AzaSol natural bio insecticide is a dried powder azadirachtin that is freely soluble in water and is stable for over 2 years (shelf life). 

When mixing Azasol with water at the time of application, it is significantly more effective than traditional neem oils, emulsifiable concentrates, or pre-mixed azadirachtin liquids. Its solubility allows superior flow characteristics for absorption and systemic utilization in plants. It is non-phytotoxic (doesn't inhibit growth) when used as directed.

How does it work?

Anti-feedant - Insects will feed less or not at all so they starve to death.
Insect Growth Regulator - Insects will not mature, reproduce or grow, so populations will not increase to damaging levels.
Anti-ovipository and Repellent - Insects will be repelled and will avoid laying eggs.

Use AzaSol to control:

Whiteflies
Scale
Mealy Bugs
Thrips
Aphids
Psyllids
Flies
Sawfiles
Caterpillars
Beetles
Weevils
Mole Crickets

AzaSol's soluble 6% azadirachtin powder can be used on trees, shrubs, turf, and vegetable or flower gardens. You can apply it as a foliar spray or soil drench.

A little goes a long way so its much more cost effective than the liquid versions.