Application of a curative, broad-spectrum insecticide can be fatal to earthworm populations.

• A. False
• B. It depends on formulation
• C. Only in moist soils
• D. True

Answer: (D)

Using a curative, broad-spectrum insecticide means you're aiming to kill a wide range of insects, not just a single pest. Earthworms live in turf soil and are exposed to the product through contact with treated soil, ingestion of contaminated soil, or uptake of residues. That exposure can kill earthworms or impair their activity, which in turn hurts soil structure, aeration, and nutrient cycling that turfgrass depends on. So the statement is true: such insecticides can be fatal to earthworm populations. While the exact impact depends on factors like product properties, rate, timing, and soil conditions, the non-target danger to earthworms is a common concern with broad-spectrum curatives, not something that's limited only to moist soils or a particular formulation.