When applying granular insecticide to treat white grubs, which factor will reduce effectiveness?

When applying granular insecticide to treat white grubs, which factor will reduce effectiveness?

• A. Thatch will reduce effectiveness
• B. Moisture level will reduce effectiveness
• C. Sunlight exposure will reduce effectiveness
• D. Cold temperature will reduce effectiveness

Answer: (A)

Granular insecticides for white grubs need to reach the soil where the grubs feed. A thick thatch layer—dead grass and debris on the soil surface—acts as a barrier, keeping many granules on top rather than allowing them to move into the soil. When granules stay in the thatch, they can’t contact the grubs, so the product can’t work as well. Moisture is actually needed to activate and wash granules into the soil, so moisture level tends to help rather than hinder. Sunlight exposure and cold temperatures are less critical factors for this type of product once it’s properly activated and watered in, whereas the barrier created by thatch most directly reduces effectiveness.

Granular insecticides for white grubs need to reach the soil where the grubs feed. A thick thatch layer—dead grass and debris on the soil surface—acts as a barrier, keeping many granules on top rather than allowing them to move into the soil. When granules stay in the thatch, they can’t contact the grubs, so the product can’t work as well. Moisture is actually needed to activate and wash granules into the soil, so moisture level tends to help rather than hinder. Sunlight exposure and cold temperatures are less critical factors for this type of product once it’s properly activated and watered in, whereas the barrier created by thatch most directly reduces effectiveness.