Green Lacewings
I noticed that my avocado tree was developing brown spots on the leaves, which were almost certainly the result of Persea mites.
So I looked up some possible cures, and it seemed like introducing a predator would be the best option and the least hassle. I’d had good luck with introduced ladybugs a few years back, which formed a stable population that survived for many years after introduction. For this pest, green lacewings are recommended. I found a nearby insectary that could provide larvae on cards and they shipped them overnight.
The little guys look cute just waiting to hatch…
I hung he cards on the leaves of the tree after incubating them overnight in a warm room, and they should hatch sometime in the next day or two, as long as the ants don’t find them first…
Update 8 Sept 2016:
The green lacewings seem to have eaten all the mites. It has been 9 months and there aren’t any signs of damage to this spring’s leaves. Yay!
The new leaves that grew seem to be developing without any bites at all. The old leaves that were too damaged have fallen off, but the surviving older leaves still show the scars of the mites. Green lacewings seem to have done the trick.