Tests have shown neem oil to be effective as an insecticide, miticide, fungicide, nematacide and as an insect antifeedant. It will not harm beneficial predators like ladybugs, spiders, bees and wasps.
1 tsp per quart of water (4 tsp/gal)
plus 1/4 tsp of liquid dish soap (1 tsp/gal) as an emulsifier
Dyna-Gro Neem Oil MSDS
Dyna-Gro Neem Oil Information
Neem Foundation Organization