VIRULENSI JAMUR ENTOMOPATOGEN BEAUVERIA BASSIANA (BALSAMO) VUILLEMIN (DEUTEROMYCOTINA: HYPHOMYCETES) TERHADAP KUTUDAUN (APHIS SPP.) DAN KEPIK HIJAU (NEZARA VIRIDULA)

Abstract

Virulence of entomopathogenic fungi Beauveria bassiana (Balsamo) Vuillemin (Deuteromycotina: Hyphomycetes) on aphid (Aphis spp.) and green stink bug (Nezara viridula). This study was conducted at the Laboratory of Plant Pests and Diseases Department of Plant Protection Faculty of Agriculture, University of Lampung. It was aimed to test the virulence  of field and commercial inoculum of B. bassiana on aphid  and  green stink bug.  The field inoculum of B. bassiana was originated from infected grasshoppers and isolated in Biocontrol Laboratory of PT Gunung Madu Plantations, Central Lampung, while  the commercial inoculum (Natural BVR) was formulated by PT Natural Nusantara.  A single exposure concentration assay (1 x 107 conidia/ml) for each inoculum was conducted by immersing the insects in fungal suspension for 10 second.  The results indicated that the virulence of field and commercial inoculum of B. bassiana was significantly different on aphid . The field inoculum  B. bassiana was highly virulent and caused 78.8% mortality, on the contrary the  commercial B. bassiana showed low virulence and caused only 27.42% mortality of aphid.  However, both inocula caused  76% and 70% mortality on green stink bug respectively.  The lethal period of  the field and commercial B. bassiana are 3.70 days and 3.72 days respectively on aphid, and 5.44 days and 4.58 days on green stink bug.  The virulence value of both inocula are 0.271 and 0.268 on aphids, and  0.195 and 0.245 on green stink bug. The virulence of both inocula is not significantly different. This results suggests that the commercial inoculum B. bassiana at 1 x 107 conidia/ml of concentration is less  effective  than the field inoculum  B. bassiana as control agent on aphid.