Ornamental and Turf Pesticide Applicators Practice Exam

Which of the following pests typically indicates root damage in turf?

1. Grasshoppers

2. Miserable black beetles

3. White grubs

4. Twilight caterpillars

The correct answer is: White grubs

The presence of white grubs is a clear indicator of root damage in turf. These larvae stage of various beetles, especially Japanese beetles and other species, feed on the roots of grasses. When white grubs are present in the soil, they can significantly weaken the grass by damaging the root system, leading to symptoms such as wilting, thinning, and discoloration of the turf. This root damage can ultimately result in patches of dead or dying grass, particularly during periods of stress, such as drought or heat. In contrast, the other pests mentioned do not typically cause direct root damage. Grasshoppers primarily feed on the foliage of plants and do not interact with the root systems. Miserable black beetles, while they can be a nuisance, do not usually target the roots of grass. Twilight caterpillars, being leaf-eating pests, damage the leaves rather than the roots. This is why the identification of white grubs is crucial in turf management, as their presence is a strong sign of underlying root problems that need to be addressed to maintain healthy grass.