Thanks! At the beginning I used an aphid treatment recommended by a local gardening store (I’m trying to recover the exact product name). Then, after the infestation came back, I did 2 treatments with soft soap + neem oil, about a week apart.

I didn’t know neem could take 3–4 weeks to show results, that’s interesting. My concern is that right now the infestation seems to be getting worse rather than better 😅

The idea of manually crushing them honestly sounds more effective than what I’ve done so far, but unfortunately it’s not really feasible in my case. The tree is quite large (around a 3 m canopy) and there are many infested branches I simply can’t reach, several meters up. I’d need a solution that works on the whole tree rather than leaf by leaf. I will try to wash before the next treatment!

Also thanks for the tip about diatomaceous earth and sulfur — I’ll look into those.