Members of the Nematoda phylum are invertebrate animals with the most incredible diversity on Earth after arthropods. Due to their ability to thrive in all types of habitats, in addition to the more than 25,000 species that have been identified, it is estimated that there are more than 100,000 members. Their superior reproductive abilities also play an important role in their distribution. A significant portion of nematodes can cause parasitic infections with high mortality and morbidity rates, negatively affecting the health of vertebrates and invertebrates. In addition, countless species can cause significant losses in agriculture that can also affect human health. However, a large group of them also has important benefits in maintaining the ecosystem due to their free-living nature. Regulating soil colonization, combating harmful microorganisms and arthropods, and regulating soil nitrogen balance are among their positive effects.

This book will mention the harmful effects of some nematodes on animal and plant health, as well as nematodes that play a role in organic control and in ensuring sustainable development in agriculture. It will also address the objectives of strengthening host defense mechanisms against nematodes.