Not sure what the Brits or the French really call these but look at the picture. Drain flies or drainfield flies are the common American names for these dudes. I had them in my septic tank /fosse in Florida, but they never got into our house in any serious number.
I moved into an otherwise very nice house in Chars that is infested with these. It didn’t help that the place was empty from April until 2 weeks ago when I finally got here from Cholet.
Along with these flies, the house was infested with spiders, which were happy to try to control them. I can live with a few, but not hundreds of these creatures.
I spent a lot of the last 2 weeks trying to suck up and get rid of both of them. I’m sure I can control the spiders reasonably well if I can control the flies.
It is not at all obvious where they are coming from. The highest concentration seems to be from the utility room, which has a floor drain, a sink and a drain for the clothes washer. I have put clear tape over all the drains, assuming they are coming from one of them, but the tape has not caught anything. I have poured a few pots of boiling water down the drains , to no effect.
The house has a fosse, so I don’t want to do anything to upset the good things going on down there. Since I just moved in, I really don’t want to make a big issue of it to the proprietors, who live across the street and seem to be a very nice couple.
So the link you provided, suggests two things that seem relevant: the life cycle of these little insects, and also a way to flush the pipes. First the life cycle indicates they can lay hundreds of eggs during the reproductive cycle. Not sure when that is, sorry…. Didn’t pick that up from the description. But it might be just a case of letting the adults die out, now that you’ve poured the boiling water down the drains…?
The second thing is that you could add vinegar and baking soda (along with the boiling water) to your drains, to help flush out the places where they’ve laid their eggs and/or where they are getting nourishment and moisture to live on. I’m not sure if this would change the pH in your foss, though…. But if you’re amenable, then it’s a good way to clean out pipes as long as you follow up with boiling water to wash any residual baking soda/vinegar down and out of the pipes.
It does sound like you are on the right track. You might see some results soon, if only from your boiling water application. Maybe give it a couple more days and see?
You probably need to open and clean the drains. That type needs something to lay eggs in …that’s probably the gunge in the drains.
Manual cleaning is best - but hot water and soda crystals afterwards will help ensure the pipes are not hiding more eggs.
It is unlikely that just collecting the ones that escape into the house will solve the problem. It is likely that there are scores of adults underground doing their thing to keep the population going. That was the way it was in my septic tank in Florida. When I opened the tank, there were thousands, but few ever made it into the house. Here , many are coming into the house- today I snagged about 50 with my cordless vacuum. It isn’t too hard to capture them, but it is tedious and I don’t feel like I am solving anything.
I would thoroughly clean all the pipes with soda crystals/washing soda/cristaux de soude in France, which are safe for the septic tank but effective at removing organic matter and the eggs it contains. AND I would add a pipe brush to scrub everything.
I have a few of them but not enough for me to want to get rid, but I have a fosse also and not sure that sending boiling water in that direction won’t do harm. There are thousands of beneficial buggies doing their thing down there that you really would not want to kill.
What is the capacity of your fosse? I can’t imagine that sending 2 litres of boiling water down drains that are 10 or more metres away from a fosse with hundreds of litres of capacity is going to do any harm. Took a long hot shower this morning that probably sent a lot more hot water to it than the 2 litres I just sent down one drain. Will advise…
I checked and cleaned the drain that the washer and sink in the utility go to. Didn’t see anything there but I put some dish soap down that line chased with boiling water. When I get hold of some vinegar i’ll try that with some baking soda.
I just tore apart everything in the utility room and I can’t really find any other source for the flies. They just have to be coming from the drains in that room.
The few flies that get into the rest of the house almost certainly come from one of those drains, too. There are almost none upstairs. There are a few in the stairwell but the stairs are directly over the utility room and there are several gaps in the stairs that the flies can get through. I keep the door shut to the utility room.
But you sealed the drains with tape and the drains would be equipped with a water trap to prevent smells and hopefully flies. Its going to be a process of elimination, tedious as it sounds. Drain flies around drains and bins but also seem to like dank moisture places. I think sterilising the drains first before re sealing. Then hunt elsewhere if no joy.
But the floor drain I suppose not. That has to be the most likely suspect, but I taped it and have put a bucket over it and can’t see anything coming up from there. It’s still a mystery and, as you say could be tedious. And maybe they’ll just disappear if we get cooler weather. That was a big problem with Florida- everything just goes wild with 9 months of heat.
My only penneth worth would be to add that no insecticides will kill insect eggs, So extreme heat or extreme cold. Example, for bed bugs I use a pressurised 180°C steamer which does the job nicely.
Pouring boiling or shower water down the pipes will only stay hot enough for possably less than a couple of metres before it become too cool to kill eggs.
High pressure drain-cleaning water-jets are enormous fun and effective jet pipes can be 40m long.
Vinegar, bi-carb can be useful, but diatomaceous earth (DE) is 100% natural,and 100% effective on 100% of insects. If you want to stick with natural, stick with DE. Apply with a paint brush, make-up brush, a powder puffer. Less is more, a thin dusting in every creac, crevice, hole, whererver you want. Run your index figer over your TV or 'poota screen, the dust on your finger is the thickness you need.
air, food, water, somewhere [safe] to breed, and heat, at variable levels depending on the lifeform. Eliminate one or more of the essentials and they’ll either die off, or go somewhere else for an easier life.
I’d keep the spiders and the house centipedes, they might look scary, but they do a cracking insect chomping job!
I don’t know where your papillon mouches are coming from, that’s your detective work. I, we on this marvellous group can steer you in the right direction and guide you in a satisfactory conclusion.
France has different pests to Blighty, they can be unnerving, but they’re not all out to get us, I hope!
