For four years, our two young pear trees succumbed each year to pear midge, which reproduces in young fruitlets, causing >98% losses. I was lucky to get ten fruit surviving each year.
This spring, I applied the biodynamic potion called horn manure to garden, including all the fruit trees. I am delighted to say that this year, 60 healthy fruit are growing on the one tree we kept after removing one in despair.
I present this as an observation rather than a proof.
Anyone else suffering that way, it may be worth applying horn manure in late autumn and late winter/early spring to see if my observation can be replicated or not….