关键词:

贝莱斯芽孢杆菌, 东京芽孢杆菌, 微生物农药, 趋避效果

Abstract:

Snails and slugs are important mollusc pests damaging vegetable crops. Traditional chemical control measures tend to cause environmental and safety risks, including enhanced pest resistance to chemicals and disruption of the ecological balance. This study aimed to screen biocontrol bacteria with both high pathogenicity and favorable repellent activity against snails and slugs, and to systematically assess their field application potential. Two biocontrol strains with promising application prospects, namely Bacillus velezensis SL-1 and Bacillus toyonensis SL-2, were isolated, screened and identified from naturally dead snails and slugs in the field.The results of pathogenicity tests revealed that the 7-day corrected mortality rates of Bacillus velezensis SL-1 and Bacillus toyonensis SL-2 against snails were 93.00% and 82.00%, respectively, while both strains caused 100% corrected mortality against slugs within 7 days. Repellent tests indicated that the indoor repellent indices of the two biocontrol bacteria were both above 80%, and their field control efficacies remained higher than 74.70%. Insecticidal spectrum expansion tests confirmed that SL-1 and SL-2 also exhibited lethal activity against Tetranychus urticae and Brevicoryne brassicae. This study systematically explored the contact toxicity and repellent effects of biocontrol bacteria on snails and slugs, which provides a theoretical foundation and practical basis for the development of highly targeted and environmentally friendly microbial pesticides.

Key words: Bacillus velezensis; Bacillus toyonensis; microbial pesticides, repellent effect