About two years ago I read up on chitin as a possible pest control/deterrent as I was always struggling with mealybugs and thrips, especially in spring, and buying IPMs was getting quite expensive.
I had the most problems with my banana tree (thrips) and my kumquats (mealy bugs). But since I added insect frass (in my case sheddings and droppings from zophobas) in the fall two years ago, this problem disappeared almost miraculously. Since then I have added a small handful every spring and haven't seen a single thrip or mite on any of my plants.
Sooo… idk, it definitely gets a "worked for me".
The plants are: a cherimoya, kumquats, figs, a banana, two monsteras, and a bunch of pitahayas (although the cuttings are only 1 year old and haven't found a permanent home yet), hoyas and a small pineapple.
Looking forward to hear everyones experiences with this!