How do you folks manage your worm bins to proactively do what you can to prevent them from introducing undesirable pests? In reading many threads I noted at least one where the discussion turned into 'what type of mite' was in the bin (good ones versus the dreaded ones). That led me to think about how would I go about identifying the risks and any action I could take to proactively prevent introducing something to the indoors (bin is in garage but near other growing media/tools/containers/amendments/etc).
I love this question!
Some have characterized my worm and soil making method as a bit excessive. For worms, there are two parts, in my opinion: the existing environment and the things you routinely introduce as food for the worms. You want to create a healthy worm bed, with diverse beneficial predator populations, to prevent outbreaks of harmful things. I think this is a largely passive process.
I introduced rove beetles, hypoapsis mites, and like three or four other types of beneficials into my grow tent. I probably directly introduced some into the worm bins when the benficials arrived, but probably also inoculated over time. I haven't recently because I'm not too worried about my bin/bins. But, after introducing beneficial to your tent, it's not a bad idea to throw a few handfuls of soil with evidently healthy beneficial predator populations. I do this when transplanting from smaller to larger pots, deliberately grabbing a few rove beetles for each pot.
If your bin is anywhere near your grow, I would sterilize and/or inoculate everything! When making soil, I sterilize the peat, aeration (rice, pumice and biochar) and compost separately. I attempt to separate all of the worms and eggs I can see from the compost prior to mixing.
As to why I don't worry about my bin/bins, prior to getting a 72 gallon (3 ft diameter and 12-14 inches deep), I used some 20-25 gallon smart pots. After moving to a 72 gallon smart pot, the pot has a critical mass of beneficial life, (I believe).
I also switched to plastic bins for the smaller batches and soil mixes because smart pots under 72 gallons dry to quickly, creating a large vertical, circular column around the edges of the pots, except for the top when under plastic or a layer of hay or rice.
So, it's two fold: 1) create at least one large AND multiple other smaller, back up bins with populations of beneficial predators, optimally ones you can see, and 2) attempt to sterilize everything going into your worm bins or grow room. Sterilized soil is then inoculated with small handfuls of soil and teas made from the existing bins.
The probability of transferring beneficials is high, and the probability of transferring harmful things is acceptably low.
