Journal of Pure and Applied MicrobiologyVol. 9 No. 4

Screening of Beauveria bassiana (Balsamo) Vuillemin Isolates Against Maize Stem Borer, Chilo partellus (Lepidoptera: Pyralidae) and the Effect of Solid Substrates on Conidial Production and Virulence

S. Renuka, Bonam Ramanujam* and B. Poornesha

National Bureau of Agricultural Insect Resources, H. A. Farm post, Bellary Road, Hebbal, Bangalore - 560024, India.

Received on 20 May 2015 and accepted on 10 August 2015

 

ABSTRACT

In the present study, eighty seven isolates of Beauveria bassiana obtained from NBAIR culture collection were screened against maize stem borer, Chilo partellus in laboratory bioassay. Six B. bassiana isolates (Bb-5a, 7, 19, 45, 14 and 23) showed higher mortality (77.25-100%) and mycosis (71.11-97.78%). These isolates were further subjected to dose and time mortality tests. Among the six isolates tested, Bb-45 showed the least LC50 (4.4x105 conidia/ml) and LT50 (136 hrs) on second instar of C. partellus. Among the different substrates tested, rice supported higher conidial production of promising isolates of B.bassiana (1.66-2.83g conidia/100g of substrate) and also induced production of virulent conidia for all the isolates.

Keywords : Beauveria bassiana, Biocontrol, Chilo partellus, LC50, LT50, Zea mays L