A Visit to Mum and Dad, and the Dreaded Blandford Fly

Dear Readers, every time I come to visit Mum and Dad, I find myself in a flurry of activity – pulling up long grass, getting rid of plants that haven’t made it, trying to clean up the stone plaque (though I definitely need to speak to the stonemasons about the best way to clean it up – I don’t want to pollute the surrounding area with caustic chemicals, but I do want to be able to read their details). Then there’s the putting the old plants on the compost heap, getting rid of the dreaded plastic pots, positioning the new plants, and finally I slump under the cherry tree and feel a great sense of peace descend. This really is the most serene spot. All you can hear is the cooing of woodpigeons (plus the occasional ‘clap’ as one of the males demonstrates his strength by ‘clapping’ his wings at the top of a rollercoaster flightpath), the chinking of the many, many house martins, and the wind in the yew trees. I bring Mum and Dad up to date with my latest news – my retirement, all the medical tests that I’ve had since I ‘saw’ them last. I find myself telling them about my heart valve defect, and telling them not to worry. When I mention my retirement I can almost hear Dad saying ‘What took you so long?’. It might seem funny to talk to people who are dead, but I also know that I’m far from being the only person who does it.

I take a walk to see how my favourite lime tree is getting on (it was blown down in a storm last year), and it seems to be doing fine. It will take many years to reach its former splendour, but I love that it is hanging on.

The lime tree today

The Lime Tree in its full splendour

Now, when Mum and Dad first moved to Dorset I remember Dad telling me to be very careful that I didn’t get bitten by ‘the Blandford Fly’. How I laughed! However, following my walk down by the stream yesterday I have picked up about five nasty bites, and although I suspect that they’re merely mosquito bites, I have been casting my eye over information about the Blandford Fly, and I think that I owe Dad an apology.

The Blandford Fly (Simulium posticatum) is a species of blackfly which lives as a larva in the weeds alongside slow-running rivers. When the females emerge, they, much like midges, require a blood meal in order to for their 200-300 eggs to mature. Along comes a handy human walker or angler or someone wearing shorts and the fly is in heaven. The bites seem to be particularly irritating and painful, and because of this are prone to becoming infected. In the worst case people are hospitalised, and the name ‘Blandford Fly’ comes from an outbreak in the 1972 when over 600 people were so badly affected within a four week period that they needed treatment at the doctor or their local hospital.

At first (as was always the case), the treatment was to spray the riverbanks where the larvae lived with a chemical biocide. This resulted in the death of many other species of blackfly (important for fish and for other invertebrates such as dragonflies) and a disruption to the ecology of the river. However, in the 1980s another way of doing things became available. River ecology expert, Dr Mike Ladle, suggested that a newly-discovered bacterium called Bacillus thuringiensis israelensis (found in the Negev desert in Israel) could be used to target the Blandford Fly specifically without endangering any other species. The river was first sprayed with the bacterium in 1991, and Dr Ladle suggests that  ‘this is probably the best example of the use of a biological agent to control a pest, in an ecologically friendly fashion, anywhere in the world.’ It does seem to have been a remarkable success – in 1980 there were 1400 recorded cases of bites, but by 1999 it was down to 45 cases. 

All the more reason, then, for alarm in 2014 when disagreements about who should fund the spraying, and new EU legislation about licences for river treatment meant that the bacteria might not be used in time for the emergence of larvae in 2015. An 80 year-old Blandford resident, Pat Ashworth, went shop to shop, street corner to street corner, with an old-school petition, and managed to get nearly 2500 signatures to say that the treatment must go ahead. I suspect that many Dorset towns and villages are basically run by feisty retired ladies who won’t take no for an answer, and more power to them (and I also suspect that this phenomenon is not limited to Dorset).

Ashworth was obviously worried about people getting sick, but she also had other concerns. Hospitals and GP practices in the West Country are under a lot of pressure in the summer due to the influx of tourists, so bite treatment would be one more thing. She also cited the name of the Blandford Fly as being a deterrent to tourists, and suggested that it could just as easily be named ‘the Wimborne Fly’, passing the blame on to another Dorset village. She was absolutely right that the fly was present along most of the river Stour downstream of Blandford, so there are a number of other towns and villages that are affected.

Spraying with the bacterial agent recommenced in 2016, so at least in Dorset the risk of a nasty bite is much reduced. However, the fly is spreading, with cases in Herefordshire and Oxfordshire, and I note with some interest that ‘garden water features’ are thought to be a factor. Well, as the insects require slow-running rivers I suspect that the average garden pond can be exonerated. Always beware of articles on invertebrates in the local and national press, these guys frequently illustrate articles about bees with hoverflies so we can assume that the level of entomological knowledge is not what it might be.

I think we forget that although the UK isn’t tropical (yet) we do have all manner of biting insects, from your average mosquito to the terrifying midges of the west of Scotland, to cleggies in Devon and horseflies more or less anywhere. As I’m sure you know, it’s the anti-coagulant that the insects inject when they bite you that is the main irritant, and if you can avoid scratching you will greatly reduce the risk of infection. I generally use a hydrocortisone cream for a brief period until the itching subsides (calamine lotion can also work and is safer). If I fear that the irritation will keep me awake I might also take chlorphenamine maleate (the active ingredient in Piriton and many of those other antihistamines) but again just for a day or so. Comfrey ointment and comfrey tea have also been recommended to me, and the ointment certainly works. I’m always open to hearing about things that work for bites, as all manner of invertebrates seem to love me just as much as I love them, so fire away!

And just for the record, as Blandford flies normally bite the lower leg, and are most active from May to June, I am pretty confident that my bites are just from a mosquito, and that they’ll be sorted out within a few days. But apologies to Dad. The Blandford Fly does appear to have been a menace historically, even if it is now more of a minor nuisance.

Incidentally, Woodhouse and Hall, the local brewery, created an ale called Blandford Fly, flavoured with, among other things, ginger, which is said to be a helpful treatment for a bite. I do love how something so unpleasant can be turned into a marketing opportunity.

The story of the Blandford Fly (with a rather unnecessary dig at EU ‘bureaucracy’ ) is here. There are some photos of the redoubtable Pat Ashworth too.

4 thoughts on “A Visit to Mum and Dad, and the Dreaded Blandford Fly

  1. Anne

    I thought of you when I was in Dorchester only a few weeks ago. I visited my late aunt’s home in Bradford Peverell and enjoyed tea in her garden: a wonderful way for me to make a final farewell to this wonderful woman in my life.


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