The toxic effect of different formulations of six Trichoderma isolates on the hatchability of Monacha cartusiana and Eobania vermiculata eggs (T. hamatum, T. viride, T. harzianum, T. koningii, T. asperellum and  T. pseudokoningii) were evaluated under laboratory conditions. The experiments were conducted at the Biological Laboratory of  Econ. Entom. and Agric.  Zoology Dept., Fac. Agric., Menoufia University.  Statistical analysis of the data indicated that there were significant differences among the 3 concentrations of each Trichoderma germ isolates on the hatchability of M. cartusiana eggs. The toxicity was increased by increasing the concentrations of each isolate.  Furthermore, there were significant differences among the six Trichoderma germ isolates in their toxic effect on the hatchability of M. cartusiana and E. vermiculata eggs.  The lowest hatchability % of M. cartusiana eggs was recorded (0.0 %) after four weeks of exposure to Trichoderma harzianum and  T. asperellum treatments at  6x10⁶ CFU / g, followed by T. asperellum treatment at  6x10⁶ CFU / g as 23.3%. As for E. vermiculata egg experiment, there were significant differences among the six Trichoderma germ isolates in their toxic effect on the hatchability of E. vermiculata eggs. The lowest hatchability percentages of E. vermiculata eggs were recorded as 3.3 and 6.7 %, after four weeks of T. harzianum and  T. asperellum treatments at  6x10⁶ CFU/g, followed by T. asperellum treatment at  4x10⁶ CFU / g as 16.7 %. There were significant differences among the tested six Trichoderma extracts in their toxic effect on the hatchability of M. cartusiana eggs. The lowest hatchability % of M. cartusiana eggs were recorded (0.0 and 3.3 %) after four weeks of exposure to T. harzianum and  T. asperellum extracts. In addition, the lowest hatchability of E vermiculata eggs was recorded (0.0 and 0.0 %) after four weeks of exposure to T. harzianum and  T. asperellum extracts treatment, followed by T. pseudokoningii extract at 26.7 %. GC-Mass spectrometry analyses of T. harzianum isolates revealed the high contents of Glacial acetic acid, 2,3-butanediol, Trichodermaerin, Aspereline A, which may be responsible for toxic effects.