Evaluation of Different Attractant Baits for Trapping Giant African Snail, Lissachatina fulica (Bowdich)
Jyothy Narayanan *
Kerala Agricultural University, Aromatic and Medicinal Plants Research Station, Odakkali, Asamannoor P.O., Ernakulam, Kerala, PIN- 683549, India.
Ancy Joseph
Kerala Agricultural University, Aromatic and Medicinal Plants Research Station, Odakkali, Asamannoor P.O., Ernakulam, Kerala, PIN- 683549, India.
*Author to whom correspondence should be addressed.
Abstract
Background: Giant African Snail (GAS) infestation requires practical trapping options that can reduce dependence on chemical molluscicides.
Aims: The study aims to identify effective and eco-friendly fermented baits prepared from locally available resources for attracting the GAS.
Study Design: Randomised Complete Block Design (RCBD).
Place and Duration of Study: GAS-infested farmers' plots located near the Aromatic and Medicinal Plants Research Station (AMPRS), Odakkali, Ernakulam district, Kerala, India, during the monsoon seasons of 2021-22, 2022-23 and 2023-24.
Methodology: Preliminary screenings followed by confirmatory trials were conducted to select superior fermented baits against GAS. The cumulative counts of snails trapped in each treatment were recorded at five and ten days after placement. The results were subjected to ANOVA, and the means were separated by DMRT and LSD (P < 0.05) for the preliminary and confirmatory trials, respectively, using GRAPES, KAU.
Results: Among the 17 treatments screened with two replications during the preliminary screening of 2021-22, the jaggery- and yeast-based baits prepared from ripe papaya and wheat flour were superior (P < 0.05), with cumulative mean counts ranging from 20 to 44.5 at 10 days after placement (DAP). During the preliminary screening of 2022-23 with 25 treatments, baits based on black gram, ripe banana, ripe papaya and wheat flour were effective, and the cumulative counts of snails at 10 DAP ranged from 29 to 76. The addition of copper sulphate (CuSO4) at 0.5-5.0 per cent to the baits reduced snail attraction compared with baits without CuSO4. A similar difference in snail numbers was observed in pulse-based baits with common salt at two concentrations (0.5 and 2.5 per cent). The cumulative mean count of GAS during the confirmatory trial of 2022-23 with seven treatments and five replications ranged from 6.2 to 44.6. At 10 DAP, the black gram-based bait outnumbered all the tested baits, with a cumulative mean count of 44.6, followed by the wheat flour- and cooked matta rice-based baits, with mean counts of 23.2 and 18, respectively. During the confirmatory trial of 2023-24 with six treatments and four replications, the cumulative mean count of snails at 10 DAP ranged from 1.75 to 39. The black gram powder- and jaggery-based bait was most superior, with a mean number of snails of 39, followed by ripe papaya- (33.75) and banana-based baits (24.75). The mean number of snails in the wheat flour-based bait was 9.25.
Conclusion: Fermented baits based on readily available resources can be installed in GAS-infested areas as a complementary strategy in integrated pest management of GAS, thereby minimising the use of harmful molluscicides such as metaldehyde. A reduction in the number of snails was noticed in fermented baits supplemented with common salt and CuSO4, demonstrating their inhibitory potential.
Keywords: Giant African Snail, Lissachatina fulica, fermented bait, attractant trap, black gram, papaya, banana, wheat flour, integrated pest management, copper sulphate, common salt, Kerala