Abstract: A fungus which has high infectivity toward a stem, leaf, bud, or flower nematode and is characterized by the production of a first type of conidiophores, conidiogenous cells, and conidia and a second type of conidiophores, conidiogenous cells, and conidia when grown in vivo or on a solid medium. The first type of conidiophores is macronematous, mononematous, simple, erect, and broadly ampulliform; the first type of conidiogenous cells is integrated, phialidic, and rarely percurrent; and the first type of the conidia is solitary, one-celled, asymmetrically ellipsoidal, lunate, and concave. The second type of conidiophore is macronematous, mononematous, simple or branched, cylindrical, subulate, and elongate; the second type of conidiogenous cells is integrated, phialidic, enteroblastic, terminal or intercalary, laterally proliferic, and indeterminate; and the second type of conidia is solitary, one-celled, bacilloid, and cylindrical. In particular, a fungal culture Esteya vermicola ATCC74485.