QUESTION: Can you save your mealworm farm from a mite infestation
ANSWER: YES YOU CAN!
When I finally got a meal worm mite infestation, I set out to find a solution. 100% of online reading will tell you that the only recourse to a mite infestation is to throw out the entire farm, sterilize and start over from scratch with a new batch of worms. What nobody tells you is that your chances of getting infested again are very high.
THE ODDS ARE AGAINST YOU
Odds are that the place where you purchased your worms has mites and the worms shipped to you have mite eggs. The substrate you are buying has an extremely high chance of having mite eggs in it. A spec of dust carried into the container by you walking by can have a mite on it... There are species of mites everywhere and some are on your body as you are reading this. Fortunately, the only mites we really care about with meal worm farms is the typical grain mite which has a number of species variants.
The mites that infest your meal worm farm are so tiny that you may not even notice them. I had noticed a fine "dust" for some time collecting along the corners and edges of my farming drawer. I figured that static electricity was adhering the dust to the side of the container. Only after some time did I see some of it moving and come to realize that it wasnt dust at all. The grain mites will want to collect where they can get the freshest air which is usually at the edges or air holes of a drawer. So if you see dust collecting, well, you probably have a mite infestation.
When I finally realized mine, I found mites all down the back of the shelf where I had my worms and they were collecting down on the floor in a huge mass. This is gross and can also be dangerous if you happen to have any other pets that can come along and sniff at the mass such as cats and dogs. Breathing a million grain mites into the nasal cavity and lungs is no good for any animal.
So I cleaned. I sanitized. I bleached. I vacuumed and threw away the bag daily. I did anything that came to mind to get rid of the infestation.
I moved my existing farm outside immediately and figured that I would have to toss it but I wanted to at least try to find a way to sanitize it safely and without killing it off.
I researched and experimented and came up with two ways to rid your farm of mites that nobody else will tell you. Both have worked for me. The first method worked quickly and allowed me to restart my farm indoors but it has some tradeoffs whereas the second method took some time but was effective at saving the entire farm and I recommend it.
METHOD 1: Sweating
Grain mites thrive in warmth and humidity, but much like meal worms, there is a line that they cannot cross in which they will simply drown and die. Luckily and simply, the grain mites will die off before the worms will. What I did was screen out all of the adult worms from the rest of the farm, dusted them off with compressed air for good measure, then placed them all by themselves with no substrate or anything else in a small GLAD brand disposable container. I closed the lid tightly and punched a couple of pin holes. Very quickly the container will get wet from all of the respiration of the worms. It will get drippy wet inside. I opened it once in awhile to replace the air and let out some moisture. My goal wasnt to kill the worms but to only drown out the mites but it is a fine line that you need to reach but not cross. Some of the worms at the bottom may die off from this. I did this some months ago and dont quite remember how it went or how long I did it, but I do know that it worked and I was able to immediately start the new inside drawer. Most of the worms were able to survive the high heat and humidity longer than the mites and any remaining eggs. The adult worms were able to pupate and begin to repopulate a clean drawer in which I worked to manage humidity much better than I did before.
METHOD 2: Diatomaceous earth
I read how this is used as a natural "pesticide" of sorts. The microscopic ground diatom shells are jagged and pierce the body of anything small that encounters them and the creature is left to dry out and die. It also acts as a natural desiccant allowing the container to stay drier also inhibiting reproduction. I didnt know if this would work but it was the only thing I could find that I could try with the remaining worm farm. The idea was not to put it into the substrate or in direct contact with the farm, I decided to use it to catch the masses of mites as they left the farm. If you can kill off all of the new bugs, they will stop mating and laying eggs and the brood will die off.
So I found a larger container, loaded the bottom with DE powder that I purchased online
, and then put the farm into it and closed it up and kept tabs on it. I immediately noticed the stream of mites climbing out of the farm and into the DE. They were amassing on top of the dead corpses of previous mites. I would occasionally reach a stick inside and stir of the masses hoping that anything left alive would succumb to the DE.
As far as I could ever tell, I never saw the mites going back into the container, so it looked like a one way trip. After about a week or two of non-stop streaming mites, I figured that this wasnt working. I noticed that my container was getting moist under the lid. It appears that the heat of summer and the respiration of the growing mealworm farm had turned this contraption into a mega mite brooder and extermination trap in one.
So I needed to remove the moisture. I chose to cut out some holes, glue in yard fabric as an insect trap and then I mounted a fan to exhaust air out one side. This moved air across the inside of the device and pulled out moisture.
The following week had fewer and fewer mites hatching or climbing out and it eventually got to where none were to be found on the outsides of the farm container. I kept maintaining the farm and it was doing fantastic out in the warmth of summer. I had never had a farm produce so heavily. I fed the sugar gliders out of the outdoor farm for weeks and let the indoor farm recuperate. Apparently meal worms like warmth. With the exhaust fan going, the farm did well up to 100F, then not so good.
I went through one or two complete cleanings of the outdoor farm until I was satisfied that I had gotten rid of the mite problem and then I brought the farm indoors into my new two drawer farm with exhaust fan.
I havent seen any mites, bugs, fungus, mildew, chunky substrate or any kind of moisture build up with this new farm design.
Now, do keep in mind that transferring worms or beetles can also mean transferring mites and mite eggs. The eggs or mites can easily attach to the insect for the ride over. You will never know if what you see is frass, grain, dust, mites or eggs. So beware! Keep your worm farms dry. I recommend installing an exhaust fan to move moist air out and you may never have a problem again.