Which part of a pesticide formulation is effective against the target pest?

• A. Active Ingredient
• B. Adjuvant
• C. Carrier
• D. Inert Ingredient

Answer: (A)

The active ingredient is the part that actually harms or kills the target pest. In a pesticide formulation, this is the component with pesticidal activity—the substance that delivers the effect you’re seeking. The other parts—adjuvants, carriers, and inert ingredients—help with applying and delivering that active ingredient: adjuvants improve coverage, adhesion, or penetration; carriers are the medium that carries the active ingredient (like a solvent or granules); inert ingredients provide solvents, stabilizers, dyes, or other non-pesticidal supports. None of those by themselves kill the pest; they just enable the product to work better or be easier to use. So, the active ingredient is the part that is effective against the pest.