Small pointed snails

Agronomist, Douglas McEachern (Landmark), has reported snails causing feeding damage to a pasture paddock south west of Holbrook, in the South West Slopes and Plains district of New South Wales. These snails are likely to be the small pointed snail (Prietocella barbara), which Douglas says are present in very high densities of around 70-100 per m². The snails are causing serious damage to phalaris, fescue, subterranean clover and arrowleaf clover. 

The small pointed snail looks very similar to, and is easily confused with, the conical snail (Cochlicella acuta). Conical snails are rarely found directly feeding on pastures and crops, preferring to feed on dead organic matter. They are mainly a problem at harvest when they can contaminate grain and seed.

The small pointed snail has a fawn, grey or brown cone-shaped shell and is up to 10 mm in length. During summer, the snails rest (aestivation) under stones and stumps, and in leaf litter. They may also congregate on posts or plants to escape the high temperatures at the soil surface. In the cooler temperatures of autumn, rainfall triggers the snails to break their resting phase and reproduce. Juvenile snails feed throughout winter and spring. Crops and pastures grown on calcareous and highly alkaline soils are most susceptible.

Control options at this time of year are somewhat limited. Molluscicidal baits are most effective when applied in autumn after moisture triggers snail activity, but before there is an abundance of food. Once snails have a readily abundant food source the effectiveness of baits is reduced. Livestock will provide some control by trampling or accidentally consuming snails when grazing. They will also knock snails from stubble.

Grain growers should be aware of the risk of snails becoming a contaminant at harvest. In most regions, the next week or two will be the last opportunity for baiting within crops as baiting must have ceased at least two months before harvest. This is to ensure the bait has broken down and does not become a contaminant of the grain itself. There is a zero tolerance for bait contamination of grain. Options available to manage snails are to windrow crops, make header modifications at harvest or to conduct post-harvest grain cleaning.

Between field seasons, there are various cultural control options available. This includes cabling, rolling, slashing and burning. Click here for further information about integrated management options that are available.

 

Take a 2-minute survey

As part of a GRDC project to improve control measures for snails (and slugs), SARDI Entomology is undertaking a study to better understand the current distribution and industry impact of snails and slugs across the southern agricultural region. A short online survey has been developed to seek grower and adviser observations of these pests on properties and/or districts. If relevant to you, complete the survey, or alternatively, contact entomologist Kym Perry (SARDI) by phone on 08 8303 9370 or via email at kym.perry@sa.gov.au to discuss directly.