Why are neonicotinoids favored for subsurface feeders in turf grub control?

• A. They bind strongly to soil particles and stay near the surface
• B. They have less binding to soil particles and move toward the root zone
• C. They are the cheapest option
• D. They evaporate quickly

Answer: (B)

Subsurface turf grub control works best when the insecticide is present where the grubs feed—the root zone. Neonicotinoids are relatively mobile in soil because they don’t bind strongly to soil particles. This lets them move with soil water down into the root zone after application, so the grubs ingest the chemical as they feed on roots. They may also be taken up by plant roots and distributed, which helps maintain contact with feeding larvae. This mobility toward the root zone explains why they’re favored for subsurface feeders. The other ideas don’t explain targeting the root zone: staying near the surface, evaporating quickly, or simply being cheap don’t describe the soil movement that places the chemical where the grubs are.