeing the finished result. It seems very strange to not having the job hanging over us and this gives us space to get on with new jobs.  We have still to prepare the supplement to Stubbs & Falk that we planned for this winter - I will get on with drafting this over Christmas so that Stuart and Alan have something to work on. The other job we need to do is to finalise the Species Status Review that has been sitting awaiting publication. This will be published in Pdf form rather than hard copy, but I think DF may arrange to print a number through Print on Demand and make them available at a reasonable rate. So, it would be useful to know if readers would want a cpy?

Friday, 7 December 2012

Hoverfly Wildguide

Well, we have got as far as is practicable. The book is finished and we must wait to see what it finally looks like. I think it will be fine and hope that readers think it worth the money. Examples of past pages are provided on previous pages.

Take a look - I think it will be excellent

Arrival date - sometime in March - probably towards the latter end


Sunday, 2 December 2012

Wildguide - nearly there

There has been pretty frenetic activity this last week and it looks very much as though we will have the book finished in a few days time. It has now been through the proof reader who spotted very few glaring errors. We remain in trepidation that we have inserted a wrongly identified fly!

Anyway, here are a few illustrations of the species pages just to give a taster of what it will look like. As you can see we have done our best to illustrate features that cause people problems!




Hoverfly course in South London

Stuart and I will be running one our very successful two-day training courses in Whitelands College, University of Roehampton on Saturday 12 and Sunday 13 January. There are at least four spaces to be filled and so anybody who is an absolute novice and wants to get to grips with hoverfly identification is welcome to book a place. More details will be supplied closer to the time for those who have booked.

We think the costs will be around £10-15 per head but I've yet to finalise this. It is a bit cheaper than normal because London is a short distance from Peterborough and we will be able to use my mother's home as a base - thus minimising accommodation costs. Anybody wanting to attend should let me know at roger dot morris at Pipex dot com - I will put you in contact with the organiser Amanda Morgan.
Hoverfly identification course run at Yarner Wood near Exeter in March 2012

 Programme

Our approach is to run courses in the winter months using specimens that have been collected specially for this purpose. The species we tend to use are those common ones that you are most likely to see. We have found this to be a far more satisfactory approach than running courses during the summer and relying on specimens caught by students. We usually do a weekend course – timing generally to suit the venue:

Morning 1 Start around 9.30

  •  Introductory talk - the Syrphidae (lasts about 2 hours)
  • Talked-through run through the key to Tribes - this usually takes up the final bit of the morning.

 Afternoon 1 end around 5pm

  •  Pupils work through specimens - taking a wide number through the key to tribes (duration depends upon ability of the group)
  • Variable - may do a talked through run at keys to species (dependent upon ability of the group).

 Morning 2 start 9.30

  •   Talked through run at keys to species /pupils run specimens to species
  • Session stops at various points to explain features e.g. wing venation
  • Talk on preparing specimens etc.

Afternoon 2 end around 4 pm

  • Talk on 'finding hoverflies'
  • Further specimen ID
  • Talk on the Recording scheme etc.

The programme tends to be a bit fluid to take account of abilities and the need to give people a break from microscopy. We bring all ID materials etc plus as many copies of Stubbs & Falk as possible - pupils should bring their own if they have them. We take breaks for tea/coffee as appropriate.

We will provide:

  •  12 Microscopes
  • 12 Sets of course literature (charged at £6.00 per person)
  • All specimens & broader collection
  • Powerpoint presentations - we usually bring a computer

What the organisers need to provide 


  • Venue
  • Sufficient bench space for 12 students – layout ideally in a standard classroom format.
  • Powerpoint projector & screen (if advised in advance we can provide a projector)
  • Tea/Coffee facilities

Please note we can only accommodate 12 students as the specimens we carry are only sufficient for this size group and we will only have sufficient microscopes for such a group.

 Costs etc - we charge for:


Fuel, tolls etc
At cost
Overnight accommodation
Work on £70-80 per night for a twin room + £30 per day for subsistence = £220
Cost of course handouts - a new version of the key to tribes in colour + a package of additional information
£6 per set per person - with a class of 12 (max) this would be £72

So, we reckon the costs for a single weekend are in the order of £350 for venues within a 250 mile radius of Peterborough. Of course that depends upon fuel costs and guest houses. We will travel as required, but clearly more remote venues may cost a bit more, especially if they involve a very long journey on the Sunday.

What usually happens is that the organising venue charges pupils at a suitable rate - usually around £30 per head. If groups decide to charge to make a profit we usually ask for a donation to Dipterists Forum.

Saturday, 1 December 2012

Developing local hoverfly groups

Stuart and I spent today with a group of hoverfly enthusiasts from Northamtonshire - part of the Northants Diptera Group. It was great to see seven people who had specimens to have checked and wanted to get a better understanding of tricky genera - Platycheirus and Cheilosia.

What is very apparent is that a combination of factors are needed to get a group mobilised and enthused. The influence of the local Wildlife Trust's continuing interest in training is very apparent. They have several venues where courses can be run, and also have microscopes available. Perhaps other Trusts could consider doing the same?

However, the biggest factor is that one person (John Showers who is Dipterists Forum's Membership Secretary) has organised field meetings and has given the group clear leadership. It would be great to see other groups doing the same. A similar level of interest has been developed in Shropshire through the Field Studies Council's 'Invertebrate Challenge' at Preston Montford. This sort of investment will hopefully yield long-term benefits with new active recorders in formerly poorly recorded counties.

We are keen to play our part. We are always happy to run courses for novices and can also run follow-up meetings if called upon to do so. We can supply most if not all of the necessary equipment but need a local organiser to handle the venue and take bookings. As I have previously blogged - our approach is to charge the basic costs and no more - a two-day weekend course usually works out in the region £300-£350 depending on the distance from Peterborough and the local cost of guest house accommodation. Does anybody fancy developing a hoverfly group in their area? If so, let us know and we will see what we can do to help move it forward.

Monday, 26 November 2012

Basic microscopes for novices

I noticed today that there was a question about suppliers of basic microscopes for novices wishing to start recording hoverflies (or for that matter other insects). I've posted a reply there but then reflected that it might make a useful subject for this blog.

Stuart Ball and I have bought micropscopes on two occasions in the past couple of years.  The first time we did this was facilitated by an OPAL grant - we bought a zoom microscope together with an optical camera and software for use on our hoverfly training courses. The following year we bought 13 basic microscopes which we use to run courses at venues where microscopes are not available. These too were funded through an OPAL grant.

In both cases we went to GX Optical near Cambridge
http://www.gxoptical.com/html/gxm_stereo_microscopes.html#c2d">Stereo

The model we bought was fairly basic and cost around £250 without a light. We chose not to have a fixed light as fixed lights can get a bit hot and will fry the entomologist and the subject-matter. Instead we use a goose-necked lamp from Homebase - about £6.00. A setup like this will not give you Leitz quality but it is pretty adequate for the basics. The camera is also pretty good and is certainly suitable for what we want to do. The combination of camera microscope and teaching kit has been a huge success and we are indebted to OPAL for the finance that made their purchase possible.

Our contact at GX Optical is Bob Town who is absolutely excellent - really helpful and willing to look at the options needed to provided the microscope you need. Do tell Bob that you come with our recommendation as we are very happy to endorse their microscopes.


uffolk CB9 9AF

Friday, 16 November 2012

Wildguide update

Fear not! The WILDGuide is progressing towards its trip to China for printing. Stuart and I have spent several more evenings sorting out further issues and preparing additional inserts. The end result will be pretty spectacular and we hope that it will act as a real stimulus to hoverfly recording.

I've had quite a few enquiries recently as to the book's progress so I thought it was probably about time we put some illustrations out that showed what it will look like. The following images are therefore a taster of what the introductory sections of the book will look like. It is packed with all sorts of information that is not in Stubbs & Falk, and will really be a genuine improvement to the literature. As I have previously commented, our aim has been to cover all of the genera and a selection of species rather than the entire fauna. Producing something comprehensive would be too big a job and would really require very different treatment.  However, a combination of our book and the keys in Stubbs & Falk should make the hoverflies a great deal easier to identify.

Readers who have done our hoverfly course will recognise this page! We have made regular use of the material prepared for the training courses we run, but have added further information.
Some of the stories about the last thirty years efforts to find hoverflies are illustrative of the advances that have happened since Stubbs & Falk was first published. It will be interesting to see what happens as a result of this book.
Although we have not specifically created conventional keys, the introductory sections have been designed along the general concept of a key. We shot nearly 200 specially prepared photographs of specimens to show characters that are described by line drawings in Stubbs & Falk. These follow the experience we have gained in teaching hoverfly identification.
We are indebted to a large number of photographers who have supplied the fabulous photographs that pack this book.
The work of preparing this book has been a huge job and it would be extremely difficult to distribute royalties in any meaningful way. The photographers who have contributed to the book will each receive a complimentary copy. We have asked that Royalties will go to Dipterists Forum and we hope that they will be used to support initiatives to increase participation in Diptera recording.

The training roadshow is currently under-way. Last weekend we went to Bristol Museum. In two weeks time we will be doing a session for the Bedfordshire, Cambridgeshire and Northamptonshire Wildlife Trust. In the New Year we will be going to Carlisle and to London, and are in the process of finding a date to run an improvers class (possibly at Cardiff Museum).

Must dash - let me know what you think of the book.

Wednesday, 31 October 2012

Helophilus trivittatus in 2012

2012 must surely go down as one of the oddest since detailed hoverfly recording started. It was spectacular because of its poor showing of many species, but there were high points. What was especially noticeable was the large numbers of eristalines seen at many localities. In some cases hogweed flowers were back to the state they were in during the 1980s - or at least they were in terms of Eristalis!

One species, Helophilus trivittatus, has occurred in exceptional numbers. It is a big brightly coloured hoverfly that obviously attracts attention from photographers as can be seen in Figure 1. The simple numbers in Figure 1 suggest a huge rise in numbers of records, but 2012 has also been an exceptional year for photographic records in which the level of recording grew by 33% in this one year. So, Figure 2, which shows the proportion of each year's records since 2004 is more representative.

Figure 1. Numbers of photographic records of Helophilus trivittatus from 2004 to 2012



Figure 2. The proportion of photographs of Helophilus trivittatus in each year from 2004 to 2012

Tuesday, 30 October 2012

Recording scheme updates

We are starting to get this year's data arriving.  It is great to see new blocks of information and the chages they make to the dataset. What did strike me today when checking the coverage maps was just how good coverage in England is getting. Sadly, the further north one goes, the weaker coverage is.

Take a look at the map - Stuart updated it on Sunday and will doubtless do so again when the next blocks of data arrive.

http://www.hoverfly.org.uk/portal.php?id=2&scol=HFF0000&bkgrd=1&ecol=H0000FF&page=4

The urban environment as a habitat for deadwood hoverflies



A recent record of a Callicera from the middle of South Woodham Ferrers reminded me of a long-lingering hobbyhorse. We pay remarkably little attention to trees in our streets and parks, and yet they must be ideal for many deadwood hoverflies. After all, many are regularly pollarded and this must create the conditions needed for rot holes. Other forms of damage will induce sap runs (Horse Chestnuts are especially prone to bacterial cankers and sap runs) and perhaps also decaying roots.

The presence of Callicera in various places, including suburban Wolverhampton, shows how rot holes can be important. There are records of Mallota cimbiciformis from central London parks and plenty of records of that ubiquitous urban species Myathropa florea.

It seems to me that there is therefore a strong case for research into the frequency of rot holes in urban trees and for an investigation into what uses these holes. Perhaps it is time for the conservation agencies to commission such studies? Maybe it could be done as a big ‘citizen science’ project? Whichever means is used, it seems to me that there is a need to develop thinking about the saproxylic biodiversity value of urban trees and to raise awareness amongst tree officers in Local Authorities.

Monday, 29 October 2012

Photographic records - some further analysis

As the winter races towards us the numbers of hoverfly photographs being posted on the web has greatly reduced. In mid summer I can spend as much as two hours a day extracting data. Today it took me ten minutes! And, for my troubles there were no new hovers but a couple of other fly families. I shall hopefully write the exercise up in detail for a peer-reviewed journal later this winter, but it is worth sharing ideas at a much earlier stage.

The number of records secured from websites and occasional records sent as photos by e-mail has just passed 10,000 and the number for 2012 has exceeded 3,000. The graph (Figure 1) tells an amazing story of how photo-recording has taken off. The rate of change is phenomenal, but what it does not show is the numbers of records that later come in from people who now maintain a separate record of what they see and send me a spreadsheet.  There are several people who now do this, so I don't need to extract their photo-data. Thus, there is a gradual transition from photo recorder to active recording scheme contributor. At least five people have made this transition and they now contribute significant numbers of records each year.
Figure 1. Numbers of records gathered from photographic websites over the period to October 29 2012.

Gaining a new active recorder is a great boost to the scheme and this can be exceptionally valuable when they make a note of everything they see. So much more can be done with big datasets and it is the relatively widespread or abundant species that are often useful for analysis of issues such as responses to climate change. Of course there are exceptions as I have previously shown with Volucella, but species such as Epistrophe eligans, Leucozona lucorum and Rhingia campestris all tell important stories about responses to environmental variables. That reminds me that Stuart and I really need to write up some of these formally!

As I highlighted the other day, photo recorders can occasionally turn up exceptionally important records and so I am keen to encourage new participants.  That is not to say that everything can be identified, but even if a confirmed ID cannot be given, the hint of a rare species' presence may be sufficient to get somebody to take a closer look at an area.

It is quite staggering just how many people do take photographs of wildlife and put them on the Web. ISpot has been exceptionally successful, but I find Flickr a very useful source too. My great regret is that around 50% of photos still have no details of where and when they were seen. So, if you take photos and place them on Flickr do put some data with them. Geotagging is great as I can usually find a 6-figure grid reference from this but even the name of the place is often enough to get a ten kilometre or one kilometre grid reference.

Figure 2. Numbers of recorders and the numbers of phot-records. One person has generated 1000+ records and one just over two hundred.
Relatively few people regularly photograph hoverflies as can be seen from Figure 2. But a few are amazingly prolific. I'm always delighted when I find a new active photographer but these days that is quite rare because I have spent so much time syrphing the net this year.

This graph shows how a relatively small minority regularly photograph hoverflies but that minority has made a very substantial contribution to the overall dataset. This is little different from the main data reaching the Recording Scheme where just 21 people contributed 50% of the data that was used in the last atlas.

Sunday, 28 October 2012

Ash dieback

Publicity concerning Ash dieback has achieved remarkable proportions in a very short space of time. And yet why did it not figure three years ago? Had there been a ban on imports three years ago when the problem became apparent maybe we would not have the problem that is faced today? As it stands, the picture looks bleak and we face the loss of a major part of our landscape and its ecology.

Still, what is done is done. We have got to find a solution. There are obvious implications as Ash is a major element of the landscape. As I drove down to Long Crendon yesterday I found myself scanning the landscape for Ash trees. On the limestone this is really a very important tree both in a landscape and a broader ecological context. Ash woodlands are commonplace on the limestone and many support very rich assemblages of saproxylic hoverflies. So we face a major crisis.

From a hoverfly perspective maybe the way forward is to develop a strategy to provide growing replacements before we loose the Ash? If  so, which species should we use? I am amazed to say that I wonder whether we should be looking at Sycamore? Obviously there is a case to be made against Sycamore but it offers some important advantages:
  • It is fast growing and appears to create dead wood situations similar to those that are offered by Ash.
  • It seems to support sap runs with similar properties to those of Ash.
  • The bark appears to have a pH that is favourable to many lichens.
  • It will grow in many of the locations that can be expected to be vacated by Ash.
  • It is not noted for its pests and is a vigorous, tough and fast growing species.
  • It supports good numbers of aphids and potentially rot hole and dead wood hoverflies.
I never thought I would end up as an advocate for Sycamore, having spent much of the 1980s trying to eliminate it from the woodlands of Mitcham Common! These days I am focused on eliminating invasive bramble from acid grasslands but there is a bigger picture to consider. There is a major conservation debate to be had and we have a lot to think about. Ash is so fundamental to our rural landscape and its ecology that there is an urgent need to do some thinking about how to respond to this crisis.

Saturday, 27 October 2012

Callicera spinolae

A recently posted photograph of a Callicera from South Woodham Ferrers caused me quite a lot of excitement.

 http://www.flickr.com/photos/rivercrouchwalker/8073739710/in/set-72157631737373239

Might it be C. spinolae? I suspected that it was as the date is right, but males are not easy to identify from photographs. I sent the link to Steve Falk who also felt this was the likely identity and posted accordingly.

Are we right? Take a look and see what you think - it will go into the Recording scheme with a slight level of caution attached. For me this is a good example of how a non-specialist can make a valuable observation - whether this is C. aurata or C. spinolae is somewhat immaterial as it shows how a rarely seen species can be picked up by casual observations.

Monday, 22 October 2012

Hoverfly training courses

For the past few years Stuart Ball and I have been running regular training courses in hoverfly identification. This year we are booked to run courses at Bristol, Carlisle, London (Roehampton) and Northamptonshire. We have a couple of other tentative bookings but might conceivably manage to schedule a further course if it is wanted.

The package we offer makes it relatively simple for a local Wildlife Trust or voluntary group to organise. We provide the microscopes, specimens, projection equipment etc. All the local organiser has to do is to find a venue capable of comfortably seating 12 people at microscopes.

We do make a charge for the course, but this is essentially to cover basic costs - fuel, overnight accommodation and food, plus the handouts. Assuming a venue within a 400 mile radius of Peterborough we usually manage to do the complete package for between £300 and £350, which if split amongst twelve people is around £30 per head.

The course is an introduction, but we are pretty confident that the majority of the class will be tackling hoverflies quite competently by the end of the weekend. Our approach is based on preserved specimens so it makes it possible to teach during the winter. We have found this to be the most effective way of getting people started.

Occassionally we go back the following year and run a more detailed weekend where people bring the material they have collected and get help with ID. Of course we also have our own material so they can have a go at tricky species.

It is a shame but we have not maintained a register of who has done our courses. This means that we don't have any measure of how well the traoining has impacted on contributions to the Recording Scheme. But there have been several very notable additions to the recorder effort. This is great because we have been trying to extend coverage into areas that are otherwise poorly recorded.

We are also in the process of developing a course that refines our 'Introduction to Diptera'. We have always felt there was something missing and so we are trying to assemble enough material to focus attention on the Brachycera - including Dolis and Empids, but starting with a key to families to make sure participants understand where the families fit in.

Do let me know if you are interested in running a course in your area.

Monday, 15 October 2012

Post field meeting reflections

This year's Autumn field meeting was far less productive than previous recent years. Unlike 2011, when we recorded over 200 species of fungus gnats, gnats were very scarce and we barely scraped past the 100 mark. Conversely, craneflies were a bit more abundant and we managed 58 species which is substantially up on recent years but still nowhere as good as lists for two decades ago. What has caused the change?
Forum members Andrew Halstead, John Bratton and Malcolm Smart
at Newborough Warren

The key point I think is that we visited many very suitable sites but the weather was much colder than in previous years. Many sites were west-facing and took most of the day to warm up, and by the time they were getting any sunshine the heat had gone out of the day. However, we cannot dismiss the effects of a very wet year which has had a detrimental impact on much of our insect fauna. Species that favour wet environments do seem to have fared better than in previous years, and Eristaline hoverflies have done comparatively well. There are slight indications that the recent downward trend in abundance of these species is being reversed, but we will really only know if the conditions persist and the fauna responds accordingly.

From a wider perspective it was extremely disappointing to see very few Heleomyzidae and Lauxanidae. Drosophilids were seemingly absent from many sites but we did manage six species of Platypezidae. All-told this was not the most inspiring of Autumn meetings but the company was good and our accommodation was pleasant. On this point I would happily recommend the Northwood Guest House in Rhos on Sea adjacent to Colwyn Bay and Llandudno. It was comfortable, our hosts David and Sandy were excellent, the breakfasts were excellent and we were made very welcome.

I am already planning 2013 meetings. At the moment we think it is time to explore Scotland in September, so a small group is likely to head north in early September. I will arrange a further four-day meeting in the south-east in October; as likely as not this will be based in Reigate, assuming we can make bookings.

My other remaining task is to sort out the venue for the Summer field meeting which I think will be in Lancaster. This is going to be a bit of an adventure because we will use self-catering accommodation at Lancaster University. This choice should bring the cost of the accommodation down to manageable levels for younger members so hopefully we will attract a new cohort of Dipterists from those who have attended recent courses.

Lunch at Newborough Warren - 
Malcolm Smart, Alan Stubbs (standing) Andrew Halstead and John Bratton.

Peter Chandler and Malcolm Smart taking advantage of a sunny spell after torrential rain.

Tuesday, 9 October 2012

Autumn Field Meeting - update

Today's weather was fantastic. One of those lovely autumn days with warm hazy sunshine. Where were the flies though?

We visited several very nice places but found remarkably few flies. That said, there were a few Platypezidae about and Peter Chandler took three species. Fungus gnats were very scarce, as were Heliomyzidae and Lauxaniidae. There were also very few hovers.

It looks as though the autumn is well and truly established in North Wales and that winter is rapidly setting in. That said, we are still only in early October but the water is jolly cold - I managed a partial dipping today bu losing my footing and falling into a muddy gully. I reckon I am at risk of becoming a liability!

Hoping for good weather tomorrow as we head off towards Colwyn Bay,

Monday, 8 October 2012

Autumn Field Meeting

Two days into the meeing and we are making good progress. It has been hard work though, especially as ever woodland seems to be full of brambles! Last year I described a woodland as a 'bramble patch with a few  trees sticking out of it'. This year the level of bramble infestation is lower but it is still very difficult to avoid shredding one's net!

Impressions so far:
  • Fungus gnats numbers are low. Samples are rather homogeneous  and  we have recorded a smaller number of species than at the same time last year.
  • Craneflies are in reasonable supply but there are relatively few Tipula species. So far, Limonia nubeculosa has been comparatively scarce.
  • There are very few Lauxaniidae - in fact virtually none!
  • Drosophilidae are very scarce. 
  • Heleomyzidae are in low numbers.
  • Hoverflies are scarce but about par for this time of year.
Our group is small but select: Alan Stubbs, Peter Chandler, Andrew Halstead, Malcolm Smart and  John Bratton plus of course yours-truly.

I had a narrow escape today whilst in pursuit of hovers on a patch of rank vegetation, falling  down a manhole whose cover had been removed. I was exceptionally lucky that I escaped with nothing worse than sitting on a few stinging nettles which duly exacted their revenge on me!

We are based in Menai Bridge for this part of the week. It is a place I knew only poorly when based in Bangor  30+ years ago.  Now, it seems positively excellent compared to Bangor; which seems to have few redeeming features. Why on earth did I live there for 3 years?

Friday, 5 October 2012

It is not too late to get out

The weekend approaches and there is still a chance of a hoverfly or two. A few are really dominant, most notably Eristalis tenax. There are plenty of places where this relatively abundant species has yet to be recorded, so a bit of effort may mean a new ten km square record (see map on HRS website for the gaps http://www.hoverfly.org.uk/portal.php?id=10959&scol=HFF0000&bkgrd=1&ecol=H0000FF&page=4). Sericomyia silentis also tends to visit ivy and may be seen occasionally at this time of year. Records are still arriving via ISpot.

October can be an extremely good month of Arctophila superbiens, which is mainly a northern and western species, but it does still occur in North Norfolk and it would be good to see more records from eastern England as well as from more western and northern localities.. This is a species that we think is likely to decline in southern regions as a consequence of climate change, so the more records we get the better its fortunes can be tracked. If it is a nice day, why not go on a quest for this hoverfly in October.

Finally, those in East Anglia should not forget the possibility of Callicera spinolae. It could turn up almost anywhere and has been found in urban parks, formal gardens and in woodlands. A peruse of the ivy patches is a worthy pursuit. But, beware, C. aurata can also fly late and is jolly similar.

As a general point it is worth noting that all records from this time of year are welcome. People tend to hang up the net and the notebook but there are flies to be seen. I noted seven species at a local ivy patch the other day and am hoping for lots of flies when we get to North Wales for Dipterists Forum's Autumn Field Meeting which starts tomorrow.


Wednesday, 3 October 2012

Ash dieback - a threat to Criorhina and other saproxylic hoverflies


A couple of days ago a friend drew my attention to an article in The Telegraph that highlighted the emerging risk of a new threat to Britain’s trees: Ash dieback caused by the fungus Chalara fraxinea. The story was deeply alarming, suggesting that it had swept across mainland Europe and was killing the majority of Ash trees that it affected.  In Denmark it is reported that 90% of trees are affected! Amazingly, despite the known problems with this pathogen, imports of trees from continental nurseries has yet to be stopped. This is despite known cases of infected trees reaching the UK via the nursery trade. At the moment all known cases involve trees whose health seems to have been monitored, allowing intervention to take place and infected stock to be destroyed. It can surely be just a matter of time before the disease takes a hold unless some urgent action is taken?

Although Ash does not immediately register in the lexicon of important trees for insects, it is actually of considerable interest, especially for the saproxylic diptera that are associated with rot holes and rotting stumps and roots. Woodlands on the borders of Lincolnshire and Northamptonshire are a good example. I never cease to be amazed at the numbers of all four of our Criorhina species in local woods. Two species really stand out: C. asilica and C. ranunculi; neither of which was very abundant in my former stomping ground in Surrey. In northern Northamptonshire they are really quite common and I would expect them to turn up in most long-established Ash woods. I was puzzled by this difference until I discussed it with Alan Stubbs who drew my attention to the key difference in the woodlands.  Those around Stamford support a high density of Ash, whereas in Surrey Oak is much more dominant.

This one small observation makes me very nervous about the future of Britain’s saproxylic hoverfly fauna. Not only would Ash dieback have devastating landscape implications; it would seriously affect one of our most important habitats. The critical issue is that of habitat continuity and in the case of saproxylics that has got to be a key consideration. It is no surprise that ancient woodlands are richer for saproxylics, as they represent the most constant supply of habitat.

What can be done? Probably not a lot, but there is a consultation on the risk assessment by FERA – see http://www.dardni.gov.uk/index/consultations/active-consultations/consultation-by-fera-on-ash-dieback.htm.

This apart, it seems to me that there is an obvious need for urgent measures to survey our Ash woods to determine their real importance for saproxylic invertebrates. This could form a large-scale citizen science project to evaluate Britain's woodlands for the threat Ash dieback poses to one element of our wildlife.