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The Sentomol Horsefly Trap – Vanquishing The Vampires.


Heading out to install the H-trap

This was my first summer at my new place, and I soon realised that the beautiful ancient woodland which borders my fields harbours a deep, dark, horrible secret: it is apparently a prime breeding-ground for the most voracious horseflies I have EVER encountered.
Every schooling session led to new blood loss for me and the horses, in spite of both being doused in the best fly repellents I could find – I was getting bitten through my breeches every single FLIPPING day while schooling. Trying to concentrate on dressage while staying alert for any savage bloodsucker landing on either of us, and being ready to swat it instantly, before it could latch on, wasn’t easy or fun.
screen-shot-2016-09-11-at-21-48-30At feed times, I stood there patiently swatting the effing things as they landed on my saintly decoy pony. Small, staid, black, and with Cushings (a coat so dense that they don’t seem to be able to bite through it, so she’s oblivious), she allowed me to establish my perfect M.O.: slap, wait for stunned horsefly to drop to the ground, stamp – I was killing about 30 a day, which was all very satisfying, but the numbers did not seem to be diminishing.
My other horses were wearing fly rugs and still being bitten, and getting increasingly peevish about it.


A pretty major (and painful) allergic reaction. My poor friend had this about 5 times in one month!

We were even being bitten while working on the yard. One of my friends has a major allergic reaction to horsefly bites and was being bitten every time she was here; in fact one time she ended up going to A&E with her arm so swollen that the nurse thought at first glance it might be broken. Serious sense of humour failure was starting… for my mares as well as for us. We were being eaten alive!
screen-shot-2016-09-11-at-21-16-20Enter the H-trap. I had heard about them, but was dubious. The idea seemed too simple, in a way. The black ball heats up and horseflies land on it, thinking it’s an animal (they are drawn by the heat signature). Finding no blood to suck, they take off vertically, go up into the hood and are trapped in the container at the top. If this worked, it was going to be an absolute miracle, but that’s what we needed!


Quick and easy to install. Done!

When the box arrived there was much excitement… it was reassuringly heavy. It took us (okay, my very helpful can-turn-his-hand-to-absolutely-anything boyfriend) about 10 minutes to erect and install. I had the job of photographer, obviously.
The only thing we needed that didn’t come in the box was a sledgehammer to whack the stand into the (at the time rock-hard) ground. Pumping up the black shiny ball took the most effort, and putting the green hood together took a couple of minutes. I was impressed… it’s very well-thought-out, and every part of this is seriously heavy-duty, it will last for years.


The caped crusaders and the decoy pony rushing to inspect the new magic gadget.

After a lot of thought, I had decided to put it in the main field about 7m from the fence nearest the arena, in the hope that it would protect both areas.
Predictably, the moment it was up, my horses immediately came charging up the field to investigate the imposter in their field. I had been worried that the sweet-itchy one might try to scratch her bum on it, but no, not a single horse has even tried to rub on it, perhaps because the ball part sways slightly in the wind. But they seem to realise what it does, because they now choose to stand near it (especially when the weather is really hot) in a part of the field where they didn’t hang around before. Interesting.
For the first few weeks, I checked the top catch pot (clear green plastic) regularly for victims. The horse fly bodies started piling up immediately, and there were hardly any accidental catches – one cranefly, two hoverflies, and a couple of nasty wasps and other freaky stingy things, some regular flies, but mostly the evil horseflies. Good news (because I worry about that sort of thing). I’ve only had to release one moth.


The gruesome evidence.

Here’s a photo of the first month’s catch. I couldn’t face lining the horrible dried-out little corpses up to count them, they were almost making me retch!
We have about 60 swallows nesting in the barn, and bats who zoom around the garden and field every night, so it is really important to me that whatever I use here is ‘green’ with no chemicals that might have adverse effects – nothing that would endanger our dedicated squadrons of bug-annihilators. I am desperately trying to protect our bees, too, so it’s very satisfying that the H-trap just hangs there benignly (unless you are a horsefly), patiently doing its thing, day in and day out. I can’t believe how effective it is, and am definitely ordering another one to cover the further paddocks (over a hundred yards away and on the other side of an enormous hedge, so a bit far for just the one to cover). I absolutely wouldn’t be without it now.

Most amazingly, NONE of us have been bitten since installing the H-trap. Not a single bite to a human. I’m not sure about the horses, but with horsefly numbers having absolutely plummeted, I doubt they are feeling like ritual sacrifices any more!


The proof: trapped horseflies. HOW satisfying?!

The Sentomol H-Trap webpage is HERE.  There is a link to a page with a “test showing reduction of population by 95%” – I have no problem at all believing this figure. There are two sizes available, I went for the large one and it definitely covers a big area: the entire barn (entrance to which is about 80 yards from the H-trap) and yard, arena, two small paddocks and about 5 acres.

If, like me, you have a horsefly problem, and have been thinking of buying one of these, but hesitating in case they don’t work, rest assured… they really do, and they are 100% worth it. Your horses (and your friends) will thank you for it.

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