Florida citrus growers currently have a lot on their plates, but a new—albeit relatively slow—problem has crept up: snails. A recent UF/IFAS Tip of the Week and the July Highlands County Citrus Growers Association newsletter discuss the issues citrus growers and other ag industries are experiencing with an invasive snail, Bulimulus sporadicus. First found in Florida in 2009, these snails are causing problems by eating tender leaves and twigs to the point of causing dieback, clogging irrigation jets, and causing foliage damage inside individual protective covers (IPCs). There are obstacles to treating snails as pests as they can retreat into their shells, avoiding agrochemicals. Additionally, they are also relatively new pests, so their life cycles are not well understood. Both the UF/IFAS Tip of the Week and the newsletter shared tips on dealing with snails in the grove.
Tips for Combating Snails
Quick control is a must, as even though snails are slow-moving, they can multiply quickly, and populations can get out of hand in a short span of time. One control option that resulted from the newsletter was weed management. Many snails are decomposers and are attracted to declining weeds. Effectively managing weeds and maintaining habitat for snail predators, like ground beetles, can be part of an effective snail management effort. In the newsletter, Highlands County Citrus Growers Association President Jim Snively reported that spraying Imidan at the maximum allowed rate was effective at knocking the snails back.
However, the UF/IFAS Tip of the Week reported on the results of a UF/IFAS lab study that measured the effectiveness of different chemical control options. The results showed that Imidan (active ingredient phosmet) at a rate of one pound per acre, had a zero percent mortality rate seven days after application. Other treatments that had a zero percent mortality rate included Celite 610 (diatomaceous earth) at 10 percent, Carbaryl at five quarts per acre, and Bifenthrin at 32 fluid ounces per acre.
Treatments that were effective included baits that contain metaldehyde or iron. IronFist (active ingredient sodium ferric EDTA), and Deadline GT (metaldehyde), both had a 90 percent mortality rate. Sluggo (iron phosphate) has a 92 percent mortality rate, and Deadline GT (metaldehyde) had a 96 percent mortality rate. Lastly, Ferroxx (iron chelate) had a 100 percent mortality rate after seven days.