IUniversities have a lot of info check their entomology department.
believe this should be under zoology or ecology? 😀
Nematodes are beneficial because they help break down organic matter into soil.
There are good and bad nematodes.
Some nematodes are good to have in your garden soil or lawn because they kill harmful grubs like masked red chafer beetle and japanese beetle and even fleas!
there is a great deal of information on this subject on the internet.
If you are writing a paper make sure that you only cite information from web sites that end with edu, org or gov. they are more credible.