Four known species of insect parasitic nematodes were recovered from Periplaneta americana and Gryllotalpa africana. They are all redescribed in the present study. Key to species along with comparative measurement chart of all known species of Leidynema, Gryllophila and Hammerschmidtiella have been provided. Based on additional features that were not provided by previous workers the emended generic diagnosis of Thelastoma, Leidynema, and Hammerschmidtiella have been provided in the present study.