It seems our fly problem is much better. I use to blow on the plants and at least 6-10 baby flies would scramble. Now I get 1-2 and even zero at times! No more young sprouts have died from the larva eating the roots. So happy! So it seems the nematodes are working. Once the soil dried on the surface I put a thick layer of diatamaceous earth. This barrier has seemed to stop the flies from laying more eggs.