ASSESSING THE EMERGING HAVOC OF SNAILS AND SLUGS ALONGWITH THEIR MANAGEMENT IN RUPANDEHI AND NAWALPARASI DISTRICTS OF NEPAL

  • Monica Pandey, Lalit Sah2 , Subeksha Shrestha , and Saurav Aryal

Among 100 Terrestrial snails and slugs found in Nepal spanning 42 genera and 24 families, the Giant African Land snail stands out as the most destructive pest of vegetable crops in tropical and subtropical regions. A comprehensive study, involving direct observations and a questionnaire survey was conducted from 12th June to 2nd July 2023. The findings, based on responses from 141 participants, reveal a significant surge in snail and slug populations over the past 4-8 years in two districts. Based on these informants the most preferred habitats in the study area include gardens followed by bari (Small field), roadside, riverside, and water sources. The survey study in Rupandehi and Nawalparasi indicates that the majority of respondents do not observe snails and slugs throughout the year. However, their prevalence notably increases during the rainy season, from June to September. The Giant African Land snail was reported to be more prominent than slugs and horntail snails in both districts. These pests were found in various habitats, including gardens, bari, walls, roads, and paddy fields (referred to as Khet), with the highest number of sightings in gardens and bari. Respondents reported that they feed on a range of vegetable crops, including cucurbits, Cole, brinjal, okra, and taro, and cause 50% damage to nursery seedlings. The most common management practices reported include collecting and disposing of them in garbage-carrying vehicles, nearby rivers, and roads as well as crushing live individuals, spreading salt on them, and spraying alcohol and detergents. Regarding predators, respondents from Rupandehi identified the Greater coucal as the most prominent predator of GALS and slugs, while in Nawalparasi, the Great egret was reported to be the most common predator of snails and slugs. Only a few respondents from both districts used molluscicides such as metaldehyde and pesticides like cypermethrin to manage the snail and slug populations.Among 100 Terrestrial snails and slugs found in Nepal spanning 42 genera and 24 families, the Giant African Land snail stands out as the most destructive pest of vegetable crops in tropical and subtropical regions. A comprehensive study, involving direct observations and a questionnaire survey was conducted from 12th June to 2nd July 2023. The findings, based on responses from 141 participants, reveal a significant surge in snail and slug populations over the past 4-8 years in two districts. Based on these informants the most preferred habitats in the study area include gardens followed by bari (Small field), roadside, riverside, and water sources. The survey study in Rupandehi and Nawalparasi indicates that the majority of respondents do not observe snails and slugs throughout the year. However, their prevalence notably increases during the rainy season, from June to September. The Giant African Land snail was reported to be more prominent than slugs and horntail snails in both districts. These pests were found in various habitats, including gardens, bari, walls, roads, and paddy fields (referred to as Khet), with the highest number of sightings in gardens and bari. Respondents reported that they feed on a range of vegetable crops, including cucurbits, Cole, brinjal, okra, and taro, and cause 50% damage to nursery seedlings. The most common management practices reported include collecting and disposing of them in garbage-carrying vehicles, nearby rivers, and roads as well as crushing live individuals, spreading salt on them, and spraying alcohol and detergents. Regarding predators, respondents from Rupandehi identified the Greater coucal as the most prominent predator of GALS and slugs, while in Nawalparasi, the Great egret was reported to be the most common predator of snails and slugs. Only a few respondents from both districts used molluscicides such as metaldehyde and pesticides like cypermethrin to manage the snail and slug populations.