I get at least one question a day, many of the same questions…sometimes new ones. Today I thought I would share some ideas on a pretty common problem. What can you do about mites in a Grindal worm culture. You can use the same concepts on whiteworms.
“…also I need a culture of grindal if you can tell me how to keep the mites out. I lost all my cultures mites this year.” - MsDevine
I hate mites. They are a difficult critter to get rid of. Fruitflies also get mites…and it’s a different species than the mites in the Grindal worms and whiteworms (and on and on with dirt dwelling critters).
The best we have come up with for the flies is to use “mite paper” under AND over the culture. Put the culture on a sheet of paper and lay a sheet of paper over the top of the culture. We use the mite paper to help prevent mites in worm cultures.
To rid a culture of mites is another story. The best method is to harvest as many worms as you can and rinse them in water repeatedly and start a new culture. The mites and their eggs float, the worms sink. So if you stir the worms in the water and wait until they sink and then decant the water, you should have an opportunity to rid the sample of most of the mites. Repeat this process until the sample is clean. Start a new culture with this clean batch of worms…in sterile soil.
In the absence of that, we have used a propane torch to scorch the top of the culture…that kills the majority of the mites (repeat several times the first day and then periodically)…surprisingly the worms are not damaged too much (we don’t feed for several days prior and the worms go deep).
Keeping a couple of cultures going in differenct locations also helps. Re-culturing on a regular basis (the harvest and rinse method of gathering starters) is a good policy. Also keeping houseplants away from the cultures seems to help.
We have found that very healthy cultures, those with almost “too many” worms (like that’s a problem? don’t lend themselves to infestations as easily as sparsely populated cultures. It seems to be better to start with a smaller culture container for the starter and “crowd” the worms than to give the worms too much space in the beginning. It takes a while to build large cultures this way, but they seem to last longer between infestations. This observation be related to a competitive issue…the worms eating the bulk of the food quickly so as not to be attractive to mites.
Of course starting with sterile soil is always a good idea, but mites seem to find GW cultures fairly quickly.