Some are sold in pressurized cans. Dry formulations include dusts which usually have a D on the label. Dusts must be used dry. Granular formulations are much larger than dust particles and also should be used dry. A wettable powder designated by a W or WP looks like a dust, but is made to mix with water.
Wettable powders require continuous agitation to maintain a suspension.
A foliar pesticide is one which is applied to the leaves of plants. When you are using any pesticide, remember to read the label carefully before using the product. Don't use the pesticide, then read the label.