PATHOGENICITY OF FOUR SPECIES OF ENTOMOPATHOGENIC FUNGI TO Sitophilus oryzae (Linnaeus) ADULT IN THE LABORATORY CONDITION

Abstract

Study on pathogenicity of four species of entomopathogenic fungi, Cordyceps javanica, Beauveria bassiana, Beauveria amorpha and Metarhizium anisopliae, against Sitophilus oryzae adult of the stored-grain insect pests was evaluated under laboratory conditions. Bioassays were conducted by introducing 10 Sitophilus oryzae adult in plastic box (13 x 10 x 10cm) containing 50 g of rice and 2 g of entomopathogenic fungi at temperature of 25 ± 1^oC and humidity of 70 ± 2% RH. Mortality and mycelial extrusion was monitored at 5 day intervals until 35 days following treatments. Evaluate the pathogenicity of four species of entomopathogenic fungi on Sitophilus oryzae adult based on five parameters: Percent insect mortality, median lethal time, percent mycelial extrusion, fungal developmental cycle and spore production. Research results have been evaluated and selected Cordyceps javanica for potential application of biocontrol of Sitophilus oryzae: Percent insect mortality 86.67 ± 2.46%; median lethal time (LT^­₅₀) 12.15 ± 0.54 days; percent mycelial extrusion 69.23 ± 1.63%; developmental cycle duration 17.43 ± 0.87 days and spore production concentration 2.3 x 10⁷ (spores/insect).