It is quite amazing how fruit flies propagate..
- Just one fruit fly can lay over 500 eggs.
- Fruit fly eggs take just 30 hours to hatch.
- Once hatched, fruit fly larva take to the air in one week.
- The entire life span of a fruit fly is about 2 weeks.
So the question is this... Where do they come from?
The answer must be from either outside your winery or from the fruit itself (for those that make from whole fruit).
In my case, I have to lean toward the fruit itself. If I consider when the first signs of fruit flies show (on or about day 4), I can conclude that the fruit flies are already in larval form at purchase.
I also have to seriously doubt that the flies are coming in from outside.
When I press, I like to compost my dead skins. I let them sit in a pile for a day or two, then stir the compost with a pitch fork. I notice that when I fork them, there are no fruit flies. You would think that if the flies were coming from the outside, there should be a cloud of them around that pile of skins.
So, I assume that the ecosystem of the fruit flies exists entirely within my winery, making it a sealed fruit fly biosphere.
In this case, I will not attract any more fruit flies by laying out a trap. The existing population is not externally increased (unlike the case of the Japanese Beetles) and will only be decreased by use of a trap.
Anyway, that is my thinking. I welcome hearing what others think about this....