You can use neem all the way up until the harvest day. What i did to rid them when i was using soiol was to not water for a few days letting the top soil dry out. Then i would take them outside oer put them in the sink and run water in them until it began to overflow. This got the eggs out and from that time on ididnt have a problem. If your not too careful with neem u can really hurt a plant. just my ywo scents!!:hippy: