Pathogenic Effect of Trichoderma Asperelliodes on Aphis Craccivora

A.A.Khattab1, T.I.El-Sayed1, M.S.Hashem2 and S.A.Ibrahiem2"


The search for new microbial agents for pest control is one of the most important goals in the field of biological control. Some fungal species showed insecticidal activities. Therefore, isolation of more local fungal strains that would be more adapted to the local pest hosts and possesses greater insecticidal activities will be of great value. Studies were carried out in Plant Protection Research Institute, Sharkia branch, Sharkia governorate, Egypt during the period of 2014 to 2015 to survey aphids on some legumes. Trichoderma asperelliodes was isolated from soil, seeds and aphid insects, and was identified morphologically by light microscope and genetically using 18-S ribosomal DNA. Effect of different pH values (5.5, 6.5, 7, 7.5 and 8.5) and temperatures (20, 23, 25, 27, 30, 35 and 40 0C) on T. asperelliodes mycelial growth rates and activity were also studied. The toxicity of T. asperelliodes spore suspension on Aphis craccivora under laboratory condition was examined under electron microscopes (SEM and TEM). The results showed that the optimum environmental conditions for mycelial growth rates of T. asperelliodes were at 300C and pH7.5. Also, T. asperelliodes has a significant effect in controlling legume aphids with LC50 value of 5.4 x 107 spores ml-1 and LT50 value of 5.1 days.

Key words

Trichoderma asperelliodes, Biocontrol, Aphis craccivora.