Diatomaceous earth in your mix keeps insects away.
Inorganic soil and fertilizers are a great preventative measure against bugs.
Dirt,moss,poo bags are all bug attractor.
I've gotten trees from nurseries that had Santa in them. I just put the old Napa8822 on the surface and they disappear.
I also use Bayer 3 in 1 systemic to keep flying insects like June bugs and rose chafers at bay. Take a bite and die. It also controls fungus and mites. I have none of these pest problems.
I'd never heard that about DE, I mean I know that powdered DE is detrimental to exoskeletons so it's effective there (like boric acid would be) but never heard that in relation to granular DE - while I've been using ~80/20 perlite/DE in my mixes, I used to use DE exclusively (or w/ lava rock bits), and have containers that have no DE, am going to have to look into how big an effect the difference is having in my garden!
Re inorganics, yes I love that about my substrates and fertilizers (instant-release, miracle-gro and the like), unfortunately around ~1.5mo ago I got a fertilizer I thought would be great (and is, in some ways), "espoma gardentone" a 3-4-4 slow-release that's all-natural and that stuff attracts ants like crazy, I remember that, after having put it down on some plants, a couple days later I was immediately regretting it as it was drawing ants to the plants... am still on the fence about ever using the stuff again on my trees!!!
Am not trying to say you're wrong but wow, just applying DE granules to the surface did that? I use the same stuff (8822 napa
) and know for a fact that ants can thrive in it, as, in the past month, I un-boxed my two oldest yamadori (yardadori- I saw your semantics thread
) and they were in ~85%/15% DE/rocks(hard stones, 'space savers' to stretch the DE I had when boxing them in training-boxes) Upon un-boxing I found incredibly active & heavily-populated ant colonies, like *tons* of activity, when I cracked these two boxes open!
I did my 1st test-run last night, using "insecticidal soap" that's made w/ select fatty-acids, it worked in that it killed the ants&aphids(mites? they're dark, but aphids can be too..), it's been 24hr so am just keeping an eye on the two plants I treated before using it everywhere I see any aphids/ants! I also got a longer hose so that I could use it to mechanically remove them with water-pressure (my tap is out front, so didn't actually have the ability to spray the trees before)
Didn't know bayer's 3-in-1 worked on fungus!!! I've got some of that and it was going to be my next step if the insecticidal soap didn't work, but now that you mention fungus I cannot help but think of the few bougies that I've got who've got very bad fungal issues on their bark, was meaning to do more vinegar / peroxide cleaning but it only seems to get the surface, not actually get rid of the fungal colonization :/
