What type of pesticide formulation is water soluble and dispersed in an oil carrier?

The correct answer is invert emulsions, which are a specific type of pesticide formulation that combines water-soluble ingredients with an oil carrier. In invert emulsions, the usual oil-in-water emulsion is inverted, leading to a water-in-oil formulation. This allows the active ingredient to be delivered effectively while stabilizing the pesticide within the oil medium. This formulation is particularly advantageous in applications where longer residual effects and high levels of penetration through plant surfaces are desired.

Other types of formulations, like dry formulations, consist of pesticides in solid form (such as powders or granules) and do not involve the water-oil interaction that characterizes invert emulsions. Microencapsulated formulations involve pesticide particles that are coated with a material that creates a tiny capsule, providing slow release of the active ingredient, rather than being water-soluble and dispersed in oil. Fumigants, typically gases used to control pests, do not fit the description of a formulation that combines water and oil. In summary, invert emulsions distinctly meet the criteria of being water-soluble and contained within an oil carrier, making them an effective choice for certain pesticide applications.