Which of the following is an example of a residual barrier spray in tick management?

• A. Applying a spray around the interior walls of the home.
• B. Treating water features with larvicide.
• C. Applying a barrier spray around the yard perimeter on vegetation to create a treated boundary.
• D. Applying fertilizer to the lawn.

Answer: (C)

A residual barrier spray is a pesticide applied to exterior surfaces along a boundary so ticks crossing that boundary encounter a persistent residue. Putting the spray around the yard perimeter on vegetation creates a treated boundary that ticks must cross to reach hosts, giving ongoing protection as the product remains active for weeks to months depending on the product and conditions. This approach targets ticks where they live and move in the yard, rather than indoors or in water.

Interior wall spraying is aimed at indoor pests and doesn’t establish an exterior boundary against ticks. Treating water features with larvicide targets aquatic mosquito larvae, not ticks. Fertilizer has no pesticidal effect and won’t reduce tick populations.