Final answer:
Nematodes have significant economic importance in agriculture due to their impact on crop yields, their role in the nutrient cycle, and their use in biological pest control.
Step-by-step explanation:
The economic importance of nematodes is multifaceted and significant. These microscopic worms play crucial roles in agriculture and ecosystem functioning. For instance, parasitic nematodes such as the root knot nematodes (Meloidogyne spp.) cause severe damage to crops by interfering with the normal uptake of water and nutrients, resulting in major yield losses.
This makes research into plant-nematode interactions and the development of nematode-resistant crops vital. In soils lacking nitrogen, certain fungi prey on nematodes, which shows their role in the nutrient cycle. Additionally, nematodes are used in biological pest control. For example, the Beauveria bassiana fungus, which infects a variety of insect pests including the emerald ash borer, offers a way to control such pests without resorting to chemical pesticides.