Planning Spring Snail Management

By Lauren M. Diepenbrock

Many citrus growers in Florida have been impacted by Bulimulus bonariensis (previously referred to as Bulimulus sporadicus) since the first reports of this pest in groves in 2020. This snail is an ongoing challenge and, with funding from the Citrus Research and Development Foundation, the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) has been developing knowledge to provide management recommendations for this pest.

Over the past three years, UF/IFAS researchers followed populations of snails in four locations in Central Florida. Activity associated with traps began in late February or March, depending on the year. Populations increased through June, often followed by a rapid decline from late July through September. Hatchling snails are too small and fragile to detect with the sampling methods used and therefore under-sampled in groves. These small young snails are hard to detect, so they likely go undetected until larger snails become active in larger numbers, which appears to be later in the spring emergence.

Despite the widespread freeze in late January/early February, it is likely that the snail populations survived and will be active again once the environmental conditions are ideal. Based on the years of sampling, it is clear that soil temperature is one of these conditions. Relative snail activity increases when soil temperatures are between 59 and 86 degrees (Ganesh, unpublished).

Based on the relative population activity that was documented from sampling, it is likely that Bulimulus bonariensis will require a minimum of two (and potentially more) management actions to reduce the populations to a point where they are not impeding irrigation.

At present, there are six baits and one liquid molluscicide registered for use on snails in Florida citrus: Deadline GT, Deadline M-Ps, Iron Fist, Ferroxx, Ferroxx AQ, Sluggo (baits) and Slug-Fest (liquid). In a laboratory study, all baits were found to be effective in killing B. bonariensis within a seven-day period. Field evaluations of baits and their timing are planned for 2026.

Lauren Diepenbrock is an associate professor at the UF/IFAS Citrus Research and Education Center in Lake Alfred.