Investigating the non-lethal effects of the bacterium Bacillus thuringiensis on the snail Achatina fulica

Articles in Press

Document Type : Complete paper

Authors

1 Department of Plant Protection, Faculty of Agriculture, College of Agriculture and Natural Resources, University of Tehran, Karaj, Iran

2 Department of Plant Protection,, Faculty of Agriculture, College of Agriculture and Natural Resources, University of Tehran, Karaj, Iran.

Abstract

The snail Achatina fulica is an imortant agricultural pest on various plant species. Bacillus thuringiensis (Bt) is a key microbial agent used for control of insect pests. Its potential for managing agricultural mollusks has not been studied. The effect of Bt was evaluated against A. fulica using both direct and indirect approaches. Lettuce was cultivated in a greenhouse and used for snail feeding. The endophytic potential of Bt was investigated using two methods: leaf spraying and root drenching of lettuce with bacterial suspension. Data collected indicated successful endophytic colonization exclusively through the leaf spray method, while plants treated via root irrigation did not harbor endophytic bacteria. The efficacy of Bt was assessed under treatments immersion of lettuce leaves in bacterial spore-crystal suspension, vegetative-phase bacterial suspension without crystals, suspension of Xanthomonas translucens and sterile distilled water. These treatments were applied to adult and non-adult snails. The results revealed no visible effect on adult snails. Non-adult exhibited a complete inhibition of lettuce feeding persisting for 21 days. The gut was aseptically dissected 14 and 22 days post-treatment for non-adults. Suspensions obtained by homogenizing the gut in sterile distilled water were cultured on nutrient agar plates. After five days, the presence of Bt spores and crystals was confirmed. Molecular analysis using PCR and sequencing of the 16S rRNA gene further validated the bacterial identity. Although no direct mortality of A. fulica was observed, the cessation of feeding in immature stages for three weeks significantly reduced the damage caused by the snail.

Keywords

Main Subjects

BIOLOGICAL CONTROL OF PESTS AND PLANT DISEASES

Articles in Press, Accepted Manuscript
Available Online from 30 December 2024

Files

Share

How to cite

Statistics