Laboratory evaluation of Beauveria bassiana (Balsamo) Vuillemin against Crawler Stage of Paracoccus marginatus (Williams and Granara de Willink) Kumar K. Indira*, Kennedy J. S.**, Suresh S.*** Department of Agricultural Entomology, Tamil Nadu Agricultural University, Coimbatore 641 003, Tamil Nadu, India *Email: poochimb@gmail.com
**jskennedy@gmail.com
***ssureshsupra@gmail.com
Online published on 24 December, 2014. Abstract Laboratory bioassay studies were carried with five different concentrations of different Beauveria bassiana (Bals.) Vuill. Strains viz., ANR (Bb), AVI (Bb), KPI(Bb), PLR (Bb), TMR (Bb) and UPI (Bb) whichwere isolated fromdifferentsources collected fromdifferent places of Tamil Nadu and tested their efficacy against crawler of papaya mealybug P. marginatus by leaf disc bioassay. The results revealed that B. bassiana starins, UPI (Bb) and ANR (Bb) were recorded The lowest LC50 values of 1.03x107 and 3.47x107 spores ml−1 respectively which showed higher virulence compared to other isolates. The LC50 values of other isolates of B. bassiana, AVI (Bb), KPI (Bb), PLR (Bb) and TMR (Bb) were 7.92x107, 1.04x108, 1.45x108 and 1.85x108 spores ml−1 respectively. At the highest concentration of 1x108 spores ml−1, the Median LT50 values for B. bassiana different isolates viz., UPI (Bb), ANR (Bb), AVI (Bb), KPI(Bb), PLR (Bb) and TMR(Bb) were 4.77, 7.00, 8.09, 9.27, 9.68 and 9.91 days respectively. Median lethal time (LT50) values were found to be inversely proportional to the spore concentration of B. bassiana. Among the different B. bassiana isolates, UPI (Bb) was found to be the promising virulent isolate. Hence by testing its field efficacy, it can be used as potential biocontrol agent for the management of papaya mealybug. Top Keywords Tapioca, Paracoccus marginatus, Beauveria bassiana, Median lethal. Top |