Controling fruit flies in worm bins
Worm bins are a productive and exciting way for city dwellers to make compost and reduce household waste inside the home. Worm bins can reduce the waste of apartment and house-dwellers by as much as 50% by effectively re-using the food wastes. Worm castings are some the richest and most biologically active soil amendments in the world, increasing veggie production by as much as 40% or 50%
Excited by the potential, worm bin owners sometime plunge in without getting enough information. Eventually a commercial fruit like a banana peel gets thrown in. In short order, fruit flies (actually most of the time fungus gnats) start to reproduce in high numbers. This is usually where the less enthusiastic home-dwellers lobby to kick the worm bin to the curb.
There are some easy tricks to eliminating these fruit fly and fungus gnat pests:
- Freeze all vegetable and fruit compost before it goes into the bin. The eggs cannot live through a hard freeze.
- Keep the bin fairly dry and keep at least twice as much shredded cardboard as kitchen waste. Moisture should be like a wrung out sponge, i.e. just moist enough to detect by touch.
- Keep a thick layer of cardboard or leaves on top of any fruit or vegetable compost in the bin
- Try to buy 100% local fruit and veggies, unmixed with industrial agricultural products. Fruit flies and fungus gnats can’t survive a good Northeast Ohio winter.
- Most importantly, add Steinernema feltiae (commonly called Sf) beneficial nematodes.
What are Sf you ask? These are a natural part of good soil ecology in southern States where fruit flies and fungus gnats live year-round. They infect the fruit fly and fungus gnat larvae that live in the soil, controlling their populations before they become a pests. Since basement or closet bins don’t see a freeze like our soils outside, introducing Sf adds a natural biological control mechanism to your bin.
Sf is often cost prohibitive, as it’s mainly used in organic farm fields, and the amount needed for a worm bin rarely jusifies the shipping cost. So Green Triangle is going to lead a co-operative purchase of these little worm bin gems. At the end of June we’re going to be ordering enough Sf for 20 regular worm bins at a cost of $5 per order. If you would like to purchase an order from us, please contact hank@greentri.org with “Sf” in the title.