Cluster flies are back

[Feltwell]

Here at Feltwell Towers, we've had cluster flies before, and I dispatched them with the aid of an "fogger" insecticide aerosol. They're in a "loft" space - which in reality, as I have attic rooms, is a small triangular shaped space right at the very top of our very tall roof. I've no reason to go in there unless I need to get to the header tank for the central heating or the cold water tank - there is no storage space.

The flies are back, and in my slightly more enlightened state I'm thinking of just ignoring them and leaving them to get on with it, and wondered if anyone knew of any reasons why not.

Firstly, cluster flies are quite different to "normal" flies - they don't go for dead animals or faeces, they are parasitic for earthworms apparently. They live outside in the ground but tend to venture into loft spaces to hibernate for the winter, and also tend to keep coming back to the same houses. There is no way of keeping them out. They pose no health hazard.

My thought is if I chuck insecticide up there I am introducing a poison of which some will inevitably seep down into my house. I'm also creating a lot of dead flies which will rot - I can't get access into most of the loft space easily. If I leave them alone they will all get out again in the spring. Other than the odd one who finds their way into the house and is a nuisance, I can't see a significant downside - can anyone else?

 

[Flyfisher]

Sounds like you have thought through the pros and cons and, from what I've just read about cluster flies on wikipedia I'd also be inclined to just ignore them, especially as they are only hibernating out of sight in a mostly inaccessible place. I'd share your concern about killing them off and then having the corpses build up. Seems better to leave them be and wait for them to fly off of their own accord in the Spring.

 

[Feltwell]

Yes - although flies aren't exactly top of my list of favourite animals, it just doesn't seem right to do the automatic "they're in my house therefore they must die" approach, especially if it's likely to do more harm than good to the house.

We had bees in my bay window, as I posted up earlier in the year. I was quite happy to leave them alone to get on with it, they weren't aggressive at all, made no mess and completed their lifecycle and died off naturally pretty quickly. Mrs F gets emails from a neighbourhood forum and at about that time there were a few other folks with bees - none of them were doing any harm but the "get the pest controller out quickly" opinions reigned supreme. No wonder bees are struggling

 

[Lime]

I agree, leave them alone if they are no nuisance.

No wonder bees are struggling

As most flying insects are too.
There is far too much insecticide used willy-nilly particularly in places insects have a "right" to be, i.e. outside in the garden!

 

[philpjuk100]

Flies?,I would leave them but if it was wasps?

 

[parkview094]

They're back for us too. There used to be a good colony living in our loft, but as it was easily accessible, I used an aerosol 'fogger' and have now installed a 30min spray. That seems to have eliminated the problem in the loft.

..There are, however, always at least 3 flies in our Kitchen. I have absolutely no idea where they are coming from. Agreed they're harmless, but if I could get rid of them I would. It's the buzzing around the light fittings that gets me..