Hey Bro. I would avoid using neem oil as the active ingredient azederachtin has been linked to a syndrome which isn't very nice. Neem will work but one action of treatment usually sees the return of the pest in question unless you use something harsh like a heavy insecticide. Milbemectin is made from fermented bacteria and spinosad is also bacteria. There is something else you can use if you can find it. Metharizium 69. It's a fungus that infests insects and grows from the inside out, essentially killing them. In short however if you can't find any of these the neem will work as long as you apply 1-2 times a week at 5ml per Litre. It's also readily available and cheap for a new grower.
IPM ( Integrated Pest Management ) is something that should be implemented to avoid such infestations. Cover all your bases and add a fungicide, a miticide, some type of insecticide and some Kelp/Fulvic acid foliar sprays. MIx your Fulvic and kelp to a 5:2 ratio Fulvic to Kelp. It helps work as a plant protection agent and is a great bio stimulant.
Good luck brother.