Ah well those are vinegar flies. They are attracted to rotting fruit. The real fruit flies which sting fruit on the tree are bigger and you don't find them hanging about in the house and around fruit scraps. And yes, I've got plenty of vinegar flies at the moment, too.
My kitchen is full of vinegar fly at the moment Liz. I walk around slapping my hands together and against the cabinets.
I had some seed sitting on the bench, wrapped in wet paper towel and with a sieve over the top and they still got underneath in huge numbers. I cleaned up every scrap of vegetable matter but left the wine bottle sitting on the bench last night during dinner, came back and they were all huddle on the lid.
Like all things, it will pass.
One woman in the Frog club used to breed vinegar flies for the newly-emerged froglets; she gave a talk one day about it. Not that I remember much but it now but after the talk we all knew much more about vinegar flies and their sex lives than any of us wanted to ;-)
It sounds like you have wisely suppressed those memories.
Does anyone know if the vinegar flies actually cause harm to fruit sitting in the fruit bowl? My understanding is that it has to already be rotten for them to get any benefit from it. Wikipedia is unhelpful on this subject because it gets distracted by their importance to the study of genetics. It implies that Australia and South Africa are the only countries where you will hear someone say, "that's not a fruit fly, it's a vinegar fly" because we regard fruit flies exclusively as pests from the family Tephritidae.
They certainly lay eggs which hatch into maggots Rob. I have seed and rotty fruit sitting on the kitchen bench for seed saving and they often get blown by the little maggots if I'm not quick enough to process them.
The fruit is on the way out anyway and the vinegar flies are attracted to whatever gases are given off and they would speed rotting once they get breeding. And they are so small they fly through fly-wire anyway to keeping them out of the house is quite difficult unless you keep all your fruit in the 'fridge. Lissa I think that the vinegar fly maggots would help rather than hinder your seed-saving efforts by stripping off the flesh and leaving the seeds.
I think you could be right. It happens so often and I process the seed anyway which seems to come to no harm.
I have a map gas cylinder with an electric ignition that was left over from my air conditioning days before retiring and I occasionally grab it and open up the compost bin and give a blast of burning propane into the bin, a bit hard to fly away without any wings, --- I also wait for that annoying blow fly that comes in when Christine is cooking, to land and ---STEP1:- aim STEP 2 :- pull trigger, STEP 3 :- laugh my guts out as as its wings and legs glow RED!!!
OH! by the way no flies were harmed in the writing of this comment lol