Georgia Pest Control Practice Test

Which pesticide formulation would likely have the shortest residual life on a porous surface?

1. Microencapsulated materials

2. Wettable powders

3. Emulsifiable concentrates

4. Oil concentrates

The correct answer is: Emulsifiable concentrates

Emulsifiable concentrates are designed to provide effective control while having a relatively short residual life, especially on porous surfaces. This formulation typically consists of oils and surfactants that allow the pesticide to mix with water. When applied to porous materials, the water component can be absorbed, leading to quicker breakdown and dissipating effects of the chemical. The other formulations tend to have longer residual effects. Microencapsulated materials release their active ingredients slowly, making them last longer on surfaces. Wettable powders are designed to remain in place and can have prolonged effectiveness since they do not readily wash off. Oil concentrates tend to adhere well due to their oily nature, which can also extend their residual activity on surfaces. Thus, emulsifiable concentrates stand out for their tendency to degrade more quickly in porous applications, allowing for shorter residual activity compared to other formulations.