Biological Control Agents Against the Bulb Mite, Rhizoglyphus robini Using Some Conidial and Fungal Filtrates

The bulb mite, Rhizoglyphus robini is a resilient pest that causes significant damage to many crops. Traditional control methods often rise about environmental impact. This study aimed to evaluate the feasibility of using four Egyptian fungal isolates as a sustainable solution for managing R. robini populations. Four fungal isolates native to the Egyptian environment, namely Aspergillus terreus, Aspergillus flavus, Myrothecium advena, and Penicillium crustostum, were subjected to laboratory evaluation of their efficacy against R. robini at different conidial concentrations, with the test concentration chosen as 3.2x106 conidia/ml. A. terreus isolate was most effective against R. robini followed by M. advena, A. flavus, and P. crustostum. The mortality rates (78.62, 69.66, 17.93, and 1.38%) and lethal concentration (LC50) values shown by A. terreus and M. advena, were (1.06×106, 1.75×106, 3.45×106, and 7.4×109) conidia /ml, respectively. The fungal culture filtrate (FCF) of the above isolates was evaluated at different concentrations in adults and eggs where the concentration (100SS) showed high efficacy (76.00, 72.73 and 51.74%) in contrast to the other fungus, P. crustostum where the mortality rate was (8.39) on adult females, respectively, and the inhibition rate was high on hatching of both egg mites of M. advena, ,A. terreus and P. crustostum where they were ( 75.57, 68.90 and 46.67%), respectively. While the fungal filtrate of A. flavus was (33.90%).