| International Journal of Current Microbiology and Applied Sciences |
| ISSN: 2319-7706 Volume 2 Number 10 (2013) pp. 268-282 |
| Toxicity of different indigen isolates of Bacillus thuringiensis on mango weevil Myllocerus undecimpustulatus (Coleoptera: Curculionidae) |
| G.T.Geetha1*, N. K. KrishnaKumar2 , H. M. Mahadeva Swamy3 , R.Asokan3 and Riaz Mahmood |
| 1Division of Entomology and Nematology, Indian Institute of Horticultural Research (IIHR), Hessaraghatta lake post, Bangalore 560089, Karnataka, INDIA 2Division of Horticulture, Krishi Anusandhan Bhawan - II, New Delhi - 110 012 INDIA 3Division of Biotechnology, Indian Institute of Horticultural Research (IIHR), Hessaraghatta lake post, Bangalore 560089, Karnataka, INDIA 4Post-Graduate Department of Studies and Research in Biotechnology and Bioinformatics, Kuvempu University, Jnanasahayadri, Shankaraghatta, Shimoga 577451, Karnataka, INDIA |
| ABSTRACT |
| Coleopteran pest control in general is entirely relied on the application of chemical insecticides. Little or no information is known about the natural presence of Bacillus thuringiensis species that possess insecticidal activity in the environment against coleopteran insect pests. The problems associated with resistance show how important it is to continue screening for new strains harboring toxins with high activity against pests. Moreover, the discovery of new toxins may also represent new genetic resources for developing genetically engineered technologies utilizing B. thuringiensis toxin genes, including integrating them into the genomes of plants of agri and horticultural interest. The present study aimed at searching for Bt strains encoding coleopteran active insecticidal crystal proteins that act more effectively against mango weevil. Thirty Bt strains were evaluated through bioassay studies. Crude protein from thirty indigen Bt isolates was extracted and used at different concentrations for bioassay against adults of M. undecimpustulatus. The per cent mortality was recorded after 24, 48 and 72 hrs of treatment. 15 native Bt isolates (50.00%) showed cent percent mortality followed by IIHR_HMM_MAD_KL (92.22%), IIHR_HMM_NAL_KL, (93.33%) at 600 g/cm 2 after treatment when compared with Bt subsp. morrisoni. pathovar tenebrionis. The present study aimed at searching for Bt strains encoding coleopteran active insecticidal crystal proteins that act more effectively against mango weevil. Thirty Bt strains were evaluated through bioassay studies. |
| Keywords |
| Bacillus thuringiensis; Bioaasay, Coleoptera; Insect resistance; Mortality; Myllocerus undecimpustul atus. |