Impact of environmental factors on the population of gastropods in commercial ornamental plant nurseries at Ludhiana, Punjab

Survey of gastropods (snails and slugs) at commercial plant nurseries at Ludhiana revealed that two biotypes of slug species, Filicaulis alte (brown slug with black spots and creamish yellow with black anterior and posterior ends, wrinkeled body with irregular polygonal network of brown lines on its dorsal surface i.e. caterpillar like) and two snail species Macrochlamys indica and Macrochlamys cassida were infesting ornamental plants. M. indica snail density varied from 1.05 ± 0.47 to 1.13 ± 0.34 snails m² at 26.5°C air temperature, 23°C soil temperature and 27.6% soil moisture in the months of March -April and September-October. F. alte brown slug with black spots slug density varied from 0.65 ± 0.06 to 0.72 ± 0.09 slugs m² at 87–96 relative humidity, 26.5–30°C air temperature and 21–25.5°C soil temperature in the months of March-April and September-October. It was found that gastropods preferred sandy loam, alkaline soil, medium in organic matter, nitrogen and high in phosphorous and potassium. This study revealed a positive correlation between population of surface active gastropods with air and soil temperature and relative humidity (RH)minimum and a negative correlation with RH maximum and soil temperature.