Evaluation of Beauveria bassiana (Balsamo) Vuillemin against Coriander Aphid, Hyadaphis coriandri (Das) (Aphididae: Homoptera)

Abstract

Laboratory bioassays were carried with seven different concentrations of Beauveria bassiana against Hyadaphis coriandri by using detached leaf bioassay technique with slight modifications. The mortality in treated aphids increased in conidial spore concentration. The highest concentration (1x10 10 conidia ml -1 ) caused maximum cumulative mortality (96.85%) at 7 days after treatment compared to the lowest concentration (1×10 4 conidia ml -1 ) with 67.61 per cent mortality. The median lethal concentration (LC 50 ) value recorded with B. bassiana was 1.5x10 4 conidia ml -1 in mixed H. coriandri population. Median lethal time (LT 50 ) values were found to be inversely proportional to the spore concentration of B. bassiana and were observed as 45.70, 67.60, 71.30, 87.04, 97.72, 120.26 and 141.57 h for 10 10 , 10 9 , 10 8 , 10 7 , 10 6 , 10 5 , 10 4 conidia ml -1 , respectively.