Diversity of entomopathogenic bacteria associated with the white grub, Brahmina coriacea

作者：Sharma Anupam^*; Thakur D R; Kanwar Sarika; Chandla V K

来源：Journal of Pest Science, 2013, 86(2): 261-273.

DOI：10.1007/s10340-012-0459-5

• Entomopathogenic bacteria
• 16S rRNA genes
• Biochemical test
• White grub
• Potato

A survey of potato fields located in the south-eastern region of Himachal Pradesh (India) was carried out in order to find out the natural pathogens infecting the white grub, Brahmina coriacea. About 88 % population of the infected grubs were found to exhibit symptoms of natural bacterial infection during the years 2007-2008. Hence, we attempted to isolate and characterize the most potent bacteria for the management of B. coriacea and tested their insecticidal activity. In this study, ten different bacterial isolates belonging to genera Bacillus, Psychrobacter, Paracoccus, Paenibacillus, Mycobacterium, Staphylococcus and Novosphingobium were isolated from B. coriacea. Bacterial species were identified based on morphology, biochemical tests and homologies of 16S rRNA gene sequences. Pathogenicity tests for all isolated bacteria at 1.0 x 10(8) cfu/ml of broth were performed on late first instar grubs. Among the bacteria tested, Bacillus cereus induced highest mortality level of 51.85 % within 7 days of treatment followed by Psychrobacter pulmonis (33.33 %), Bacillus psychrodurans (25.93 %), Bacillus pumilus (25.93 %), Paenibacillus tylopili (22.22 %) and Novosphingobium capsulatum (18.52 %). Mortality levels were further increased up to 100 % by B. cereus followed by 88.89 % by P. pulmonis after 30 days of treatment. Our results indicate that B. cereus, P. pulmonis, B. psychrodurans, B. pumilus, P. tylopili and N. capsulatum may be valuable biological control agents for white grubs, B. coriacea.

• 出版日期2013-6