IntroductionThe Eudrilidae earthworms are endemic to the Ethiopian region (Reynolds, 1994). They present extreme variations in the sexual apparatus, particularly of the female organs (Omodeo, 2000;Blakemore, 2002. Eudriline evolution has resulted in economy of sperm production. Modifications in the male apparatus appear to reduce, or prevent, gregarine ravages (Sims, 1987). Eudrilus eugeniae has achieved a pantropical distribution (Omodeo, 2000).Megascolecidae is the most diverse family of earthworms (Blakemore, 2002); it has over 1000 species (Sims and Gerard, 1985;Blakemore, 2002). Most of them are native to Asia (Blakemore, 2002) and Australia (Sims and Gerard, 1985). One genus of the family Acanthodrilidae, Diplocardia, is native to North America. Several genera of Megascolecidae sensu stricto [i.e. Arctiostrotus, Argilophilus, Chetcodrilus, Drilochaera, Driloleirus (the only meroic genus), Kincaidodrilus, Macnabodrilus, Nephrallaxis, and Toutellus], placed under the as of yet poorly defined tribe