Bioefficacy of Bacillus sphaericus R3 Against Spilarctia obliqua wlk (Lepidoptera: Arctiidae)

Bihar hairy caterpillar Spilarctia (Spilosoma) obliqua wlk (syn., Diacrisia obliqua walker), is a polyphagous insect pest of several crops causing economic losses by means of defoliation. Bacillus sphaericus R3 showed considerably high larvicidal activity (81.75% mortality) after treatment (1 -7 days) over control (7.0%) against Spilarctia obliqua wlk. Dose mortality suggested that feeding of Spilarctia obliqua wlk on treated leaves with variable spore population (10 6 - 10 11 CFU mL -1 ) of Bacillus sphaericus R3 was more effective after 7 days. The toxicity in terms of lethal spore population per ml (LC 50) of Bacillus sphaericus R3 was found to be 5.72 x 10 4 & 3.10 x 10 6 spores mL -1 , respectively after 3 and 7 days of feeding. Based on the LC 50 (spores mL -1 ) values for the strain it is concluded that Bacillus sphaericusR3 has potential to be used as an effective biocontrol agent (biological component of IPM) against Spilarctia obliqua wlk. (Singh SK, Mishra PK, Tandon SM. Bioefficacy of Bacillus sphaericus R3 Against Spilarctia obliqua wlk (Lepidoptera: Arctiidae). Nat Sci 2015;13(3):58-62). (ISSN: 1545-0740). http://www.sciencepub.net/nature. 10