Faktor-faktor Yang Mempengaruhi Patogenesitas Beauveria Bassiana Terhadap Bubuk Buah Kopi (Hypothenemus Hampei) = Factors Affecting Pathogenicity ofBeauveri Bassiana against Coffee Berry Borer (Hypothenemus hantpai)

Abstract This research was aimed to evaluate the pathogenicity of Beauveria bassiana (Balsamo) Vuillemin against Coffe Berry Borer (CBB), Hypothenemus hampei Ferrari (Coleoptera : Scolytidae) which had been developing by the Biological Laboratory at the Estate Crop Service in Yogyakarta Special Territory. A 2 x 3 factorial arranged in Completely Randomized Design with five replications was applied to evaluate effect of propagation media and spore density under laboratory condition, and four replications for under field condition. The media were corn and potato-sugar extract and the spore density rates were 2 x 107,4 x 107, and 6 x 107 spores ml1. A nested design was applied to evaluate the effect of inoculum sources, 'old isolate' and 'new isolate' (repassage). Randomized Complete Block Design was applied to evaluate the effect of synchronization between spraying time of B. bassiana spores and the CBB infestation. Results showed that the pathogenicity of the tested isolate of B. bassiana was very low. Under the laboratory condition, the propagation media did not affect significantly the mortality of adult CBB, while the. spore density affected it significantly The mortality at the density rate of 6 x 107 spores ml"1 (56%) was relatively similar to 4 x 107 spores ml"1 (44%), but it was significantly higher to 2 x 107 spores ml"1 (27%). The mortalities under field conditions were lower than those of under laboratory conditions. In the field, the propagation media and the spore density did not affect significantly to the mortality rate of the CBB. The mortality at the rates of 6 x 107, 4 x 107 and 2 x 107 spores ml'1 were 30,28 and 17%, respectively. The inoculum source did not affect significantly to the CBB mortality level. The CBB mortality due to the 'old isolate' and 'new isolate' of the B. bassiana were 42 and 41%, respectively, so that re-passage effort did not increase its virulence. The B. bassiana effectiviy was significantly influenced by the synchronization between time spraying of the spores and CBB infenstation. The spores spraying was recommended at the initial CBB infestation i.e. when several fruits start being infested. Keywords : Beauveria bassiana � coffee � Hypothenemus hampe