Hey, just a tip,
when I use neem oil I use it roughly 5ml to one litre warm water...IMPORTANT.. one drop liquid dish soap,,in your kitchen,that kind, it helps break up the oil,cause thats what neem is and it will sit on the surface of water,,, and stir propely,,when sprayer shake your sprayer often to ensure the solution dosnt seperate,,the dish soap also helps the oil soak in,,and spray both sides of leaf...
I often make a litre of neem oil spray and the excess is used ,in small amounts ,over soil as a soil drench, so its in the system. Neem oils systemic,,, So dont use as a soil drench for two weeks before harvest,maybe more, And I wouldnt use on plants less than 3-4weeks old unless nessacary, as it has trace elements in and can cause leaf brun. It looks like that from my exp./
This is a small small amount over soil,just enough to soak in,and be taken up.
Any excess left from spray has to be drained from sprayer,as neem oil seperates and wont keep for more than an hour, after that It will but will become ineffective. Try do foilar spray every 3-5 days for 4 times, then stop and if pests are still a problem use somthing different so the pests dont become immune to neem. Try nictione spray. Can tell You my recipe if you like.
Remember,neem wont kill them striaght away, it screws with the pests life cycle, so use more than once to be effective,,
Thats how Ive used the stuff with good effect,,Hope that helps..
Take it easy..........