Molluscicidal activity of Nicotiana tabacum extracts on the invasive snail Pomacea canaliculata.

Botanical molluscicides for controlling the invasive snail Pomacea canaliculata have attracted worldwide attention because of their cost and environmental friendliness. Aqueous extracts from discarded tobacco leaf (Nicotiana tobacum) were evaluated for molluscicidal activity against different-sized P. canaliculata under laboratory conditions. The results showed that over 90% of the snails died in 1 g/L tobacco extract within 4 days, and the survival of P. canaliculata was inversely proportional to the snail size, tobacco extract concentration and length of exposure time. Adult males were more susceptible to tobacco extract than females. The snails had few chances to feed or mate in 0.5 g/L tobacco extract, and reproduction was greatly limited in 0.2 g/L. The growth of juvenile snails was inhibited in 0.2 g/L tobacco extract, but adults were unaffected. The antioxidant capacity of P. canaliculata in response to tobacco extract can be size- and sex-dependent, and the activities of superoxide dismutase, catalase, and acetylcholinesterase and the contents of glutathione and malondialdehyde were increased in adult males. These results suggest that discarded tobacco leaves can be useful as a molluscicide for controlling the invasive snail P. canaliculata based on its effects on survival, behaviour, food intake, growth performance and antioxidant capacity.