Hi Ivan, can't help with any personal knowledge I'm afraid, but just in case you haven't already discovered it there's some background information here:
http://www.blackfly.org.uk/index.html
The repellant that works best for me is Smidge, which seems to deter a range of biting insects but I don't know whether it works on blackflies specifically.
Hi Ivan,
The fly you are talking about is Simulium posticatum. It is called the Blandford fly because it is a minor public health problem in Dorset where there are many clinical reports of reactions to the bite of this blackfly that does not really occur with other Simulium in the UK. It is also called the Stonesfield stinger or Woodstock fly in Oxfordshire, which is the only other area where bites are a problem.
Like other Simulium the larvae and pupae can be found in flowing water only, the larvae attaching to rocks, stones or trailing vegetation to feed on microscopic organisms and particles in the water - attempts have been made to try to control the larvae in streams and rivers using insecticides (on particles) or the bacillus BTI (granular).
The distribution is limited, Crosskey & Crosskey ( 2002, Dipt Digest 9, 25-60) in their fantastic and comprehensive survey of SE England found it in Dorset, Oxfordshire (around Oxford, R. Cherwell and R Thame, see also Williams 1991, Entomologist, 33-36). There are records from Surrey and Sussex but not biting humans.C&C did not find it out in E Anglia nor did Rory Post in his studies.
The most effective repellent is probably anything containing DEET and DMP - tedious to use. In Canada where Simulium are a real problem (like midges in Scotland) people resort to wearing hats with veils! There is very little evidence to suggest that eating marmite, etc has any real effect on repelling biting flies. Lots of ideas have been put forward with little effect.
As to why this species is more of a pest with the wheals it generates in some people will be down to a) the components in the saliva and b) the differential reaction of people (delayed hypersensitivity).
hope this helps
Richard
Hi Cathy,
D. fusca has hairs on the wing cells rather than just veins, so I suspect this is either D. chorea or D. mitis from the wing photos. The legs are missing which help separate the two - as does looking at the genitalia under the microscope. The Stubbs and Kramer key (available from Catalogue of the Craneflies of the World literature section) (it was available on the old DF site but I'm not sure yet if it is here) illustrates the genitalia and that's your best next step.
Cheers Pete
Stubbs, A.E.; Kramer. J. 2016i. Key to Limoniid craneflies with a closed discal cell, by Alan Stubbs, 2001, revised by John Kramer, 2016. Published by the authors as PDF (17 pages); date of latest version: 19 June 2018
There is a useful article by Roger Crosskey in DD vol 12, no. 1, 2005, pp 27-58: A perspective on anthropophily in British blackflies, with keys for the identification of the culprit species.
AFB
Hi, it does look very like Appendicia from the photos - nice find :) To be 100% sure I'd have to key it myself but I'm 90% sure.
Thanks Chris,
I've got the specimen, so I'll let you see it when things open up again.
Thanks Nigel. Via e-mail I have also had confirmation from Michael Ackland that this is Anthomyia procellaris.
He has also sent the attached photos to show the difference between males of the three similar species A. pluvialis, A. procellaris and A. imbrida, with the following notes:
"My intention is not only to supply a name when I am asked to ID an antho, but to make further use of the opportunity to offer the reason or characters which might help in the future, and I think this is much more helpful. (if I can).
The shape of the lateral postsutural black mark (lateral view) in the males of Anthomyia pluvialis, procellaris and imbrida can almost always be separated by the hind margins of these black marks. In pluvialis it does not reach the thorax margin, in procellaris it does, and in imbrida it has an indentation."
By the way this image was taken at Preston Montford in 2007 - Sciomyzidae and Scathophagidae workshop.
Thanks very much Pete; I'll have a go at working through that key today. I still have the legs luckily enough.
Not Fucellia I think, Adam. I can't see the widely-spaced setae characteristic of this genus in your wing picture. I would suggest that you stick to males until you have built up a lot of experience of this family. I've been doing them for years, and most of my females still end up as unidentified discards. Sorry I can't be more helpful.
Howard.
Hi Pete,
Sorry this took me while; I settled on Dicranomyia mitis in the end as the apex of the yellow femur seems diffuse. I struggled with ID from the genitalia (I reached the limit of magnification) but perhaps you could give me some pointers on the photos attached?
Many thanks in advance,
Cathy B
Hi Sue, I posted a link to this over on the DF Facebook group and Rui Andrade has replied to say that it is Nostima picta, one of the shoreflies in family Ephydridae. NBN Atlas seems to have it as Philygria picta. Not a species I've ever seen; Martin Drake describes it as widespread but local in dry or damp grassland.
Hi Sue. Nostima is the correct genus for this species. It had been synonymized with Philygria, but current thinking has restored its generic status. I would appreciate having some locality details, please.
I seem to have the same issue trying to access the same file, do I have the same tick box unticked?