Mohammad Rafiq Siddiqi2014-06-052014-06-051983Pak. J. Nematol., 1(1):63-77, 1983http://hdl.handle.net/123456789/2414Ecological adaptations of Tylenchida, Aphelenchida, Dorylaimida and Triplonchida (= Diphtherophorina Coomans & Loof, 1970, new synonymy) are discussed. The ectoparasites are categorised as (a) passive feeders, (b) migratory root surface feeders, (c) migratory deep root tissue feeders, (d) sedentary root ectoparasites and (e) migratory ectoparasites of aerial parts. The endo-parasites are grouped under (a) migratory endoparasites of aerial parts, (b) migratory endoparasites of subterranean parts and (c) sedentary endoparasites.enArticle