Distribution status and molecular characterisation of the invasive giant African land snail Lissachatina fulica in agricultural ecosystems of Tamil Nadu, India

Abstract

The tropical invasive species Giant African Land Snail Lissachatina fulica is one of the worst of hundred invasive species in the world listed by IUCN. The snail severely affects agricultural and horticultural crops and home gardens throughout the tropics. The snail has reached India in 1847 and later it has spread into South India around the 1920s. An extensive survey was conducted in Tamil Nadu from 2016 to 2020 to detect the current distribution and assess the extent of damage caused to agriculture and horticulture crops by this snail. The Giant African Snail populations are found to be present in 29 localities spanning nine districts of Tamil Nadu. Fifteen snail samples were subjected to molecular characterization using the cytochrome oxidase subunit I (COI) gene. Three distinct haplotypes were identified by comparing the sequences with already available sequences from published research. The haplotype and nucleotide diversities were calculated and are found to be low when compared to other geographical regions. In urban inhabitations, the snail is found to be a menace in human settlements and the pest status of the snail is prominent in the rural areas of Tamil Nadu. The study has recorded that L. fulica now is an established pest in paddy, mulberry, banana, coconut, vegetable crops, tapioca, tuberose and several other important agriculture crops in several regions of Tamil Nadu.