What type of pesticide is designed to control roundworms?

Nematicides are specifically designed to control nematodes, which are a type of roundworm that can be detrimental to plants. These pesticides target the life cycle of nematodes, disrupting their reproduction and ultimately leading to their death. This is particularly important in agriculture and gardening, where nematodes can cause significant damage to crops by feeding on plant roots, leading to reduced yields and quality.

In contrast, pheromones are chemicals used to attract or repel insects, not specifically targeting roundworms. Repellents are substances intended to ward off pests rather than kill them, and miticides focus on controlling mites, which are a different type of pest entirely. Therefore, the understanding of pesticide categories highlights why nematicides are the correct choice for controlling roundworms.