Killing Flies?

Noticed last year that it was hard to kill some types of flies. Same problem again this summer.Any reccomendations for fly killers. Have noticed thatMortein and Raid are quite ineffective, getting better results with Budget Fly Killer.

Yep - I've noticed that too.Am in Chch, where we don't get as many house flies as in more humid areas of NZ.There's absolutely no doubt that houseflies can and have developed resistance to pesticides.
I just checked the label on a Mortein can we have here, which is synthetic pyrethroid based.Some houseflies seem to shrug it off.
Fly spray formulas used to contain an ingredient called piperonyl butoxide, (PBO) used with pyrethrum or synthetic pyrethroids, which gave quick "knock-down" property to the spray.But I see that there are now some serious safety concerns about prolonged human exposure to this stuff.Perhaps the "budget" brand still contains piperonyl butoxide, but it looks like the major multinationals behind the big brand names have quietly removed PBO from their product line.I'll have a look next time I'm at the supermarket.
http://www.mailman.columbia.edu/news/commonly-used-insecticide-linked-delayed-mental-development
Read the labels.Those "robo-can" type spray things based on pyrethrum are probably safer than using fly spray, at least partly because their effectiveness is based on the repellent property of pyrethrum.

I prefer not to use fly spray as I'm highly allergic to it and I don't think it's good for us to breathe it in anyway. I've been buying those sticky fly papers from the $2 Shop and they do work quite well. When the flies annoyingly avoid landing on them, a swat with the newspaper does the trick. About the only time I spray is if I'm going out for some time and can leave a room shut up.

we've set up a few traps outside. bunnings ones for about $6. Seem to fill up within a week so surely that reduces the numbers inside. Tried to make my own sticky paper last year from internet recipe and failed miserably

Buy an insect zapper for about $10. Looks like a tennis raquet and has a thousand volt mesh. They really work well, especially on moths that the fly sprays are ineffective on.

Yes thats my suspicion too. Certainly noticed in the last couple of years that the big brand names dont live up to their advertising.Or flies have developed immunity.

We got new retractable fly screens, they are brilliant!, the odd one that does get in is dealt to by our little kitten (f@#k you Gareth Morgan)

I had a quick look at the shelf in Countdown.
Their "Homebrand" standard fly-spray does indeed contain PBO.The Raid and Mortein branded product does not - each were a blend of three synthetic pyrethroids.
That probably explains why the "name brands" don't seem to work as well as they used to.PBO was a synergist - increasing the effectiveness of pyrethroids.
They probably use a blend of 3 synthetic pyrethroids to reduce development of resistance.I don't see evidence that resistance has developed to natural pyrethrum - which has been used for a very long time (but is more expensive than synthetic pyrethroids).
Curious that it appears that as a result of one study, the multinationals seem to have quietly ditched PBO.Unless I missed it (quite possible), I don't recall widespread public concern."Pregnant women exposed to fly-spray (ie - almost all of it used to contain PBO) risks retarded mental development of children" would have been quite a headline - I would have thought.

Get more spiders they eat the flies!