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#1 2011-03-16 20:14:57

jonM
Registered user
Name: Jon Mortin
Registered: 2009-03-09
Posts: 420

Tabanus bovinus

I identified this very battered specimen (a roadside casualty) as Tabanus bovinus (a male). Then I discovered T.bovinus is quite rare in the UK and it would be the first record on the BRERC (former county of Avon) database (although there is a specimen from Clevedon,North Somerset in Bristol Museum). This specimen was found in Cleeve, North Somerset. I have re-examined it but it still seems to key out as T.bovinus. It is about 18mm in length (but is missing the tip of its abdomen). Can anyone confirm my identification based on this photo?


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#2 2011-03-17 01:48:39

falky
Registered user
Name: Steven Falk
From: Kenilworth
Registered: 2009-11-30
Posts: 416

Re: Tabanus bovinus

Jon,

It is impossible to be certain from your image, but the size suggests it ought to be something in the sudeticus-bovinus area, and it is exceptionally orange for sudeticus and accords with the traditional concept of bovinus. However, I have been told that exceptionally pale sudeticus can occur. If Andrew Grayson is reading this, he may be able to advise more.

PS I'm at Oxford Museum on Friday where hopefully I'll be able to confirm whether my New Forest material of Hybomitra solstitialis is the real Mccoy (and seemingly the first British records for many years)

Falky

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#3 2011-03-17 01:56:40

Richard Dickson
DF Members
Name: Richard Dickson
Registered: 2008-11-24
Posts: 323

Re: Tabanus bovinus

I notice no-one is in a hurry to commit themselves! Isn't it embarassing that this spectacular flies can be so difficult! Is it possible to examine the eyes? With a x10 hand lens it is not difficult to see the two zones in the other very big species - T.sudeticus and T.autumnalis. The upper zone has larger facets. This is something different from eye-bands, which usually disappear after death. I notice your specimen has dark markings laterally on abominal terga 2 and 3, which Stubbs & Drake says T.bovinus should not have. I have certainly made too many mistakes with tabanids in the past to risk expressing an opinion, I'm afraid! Good luck. Richard.

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#4 2011-03-17 12:59:05

malcolmsmart
Committee
Name: Malcolm Smart
From: Wolverhampton
Registered: 2008-02-26
Posts: 395

Re: Tabanus bovinus

I don't have a specimen of T. bovinus for comparison but I have photographed the eyes of a male T. sudeticus showing the contrasting size eye facets to compare with your specimen. Hope this is of help.
Malcolm


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#5 2011-03-17 21:34:49

jonM
Registered user
Name: Jon Mortin
Registered: 2009-03-09
Posts: 420

Re: Tabanus bovinus

As far as I can tell the eye facets are all roughly the same size. Also sudeticus has never been recorded in our region. I have attempted to photograph the eye facets, but may have to submit this as a separate post.

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#6 2011-03-17 21:36:51

jonM
Registered user
Name: Jon Mortin
Registered: 2009-03-09
Posts: 420

Re: Tabanus bovinus

here is my photo, taken with a compact digital camera through the eyepiece of my binocular microscope!

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#7 2011-03-17 21:42:33

jonM
Registered user
Name: Jon Mortin
Registered: 2009-03-09
Posts: 420

Re: Tabanus bovinus

Although the facets seem to be the same size, my photo may not show this as the ones nearest the camera seem larger? (2nd attempt to upload...)

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#8 2011-03-17 21:52:25

jonM
Registered user
Name: Jon Mortin
Registered: 2009-03-09
Posts: 420

Re: Tabanus bovinus

3rd attempt to upload a reduced size file/image...


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#9 2011-03-18 01:06:35

malcolmsmart
Committee
Name: Malcolm Smart
From: Wolverhampton
Registered: 2008-02-26
Posts: 395

Re: Tabanus bovinus

It does indeed look interesting and worth following up. There's no point in messing around further with photographs. The current Tabanid specialist in UK is Andrew Grayson (who also leads the Oestridae study Group). I suggest that you consider sending your specimen to him for firm identification. Failing that, you could send it to Alan Stubbs or to me to check it. You can e-mail us privately via this website.
Malcolm

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#10 2011-03-31 01:46:30

Dark Horse
Registered user
Name: Andy Grayson
From: Kirkbymoorside
Registered: 2009-07-18
Posts: 37

Re: Tabanus bovinus

Hello Everyone.  What a pity I've only just noticed this topic now.  I've not looked at the DF website for some time, having been pre-occupied with the 3 'w's [writing, work, women - unfortunately, too much of the former two, and not much of the later]. 

Dear jonM.  From the photographs, your specimen would appear to be a male Tabanus bovinus [99-100% sure].  I'd certainly be happy to examine it sometime and confirm it as such.  Tabanus bovinus males are quite distinct from those of T. sudeticus, and easily diagnosed from T. sudeticus by the eye-facets character.  The females of T. bovinus and T. sudeticus have long caused identification problems, which still are not resolved.  I've personally not yet been able to satisfactorily resolve them, as I have only one battered and pest-eaten true female T. bovinus specimen available to me for examination [probably from continental Europe].  There is a lot of confusion in the literature, and it seems readily apparent to me that most British authors did not correctly recognised true T. bovinus, hence described differences between the two species based on the examination of T. sudeticus females alone.  I suspect that the larval habitat of T. bovinus will prove to be the margins of ponds and lakes, and similar habitats; whereas the larval habitat of T. sudeticus appears to be bogs and boggy flushes.  Also, I suspect that typical female true T. bovinus will prove to be patterned like an orange Hybomitra, and that there may be an obvious difference in the eye-colouration during life, as claimed by Brauer about 150 years ago.  Anyway - enough on that for now.

Dear falky. Firstly, congratulations on a very fine and enjoyable presentation at the DF AGM in Oxford last November.  I didn't get a chance to have a chat with you afterwards, which is a shame, as you rather threw me during the presentation when you produced your photographs of 'Hybomitra solstitialis', then asked me about the British records, upon which I had to say there was doubt about the validity of all the records of which I was aware at the time [upon further investigation 'H. solstitialis' had always proved to be something else].  I say 'rather threw me' because I was expecting you to probably produce a photograph of variant H. distinguenda, but what came up on screen looked nothing like any of the species I know from the New Forest.  What you had taken was superficially like H. muehlfeldi, which I would not expect in the New Forest, as it appears to be restricted to a different habitat [typically: where extensive Phragmites beds occur on permanently-water-logged deep mud at the margins of large lakes].  To cut a long story short, I suspect that you did indeed take the true H. solstitialis in the New Forest, and correctly recognised it of course.  A few years back, Alan Stubbs correctly recognised that there are a series of true H. solstitialis from various British localities in the Verrall/Collin collection at Oxford.  I currently have three of these specimens on loan, a male and two females.  I have spent a great deal of time evaluating these against all the literature and the numerous Hybomitra I have available for comparison etc.  I still have some work to do on the male, but I am certain that the two females are distinct from the other eight known British Hybomitra species.  I am also certain that H. solstitialis was correctly recognised by Chvála et al. (1972), and that the two females I borrowed, from Rhinefield Walk, in the New Forest, and Chippenham Fen [which is not a typical Cambridgeshire fen, and has deep boggy areas within woodland], are indeed true H. solstitialis.  Chvála et al. (1972) correctly states that [in the female] H. solstitialis is "Most easily confused with H. muehlfeldi, but shape of cerci and subgenital plate quite different."  I have 94 female H. muehlfeldi to hand, and have found it rather frustrating that not only do female H. muehlfeldi superficially look like those of H. solstitialis, but the range of external character-variation in H. muehlfeldi has prevented me from establishing any reliable characters to separate female H. solstitialis from female H. muehlfeldi.  Fortunately, the entirely different cerci and subgenital plates, serve to reliably diagnose these species from each other.

Well that is certainly enough from me for now!

Andrew Grayson

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#11 2011-03-31 02:03:21

jonM
Registered user
Name: Jon Mortin
Registered: 2009-03-09
Posts: 420

Re: Tabanus bovinus

Dear Andrew

Thanks very much for that. The specimen is extremely fragile (another bit of the abdomen fell off recently) so I am reluctant to post it! How about I donate or lend or bring it to either Bristol Museum or the BENHS collections at Dinton Pastures? I wanted to at least submit a photo for id checking before it completely disintegrates! I may also re-photograph it as I have a better camera now...
Jon

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#12 2011-03-31 02:05:29

falky
Registered user
Name: Steven Falk
From: Kenilworth
Registered: 2009-11-30
Posts: 416

Re: Tabanus bovinus

Andrew (or should I call you Black Beauty), I checked one of my New Forest solstitialis at Oxford after my last response and it is identical to their material but different to muehlfeldi (esp the dark notopleuron but various other features too). But what was so lucky was seeing an ovipositing female, then another newly emerged one nearby. Both observations are linked to transiton mire i.e. peaty wetland that falls between true bog and poor-fen. Easiest bit of autecology for a rare insect I've achieved to date,

Falky

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#13 2011-03-31 14:25:07

Dark Horse
Registered user
Name: Andy Grayson
From: Kirkbymoorside
Registered: 2009-07-18
Posts: 37

Re: Tabanus bovinus

Well Steve, my hair is jet black [but that's just dye]: as for beauty - I think not - so 'black beast' would probably be more appropriate!  Unfortunately, I'm old enough to remember 'Black Beauty', but didn't watch it, as it was a 'girlie' programme. 

Your observations and ecological assessment of Hybomitra solstitialis are very interesting, indeed invaluable, and show the benefit of being in the right place at the right time.  Having examined a great many Hybomitra muehlfeldi females [94], and compared them with the two of H. solstitialis that I have on loan, I consider that you really have to examine the cerci and subgenital plate in order to reliably separate these superficially-similar species from each other.  There are other reliable ways to separate them from all other British Hybomitra.  Body-colouration in Hybomitra acts as a guide to species, but is never totally reliable as a diagnostic character, and its usage as such is fraught with difficulties.  As a general rule, Hybomitra specimens with less orange on the abdomen, also tend to have darker notopleura and antennae; moreover, it is not unusual for the basal antennal segments to be at least partly orange in ground colouration in female H. muehlfeldi.  One of the reasons that H. muehlfeldi was erroneously recorded from some areas of Britain was that 'paler' H. bimaculata females tend to have orange notopleura - hence were identified as H. muehlfeldi on that basis alone.

Andrew (or Andy)

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#14 2011-03-31 14:33:17

Dark Horse
Registered user
Name: Andy Grayson
From: Kirkbymoorside
Registered: 2009-07-18
Posts: 37

Re: Tabanus bovinus

Jon. I wouldn't post this fragile specimen either, as damage would be likely to occur, although it does tend to surprise me that specimens usually arrive via post with no damage.  I'm intending to be at the DF meeting in Exeter in a few months time, so it might be possible to arrange for me to see it/borrow it etc.  The best news is - you've got a better camera - so get snapping away and post a few more pics!

Andrew Grayson

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#15 2011-05-10 23:31:48

jonM
Registered user
Name: Jon Mortin
Registered: 2009-03-09
Posts: 420

Re: Tabanus bovinus

Here are some slightly better images taken with my new camera!

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#16 2011-05-10 23:39:49

jonM
Registered user
Name: Jon Mortin
Registered: 2009-03-09
Posts: 420

Re: Tabanus bovinus

My cropped images were more than 512kB! That's the downside of a better camera. Here is an even more cropped image....


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#17 2011-05-10 23:43:43

jonM
Registered user
Name: Jon Mortin
Registered: 2009-03-09
Posts: 420

Re: Tabanus bovinus

and another of the abdomen in side view...


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#18 2011-05-10 23:51:02

jonM
Registered user
Name: Jon Mortin
Registered: 2009-03-09
Posts: 420

Re: Tabanus bovinus

and another side view. Just realised I can reduce the file size by opting for lower quality...

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#19 2011-05-10 23:53:55

jonM
Registered user
Name: Jon Mortin
Registered: 2009-03-09
Posts: 420

Re: Tabanus bovinus

another attempt...


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