What role do adjuvants play in mosquito adulticiding sprays and what is one potential risk of them?

• A. They improve deposition, spread, or penetration; potential risk includes increased dermal or inhalation irritation and drift.
• B. They kill mosquitoes directly; risk is chemical burn to water.
• C. They replace the active ingredient if not used correctly.
• D. They have no effect on deposition or drift.

Answer: (A)

Adjuvants modify how the spray behaves after application to improve the active ingredient’s effectiveness. They help droplets deposit more evenly on surfaces mosquitoes rest on, spread across those surfaces, and sometimes assist the spray in penetrating through vegetation or small cracks where mosquitoes may hide. Because they change the physical properties of the spray, they also influence exposure risks. A potential problem is that adjuvants can increase dermal or inhalation irritation for applicators or bystanders, and they can alter droplet behavior in a way that raises spray drift to non-target areas.

These additives don’t kill mosquitoes by themselves, and they don’t replace the active ingredient if used incorrectly. They do have an impact on deposition and drift, unlike options that claim no effect on these factors.