Yes, I get the same thing in NE Wisconsin. The fruit flies loved the tomatoes I had on the counter when I cleaned the garden out in the fall. I had to take extra care to cover everything with bedding in the bin. I even laid used paper plates and cardboard over the top of the food and bedding in attempt to snuff them out. After I did this and cleaned up the kitchen they flew around aimlessly for a couple of days and then disappeared. Currently I am laying shreds of food on top of the bedding and haven't seen a fruit fly since November.

We have fungus gnats (many folks call them fruit flys - but there is a distinct difference) which love compost. They will then begin laying eggs (invisible) in any and all potting soil of houseplants too! Got rid of them in houseplants using organic remedy - but not appropriate for vermiculture.

Can I safely add Baking Soda to my worm bin?

Hi Anisten (from a neighbour down the 401)
You could freeze or microwave the food first before feeding. I always freeze to prevent a fruitfly invasion. Easier to prevent than cure...
Also putting lots of shredded paper on top will deter them as well....they don't like to dig/work for their food.

lolamina, I wouldn't add baking soda to the bin at all. Too much salt for them.

Hello Jasdip, I don't have any problems @ all now that it is winter but come summer I have found even when I freeze doesn't seem to make a difference. I noticed we are neighbours on the composting forum I believe. I am Maria Scicluna on there

Hi Anisten,
I live in Kitchener, and we're on the GF vermicomposting forum.
I'm wondering if what you're seeing are fungas gnats, since freezing doesn't help your fruit fly problem in the summer. Once the food is gone, so will the fruit flies, except fungas gnats. They live in damp moist conditions so the bins are ideal.
They say they are remarkably different, but I can't tell the difference between ff, and fg. Mind you I've never looked at any through a magnifying glas. I used to get fg periodically in my houseplants, that's how I knew what they were.

Fruit flies are fat and brownish.
Fungus gnats are black and thinner, sort of mini mosquitoes.

I freeze my food and have had fruit flies all winter long. I didn't have them in the late fall. I believe they are coming in on the store bought fruits and veggies. Very frustrating.

Thanks for the description Fosteem. Good to know!

fosteem1 what zone do you live in? Here in Canada obviously our fruits come from the south and oversees yet no fruit flies in the winter even with a banana turning black right on the countertop. maybe if you live in a warmer zone then their internal God given clock tells them it is time to hatch.
My bin is indoors as I really don't like all the critters that invade the bin outdoors, I am ok with the ones that invade on a purely indoor bin.

Starting to see fruit flies this week. They had been gone since late November. At this time of year they are probably breaking out of their pupa's.