The susceptibility of the third larval instar of the Oryctes agamemnon to infection and subsequent death by exposure to three native entomopathogenic fungi (NEPF); Beauveria bassiana, Metarhizium anisopliae and Lecanicillium lecanii was determined. Three concentrations of each NEPF isolate were used for dose-response mortality against the 3rd larval instar. Mortality rates of the larvae reached 34.2, 48.1 and 55.5% at the concentrations (104, 106 and 108 conidia/ml) of B. bassiana. M. anisopliae recorded mortalities reached 39.5, 57.4 and 60.8% to the target larvae. Similarly, the accumulated mortality of the 3rd instar larvae recorded 17.4, 26.4 and 29.2% for L. lecanii. The LT50 values of the 3rd instar of O. agamemnon larvae recorded 9.9 and 11.3 days for the two concentrations that achieved 50% mortality for B. bassiana and M. anisopliae respectively. M. anisopliae was the most efficient one, followed by B. bassiana and L. lecanii. The proteolytic activity of the three NEPF was investigated under different factors (incubation periods, temperature and pH). The results showed that the maximum activity of protease produced by B. bassiana, L. lecanii and M. anisopliae was recorded after 6 days of incubation with 28°C incubation temperature in the medium initially adjusted to pH 6.

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