I too would love to know how to deal with these bastards in a permie way. Right now, I'm tempted to try my friend's advice and go the controlled burn route. But that might just be the infernal itching and subsequent lack of sleep and garden time talking..Anywho, since I've been stuck inside for fear of getting yet more bites in the most indecent of places, I have been researching trying to find a solution. I don't know that I'm any closer to one, but thought I'd share some of what I discovered in my quest. From what little research I could find, it seems that chiggers have "tremendous “ecological potency”, occupying regions within a wide variety of temperature, vegetation, and pH of the soil. In an experimental study, the type and layers of vegetation or organic matter, morphological surface of the soil, and the amount of moisture and solar radiation had no significant affect on the distribution of N. autumnalis."
I feel like we have definitely noticed a serious increase in their presence this year, even though we went a month without real rain. We have even been getting bit in the garden, much of which is mulched with woodchips. I have to wonder if the 17 or more truckloads of leaves we saved from going to the dump and then distributed throughout our garden and surrounding areas may have been helpful to them. Or possibly even brought in adults/eggs from other sites. It sounds like they do like to overwinter and/or lay eggs in leaf litter. One of the worst rounds of bites happened when we were in a shaded area where we had put copious amounts of leaves. No understory vegetation present.
If the leaves did lead to the increased numbers, it makes me wonder if turning them into leaf mold first would reduce said issue? We had so many, that lots of the leaf bags were just emptied out onto the ground as is.
"While no predators of Neotrombiculus autumnalis have been recognized in the literature thus far, strategies to reduce the number of pests in the field have involved the use of gamasid species Amblyseius cumcumeris and A. agrestis. (Scholer, 2006)"
So possibly these other mites could battle with the bad ones? I always wonder when introducing beings like that whether there could be unintended consequences or innocent bystanders though.
Another discovery I made was that applying an oil or salve all over does seem to hinder their ability to ascend up the body. I tried it and got no bites above the ankles. But if you wear socks, as most suggest when venturing into chigger territory, the oil rubs off on them and you end up with all the bites concentrated on the feet. 100ish chigger bites in one place really dials up the crazy making factor.
Multiple Environmental Factor Analysis in Habitats of the Harvest Mite Neotrombicula autumnalis (Acari: Trombiculidae) Suggests Extraordinarily High Euryoecious Biologyweb
While not specifically about chiggers, perhaps some leads on predators here?
Natural Enemies of Mites
I read another article by an MD saying that household vinegar was a great treatment to apply after possible exposure. He claimed it would reduce itching and shorten the duration or even possibly prevent the papules forming if applied early enough. Tried this with some benefit, but I didn't catch them until after they were already itchy welts, so hard to know. Seemed worth a shot, given the minimal effort. I saw a few people suggesting vinegar as a repellant as well.
Through a little research I found that Jewelweed(Impatiens capensis) is commonly used to treat bites and stings and such. Although it doesn't kill chiggers, it seems that it does help reduce their effects. This is a plant I haven't tried. Anyone having success with it?
I tried Jewelweed with the worst round of bites and found it offered some relief, but it did not last very long. But then nothing really did. I haven't tried it on single, isolated bites. That might be a better gauge of effectiveness than the 100 concentrated ones on my feet, but I digress. I took several plants, ran them through the blender with a bit of water (might have used a little witch hazel?) and strained the juice off. I froze this into ice cubes for later use. These are what I used. I do wonder if the cold was what created part of the relief. Some folks make salves and soaps out of jewelweed, which might work differently. You could also use the fresh plant (though I'd wash it first to make sure there aren't chiggers on it!). This works better with younger plants, as they get kind of fibrous and less juicy with age. But if you crush up the stem, especially near the root, you can use that as a poultice.
Mostly, I use a plantain (Plantago major or lanceolata) salve as my go to and found it helps quite a bit with more isolated bites. It is good for drawing stuff out and helps prevent secondary infections as well as speed healing. I am going to try making a salve of plantain and pine resin to see if that can help draw things out better from these awful bites. I wonder if its the stylosome that makes them so itchy and if so, if it can be dissolved or drawn out more quickly.
I also read that Wild Cherry (Prunus serotina) can help reduce histamine reactions, but have not been able to find much about how best to use it or if that would be appropriate in this situation.